All practice questions

A 45-year-old man is evaluated in the hospital due to a new-onset diffuse rash and severe diarrhea. He underwent an allogeneic hematopoietic stem cell transplantation for acute myeloid leukemia four weeks ago. His current medications include tacrolimus, acyclovir, and fluconazole. His temperature is 38.2°C (100.8°F), blood pressure is 110/70 mm Hg, and pulse is 98/min. Physical examination reveals a generalized maculopapular rash that prominently involves the palms and soles. His abdomen is mildly tender to palpation, and he reports having 6 to 8 large-volume watery stools daily over the past three days. Laboratory studies show markedly elevated alkaline phosphatase and total bilirubin levels. Which of the following best describes the primary immunopathologic mechanism responsible for this patient's current clinical presentation?

A 48-year-old man comes to the primary care clinic reporting progressive fatigue, excessive sweating, and generalized joint pain, particularly in his knees and hands, over the past two years. The patient mentions that his wedding ring no longer fits and he recently had to purchase larger shoes. His medical history is unremarkable, and he takes no medications. Vital signs show a blood pressure of 155/95 mmHg, a heart rate of 76/min, a respiratory rate of 14/min, and a BMI of 29 kg/m^2. Physical examination reveals a prominent jaw, widely spaced teeth, coarse facial features, and enlarged, doughy hands. Which of the following is the most appropriate next step in laboratory evaluation?

A 28-year-old woman is brought to the emergency department by her roommate after being found confused and lethargic in her apartment. The roommate reports that the patient recently lost her job and has been complaining of a severe 'ringing in her ears' for the past 12 hours. Empty over-the-counter medication bottles were found on her nightstand.

Vital signs are temperature 38.1°C (100.6°F), blood pressure 110/65 mm Hg, pulse 118/min, and respiratory rate 26/min. Physical examination reveals diaphoresis and diffuse hyperreflexia, but no focal neurologic deficits.

Laboratory studies are obtained:

Based on the integration of these laboratory findings, which of the following best characterizes the patient's acid-base status?

A 74-year-old man is brought to the emergency department by his family due to the sudden onset of severe, unrelenting abdominal pain that began $2$ hours ago. He reports the pain is diffuse, $10/10$ in intensity, and associated with one episode of non-bilious emesis. He has a history of hypertension, type 2 diabetes mellitus, and permanent atrial fibrillation. He was previously prescribed apixaban but stopped taking it three weeks ago because he could not afford the refill.

Vital signs are: temperature $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure $105/65$ mmHg, pulse $118$/min and irregularly irregular, and respirations $22$/min.

Physical examination reveals a patient in obvious distress, writhing on the stretcher. Cardiopulmonary examination is unremarkable except for an irregularly irregular rhythm. Abdominal examination reveals a soft, non-distended abdomen with normal bowel sounds. There is diffuse mild tenderness to deep palpation, but no rebound, guarding, or rigidity is present.

Laboratory studies show:
Leukocyte count: $18,500/\text{mm}^3$
Serum creatinine: $2.3$ mg/dL (baseline $1.0$ mg/dL)
Serum lactate: $4.8$ mmol/L

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

A 62-year-old woman is evaluated in the intensive care unit for sudden-onset high fever, rigors, and altered mental status. Five days ago, she received chimeric antigen receptor (CAR) T-cell therapy for relapsed diffuse large B-cell lymphoma. Her temperature is 39.8°C (103.6°F), blood pressure is 82/45 mm Hg, pulse is 134/min, and respirations are 28/min. Oxygen saturation is 88% on room air. Physical examination reveals a lethargic patient with warm, flushed extremities. Cytokine release syndrome (CRS) is suspected, though concurrent sepsis cannot be excluded. Arrange the following management steps in the most appropriate chronological sequence for this patient's acute immunologic complication.

A 54-year-old man is evaluated in the hospital for fever and right-sided chest pain. He is currently on day 14 of induction chemotherapy for acute myeloid leukemia. For the past 10 days, his absolute neutrophil count has been consistently below 100/mm³. Over the last 24 hours, he has developed a temperature of 39.2°C (102.6°F), a nonproductive cough, and pleuritic chest pain. Vital signs show a heart rate of 110/min, blood pressure of 115/70 mm Hg, and respiratory rate of 22/min. Oxygen saturation is 94% on room air. Auscultation reveals focal crackles over the right upper lung field. A high-resolution CT scan of the chest without contrast demonstrates a 2.5-cm dense macronodule in the right upper lobe surrounded by a distinct zone of ground-glass attenuation. Based on these imaging findings and the clinical presentation, which of the following is the most likely diagnosis?

A 34-year-old woman, 4 weeks postpartum, is admitted to the neurology service following a sudden-onset, severe 'thunderclap' headache associated with transient left-sided visual field deficits. Her blood pressure on admission is 178/105 mmHg. A non-contrast head CT shows no evidence of acute hemorrhage. Subsequent magnetic resonance angiography (MRA) of the brain reveals diffuse, multifocal segmental narrowing and dilation of the cerebral arteries, consistent with a 'string of beads' appearance. She is diagnosed with reversible cerebral vasoconstriction syndrome (RCVS). The patient is otherwise healthy but mentions she recently began using several non-prescription products to manage a mild respiratory illness and combat sleep deprivation. To identify the underlying precipitant of this patient's current condition, which of the following historical elements are MOST critical to explicitly elicit? (Select all that apply)

A 42-year-old woman presents to the emergency department complaining of sudden-onset shortness of breath and right-sided pleuritic chest pain. She recently returned from a 14-hour international flight. She has no significant past medical history and takes no medications other than oral contraceptives.

Vital signs:
Temperature: 37.1°C (98.8°F)
Blood pressure: 128/78 mm Hg
Heart rate: 115/min
Respiratory rate: 26/min
Oxygen saturation: 88% on room air

Arterial blood gas analysis on room air reveals:
pH: 7.48
$PaCO_2$: 28 mm Hg
$PaO_2$: 55 mm Hg
$HCO_3^-$: 20 mEq/L

Assume the inspired partial pressure of oxygen ($P_IO_2$) is 150 mm Hg and the respiratory quotient ($R$) is 0.8.

What is this patient's alveolar-arterial ($A-a$) oxygen gradient in mm Hg?

A 58-year-old man with a 10-year history of type 2 diabetes mellitus is brought to the emergency department by his wife due to severe nausea, vomiting, and generalized weakness for the past 48 hours. He recently had a viral upper respiratory infection and has had poor oral intake. His medications include metformin, empagliflozin, and lisinopril. Vital signs show a blood pressure of $98/62$ mmHg, heart rate of $115$/min, and respiratory rate of $24$/min. Physical examination reveals dry mucous membranes.

Laboratory studies show:

Arterial blood gas analysis reveals a pH of $7.24$.

Which of the following is the most direct underlying metabolic mechanism precipitating this patient's primary acid-base disturbance?

A 61-year-old man is diagnosed with advanced non-small cell lung cancer. Immunohistochemical analysis of his biopsy specimen reveals a high tumor mutational burden and robust expression of programmed death-ligand 1 (PD-L1). He is initiated on pembrolizumab, an immune checkpoint inhibitor. The pathogenesis of this patient's pre-treatment immune evasion relies on a specific sequence of cellular interactions collectively known as adaptive immune resistance. Arrange the following pathophysiological events in the chronological order that leads to tumor-induced T-cell anergy.

Match each clinical vignette describing a patient with an unexplained bleeding diathesis or abnormal coagulation profile to the most appropriate targeted laboratory test to establish the diagnosis.

A 26-year-old individual presents to the outpatient clinic requesting sexually transmitted infection screening. He reports a high-risk, unprotected sexual encounter approximately 12 days ago. For the past 48 hours, he has experienced a sore throat, low-grade fever, myalgias, and significant fatigue. Physical examination reveals bilateral cervical lymphadenopathy. The physician suspects acute human immunodeficiency virus (HIV) infection.

Arrange the following laboratory tests in the correct sequential order for diagnosing and subsequently establishing the baseline immunological status of this patient, in accordance with the standard testing algorithm.

A 52-year-old man comes to the continuity clinic reporting a 3-month history of worsening fatigue, low energy, and new-onset constipation. He states, 'I think my depression is coming back because work has been incredibly stressful lately.' He has a past medical history of major depressive disorder, which has been well-controlled on citalopram for the past 4 years, and essential hypertension treated with amlodipine. His vital signs are within normal limits. Physical examination reveals mild conjunctival pallor but is otherwise unremarkable. The physician considers diagnosing a depressive relapse and adjusting his psychiatric regimen. To avoid a critical diagnostic error and prioritize high-morbidity conditions, which of the following inquiries is most essential during this medical history evaluation?

A $32$-year-old woman is evaluated in the emergency department for right lower extremity swelling and severe calf pain that started $2$ days prior. Her medical history is significant for $3$ consecutive first-trimester pregnancy losses, but she is otherwise healthy. She takes no medications and has no recent history of surgery, trauma, or prolonged travel. Her vital signs are temperature $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure $118/76\text{ mmHg}$, pulse $88\text{/min}$, and respirations $14\text{/min}$. Physical examination reveals a swollen, erythematous, and tender right calf. A Doppler ultrasound of the right leg confirms a popliteal deep venous thrombosis. Initial laboratory tests show a normal prothrombin time (PT) but an activated partial thromboplastin time (aPTT) of $62\text{ seconds}$ (reference range: $25-35\text{ seconds}$). Which of the following is the most appropriate next step in the laboratory evaluation of this patient's abnormal coagulation profile?

A 52-year-old woman is evaluated in the clinic for a 4-month history of progressive fatigue, abdominal fullness, and bilateral lower extremity swelling. She has no chest pain, orthopnea, or paroxysmal nocturnal dyspnea. Medical history is significant for Hodgkin lymphoma diagnosed at age 28, for which she was treated with systemic chemotherapy and mantle field radiation therapy. Vital signs show a temperature of 37.0°C (98.6°F), blood pressure of 112/76 mm Hg, heart rate of 88/min, and respiratory rate of 16/min. The lungs are clear to auscultation bilaterally. Abdominal examination reveals shifting dullness and a liver edge palpable 4 cm below the right costal margin. Bilateral 2+ pitting edema is present up to the knees. Which of the following physical examination findings are most likely to be present in this patient? (Select all that apply)

An emergency medicine physician evaluates a pregnant patient at 20 weeks gestation who reports acute, severe right lower quadrant abdominal pain that started 12 hours ago. She has experienced one episode of emesis and ongoing nausea. Vital signs show a temperature of 38.2°C (100.8°F), blood pressure of 110/70 mmHg, and heart rate of 105/min. On physical examination, there is pronounced focal tenderness over the right lower quadrant accompanied by voluntary guarding. Initial laboratory studies demonstrate a leukocyte count of 16,000/mm³. The clinical team strongly suspects acute appendicitis.

Arrange the following diagnostic modalities in the correct sequential order for evaluating this patient's condition, starting with the most appropriate initial step and proceeding to the final confirmatory and therapeutic step if the preceding studies are non-diagnostic or unavailable.

A $23$-year-old female presents to the emergency department complaining of profound fatigue, muscle weakness, and severe dizziness whenever she stands up. She works as a professional dancer and admits to being under immense stress before an upcoming audition. On physical examination, her supine blood pressure is $102/64$ mm Hg with a heart rate of $92$/min. Upon standing, her blood pressure drops to $84/52$ mm Hg and her heart rate increases to $122$/min. Her mucous membranes are dry, and skin turgor is decreased.

Laboratory evaluation reveals the following:

Which of the following is the most likely etiology of this patient's clinical and laboratory findings?

A 58-year-old man with end-stage renal disease on hemodialysis presents to the emergency department with acute-onset dyspnea, lightheadedness, and left-sided chest discomfort. The symptoms began shortly after he missed his last two dialysis sessions. His temperature is 37.1°C (98.8°F), blood pressure is 84/52 mm Hg, pulse is 122/min, and respirations are 24/min. Pulse oximetry shows 95% on room air. Physical examination reveals elevated jugular venous pressure, clear lung fields, and distant heart sounds. A point-of-care ultrasound (POCUS) of the heart is performed. The subxiphoid view demonstrates a large, circumferential anechoic space separating the epicardium from the pericardium. Additionally, the apical four-chamber view reveals inward scalloping of the right ventricular free wall during early diastole. Based on the interpretation of these imaging findings, which of the following is the most appropriate next step in management?

A 35-year-old woman comes to the clinic to discuss recent laboratory results. A basic metabolic panel obtained during a pre-employment physical examination showed an elevated serum calcium level. The patient feels completely well and has no fatigue, abdominal pain, bone pain, or changes in bowel habits. She has no significant past medical history and takes no medications or over-the-counter supplements. She exercises vigorously four times a week. Vital signs are within normal limits. Physical examination is unremarkable.

Laboratory studies reveal the following:

Which of the following is the most likely underlying mechanism for this patient's laboratory findings?

A 34-year-old man is evaluated in the surgical ward 12 hours after undergoing open reduction and internal fixation of a comminuted right tibial shaft fracture. He is complaining of severe, unrelenting right leg pain that has progressively worsened and is not relieved by his prescribed intravenous opioids. His vital signs are stable. The surgical team is concerned about the development of acute compartment syndrome. Which of the following physical examination findings are considered reliable, early clinical indicators of this emergent condition? (Select all that apply)