Question: A 64-year-old man presents with nausea, vomiting, and weakness. He states that his wife made him come in when he fainted today while attempting to stand up. He otherwise states he has noticed some visual changes, including noting a yellow tint to objects. He has a history of heart failure with reduced ejection fraction, obesity, diabetes, hypertension, acute coronary syndrome, atrial fibrillation, and peripheral vascular disease. His temperature is 98.5°F (36.9°C), blood pressure is 153/91 mmHg, pulse is 40/min, respirations are 15/min, and oxygen saturation is 97% on room air. Physical exam reveals a frail man who is unable to ambulate secondary to lightheadedness. His neurological exam is otherwise non-focal. An ECG is performed as seen in Figure A. Which of the following is the most likely etiology of this patient’s symptoms?

Answer: Digoxin

Explanation:
This patient with a history of heart failure with reduced ejection fraction and atrial fibrillation is presenting with nausea, vomiting, visual changes, bradycardia, and premature ventricular complexes, which are concerning for digoxin toxicity. Note that digoxin can be given in patients with poor cardiac function and atrial fibrillation; thus it is a plausible home medication for this patient.

Digoxin is a cardiac glycoside that is used in conditions such as heart failure with reduced ejection fraction and atrial fibrillation. While it does not lower mortality, it may reduce symptoms of heart failure. Digoxin toxicity classically presents with gastrointestinal symptoms (nausea/vomiting), blurred vision or yellow halos, and cardiac dysrhythmias. While there is a myriad of dysrhythmias, digoxin can cause bradycardia, atrioventricular block, and premature ventricular contractions. ST-segment scooping can be seen with digoxin use both in toxicity but also with regular therapeutic use. Toxicity is treated with anti-digoxin antibodies.

Patocka et al review digoxin toxicity. They note that this medication has a narrow therapeutic range and recommend close monitoring. Toxicity depends on severity and can be treated with anti-digoxin antibodies.

Figure/Illustration A is an ECG demonstrating bradycardia and premature ventricular complexes (red circles). This is consistent with digoxin toxicity.

Incorrect Answers:
Answer A: Amiodarone is an antidyshythmic agent with toxicities including bradycardia, heart block, a prolonged QT interval, hepatitis, interstitial lung disease, hypothyroidism, corneal deposits and optic neuropathy. This patient could use amiodarone for his atrial fibrillation, but the visual disturbances are more typical of digoxin toxicity.

Answer C: Diltiazem is a calcium channel blocker that would cause hypotension, bradycardia, and hyperglycemia. Treatment would involve immediate administration of calcium and vasopressors such as epinephrine. Other treatments in severe toxicity may include glucagon, dextrose, and insulin (to increase cardiac contractility).

Answer D: Procainamide is the preferred antidysrhythmic in tachydysrhythmias associated with Wolff Parkinson White syndrome. It may cause drug-induced lupus and other dysrhythmias in overdose but would not cause this patient’s constellation of symptoms. Procainiamide is used rarely for atrial fibrillation and is only available for intravenous infusion in the US.

Answer E: Propranolol toxicity would present with bradycardia, hypotension, confusion, seizures, and hypoglycemia. Treatment is centered on glucagon, calcium, and vasopressors such as epinephrine. In severe toxicity, lipid emulsion therapy and insulin/dextrose should be administered.

Bullet Summary:
Digoxin toxicity may present with nausea, vomiting, visual changes, bradycardia, and premature ventricular complexes.


Question:
A 57-year-old man presents to the emergency department with several days of malaise, weakness, and night sweats. Today, he experienced a headache with blurry vision, thus prompting his presentation. The patient has a history of diabetes and is followed closely by an endocrinologist. Otherwise, he has lost 10 pounds over the past month. His temperature is 100°F (37.8°C), blood pressure is 122/90 mmHg, pulse is 84/min, respirations are 16/min, and oxygen saturation is 99% on room air. Physical exam is notable for a thin man but is otherwise unremarkable. His visual acuity is 20/100 in both eyes, though he says that he normally has 20/20 vision. His gait is mildly ataxic as well, but his neurological exam is otherwise nonfocal. Laboratory studies are ordered as seen below.

Hemoglobin: 10 g/dL
Hematocrit: 31%
Leukocyte count: 57,500/mm^3 with 35% blasts
Platelet count: 109,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.1 Eq/L
HCO3-: 22 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.1 mg/dL
Calcium: 10.0 mEq/L

Which of the following is the most likely diagnosis?

Answer: Chronic myelogenous leukemia

Explanation:
This patient is presenting with symptoms of malignancy (malaise, weakness, and night sweats) and has a white blood cell count > 50,000/mm^3 in the setting of > 20% blasts, which are concerning for chronic myelogenous leukemia (CML). Given the blurry vision and ataxia in the setting of increased blasts, this patient may be suffering from a hyperviscosity syndrome secondary to a blast crisis, which can be seen in CML.

CML is a neoplastic proliferation of myeloid stem cells. Patients are often asymptomatic and may present with a white blood cell count > 50,000/mm^3. There are many different presentations. The chronic phase presents with < 10% blasts and is often asymptomatic. The accelerated phase has increased blasts, and patients present with fatigue, weight loss, malaise, night sweats, abdominal pain, and hepatosplenomegaly. Finally, the blast phase presents similar to the accelerated phase but with more severe symptoms. The blast phase may evolve into a blast crisis (> 20% blasts) which could cause a hyperviscosity syndrome. Hypervicosity syndrome may require IV fluids and leukapheresis. The most common translocation in CML is the 9;22 translocation which forms the BCR:ABL gene product.

Jain et al. review CML. They note the outcomes in patients in the blast phase in CML and how there are more poor outcomes associated with this phase. They recommend paying close attention and obtaining a CBC with a differential to determine the percent blasts.

Incorrect Answers:
Answer A: Acute lymphoblastic leukemia is more common in pediatric patients and presents with pancytopenia, fatigue, recurrent infections (from leukopenia), and bleeding (from thrombocytopenia). Other findings include systemic symptoms, malaise, fever, bone pain, lymphadenopathy, splenomegaly, and hepatomegaly.

Answer B: Acute myelogenous leukemia is a malignancy of myeloblasts and presents in the elderly. Patients will present with fatigue, malaise, weight loss, anorexia, fever, leukocytosis, anemia (causing fatigue), thrombocytopenia (causing bleeding), and neutropenia (leading to life-threatening infections). Auer rods can be seen on peripheral smear.

Answer C: Chronic lymphocytic leukemia is a monoclonal proliferation of incompetent mature B cells that occurs in elderly men and is the most common form of leukemia in the west. Patients are often asymptomatic and may have a white blood cell count > 50,000/mm^3. When symptomatic, patients may experience chills, weight loss, and weakness (note these symptoms are nonspecific). Peripheral smear will show smudge cells.

Answer E: Multiple myeloma is common in the elderly and presents with CRAB: hyperCalcemia, Renal insufficiency, Anemia, and lytic Bone lesions/Back pain. The diagnosis is supported with protein electrophoresis and confirmed when biopsy demonstrates increased plasma cells.

Bullet Summary:
Chronic myelogenous leukemia presents with increased white blood cells which may be >50,000/mm^3 (possibly with elevated blasts).


Question: A resident physician places a patient’s home medications in for their admission orders during an overnight admission. They order the patient’s home medications including clobazam; however, they accidentally order clonazepam. Subsequently, the patient is over-sedated and has to be transferred to the ICU for airway monitoring. Which of the following is the most appropriate method for preventing future similar occurrences?

Verify the patient’s home medications with the patient

Add an alert in the electronic medical system for medications that sound similar

Have nursing perform the medication reconciliation

Reprimand and educate the resident to check medications more carefully

Answer: Add an alert in the electronic medical system for medications that sound similar

Explanation:
A medical error occurred where 2 similar-sounding medications were confused, leading to an adverse event. The most appropriate way to prevent this error from occurring is a system-based approach, such as adding an alert in the electronic medical system for medications that sound similar.

Medical errors commonly occur in the medical system given the complexity of delivering patient care. The best way to prevent future errors from occurring is a systems-based approach where the system is built to catch errors rather than relying on the diligence of staff. In a systems-based approach, there is an algorithmic method set in place for situations where errors are common. Examples of systems-based approaches to avoiding medical errors include time-outs for procedures, use of the electronic medical record and ordering system to generate stops and checks, and built-in procedures such as a pharmacist verifying all medical orders. The best way to prevent future errors, when possible, is a systems-based approach as it does not rely solely on individuals given that individuals are fallible and may not always avoid mistakes.

Condren et al. review a systems based approach in the medical system. They note that a systems-based approach reduces medication errors. For this reason, systems-based approaches are recommended whenever possible.

Incorrect Answers:
Answer B: Entering medications only on morning rounds with multiple providers is not a plausible strategy as patients will not receive medications they may need at other times, such as overnight. It is always a good idea to verify medications with the team on morning rounds to catch any possible errors that may be missed, but this would not necessarily fix errors that occur at other times of the day.

Answer C: Having nursing perform the medication reconciliation is not the best solution in this case, as the core problem was that the wrong medication was entered due to similar-sounding medication names. However, it is always a good idea to have multiple providers (e.g., nurses, pharmacists) verify information, check this with the physician team, and then verify the dose and route of administration when giving the medication.

Answer D: Reprimanding and educating the resident to check medications more carefully is not a solution to this problem. It does not seem that the resident does not understand the pharmacology or medication prescribed but made an understandable error. Explaining the need for care is important; reprimanding the resident is not.

Answer E: Verifying the patient’s home medications with the patient should always be performed, but it would not fix this issue with similar-sounding medications. It would catch errors such as new medications that are not on the patient’s medication list or out-of-date medications remaining on the list.

Bullet Summary:
A systems-based approach is the most appropriate way to prevent future errors from occurring.


Question: A 22-year-old man presents to the emergency department with difficulty breathing. He has experienced similar symptoms before. Today, he was hit in the face with a football, followed by significant swelling of his lips and tongue. The patient speaks with a muffled voice. His temperature is 98.1°F (36.7°C), blood pressure is 120/83 mmHg, pulse is 80/min, respirations are 16/min, and oxygen saturation is 98% on room air. Physical exam reveals swollen lips and a protruding, enlarged tongue. His breath sounds are clear. He demonstrates no rash and his abdomen is soft and nontender. Which of the following is the most effective therapy for this patient?

Answer: Fresh frozen plasma

Explanation:
This patient is presenting with recurrent episodes of significant swelling of his lips and tongue with minor trauma, which are concerning for hereditary angioedema. Fresh frozen plasma is the most effective therapy for hereditary angioedema of the options listed.

Angioedema is a potentially life-threatening condition that presents with severe edema of the gastrointestinal and respiratory tracts. It can be caused by antigens, medications, and trauma or may occur spontaneously. It often presents with notable edema of the lips and tongue and may threaten the airway. There are 3 subtypes. Hereditary and acquired angioedema occur secondary to a deficiency of C1-esterase inhibitor. As a result, the most effective therapy is to administer fresh frozen plasma which has C1-esterase inhibitor. On the other hand, drug-induced angioedema (often from angiotensin-converting enzyme inhibitors and angiotensin receptor blockers) does not respond well to C1-esterase inhibitor replacement and supportive therapy; discontinuing the offending agent is the mainstay of therapy. Other effective but costly treatments that can be used in hereditary angioedema include: icatibant, ecallantide, and C1 inhibitor.

Paige and Anderson note the management of hereditary angioedema. They review the different treatments and discuss C1-esterase inhibitor replacement. They recommend this treatment for acute episodes.

Incorrect Answers:
Answer A: Dexamethasone and other steroids can be given in acute allergic reactions and may reduce the recurrence of symptoms but are unlikely to be effective in angioedema, nor are they the most effective therapy. Steroids can take up to 4 hours to begin having any effect.

Answer B: Diphenhydramine is an antihistamine that could be given for anaphylaxis or urticaria and works immediately; however, it is not the mainstay of therapy for angioedema nor is it the most effective therapy. It is the mainstay of therapy for urticaria. It can also be given in anaphylaxis.

Answer C: Epinephrine is the treatment of choice for anaphylaxis which presents with urticaria, upper airway swelling, hypotension, nausea/vomiting, and wheezing. It is often given in angioedema but has limited efficacy when compared to fresh frozen plasma.

Answer E: Tranexamic acid is effective in treating angioedema and current evidence supports its use; however, the mainstay of therapy is still fresh frozen plasma. Tranexamic acid is also used in hemorrhagic shock to stop fibrinolysis and reduce bleeding.

Bullet Summary:
A possible treatment in hereditary or acquired angioedema is the administration of fresh frozen plasma to replace C1-esterase inhibitor.


Question: A 30-year-old man presents to the emergency department with diarrhea. He states he has had profuse, watery diarrhea for the past 24 hours. He notes that eating and drinking make him defecate more, thus he has been refraining from drinking. He is otherwise healthy and takes no medications. His temperature is 97.7°F (36.5°C), blood pressure is 84/64 mmHg, pulse is 130/min, respirations are 17/min, and oxygen saturation is 99% on room air. Physical exam reveals dry mucous membranes with an otherwise benign exam. The patient is given 1L of normal saline and drinks 1L of oral fluids. His blood pressure is subsequently 120/70 mmHg and pulse 95/min. Which of the following is the most appropriate next step in management?

Answer: Rest and oral rehydration

Explanation:
This patient is presenting with a likely diarrheal illness given he has profuse, watery diarrhea and his vitals normalized with oral and IV hydration. Since the patient is young and healthy, oral hydration and rest are all that is needed for management.

Diarrheal illness is a common chief complaint with variable workups pending on the patient's clinical status. Young, healthy, non-immunosuppressed patients who can tolerate an oral diet require only reassurance and oral hydration, as most cases of viral and bacterial diarrhea will resolve on their own. Moreover, most cases of diarrhea are caused by viral etiologies which simply require supportive therapy. This is even true in bacterial diarrhea as long as the patient's vitals normalize and they can tolerate an oral diet. It is important to consider inflammatory causes of diarrhea (such as ulcerative colitis or Crohn disease) as this would change the workup and management.

Schiller et al. discuss different types of diarrhea. They review the management and diagnosis of diarrhea and its different forms, including chronic forms. They recommend noting the difference between different causes and working up and treating them appropriately.

Incorrect Answers:
Answer A: Ciprofloxacin is an antibiotic that can be used for bacterial/infectious diarrhea. It should not be given in young, healthy patients and would only be indicated in the setting of bacterial diarrhea in ill patients, patients with persistent symptoms, or patients who are immunosuppressed. Bacterial diarrhea would present with fever, abdominal pain, and bloody/purulent diarrhea.

Answer C: Stool culture should not be empirically performed in young, well-appearing patients. It may be performed in hospitalized patients who are more ill or in patients who are going to start antibiotic therapy. It may also be performed in patients with persistent diarrhea.

Answer D: A stool ova and parasite study would not be performed unless there was a suggestive history or exposure (such as drinking unfiltered water) in the setting of fatty, foul-smelling diarrhea. This would raise suspicion for Giardia lamblia which would be treated with metronidazole.

Answer E: Stool PCR for viral etiologies of diarrhea is not useful as the management of viral diarrhea is supportive therapy in most cases. On occasion, it may be performed in critically ill patients to determine the etiology of their symptoms. It should not be performed routinely.

Bullet Summary:
Healthy patients with limited diarrheal illness require supportive therapy only (in particular, oral hydration) and do not need more invasive diagnostic tests.


Question:
A 67-year-old man presents to the emergency room with a 2 day history of progressively worsening fatigue and shortness of breath. His past medical history is significant for previous myocardial infarction, a 30-pack-year smoking history, gastroesophageal reflux disease, and poorly controlled hypertension. The patient’s only home medication is omeprazole. His temperature is 98.6°F (37°C), blood pressure is 140/90 mmHg, pulse is 90/min, respirations are 30/min, and oxygen saturation is 88% on room air. Physical exam is significant for a jugular venous pressure of 15 cm, an S3 heart sound, bibasilar crackles, and 2+ pitting edema to the knees bilaterally. His abdomen is soft and non-tender. His neurological exam is nonfocal and he walks with a steady gait. An arterial blood gas shows the following:

pH: 7.56 (normal 7.35-7.45)
pCO2: 25 mmHg (normal 35-45 mmHg)
HCO3: 29 mEq/L (normal 22-26 mEq/L)
pO2: 62 mmHg (normal 80-100 mmHg)
SaO2: 87% (normal 95-100%)

Which of the following is the most appropriate treatment?

Answer: Furosemide

Explanation:
This patient with multiple risk factors for heart failure (previous myocardial infarction, smoking history, hypertension), worsening fatigue, shortness of breath, respiratory alkalosis, and signs of fluid overload (S3 heart sound, elevated jugular venous pressure (JVP), bibasilar crackles, peripheral edema) most likely has acute decompensated heart failure (ADHF). The most appropriate initial management for patients in ADHF is a loop diuretic such as furosemide.

Heart failure (HF) is a condition in which the heart does not pump effectively and can be due to either difficulty with relaxation in diastole or contraction in systole or a combination of both. Risk factors for this condition include myocardial infarction, diabetes mellitus, valvular disease, cigarette smoking, hypertension, and obesity. Left-sided HF leads to decreased forward flow into the systemic circulation and increased congestion in the pulmonary circulation which clinically manifests as shortness of breath, pulmonary edema, and crackles on lung exam. Early pulmonary edema leads to a ventilation/perfusion (V/Q) mismatch which causes hypoxia. Hypoxia leads to a compensatory increase in the respiratory rate, which leads to hypocapnia and respiratory alkalosis. The most appropriate initial treatment for patients in ADHF is a loop diuretic such as furosemide, which helps alleviate fluid overload. Other treatments for acute exacerbations may include nitroglycerin (in hypertensive patients) and BIPAP.

Yancy et al. discuss the most recent ACC/AHA guidelines for the management of heart failure. They review current testing and treatment regimens. Acute episodes may be managed with loop diuretics to reduce volume overload and improve symptoms.

Incorrect Answers:
Answer B: Ivabradine inhibits the funny current, an electrical current that leads to spontaneous depolarization in pacemaker cells, leading to decreased heart rate. It reduces the risk of hospitalization in patients with chronic heart failure with reduced ejection fraction (HFrEF). However, it should not be started in ADHF due to lack of mortality benefit and should be held in ADHF patients with severe decompensation due to decreased heart rate leading to decreased cardiac output.

Answer C: Metoprolol is a beta-blocker that reduces mortality when used in patients with chronic HFrEF. However, beta-blockers can worsen decompensated HFrEF due to negative inotropy and should not be started in ADHF.

Answer D: Sacubitril and valsartan is a combination angiotensin receptor-neprilysin inhibitor (ARNI) that improves mortality in patients with chronic HFrEF. ARNIs, angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) should not be started in ADHF due to concern for hypotension and worsening renal function. However, either an ARNI, ACE inhibitor or ARB should be started prior to discharge.

Answer E: Spironolactone is a mineralocorticoid receptor antagonist that reduces mortality in chronic HFrEF. However, high-dose spironolactone does not improve outcomes as first-line therapy in ADHF (Anstrom et al. JAMA Cardiology 2017).

Bullet Summary:
Patients with acute decompensated heart failure present with fatigue, dyspnea, bibasilar crackles, respiratory alkalosis on arterial blood gas, edema, and other signs of fluid overload.


Question: A 45-year-old man with a past medical history of obesity presents with a concern about his sexual performance. He has a history of depression which is well managed with fluoxetine. He states that since starting the medication, his sexual drive has increased, yet he is unable to achieve orgasm. As a result, he refuses to take the medication anymore. He has a past medical history of diabetes and notes that his home blood glucose readings have been higher lately. His temperature is 98.3°F (36.8°C), blood pressure is 127/82 mmHg, pulse is 88/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam reveals an obese man in no acute distress with a normal affect and non-focal neurologic exam. The physician agrees to change the patient’s antidepressant. Which of the following is the most appropriate treatment for this patient?

Answer: Bupropion

Explanation:
This patient is presenting with anorgasmia in the setting of treatment with a selective serotonin reuptake inhibitor (SSRI). Given his obesity, worsening home blood glucose levels, and desire for improved sexual performance, bupropion is an appropriate medication.

Bupropion is an antidepressant that is not used first-line except in certain circumstances. Situations where bupropion is an appropriate agent for the management of depression include smoking cessation as it decreases smoking cravings. Bupropion is also weight neutral and is preferred in obese patients, patients who are gaining weight on other medications, and patients with poorly-managed diabetes. Finally, it does not have any sexual side effects in contrast to SSRIs. However, bupropion lowers the seizure threshold and should be avoided in patients at higher risk for seizures. Bupropion is sometimes given with other antidepressants for patients with persistent or refractory symptoms.

Patel et al. review bupropion. They note the effectiveness of bupropion in managing depression and note that it can be given with other agents. They recommend its use, in particular, for smoking cessation or patients who need a more weight-neutral treatment.

Incorrect Answers:
Answer B: Electroconvulsive therapy is a highly effective therapy for depression; however, it is generally used in cases of severe suicidality, malnutrition due to food refusal secondary to depressive disorder, or last line when other medications have failed. This patient is primarily experiencing sexual side-effects and has gained weight, making bupropion a more viable initial alternative.

Answer C: Escitalopram is merely a different SSRI that will lead to similar side effects. Thus, it would not be appropriate. Changing SSRIs is appropriate if the first SSRI does not work after an appropriate trial period of at least 4 weeks in the management of depression. Other changes when an SSRI fails to control symptoms include increasing the dose.

Answer D: Mirtazapine is an antidepressant that increases appetite and leads to weight gain and would further worsen this patient’s obesity. It is preferred in conditions such as anorexia nervosa given weight gain is preferable in this population.

Answer E: Phenelzine is a monoamine oxidase inhibitor and is usually used third-line (or later) in the management of depression given side-effects such as hypertensive crisis and the long washout period and interactions with other medications. Bupropion is a safer initial alternative.

Bullet Summary:
Patients with depression who experience sexual side effects or weight gain on SSRIs may be switched to bupropion.


Question: A 33-year-old woman presents to the emergency department with foul-smelling vaginal discharge. She states that it started 1 day ago and has not improved with hygiene products. She is sexually active and uses condoms. She does not complain of any abdominal or pelvic pain but states she has some mild burning when urinating. Her temperature is 97.6°F (36.4°C), blood pressure is 111/74 mmHg, pulse is 81/min, respirations are 12/min, and oxygen saturation is 98% on room air. Physical exam is notable for thick, white discharge from the cervix. There is no cervical motion or adnexal tenderness or masses. Some whitish discharge is noted from the urethra. A urine pregnancy test is negative. Which of the following is the most appropriate treatment for this patient?

Answer: Ceftriaxone and doxycycline

Explanation:
This nonpregnant woman is presenting with a thick, white cervical discharge, dysuria, and urethral discharge without cervical motion tenderness or adnexal tenderness which is concerning for urethritis without pelvic inflammatory disease. She should be treated with ceftriaxone and doxycycline to cover for the most common organisms.

The most common bacterial sexually transmitted infections include Neisseria gonorrhoeae and Chlamydia trachomatis. They can cause urethritis, cervicitis, and pelvic inflammatory disease. The diagnosis is made clinically with the appropriate history (vaginal discharge, high-risk sexual behavior) and physical exam (purulent cervical discharge +/- cervical motion tenderness, adnexal tenderness). The diagnosis should be confirmed with PCR; however, this should not delay treatment. Treatment should be given empirically, and the preferred regimen is ceftriaxone and doxycycline in men and nonpregnant women. In pregnant women, ceftriaxone and azithromycin may be used. Metronidazole is added empirically to cover for Trichomonas vaginalis.

Jennings and Krywko review pelvic inflammatory disease. They note that pelvic inflammatory disease is an inflammation of the upper genital tract due to an infection that can affect the uterus, fallopian tubes, and ovaries. They discuss the need for treatment and complications that can occur without treatment. They recommend timely diagnosis and treatment.

Incorrect Answers:
Answer A: Azithromycin is only indicated to cover chlamydia in pregnancy since doxycycline cannot be given to pregnant patients. Coverage for gonorrhea is also mandatory given this patient’s symptoms.

Answer B: Ceftriaxone is insufficient coverage for chlamydia or gonorrhea as chlamydia requires treatment with doxycycline, and gonorrhea requires double coverage from ceftriaxone in addition to doxycycline.

Answer C: Ceftriaxone and azithromycin is the preferred regimen to treat chlamydia and gonorrhea in pregnant patients since pregnant patients cannot receive doxycycline.

Answer E: Metronidazole is an appropriate treatment for bacterial vaginosis which presents with a fishy odor, white/gray vaginal discharge, and positive clue cells on wet mount.

Bullet Summary:
The treatment of choice for urethritis is ceftriaxone and doxycycline in nonpregnant patients.


Question: A 44-year-old man presents to the emergency department with palpitations. He has a history of anxiety managed with fluoxetine and lorazepam. He also has hypertension but does not take any medications. Today, his symptoms have been persistent despite taking his medications. He says that he feels lightheaded and can’t walk. His temperature is 98.7°F (37.1°C), blood pressure is 120/72 mmHg, pulse is 183/min, respirations are 25/min, and oxygen saturation is 99% on room air. Physical exam reveals a somnolent and uncomfortable man. His pulse is rapid and regular. An ECG is performed as seen in Figure A. During the exam, the patient states that he feels lightheaded and appears occasionally somnolent. Which of the following is the most appropriate treatment for this patient?

Answer: Cardioversion

Explanation:
This patient is presenting with palpitations and an ECG demonstrating a wide complex tachycardia with a delta wave which are concerning for a tachydysrhythmia secondary to Wolff Parkinson White syndrome. Given his poor CNS perfusion (somnolence during his tachycardia despite a “normal” blood pressure), the most appropriate next step in management is cardioversion.

Wolff Parkinson White syndrome (WPW) is a pre-excitation syndrome where an accessory electrical pathway exists between the atria and ventricles that bypasses the AV node. WPW can demonstrate antidromic conduction where the accessory pathway leads to anterograde conduction causing a wide-complex tachycardia that is often mistaken for ventricular tachycardia. In this circumstance, the QRS is wide and a delta wave is often present but may be difficult to discern. If ever uncertain as to whether the diagnosis is ventricular tachycardia or WPW, cardioversion is a safe and effective intervention for both rhythms. Unstable patients with either WPW or ventricular tachycardia should undergo cardioversion immediately. Other treatments for WPW in stable patients may include procainamide. Ablation may present future episodes.

Bartlett and Friedman review the pathophysiology of WPW. They discuss the congenital presence of impulse-conducting fascicles leading to this condition. They also delve into the management and recommend rhythm agents and ablation as a modality of treatment.

Figure/Illustration A is an ECG demonstrating a wide complex (red arrow) tachycardia with a delta wave (blue arrow). These ECG findings are characteristically seen in WPW syndrome.

Incorrect Answers:
Answer A: Adenosine would be indicated after vagal maneuvers in the management of supraventricular tachycardia (SVT). SVT presents as a narrow complex tachycardia without P waves. It is regular (in contrast to atrial fibrillation). Failure to respond to vagal maneuvers or adenosine warrants cardioversion. If this patient was perfusing his CNS, a trial of adenosine could be appropriate given it has a short half-life and may differentiate ventricular tachycardia from SVT with aberrancy or a bundle branch block.

Answer B: Amiodarone may be used in stable ventricular tachycardia to control the rhythm and convert it to sinus. It would not be appropriate in a hemodynamically unstable patient. It can be used in other dysrhythmias as well including atrial fibrillation and atrial flutter.

Answer D: Defibrillation is only indicated in pulseless, shockable rhythms including ventricular fibrillation (disorganized electrical activity), pulseless ventricular tachycardia (wide complex tachycardia), and pulseless torsades des pointes (twisting of the QRS complexes around an isoelectric baseline). It could cause cardiac arrest if performed on a patient with a pulse.

Answer E: Procainamide is an antidysrhythmic that can be used in tachydysrhythmias that occur in WPW. Given that this patient is unstable, it is more appropriate to perform cardioversion.

Bullet Summary:
Unstable tachyarrhythmias in the setting of Wolff Parkinson White syndrome require cardioversion.


Question: A 55-year-old man presents to his primary care physician with fatigue, malaise, and a painful rash. The patient states that his symptoms have been worsening over the past week. He also has experienced abdominal pain and diarrhea. He has a medical history of obesity and smokes regularly. His temperature is 97.5°F (36.4°C), blood pressure is 142/82 mmHg, pulse is 85/min, respirations are 15/min, and oxygen saturation is 98% on room air. Physical exam is notable for an erythematous rash with papules and plaques on the patient's face, torso, and extremities. He states that the rash is painful. A fingerstick blood glucose is unable to accurately read his blood glucose and gives a reading of > 500 mg/dL. Which of the following is the most likely underlying pathophysiology of this patient’s condition?

Answer: Alpha cell tumor

Explanation:
This patient is presenting with necrolytic migratory erythema (a painful, erythematous rash with papules and plaques) with gastrointestinal symptoms (abdominal pain and diarrhea) and hyperglycemia, which are concerning for a glucagonoma. A glucagonoma is a tumor of the alpha cells.

A glucagonoma is a tumor of the alpha cells of the pancreas. This tumor pathologically secretes glucagon leading to profound hyperglycemia that is refractory to the normal treatments for diabetes. Patients also present with a classic rash termed necrolytic migratory erythema which presents with painful, erythematous papules and plaques. Other findings include gastrointestinal symptoms including anorexia, abdominal pain, and diarrhea. Hematologic findings include a normocytic, normochromic anemia. The diagnosis can be supported with a glucagon level, which will be elevated. Imaging of the pancreas by CT or MRI (more accurate) can further support the diagnosis.

Zandee et al. review glucagonoma. They note the presentation and symptoms associated with a glucagonoma, including the classic rash and elevated blood glucose. They recommend considering this diagnosis in patients who present with rash and hyperglycemia refractory to typical treatments.

Incorrect Answers:
Answer B: Beta-cell destruction is the pathophysiology of type I diabetes mellitus which presents with polydipsia, polyuria, weight loss, and hyperglycemia (typically in a pediatric patient). It can progress to diabetic ketoacidosis which presents with hyperglycemia, an anion gap acidosis, altered mental status, and Kussmaul respirations.

Answer C: Beta-cell tumor describes an insulinoma, which would present with hypoglycemia refractory to glucose administration. This condition is caused by increased release of insulin. The diagnosis should be suspected in the setting of hypoglycemia, an elevated insulin level, and an elevated C-peptide level. Imaging of the abdomen/pancreas with an MRI will reveal the insulin-secreting mass.

Answer D: Hypercortisolism can cause Cushing syndrome which presents with hyperglycemia, obesity, striae, limb/muscle atrophy, mood changes, and hypertension. A buffalo hump and moon faces may also be seen. This condition can either be from endogenous ACTH production or cortisol production or can be from exogenous steroid use.

Answer E: Insulin resistance is the pathophysiology of type 2 diabetes mellitus and presents with obesity, hyperglycemia, and an elevated hemoglobin A1c. The mainstay of management is weight loss, though medications such as metformin, sulfonylureas, or insulin are often needed.

Bullet Summary:
A glucagonoma is a tumor of the alpha cells of the pancreas that hypersecretes glucagon.


Question: A 55-year-old man presents to the emergency department with worsening dyspnea over the past 48 hours. He recently had a cold that kept him home from work for the past week. He has a past medical history of diabetes, obesity, and hypertension. He had his Achilles tendon repaired 4 weeks ago and he has been less mobile. His temperature is 99.2°F (37.3°C), blood pressure is 150/85 mmHg, pulse is 82/min, respirations are 16/min, and oxygen saturation is 100% on room air. Physical exam is notable for dyspnea provoked by walking short distances. Jugular venous distension is noted on exam. The patient’s blood pressure is 130/70 mmHg during inspiration. A bedside echocardiogram demonstrates impaired diastolic filling with normal ventricular contractility. An ECG is performed as seen in Figure A. Which of the following is the most likely diagnosis?

Answer: Constrictive pericarditis

Explanation:
This patient is presenting with a preceding viral illness, dyspnea, jugular venous distension, pulsus paradoxus (blood pressure drop from 150/85 to 130/70 mmHg during inspiration), an echocardiogram with impaired diastolic filling, and diffuse ST elevation with PR depression on ECG. This constellation of symptoms is concerning for constrictive pericarditis.

Constrictive pericarditis occurs when the pericardium becomes thickened and fibrotic. In contrast to other types of pericarditis, in constrictive pericarditis, there is impaired diastolic filling and thus impaired cardiac function. There are many possible etiologies of constrictive pericarditis including infection, inflammatory conditions, or idiopathic. Patients will present with dyspnea, hypotension, tachycardia, a pericardial friction rub, and positional chest pain (usually worsened by laying back and relieved by leaning forward). Patients may also demonstrate jugular venous distension, lower extremity edema, worsening dyspnea, and congestive hepatopathy. ECG may demonstrate diffuse ST elevation with PR depression, and an echocardiogram will demonstrate impaired diastolic filling and may demonstrate a thickened pericardium. The diagnosis can be supported with pulsus paradoxus (a drop of blood pressure by > 10 mmHg during inspiration).

Welch reviews constrictive pericarditis. He discusses constrictive pericarditis and how the inelastic pericardium inhibits cardiac filling possibly causing unexplained heart failure. Welch notes making the diagnosis is very challenging and requires meticulous echocardiograph assessment.

Figure/Illustration A demonstrates diffuse ST elevation (blue arrows) with PR depression (black arrows). This is consistent with pericarditis.

Incorrect Answers:
Answer A: Cardiac tamponade can occur after trauma, in the setting of infection, or in the setting of autoimmune disease and is more likely to occur with a rapid accumulation of pericardial fluid. While pulsus paradoxus would be present in this condition, muffled heart sounds and electrical alternans would be more likely to be seen on ECG. Echocardiography would demonstrate an echogenic rim of fluid around the heart.

Answer C: Myocardial infarction presents with chest pain, dyspnea, hypotension, tachycardia, and ST elevation in a vascular distribution. Note that this patient’s ST elevation is diffuse and there is no reciprocal ST depression. Moreover, the pattern of chest pain in myocardial infarction is typically exertional and not positional.

Answer D: Pulmonary embolism may present with pleuritic chest pain, shortness of breath, tachycardia, hypoxia, hemoptysis, a history of hypercoagulability, and recent stasis or surgery (such as this patient’s recent Achilles tendon surgery). It can cause obstructive shock leading to hypotension and tachycardia. Note that right heart strain and sinus tachycardia would be seen on ECG.

Answer E: Restrictive cardiomyopathy presents very similarly to restrictive pericarditis. Note that in restrictive cardiomyopathy, patients will also have impaired diastolic filling; however, it is due to a myocardium that will not expand rather than the pericardium impairing filling. It can occur secondary to conditions such as amyloidosis or hemochromatosis as well as other chronic inflammatory states. The ECG findings are nonspecific but may include low voltage QRS complexes, ST segment changes, T wave changes, bundle branch blocks, and pathologic Q waves (abnormally deep and wide Q waves). The diagnosis can be supported with an ultrasound demonstrating impaired diastolic filling and possible myocardial speckling if a protein (amyloid) is present and deposited in the myocardial wall. The diagnosis can only definitively be confirmed with a biopsy which is highly invasive.

Bullet Summary:
Restrictive pericarditis presents with chest pain that is positional, pulsus paradoxus, a friction rub, and diffuse ST elevation with PR depression on ECG.


Question: A 17-year-old boy presents to the emergency department after a car accident. He drove his car into a pole while speeding at night. He has no past medical history and takes no medications. The patient is unable to offer a history and repetitively asks the nurses what happened. He knows his name and address and is able to remember other information about himself. He is complaining of a headache. His temperature is 97.6°F (36.4°C), blood pressure is 122/74 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 98% of room air. Physical exam reveals a confused young man. Cranial nerves 2-12 are intact and the patient has normal strength and sensation. He demonstrates a stable gait. Throughout the exam, he continuously asks what happened to him. A head CT scan is ordered. Which of the following is the most likely diagnosis?

Answer: Concussion

Explanation:
This patient is presenting after a motor vehicle accident with confusion, repeated questioning, and a normal neurologic exam aside from his inability to remember the events that occurred. This constellation of symptoms is concerning for a concussion.

A concussion occurs after blunt trauma to the head and is common in athletics and motor vehicle collisions. Patients may present initially with symptoms including confusion, repeat questioning, repeating themselves, and amnesia surrounding the event. A thorough neurological exam is important as there should be no neurologic deficits in a concussion. Patients with a classic history and reassuring exam require rest from physical and cognitive activity. Post-concussive syndrome may present with chronic headaches, dizziness, trouble sleeping, trouble focusing, nausea, and difficulties with learning and concentrating. Mood changes such as depression and anxiety are common. Any patient with a concerning mechanism or symptoms should have a head CT to rule out other more severe diagnoses.

Pertab et al. review concussion and its presentation. They note that concussion can cause many symptoms including trouble focusing, mood changes, headaches, and also autonomic nervous system anomalies. They recommend reviewing the constellation of symptoms to make the diagnosis.

Incorrect Answers:
Answer A: Cerebral contusions are common after head trauma and may present with confusion, obtundation, neurologic deficits, and amnesia. While a severe concussion and a cerebral contusion have overlap, given this patient’s age, mechanism, and symptoms, concussion is more likely. A head CT would demonstrate contusion (hyperdense intraparenchymal lesion) with a possible contrecoup injury.

Answer C: Diffuse axonal injury occurs after a severe CNS injury with an obtunded patient who is typically unresponsive. CT imaging will show blurring of the gray-white interface with punctate hemorrhages. These patients have a very poor prognosis. They often are obtunded with minimal neurologic function.

Answer D: Epidural hematoma presents with trauma and the classic “talk and die” syndrome including a lucid interval followed by progressive obtundation and fixed, dilated pupils. Symptoms are rapidly progressive as this is an arterial bleed. CT scan would demonstrate a hyperdense lens-shaped lesion (composed of blood). A burr hole may relieve pressure and can be life-saving.

Answer E: Subarachnoid hemorrhage may present after trauma with a severe headache and meningeal signs. Patients may demonstrate focal neurologic deficits in severe cases. CT scan will demonstrate blood in the subarachnoid space and lumbar puncture would demonstrate blood in the CSF. A CTA may also localize the site of bleeding and if any aneurysm is present.

Bullet Summary:
A severe concussion can present with confusion, repeat questioning, and amnesia.


Question: A study is performed that looks at individuals who suffer from opioid use disorder and the effect the disorder has on their daily life and functionality. Individuals are surveyed using a validated method and followed up in 6-month intervals for 5 years. At the end of the study period, 40% of individuals have replied to the survey throughout the entire period. Analyzing only those subjects who responded throughout the entire period, it is determined that opioid use disorder only minimally impairs individuals in their daily functioning. Which of the following most likely occurred in this study?

Answer: Attrition bias

Explanation:
This study following individuals who abuse opioids with a 40% follow-up response rate suggests that opioid use disorder (known for impairing daily functioning) has only a minor effect on patient functionality. This is most likely secondary to attrition bias, or a loss to follow-up of participants in a non-random fashion whereby more severe cases stopped responding and were thus left out.

Bias in studies distorts outcomes and can make interpreting results challenging. For this reason, it is important to be meticulous when designing a study with every effort to minimize bias. The attrition bias can occur when individuals are lost to follow-up in a non-random fashion. For example, consider the assessment of daily functionality via a validated method in individuals with coronary artery disease. Those who are severely impaired from disease progression may not follow up in this study, thus altering results and removing more severe cases from the analysis. Having a higher response rate can help mitigate this bias, but is more costly as it may be difficult to ensure that every participant follows up.

Nunan et al. discuss the attrition bias. They note how it can affect studies and the data collected. They recommend mitigating the attrition bias for more accurate results and clinical application.

Incorrect Answers:
Answer B: Confounding variables are variables that are correlated with the studied variable that better explain the difference between 2 groups. For example, it may be found that alcohol is associated with lung cancer when in reality, the confounding variable of smoking (more common in individuals who drink alcohol) explains this difference.

Answer C: Late-look bias occurs when patients with severe disease are not studied because they are dead, critically ill, or unavailable to be studied, making the disease overall appear less severe. For example, patients with HIV may not have increased morbidity and mortality in a study. However, this may be a result of all the critically ill cases being too sick or dead and thus unable to participate thus distorting the outcome.

Answer D: Recall bias occurs when individuals with disease or an adverse outcome are more likely to recall an exposure given the occurred outcome, skewing their memory and thus the results. For example, pregnant mothers who have a newborn with a defect or condition may be more likely to recall certain exposures (such as exposure to pollution).

Answer E: Volunteer bias occurs when people who volunteer for a study are fundamentally different from the general population or those who do not volunteer. An example may be individuals volunteering in a study involving exercise as those who are interested in participating in an exercise study may be more motivated or healthier at baseline.

Bullet Summary:
Attrition bias occurs when individuals are lost to follow-up in a non-random fashion leading to skewed results.


Question: A 23-year-old woman presents to labor and delivery at 40 weeks gestation with abdominal contractions and leakage of fluid from her vagina. She subsequently undergoes an uncomplicated vaginal delivery. The child is healthy and is heated, suctioned, and stimulated. While holding her newborn, the mother endorses a headache, blurry vision, and abdominal pain. Her temperature is 98.0°F (36.7°C), blood pressure is 194/104 mmHg, pulse is 100/min, respirations are 18/min, and oxygen saturation is 98% on room air. Physical exam reveals an uncomfortable woman. There is blood in her vagina and her uterus is contracted. Her cranial nerve exam is unremarkable and she has normal strength and sensation. Laboratory studies and a urinalysis are pending. Which of the following is the most appropriate next step in management?

Answer: Magnesium

Explanation:
This postpartum patient is presenting with hypertension, headache, blurry vision, and abdominal pain, which are concerning for a diagnosis of preeclampsia. The most appropriate initial intervention is magnesium.

Preeclampsia classically presents after 20 weeks gestation (or earlier in the setting of a molar pregnancy) with hypertension and proteinuria. Other symptoms that may be indicative of preeclampsia with severe features include headaches, visual changes, and abdominal pain. Other features consistent with preeclampsia include thrombocytopenia, kidney insufficiency, impaired liver function, and pulmonary edema. The diagnosis can be supported when a pregnant patient is both hypertensive and demonstrates an elevated protein in her urine. It is possible for postpartum patients to experience preeclampsia. Though the fetus and placenta have been delivered, which is the definitive treatment of preeclampsia, further medical management is still needed. The most important initial step in management is to administer magnesium which is neuroprotective and also modestly lowers blood pressure. Further care involves blood pressure control and benzodiazepines as needed to abort seizure episodes (though note that if a patient with preeclampsia is having seizures, by definition, they have eclampsia).

Al-Safi et al. discuss preeclampsia and eclampsia. They note that postpartum preeclampsia and eclampsia can occur within the first week after delivery. They recommend that mothers should be educated on what symptoms to look for.

Incorrect Answers:
Answer A: CT head may be indicated, in particular, if an intracranial hemorrhage was thought to be the cause of this patient’s headache and vision changes. A subarachnoid hemorrhage would present with the classic “thunderclap” headache with blood in the subarachnoid space on head CT. A CTA may localize a bleeding aneurysm and a lumbar puncture would show an elevated red blood cell count in the CSF. It would not explain this patient’s hypertension and abdominal pain. Note that a CT head is not a CTV which is specific venous imaging.

Answer B: Labetalol is an appropriate blood pressure medication to give in pregnancy; however, it is more appropriate to first give magnesium as this agent is neuroprotective and is the first-line agent of choice in preeclampsia.

Answer D: MRV head or a CTV head would be appropriate in the workup of cerebral venous thrombosis which is common in the setting of hypercoagulability (such as in the postpartum period) and presents with headache, blurry vision, and seizures. Note that it would not explain this patient’s profound hypertension. It would be more reasonable to first empirically treat this patient's possible preeclampsia.

Answer E: Ondansetron and morphine would be appropriate symptomatic management of this patient but would not treat her underlying preeclampsia. It is more appropriate to first treat the life-threatening diagnosis before symptom management. If this patient’s hypertension was thought to be due to pain, then morphine could be helpful.

Bullet Summary:
Preeclampsia can occur in the postpartum period and should be managed with magnesium sulfate.


Question: A 7-year-old boy presents to the emergency department after an episode of jerking his extremities followed by confusion. This has happened in the past, but his mother thought he was fabricating his symptoms. She has taken him to a free health clinic to have him seen by a doctor who prescribed medication; however, she has been unable to fill the prescription. He has had an MRI of the brain with no acute findings in the past. The mother states this episode lasted about 3 minutes and involved full-body jerking. After the episode, the child was non-responsive but was breathing on his own. The child has a history of migraine headaches with aura that resolve with ibuprofen. He is otherwise healthy and has no medical problems or recent illness and is up to date on his vaccinations. His temperature is 97.6°F (36.4°C), blood pressure is 100/64 mmHg, pulse is 90/min, respirations are 12/min, and oxygen saturation is 99% on room air. The patient is protecting his airway but is unable to answer questions. He is able to move the right upper and lower extremity. He initially is unable to move his left upper and lower extremity and has a left facial droop; however, after a few minutes, he has 4/5 strength in the affected side with resolution of his facial weakness. The mother notes that this is similar to his past episodes. Which of the following is the most appropriate management?

Answer: Observation

Explanation:
This patient is presenting after a seizure (tonic-clonic jerking of his extremities) and is currently postictal given that he is obtunded. Given that the patient is not moving the left side of his body, he is likely suffering from Todd paralysis, which can occur after seizures and resolves on its own with only observation.

A generalized tonic-clonic seizure may present with full-body tonic-clonic activity with altered mental status. After a generalized tonic-clonic seizure, patients can be postictal and appear to be obtunded. Other than ensuring adequate oxygenation/ventilation and evaluating for the cause of the seizure, there is no further intervention needed as this postictal state will improve with time. After seizures, some patients present with Todd paralysis, which is a focal paralysis after a seizure. This may mimic a stroke, and thus the patient’s risk factors and known seizure history should be factored into the decision. Todd paralysis does not require any intervention and will improve with time and observation only.

Xu et al. review Todd paralysis. They note that Todd paralysis is characterized by temporary limb weakness or hemiplegia and usually occurs following a seizure. They recommend that it can be difficult to differentiate Todd paralysis from a stroke in certain patient populations.

Bullet Summary:
Answer A: Alteplase is a thrombolytic that could be used in an acute ischemic stroke if given within 4.5 hours of symptom onset without any contraindications to its use. It would only be given after the CT scan of the head has been performed and other reversible causes have been addressed in the setting of acute ischemic stroke. Alteplase is not given when neurologic symptoms are thought to be secondary to Todd paralysis. In fact, seizure and Todd paralysis would be a contraindication to thrombolytic use in stroke.

Answer B: CT head, in addition to a fingerstick blood glucose, should immediately be performed in all patients with sudden onset focal neurologic deficits thought to be secondary to a stroke. A stroke would present with sudden onset focal neurologic deficits. However, it is common for patients to be obtunded and have focal neurologic deficits after a seizure and this would not warrant a stroke workup unless clinical suspicion exists. This patient has no risk factors for stroke and his improving strength suggests against a stroke. Moreover, he has a history of a normal MRI of the brain.

Answer C: Diazepam would only be given for a patient who is actively seizing as it is a benzodiazepine with a long half-life. Note that it is not indicated in a postictal patient as there is no ongoing seizure. Benzodiazepines are not given as preventive measures for seizures.

Answer E: Sumatriptan may be indicated to treat a migraine, which presents with a pulsatile, unilateral headache and is more common in women. Hemiplegic migraine can cause focal neurologic deficits, and it would be reasonable to treat a migraine headache if a patient had focal neurologic deficits and a history of known hemiplegic migraines. Patients will either have a frequent history of hemiplegic migraines themselves or in their family.

Bullet Summary:
Focal neurologic deficits (Todd paralysis) can be seen after a seizure and will resolve with observation.


Question: A 43-year-old man presents to the emergency department acutely with altered mental status. He uses intravenous drugs and is unable to offer a history. He was found unconscious in a park. His temperature is 99.0°F (37.2°C), blood pressure is 80/40 mmHg, pulse is 156/min, and respirations are 26/min. Physical exam reveals an obtunded man covered in vomit, with track marks on his arm and several skin abscesses. The patient is given 4 liters of Ringer lactate and intravenous antibiotics. As the fourth liter of fluids is finishing, the patient is noted to have jugular venous distension and an oxygen saturation of 92% on nonrebreather. He is subsequently intubated. An ECG is obtained as seen in Figure A. The patient is started on norepinephrine, and his blood pressure is subsequently found to be 85/44 mmHg. Which of the following is the most appropriate next step in management?

Answer: Epinephrine

Explanation:
This patient who uses intravenous drugs with skin abscesses (the likely source of his infection) is hypotensive and tachycardic, with a blood pressure that is not responding to IV fluids; this is concerning for septic shock. Given his persistent hypotension, he should be started on vasopressors of which norepinephrine is first line and epinephrine is second line.

Septic shock is a life-threatening, systemic bacterial infection that leads to vasodilation and endothelial dysfunction. Early management is centered on IV fluids, blood cultures, broad-spectrum antibiotics, and workup to uncover the source. If the patient's blood pressure does not respond to IV fluids (by definition, their blood pressure will not respond to fluids in septic shock), vasopressors should be started with a goal mean arterial pressure > 65 mmHg. The first line vasopressor is norepinephrine, which can be titrated up for maximal effect. If this vasopressor fails to reach blood pressure goals, then the next vasopressor is either vasopressin or epinephrine (either is acceptable). If the second line vasopressor fails to increase blood pressure, then the third line vasopressor is vasopressin or epinephrine (whichever was not used as the second line pressor). Finally, the fourth line vasopressor for septic shock is phenylephrine.

Levy et al. review sepsis. They update the Surviving Sepsis campaign which gives the most up to date management guidelines of sepsis including adequate fluid resuscitation, broad-spectrum antibiotics, and vasopressors. They recommend early antibiotics and resuscitation to minimize morbidity and mortality.

Figure/Illustration A is an ECG demonstrating sinus tachycardia. Note the presence of P waves (red arrows highlighting several examples) that are present throughout all leads.

Incorrect Answers:
Answer A: Cardioversion would be appropriate in an unstable patient with unstable vital signs in the setting of atrial fibrillation with rapid ventricular response to convert the patient to normal sinus rhythm. Atrial fibrillation would present with an irregularly irregular rhythm without P waves. Cardioversion would not be indicated in sinus tachycardia.

Answer C: Hydrocortisone is a potent glucocorticoid that also has mineralocorticoid properties. While giving an IV steroid may have a permissive effect on blood pressure (via upregulating alpha-1 receptors on the vasculature) there is no reason that this patient would have a low cortisol level (such as in chronic steroid use). Epinephrine is a better answer in this case, though steroids can be considered. Steroids are typically reserved for patients failing at least 2 vasopressors (unless they have a known cortisol-deficient state).

Answer D: Normal saline is unlikely to benefit this patient as he has already been sufficiently fluid resuscitated. Moreover, it seems the patient may be developing pulmonary edema (hypoxia, jugular venous distension), a sign of fluid overload.

Answer E: Phenylephrine is the fourth line vasopressor and is an alpha-1 agonist. It is much less potent than norepinephrine and epinephrine, and would not be started in the management of septic shock until the patient has received epinephrine, norepinephrine, and vasopressin.

Bullet Summary:
In septic shock, the vasopressors given (in order) are norepinephrine, epinephrine/vasopressin, then phenylephrine.


Question: A 32-year-old man presents to the emergency department with pain upon defecation. His symptoms started a few weeks ago but have been worsening. Sometimes he notes blood on the toilet paper. He has to strain to have bowel movements and has trouble defecating secondary to pain. He is generally healthy and does not smoke. The patient is a software engineer and enjoys hiking, going to nightclubs, and dancing. His temperature is 98.1°F (36.7°C), blood pressure is 112/83 mmHg, pulse is 83/min, respirations are 13/min, and oxygen saturation is 98% on room air. Physical exam reveals a small, superficial fissure that is lateral to the anus and lateral to the midline. Which of the following is the most appropriate management for this patient?

Testing for HIV, fecal occult blood, and sexually transmitted diseases

Answer: Testing for HIV, fecal occult blood, and sexually transmitted diseases

Explanation:
This patient is presenting with pain upon defecation, constipation, and a fissure lateral to the midline which is suggestive of an anal fissure. Anal fissures lateral to the midline are associated with inflammatory and infectious etiologies; thus, further workup (testing for HIV, fecal occult blood testing, and sexually transmitted disease testing) is needed rather than merely symptomatic treatment.

Anal fissures present with exquisite pain upon defecation which may lead to fecal retention and constipation. Commonly, anal fissures are caused by constipation, local trauma (such as anal intercourse), or a tight anal sphincter. Anal fissures that occur secondary to trauma are usually midline. On the other hand, lateral anal fissures are a harbinger of more serious alternative diagnoses and require further workup. Lateral anal fissures can be caused by infections (HIV being one of the most concerning as well as syphilis or tuberculosis), Crohn disease, granulomatous disease, malignancy, as well as foreign bodies. For this reason, lateral anal fissures should not only be treated symptomatically but require testing for sexually transmitted diseases, inflammatory conditions, and malignancy to determine the underlying etiology based on the patient’s risk factors and associated symptoms.

Steele and Madoff review anal fissures. They note that while both operative and non-operative interventions may be indicated in the management of an anal fissure after alternative diagnoses have been ruled out, advances in medical management may spare patients sphincter-dividing surgery. They recommend considering all modalities.

Incorrect Answers:
Answer A: CT scan of the abdomen and pelvis followed by an MRI may be the most appropriate testing if a perirectal abscess is suspected. These abscesses can track very deep. For this reason, further imaging and drainage in the operating room followed by antibiotics are indicated rather than a simple bedside incision and drainage. Imaging may be indicated in this patient after medical workup fails to elucidate an etiology.

Answer B: Incision, drainage, ciprofloxacin, and metronidazole may be indicated for a perianal abscess (note, this is not a perirectal abscess), which presents with a tender, fluctuant mass right next to the anus. The diagnosis can be made clinically or supported by an ultrasound.

Answer C: Surgical excision may be performed in the management of a perianal fistula, which presents with a draining tract next to the anus that releases purulence or fecal contents causing staining of the patient’s underwear and irritation of the skin. The diagnosis is made with an exam and a CT, MRI, or fistulogram followed by a fistulotomy.

Answer E: Topical lidocaine, sitz baths, and fiber supplements are the appropriate management of an anal fissure that is midline and secondary to a clear cause such as trauma or constipation. It would be inappropriate to only treat this patient symptomatically with a lateral anal fissure as this is a sign of a more serious diagnosis.

Bullet Summary:
Anal fissures that are lateral to the midline require workup for sexually transmitted infections, cancer, and autoimmune disease.


Question: A 57-year-old man is brought to the emergency department by his wife with confusion. He was seen in the emergency department 2 days ago for profuse epistaxis. His primary care provider was concerned and had advised him to go to the hospital, as the patient is on warfarin for atrial fibrillation. However, his bleeding resolved with pressure and nasal packing. Upon presentation to the ED today, his temperature is 97.6°F (36.4°C), blood pressure is 64/33 mmHg, pulse is 160/min, respirations are 32/min, and oxygen saturation is 100% on room air. Physical exam reveals an obtunded man who cannot answer questions. A dark, purpuric rash is noted on his torso and extremities. The patient’s nasal packing is removed with no further bleeding. The patient is given IV fluids and blood cultures are drawn. Which of the following should be administered first?

Answer: Clindamycin

Explanation:
This patient is presenting with nasal packing, hypotension, tachycardia, a dark, purpuric rash, and confusion, which are concerning for toxic shock syndrome. The most important initial step in management is to administer clindamycin.

Toxic shock syndrome is a life-threatening diagnosis caused by Streptococcus pyogenes or Staphylococcus aureus and occurs commonly secondary to retained tampons or nasal packing. Patients are critically ill and require immediate management with fluids, vasopressors, and blood cultures. Source control is imperative, and the foreign body causing the infection must be removed. Next, broad-spectrum antibiotics should be started immediately. Clindamycin is often preferred as the first agent as this lincosamide antibiotic not only covers Staphylococcus aureus and Streptococcus pyogenes, but also has the theoretical benefit of suppressing toxin production. Further management is centered on fluid administration, vasopressors, and monitoring and care in an ICU setting as these patients are typically critically ill.

Russell and Pachorek review the treatments for toxic shock syndrome. They note that clindamycin is particularly important in toxic shock syndrome that is complicated by toxin production. They recommend that administration may reduce toxin production and could improve outcomes.

Incorrect Answers:
Answer B: Meropenem is a broad-spectrum antibiotic that covers most organisms except for MRSA. It is generally not used as a first-line agent unless the patient has allergies to other antibiotics or the infectious organism is only sensitive to this agent. Even in toxic shock syndrome, it would not be used as a first-line agent.

Answer C: Penicillin may be used for infections such as streptococcal pharyngitis, which presents with a sore throat, fever, and tonsillar exudates. It is a relatively weaker antibiotic and would not be used in a critically ill patient with toxic shock syndrome.

Answers 4 & 5: Piperacillin-tazobactam and vancomycin represent a powerful broad-spectrum regimen of antibiotics that covers gram-positives, gram-negatives, Pseudomonas aeruginosa, and anaerobes (piperacillin-tazobactam) as well as further gram-positive coverage and MRSA (vancomycin). Though this is a potent antibiotic combination, neither of these takes priority over clindamycin given the possible benefit of toxin suppression from clindamycin. In this patient, clindamycin and piperacillin-tazobactam would be an appropriate antibiotic regimen.

Bullet Summary:
Clindamycin may suppress toxin production and should be given early in toxic shock syndrome.


Question: A 37-year-old woman presents to the emergency department in cardiac arrest. She was found to have altered mental status at home, and during transport to the hospital, she became pulseless. Cardiopulmonary resuscitation is ongoing and 2 intravenous lines are placed. The patient is obese, and her only medication is an oral contraceptive pill. She recently underwent Achilles tendon repair. She otherwise is known to smoke cigarettes on occasion. Physical exam is notable for a critically ill patient with chest compressions ongoing. The monitor shows pulseless electrical activity. Her right lower extremity is in a post-operative splint. The patient regains her pulse after several rounds of CPR and epinephrine. A bedside echocardiograph is notable for a dilated and hypokinetic right ventricle with septal bowing into a hyperkinetic left ventricle. Which of the following is the most likely diagnosis?

Answer: Obstructive shock

Explanation:
This obese patient on oral contraceptive pills with recent orthopedic surgery (Achilles tendon repair) is presenting in cardiac arrest. Given the bedside echocardiograph that is notable for a dilated and hypokinetic right ventricle with septal bowing into a hyperkinetic left ventricle, the most likely diagnosis is a pulmonary embolism that is causing obstructive shock.

Pulmonary embolism is most commonly caused by a deep vein thrombosis in the veins of the lower extremity that travels to the pulmonary circulation. Patients will present with pleuritic chest pain, hypoxia, sinus tachycardia, and hemoptysis. Massive pulmonary emboli can cause hemodynamic instability. Patients may become hypotensive, tachycardic, and ultimately pulseless. The pulmonary embolism can obstruct blood flow from the right ventricle to the pulmonary artery, leading to a dilated and hypokinetic right ventricle with septal bowing and a hyperdynamic left ventricle. This is a type of obstructive shock. Treatment of a massive pulmonary embolism causing hemodynamic instability may involve thrombolytics or thrombectomy.

Standl et al. review obstructive shock. They note that obstructive shock is caused by an obstruction of blood flow out of (or in the case of tamponade, into) the heart. They recommend that treating the underlying cause is the only effective management option.

Incorrect Answers:
Answer A: Cardiogenic shock is caused by cardiac dysfunction in conditions such as myocardial infarction or heart failure. Cardiac dysfunction then leads to impaired systemic perfusion. Initial management includes treating the underlying cause (e.g., cardiac catheterization for an ST-elevation myocardial infarction) and vasopressors (e.g., norepinephrine) to maintain the patient’s blood pressure.

Answer B: Hemorrhagic shock is a common cause of shock in trauma and presents with hypotension and tachycardia secondary to blood loss. A narrowed pulse pressure may be the first sign of hemorrhagic shock. The mainstay of management is blood transfusion and an intervention to stop the bleeding.

Answer C: Neurogenic shock occurs when there is central nervous system trauma (often to the cervical spine) leading to decreased sympathetic tone systemically. Patients will present with hypotension and bradycardia (contrast with tachycardia in hemorrhagic shock), and management is centered on vasopressors to maintain blood pressure and neurosurgical intervention for the underlying etiology. IV fluids can also be given to maintain blood pressure.

Answer E: Septic shock occurs when a systemic infection leads to vasodilation and endothelial dysfunction with hypotension refractory to fluid resuscitation. The mainstay of management includes fluids, blood cultures, vasopressors, and broad-spectrum antibiotics. Early administration of antibiotics improves outcomes.

Bullet Summary:
Pulmonary embolism is a common cause of obstructive shock.


Question:
A 49-year-old man presents with 3 months of generalized weakness. He has had a chronic cough and a 20 pound unintentional weight loss over the past 6 months. He has a medical history significant for high blood pressure, hyperlipidemia, and seasonal allergies with no prior surgical history. He has no history of tobacco use. He moved from India 7 years prior to presentation. He currently lives in Oregon and has not left the west coast since moving. His temperature is 99°F (37.2°C), blood pressure is 100/70 mmHg, pulse is 76/min, and respirations are 16/min. His physical exam is significant for hyperpigmentation of the oral mucosa and temporal muscle wasting. Radiography of the abdomen demonstrates bilateral adrenal calcifications. Laboratory values are as follows:

Serum:
Na+: 130 mEq/L
Cl-: 96 mEq/L
K+: 5.2 mEq/L
HCO3-: 24 mEq/L
Morning cortisol: 2 ug/dL
30-minute cortisol during cosyntropin test: 8 ug/dL (normal > 18 ug/dL)
Morning adrenocorticotropic hormone (ACTH) concentration (serum): 80 pg/mL (normal 10-60 pg/mL)

Which of the following is the most appropriate next step in management?

Bilateral adrenalectomy, prednisone, and fludrocortisone

Rifamycin, isoniazid, pyrazinamide, ethambutol, and hydrocortisone therapy

Hydrocortisone and immunoglobulin therapy

Answer: Rifamycin, isoniazid, pyrazinamide, ethambutol, and hydrocortisone therapy

Explanation:
This man from India presents with generalized weakness, chronic cough, unintentional weight loss, skin hyperpigmentation, hyponatremia, hyperkalemia, hypocortisolism, cosyntropin stimulation test failure, elevated ACTH, and bilateral adrenal calcifications on radiography. These symptoms and signs in this patient are most consistent with adrenal tuberculosis requiring RIPE therapy (rifamycin, isoniazid, pyrazinamide, ethambutol) as well as glucocorticoid and mineralocorticoid therapy.

Adrenal insufficiency occurs when the adrenal glands do not produce enough cortisol and aldosterone. Primary adrenal insufficiency is due to dysfunction at the level of the adrenal glands themselves, as opposed to upstream factors such as the pituitary gland. Primary adrenal insufficiency in developed nations is most often caused by autoimmune disease. In developing nations, adrenal tuberculosis is a significant cause of primary adrenal insufficiency. Adrenal tuberculosis often presents with a history of tuberculosis or tuberculosis symptoms, as well as symptoms of adrenal insufficiency such as fatigue, unintentional weight loss, and hyperpigmentation. Patients often have hyponatremia, hyperkalemia, low morning cortisol, a failed cosyntropin test, and high ACTH concentrations. Radiography may demonstrate bilateral adrenal calcifications, and/or adrenal enlargement. Tuberculosis can infect all cortices of the adrenal glands bilaterally, and therefore treatment requires eradicating the infection with multi-drug therapy (RIPE therapy) as well as replacement of glucocorticoids and mineralocorticoids, which may be achieved by high-dose hydrocortisone or other combinations of steroids that together provide glucocorticoid and mineralocorticoid replacement.

Vinnard and Blumberg outline the signs and symptoms, histopathology, lab results, imaging, differential diagnosis, and treatments associated with adrenal tuberculosis. They recommend early recognition and treatment.

Incorrect Answers:
Answer A: Bilateral adrenalectomy, prednisone therapy, and fludrocortisone therapy are incorrect because medical therapy should first be attempted to eradicate the infection before undergoing surgery. Bilateral adrenalectomy may be considered if there is suspicion of lung cancer with metastasis to the bilateral adrenal glands. Patients will require lifelong replacement therapy.

Answer B: Dexamethasone alone is incorrect because this patient likely has tuberculosis and should be treated for it. Additionally, this patient has signs of mineralocorticoid deficiency (hyponatremia, hyperkalemia), and patients often require mineralocorticoid therapy or a high dose of a glucocorticoid with mineralocorticoid activity (e.g., hydrocortisone). Dexamethasone has minimal to absent mineralocorticoid activity.

Answer C: Hydrocortisone therapy and immunoglobulin therapy are incorrect because this patient has adrenal tuberculosis. Although autoimmune adrenalitis can cause primary adrenal insufficiency, immunoglobulins are not used to treat this condition.

Answer D: Prednisone taper would be appropriate for acute conditions such as an asthma or COPD exacerbation. While prednisone will treat the symptoms of primary adrenal insufficiency, it will not treat active tuberculosis infection. Primary adrenal insufficiency in developed nations is most often caused by autoimmune adrenalitis (Addison disease) and presents with fatigue, unintentional weight loss, abdominal pain, hyperpigmentation, and muscle weakness. In this condition, long-term steroid therapy is indicated.

Bullet Summary:
Patients with adrenal tuberculosis should be treated with rifamycin, isoniazid, pyrazinamide, ethambutol, as well as glucocorticoid and mineralocorticoid replacement.


Question:
A 5-year-old boy presents to his primary care physician for recurrent colds, fatigue, and fussiness. Over the past several weeks, the child has been more fatigued and his parents state that “he always seems to be sick.” They state that sometimes he complains about his bones hurting and they note that he is less playful. He is up to date on his vaccinations. His temperature is 102°F (38.9°C), blood pressure is 92/60 mmHg, pulse is 115/min, respirations are 23/min, and oxygen saturation is 99% on room air. Physical exam is notable for diffuse non-tender lymphadenopathy. Abdominal exam reveals hepatosplenomegaly. Laboratory studies are ordered as seen below.

Hemoglobin: 8.0 g/dL
Hematocrit: 23%
Leukocyte count: 27,500/mm^3 with 35% lymphoblasts
Platelet count: 49,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 101 mEq/L
K+: 4.0 Eq/L
HCO3-: 24 mEq/L
BUN: 16 mg/dL
Glucose: 100 mg/dL
Creatinine: 0.7 mg/dL

Which of the following is the most likely diagnosis?

Answer: Acute lymphoblastic leukemia

Explanation:
This pediatric patient is presenting with recurrent colds, fatigue, non-tender lymphadenopathy, hepatosplenomegaly, and leukocytosis with increased lymphoblasts, which are concerning for acute lymphoblastic leukemia (ALL).

ALL is the most common hematologic cancer in pediatric patients. It initially presents with a vague constellation of symptoms including fatigue, fevers, easy bleeding/bruising, bone pain, lymphadenopathy, hepatosplenomegaly, and possibly testicular enlargement. The diagnosis is supported when the white blood cell count (which can be low, normal, or high) demonstrates increased lymphoblasts. Further confirmatory testing may include testing for the 12:21 translocation, which is more common with a better prognosis, or the 9:22 translocation (the Philadelphia chromosome), which is less common and denotes a poor prognosis.

Onciu reviews ALL. He notes that ALL has a high cure rate with intensive chemotherapeutic regimens and that new research is improving outcomes in this very common condition. He recommends early treatment with these regimens for an improved prognosis.

Incorrect Answers:
Answer B: Acute myelogenous leukemia is a malignancy of myeloblasts and is more common in the elderly. Patients will present with systemic symptoms, weight loss, anorexia, leukocytosis, anemia (causing fatigue), thrombocytopenia (causing bleeding including gingival bleeding and bleeding from the gastrointestinal tract), and neutropenia (predisposing patients to life-threatening infection). Myeloblasts produce increased amounts of myeloperoxidase which can lead to the formation of Auer rods that can be seen on peripheral smear.

Answer C: Chronic myelogenous leukemia is a neoplastic proliferation of myeloid stem cells and presents with a leukocyte count > 50,000/mm3. There are different presentations for this condition. Most patients present in the chronic phase with minimal symptoms (and a low blast count); however, they can also present with an accelerated phase and a blast phase which can lead to a hematologic emergency termed a blast crisis which may cause a hyperviscosity syndrome.

Answer D: Leukemoid reaction is an overly robust immune reaction (often to infection) that resembles chronic myelogenous leukemia. However, the leukocyte alkaline phosphatase level is elevated. This elevated level indicates it is a robust immune response rather than increased cell levels from malignancy.

Answer E: Parvovirus B19 infection presents with erythema infectiosum (fifth disease) which may include "slapped cheek" rash, fever, malaise, and possibly respiratory symptoms. In healthy patients, symptoms are usually minimal and self-limited. However, in patients with hemoglobinopathies (such as sickle cell disease), the transient halt in erythropoiesis that occurs in addition to hemolysis may lead to significant anemia requiring transfusion.

Bullet Summary:
Acute lymphoblastic leukemia presents in pediatric patients with pancytopenia, fatigue, repeat infections, easy bleeding, bone pain, lymphadenopathy, hepatosplenomegaly, and increased blast cells on peripheral smear.


Question: A 60-year-old man presents to his primary care physician with weight gain. He states that ever since his wife died 4 months ago, he has been eating and sleeping more and no longer engages in any activities he once enjoyed such as hiking or fishing. He feels guilty for not spending more time with his wife before she died. He was recently fired for making several major bookkeeping mistakes at work as an accountant as he had trouble focusing. The patient is requesting oxycodone at this appointment as he states he has burning pain in his legs that feels worse now than it has in years past. The patient has a past medical history of obesity, poorly controlled diabetes, hypertension, and peripheral vascular disease. His temperature is 98.7°F (37.1°C), blood pressure is 129/82 mmHg, pulse is 83/min, respirations are 15/min, and oxygen saturation is 99% on room air. Physical exam reveals a stable gait and reduced sensation symmetrically over the lower extremities. He complains of electric pain when touching his lower extremities. His affect seems depressed. Which of the following is the most appropriate treatment for this patient?

Answer: Venlafaxine

Explanation:
This patient is presenting with sleep changes, interest loss, guilt, decrease in energy, and trouble concentrating for greater than 2 weeks concerning for major depressive disorder. In the setting of his diabetic neuropathy (lower extremity burning pain in the setting of poorly managed diabetes), a serotonin-norepinephrine reuptake inhibitor (SNRI) such as venlafaxine is the most appropriate initial treatment for this patient.

Major depressive disorder should always initially be managed with cognitive behavioral therapy and often medication. Typically, the first-line medication is a selective serotonin reuptake inhibitor (SSRI). However, SNRIs such as venlafaxine and duloxetine are viable first-line options. They are particularly preferred in patients with diabetic neuropathy as they treat both diabetic neuropathy and depression. SNRIs are also generally considered to be less sedating than SSRIs. For this reason, SNRIs are often a better initial drug in depression than SSRIs in diabetic patients with peripheral neuropathy.

Sansone and Sansone discuss SNRIs and their uses. They discuss how there are different efficacies and propensities of the different SNRIs. They recommend choosing an appropriate SNRI based on the patient's needs and comorbidities.

Incorrect Answers:
Answer A: Amitriptyline is a tricyclic antidepressant that can be used to treat depression in patients who also suffer from other neuropathic pain conditions or conditions such as fibromyalgia or irritable bowel syndrome. While it may also be used in diabetic neuropathy and depression, there is higher toxicity with this medication than SNRIs. For this reason, SNRIs are preferred. A TCA might be appropriate if the patient had already failed other first-line agents.

Answer B: Bupropion is a weight-neutral antidepressant that can be used in smoking cessation and patients who are trying to avoid the sexual side effects of SSRIs (anorgasmia). It would not address this patient's diabetic neuropathy, though it could be beneficial for his obesity.

Answer C: Escitalopram is an SSRI that could be used first-line for major depressive disorder. However, if a patient has a concomitant condition, it is better to choose a single agent that addresses both problems; thus, SNRIs are better first-line medications in this patient with diabetic neuropathy.

Answer D: Phenelzine is a monoamine oxidase inhibitor that can be used in atypical depression or as a third-line or later agent in the management of depression. This agent can cause a hypertensive crisis in the setting of tyramine consumption, has many medication interactions, and a long washout period. Thus, it is not usually a first or second-line agent. However, it is highly effective in patients who have failed other first-line agents and should still be used in appropriate candidates.

Bullet Summary:
SNRIs are appropriate first-line agents for major depressive disorder in patients with diabetic neuropathy.


Question: A 66-year-old man presents to the emergency department with shortness of breath. He typically has poor exercise tolerance and is only able to walk from his house to his mailbox before becoming dyspneic. He now has shortness of breath even at rest. He had a cold recently but has no new medical problems. His past medical history is notable for a myocardial infarction 7 years ago, COPD, heart failure with a left ventricular ejection fraction of 22%, obesity, diabetes, and peripheral vascular disease. His temperature is 97.7°F (36.5°C), blood pressure is 124/82 mmHg, pulse is 140/min, respirations are 32/min, and oxygen saturation is 78% on room air. Physical exam reveals an uncomfortable man with increased work of breathing. He demonstrates bilateral crackles and wheezing on pulmonary exam. The patient is started on BiPAP, and his oxygen saturation improves to 94%. An ECG is performed, as seen in Figure A, and a chest radiograph is performed, as seen in Figure B. Which of the following is the most appropriate next step in management?

Answer: Digoxin

Explanation:
This patient with a history of heart failure with reduced ejection fraction is presenting with respiratory distress (increased work of breathing, hypoxia, wheezes, and crackles) in the setting of atrial fibrillation (ECG with irregularly irregular rhythm without P waves) with rapid ventricular response and pulmonary edema on chest radiograph. Digoxin is an appropriate medication that can both control the heart rate in atrial fibrillation and increase cardiac contractility and potentially improve respiratory symptoms in this decompensated patient with heart failure.

Atrial fibrillation presents on ECG with an irregularly irregular rhythm without discernible P waves. The initial management of atrial fibrillation with rapid ventricular response is rate control. If the patient is stable, possible first-line agents include beta-blockers (e.g., metoprolol) or calcium channel blockers (e.g., diltiazem). These agents may reduce cardiac contractility and worsen complications such as pulmonary edema in the setting of heart failure with reduced ejection fraction when the patient is in a decompensated state. If the patient has a reduced ejection fraction and requires rate control, then digoxin is a highly effective medication that blocks the AV node and increases cardiac contractility. Any hemodynamically unstable patient with atrial fibrillation with rapid ventricular response should immediately be cardioverted.

Moskowitz et. al review the management of atrial fibrillation. They note that in the management of atrial fibrillation with rapid ventricular response, metoprolol is commonly used in the intensive care setting, is more successful than amiodarone, and had better rate control when compared to diltiazem.

Ehle et. al note that digoxin is approved to control ventricular response in patients with chronic atrial fibrillation and is the only oral agent with positive inotropic effects approved for the management of mild to moderate heart failure.

Figure/Illustration A is an ECG demonstrating an irregularly irregular rate/rhythm (note the spacing of the blue arrows indicating the QRS complexes) without P waves, which is suggestive of atrial fibrillation. Figure B is a chest radiograph demonstrating bilateral, hazy interstitial infiltrates, which are concerning for pulmonary edema.

Incorrect Answers:
Answer A: Albuterol and prednisone would be appropriate management of a COPD flare, which presents in a patient with a history of smoking with dyspnea, wheezing, increased work of breathing, and a barrel chest. While this patient’s wheezing may be secondary to his COPD, it is much more likely to be a cardiac wheeze given his chest radiograph findings including pulmonary edema. Treating his atrial fibrillation is more likely to alleviate his pulmonary symptoms. Other treatments in COPD include ipratropium and BiPAP.

Answer C: Diltiazem would be an appropriate rate control agent for atrial fibrillation with rapid ventricular response, particularly in the setting of a COPD flare as it will not impair the mechanism of albuterol (which should be given as a nebulizer in COPD flares). In this patient, further impairing cardiac contractility with a calcium channel blocker may worsen his underlying pulmonary edema (given his reduced ejection fraction).

Answer D: Intubation would be indicated if this patient’s respiratory status were worsening, including failure to oxygenate, failure to ventilate, or impending respiratory failure. This patient’s respiratory status has improved on BiPAP; thus intubation is not needed.

Answer E: Metoprolol, like diltiazem, would reduce cardiac contractility and may worsen pulmonary edema, in particular, in a patient with a reduced ejection fraction. It also may cause COPD symptoms to emerge, as beta-2 blockade may cause bronchoconstriction (even though metoprolol is beta-1 selective). It would be indicated as outpatient rate control for a patient with atrial fibrillation who can tolerate a beta-blocker, and is preferred in patients with a history of acute coronary syndrome, as it reduces mortality.

Bullet Summary:
Patients with atrial fibrillation with rapid ventricular response with a reduced ejection fraction may be optimally managed with digoxin, which blocks the AV node and increases cardiac contractility.


Question: A 23-year-old man presents to the emergency department after he was rescued while hiking in Alaska. The patient was found on a mountain trail non-responsive. His temperature is 91°F (32.8°C), blood pressure is 103/61 mmHg, pulse is 60/min, respirations are 11/min, and oxygen saturation is 97% on room air. The patient is placed under a warm air circulator, and his extremities are bathed in warm water. An ECG is performed as seen in Figure A. Dark bullae are noted on the patient's extremities. His mental status rapidly improves with warming. Laboratory studies are ordered and are pending. Which of the following is most likely to be found in this patient?

Answer: Hypocalcemia

Explanation:
This patient is presenting after being found outside with hypothermia and frostbite (dark bullae noted on the extremities in the setting of being out in the cold). Frostbite can lead to rhabdomyolysis, which may cause hyperkalemia (causing ECG changes including peaked T waves and QRS widening as seen in this patient) and hypocalcemia (the most common electrolyte finding in frostbite).

Frostbite occurs when there is an extensive freezing injury to tissues and can cause benign swelling, erythema, and pain, all the way to insensate extremities with necrosis and permanent dysfunction. More severe forms of frostbite can cause rhabdomyolysis or breakdown of the muscles. Breakdown of the muscle cells leads to leakage of the intracellular contents. Common electrolyte derangements include hyperkalemia and hypophosphatemia. Hypocalcemia is the most common electrolyte derangement in rhabdomyolysis. It occurs due to the deposition of calcium in the necrotic muscle cells and the sequestration of calcium in the exposed sarcoplasmic reticulum. Note that hypocalcemia requires no treatment unless it is causing symptoms or ECG changes (such as QT prolongation). The management of rhabdomyolysis is centered on fluid administration to protect the kidney from myoglobin which is released from damaged muscles and is nephrotoxic.

Zimmerman and Shen review rhabdomyolysis. They note that rhabdomyolysis can be commonly associated with myoglobinuria, hyperkalemia, hypocalcemia, and hyperphosphatemia. They suggest that an elevated creatine kinase level is indicated to support the diagnosis.

Figure/Illustration A is an ECG demonstrating peaked T waves (blue arrows) which are associated with hyperkalemia.

Incorrect Answers:
Answer A: Elevated troponin may be seen in rhabdomyolysis. This is a non-cardiac cause of an elevated troponin; however, this is less common than hypocalcemia in rhabdomyolysis and is neither sensitive nor specific.

Answer C: Hypomagnesemia is not a common electrolyte disturbance seen in rhabdomyolysis; however, hypomagnesemia may cause hypocalcemia (from impaired PTH release) and hypokalemia (from renal wasting of potassium). Note that this mechanism is separate from rhabdomyolysis.

Answer D: Hypophosphatemia is common in refeeding syndrome and malnourished patients (such as those with alcohol use disorder) and presents with diffuse muscle weakness. Rather, hyperphosphatemia would be seen in rhabdomyolysis as it is released from damaged muscle cells.

Answer E: Red blood cells on urine microscopy would be seen in a nephritic syndrome in addition to red blood cell casts. Note that the urine dipstick will be positive for red blood cells in rhabdomyolysis due to cross-reactivity with myoglobin; however, there are minimal/no red blood cells actually present.

Bullet Summary:
Frostbite can result in rhabdomyolysis which commonly causes hyperkalemia, hyperphosphatemia, and hypocalcemia (the most common derangement).