All practice questions

A $22$-year-old man with type 1 diabetes mellitus is being treated in the intensive care unit for diabetic ketoacidosis. He has been receiving a continuous intravenous regular insulin infusion, intravenous fluids, and potassium replacement for the past $14$ hours. Current laboratory evaluation reveals a blood glucose of $178$ mg/dL, a serum bicarbonate of $20$ mEq/L, and a calculated anion gap of $9$ mEq/L. The patient is awake, alert, and reports feeling hungry. The physician decides to transition the patient to a subcutaneous insulin regimen. Arrange the following management and monitoring steps in the correct chronological sequence to safely accomplish this therapeutic de-escalation.

A 58-year-old man is brought to the emergency department by his wife due to fever, severe headache, and confusion that started 12 hours ago. He has a past medical history of alcohol use disorder, type 2 diabetes mellitus, and hypertension. His temperature is 39.2°C (102.6°F), blood pressure is 110/70 mmHg, and heart rate is 115/min. On physical examination, he is lethargic but arousable. There is significant resistance to passive neck flexion. Funduscopic examination shows no papilledema. Lumbar puncture is performed, and cerebrospinal fluid (CSF) analysis reveals a leukocyte count of 2,400/mm³ (90% neutrophils), a glucose level of 30 mg/dL, and a protein level of 150 mg/dL. Gram stain of the CSF is pending.

Which of the following pharmacologic agents should be included in his immediate empiric regimen? (Select all that apply)

A 71-year-old man is evaluated in the intensive care unit for new-onset tachypnea and pleuritic chest pain. He was admitted one week ago for severe community-acquired pneumonia requiring mechanical ventilation, from which he was successfully extubated yesterday. He has a history of severe chronic kidney disease with a baseline glomerular filtration rate of $12 \text{ mL/min/1.73 m}^2$, not currently on dialysis. Vital signs today include a heart rate of $115\text{/min}$, blood pressure $105/65\text{ mmHg}$, and oxygen saturation of $90\%$ on room air. A computed tomography scan of the chest with intravenous contrast reveals a saddle pulmonary embolus. An intravenous anticoagulant relying on a highly sulfated glycosaminoglycan to bind an endogenous protease inhibitor is initiated. Four days later, routine laboratory studies reveal a platelet count of $85,000/\text{mm}^3$, decreased from a baseline of $210,000/\text{mm}^3$ on admission. No new medications have been added, and physical examination is unremarkable except for mild bilateral lower extremity edema. A specific functional platelet assay returns positive. The initial anticoagulant is immediately discontinued. Based on the patient's underlying comorbidities, which of the following best describes the molecular mechanism of the most appropriate alternative therapy?

A 68-year-old man is admitted to the hospital with a 3-week history of low-grade fevers, chills, and generalized fatigue. He recently underwent a cystoscopy for benign prostatic hyperplasia. On physical examination, his temperature is 38.2°C (100.8°F), and a new holosystolic murmur is heard at the cardiac apex. Blood cultures grow gram-positive cocci in pairs and short chains that are catalase-negative and grow in 6.5% NaCl broth. Transesophageal echocardiography reveals a 1.2-cm vegetation on the mitral valve.

The patient is started on continuous-infusion ampicillin and once-daily gentamicin to achieve synergistic bactericidal activity. Two days later, antimicrobial susceptibility testing results are reported as follows:

Given these results, gentamicin is discontinued, and ceftriaxone is added to the ampicillin regimen. Which of the following best describes the precise molecular mechanism responsible for the lack of ampicillin-gentamicin synergy in this patient's isolate?

A 54-year-old woman is evaluated in the intensive care unit for worsening respiratory status. She was admitted 14 days ago for management of extensive third-degree burns covering 40% of her total body surface area. Over the past 24 hours, she has developed a new-onset fever, tachycardia, and increased purulent endotracheal secretions requiring higher ventilator settings. Her temperature is 39.4°C (102.9°F), blood pressure is 90/55 mmHg, and heart rate is 118/min. A Gram stain of the endotracheal aspirate reveals numerous neutrophils and Gram-negative bacilli. The organism is non-lactose-fermenting, oxidase-positive, and produces a blue-green pigment on culture. Antimicrobial susceptibility testing results for the isolate are shown below:

Which of the following cellular mechanisms best explains this isolate's specific antimicrobial resistance profile?

A $67$-year-old male presents to the primary care clinic for a routine follow-up. Five years ago, he underwent a mechanical mitral valve replacement and has been maintained on chronic warfarin therapy. His target international normalized ratio (INR) is between $2.5$ and $3.5$. Over the past year, his laboratory values have been stable on a daily warfarin dose of $5$ mg. Six days ago, he was evaluated at an urgent care facility for a suspected urinary tract infection and was prescribed a $7$-day course of trimethoprim-sulfamethoxazole. The patient reports feeling well today. He denies any epistaxis, hematuria, melena, or easy bruising. Vital signs are within normal limits. Physical examination reveals clear lungs, normal heart sounds with a distinct mechanical click, and no petechiae or ecchymoses. His neurologic examination is unremarkable. A point-of-care INR obtained in the clinic today is $7.4$. Which of the following is the most appropriate next step in management of this patient?

A 42-year-old woman with a history of bipolar I disorder is admitted to the inpatient psychiatric unit with an acute manic episode. She has previously been nonadherent to medications but now agrees to initiate treatment with lithium carbonate. She has no other medical conditions and takes no other medications. Her physical examination is unremarkable. In addition to monitoring serum drug concentrations, which of the following laboratory parameters are necessary to evaluate at baseline and periodically during long-term maintenance therapy with this medication? (Select all that apply)

A 62-year-old male establishes care at a primary care clinic for a persistent, dry cough that has bothered him for the past three months. The patient states the cough often wakes him at night and is not relieved by over-the-counter antitussive syrups. He denies any fever, weight loss, hemoptysis, or shortness of breath. His past medical history is notable for hypertension, hyperlipidemia, and osteoarthritis. Vital signs are within normal limits. Auscultation of the lungs reveals clear breath sounds bilaterally with no wheezes or crackles. Laboratory testing shows an absolute eosinophil count of $350/\mu L$ (normal: $15 - 500/\mu L$). A recent chest radiograph shows no abnormalities. Which of the following historical inquiries is the most appropriate next step to establish the diagnosis?

During a routine follow-up in the outpatient cardiology clinic, a 48-year-old man complains of worsening abdominal fullness, leg swelling, and generalized fatigue over the last six months. The patient emigrated from India ten years ago and received a prolonged course of multiple antimicrobial agents for a chronic, productive cough when he was in his twenties. He reports no alcohol use. Vital signs include a temperature of 37.0°C (98.6°F), blood pressure of 112/74 mm Hg, and pulse of 94/min. Upon physical examination, the internal jugular veins remain distended while he is seated at a 45-degree angle; observation of the venous column reveals a paradoxical rise when the patient takes a deep breath. Palpation of the anterior chest wall yields an absent apical impulse. Cardiac auscultation reveals normal S1 and S2 sounds, immediately followed by a sharp, high-pitched early diastolic sound at the left sternal border. Lung fields are clear to auscultation bilaterally. Abdominal examination reveals a tense, protuberant contour with shifting dullness. The liver edge is easily palpable 4 cm below the right costal margin. Bilateral lower extremities exhibit 2+ pitting edema extending to the knees. Laboratory evaluation demonstrates a serum albumin of 3.2 g/dL, total bilirubin of 1.8 mg/dL, and aspartate aminotransferase of 62 U/L. Based on these physical examination findings, which of the following is the most likely diagnosis?

A 48-year-old man presents to the emergency department with an 8-hour history of severe, unremitting epigastric pain that radiates to his mid-back. He reports that the pain is exacerbated by lying supine and is partially relieved by leaning forward. He has had two episodes of non-bloody, non-bilious emesis since the pain began. His medical history is notable for hypertension treated with amlodipine. He does not use tobacco but drinks 3-4 alcoholic beverages daily. His temperature is $37.8^\circ\text{C}$ ($100^\circ\text{F}$), blood pressure is $138/86\text{ mmHg}$, pulse is $105/\text{min}$, and respiratory rate is $18/\text{min}$. Physical examination shows a distressed patient with marked epigastric tenderness to palpation, but no rebound tenderness or guarding. Bowel sounds are hypoactive. Which of the following diagnostic tests should be included in the initial diagnostic workup of this patient? (Select all that apply)

A 48-year-old woman presents to the emergency department reporting a temperature of 38.4°C (101.1°F) measured at home. She is currently undergoing adjuvant chemotherapy with docetaxel and cyclophosphamide for stage II breast cancer; her last cycle was 10 days ago. She reports mild fatigue but denies chills, cough, dyspnea, abdominal pain, or dysuria. She lives with her husband 15 minutes away from the hospital and has been independently performing all daily activities.

Vital signs on arrival show a blood pressure of 122/78 mmHg, pulse of 88/min, respiratory rate of 14/min, and oxygen saturation of 99% on room air. Physical examination reveals a well-appearing, well-hydrated woman with no focal source of infection. An implanted venous port site shows no erythema or tenderness.

Laboratory studies reveal:
Hemoglobin: 10.5 g/dL
Leukocytes: 800/mm³
Absolute neutrophil count (ANC): 300/mm³
Platelets: 120,000/mm³
Comprehensive metabolic panel: within normal limits

Blood and urine cultures are obtained, and she is promptly given a dose of intravenous cefepime. After 4 hours of observation in the emergency department, she remains afebrile and hemodynamically stable, and she tolerates oral fluids without difficulty. Based on this patient's clinical risk profile and treatment response, which of the following is the most appropriate disposition?

A 68-year-old man is evaluated in the urgent care clinic for a 24-hour history of severe, progressive pain and swelling in his right knee. He is unable to bear weight on the affected leg. His medical history is significant for type 2 diabetes mellitus, hypertension, and stage 4 chronic kidney disease with a baseline estimated glomerular filtration rate (eGFR) of $24 \text{ mL/min/1.73 m}^2$. Current medications include amlodipine, insulin detemir, and calcium acetate. Vital signs are temperature $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), pulse 88/min, and blood pressure 138/84 mm Hg. Physical examination reveals a swollen, erythematous, and exquisitely tender right knee with a moderate effusion. Arthrocentesis is performed. Synovial fluid analysis reveals a leukocyte count of $28,000/\mu\text{L}$ (85% neutrophils) and the presence of negatively birefringent, needle-shaped crystals under polarized light microscopy. Gram stain is negative. Which of the following is the most appropriate pharmacologic intervention for this patient's acute joint condition?

A 22-year-old male university student is transported to the emergency department after falling approximately 3 meters (10 feet) from a balcony and striking his head on concrete. Emergency medical services report that he was initially conversant at the scene but became increasingly somnolent during transit. Upon arrival, he does not open his eyes to pain, makes no verbal sounds, and withdraws his left arm from painful stimuli. Vital signs demonstrate a blood pressure of 185/105 mmHg, a heart rate of 48/min, and a respiratory rate of 8/min with irregular breathing patterns. Physical examination reveals a right pupil that is 7 mm and unresponsive to light, while the left pupil is 3 mm and briskly reactive. Which of the following is the most appropriate immediate next step in management?

A 54-year-old woman presents to the emergency department after recording a temperature of 38.5°C (101.3°F) at home two hours ago. She has a history of stage II right breast cancer and underwent a lumpectomy six weeks ago. She is currently receiving adjuvant chemotherapy, with her most recent cycle of docetaxel and cyclophosphamide administered 8 days ago. The patient reports mild fatigue but denies chills, cough, shortness of breath, dysuria, abdominal pain, or diarrhea. She has no other significant medical conditions. She lives 10 miles from the hospital with her husband, who drove her to the emergency department today.

Temperature is 38.3°C (100.9°F), blood pressure is 122/78 mm Hg, pulse is 92/min, and respiratory rate is 16/min. Pulse oximetry is 99% on room air. The patient appears comfortable and in no acute distress. The implanted central venous catheter site is clean without erythema, induration, or tenderness. Cardiopulmonary examination is normal. The abdomen is soft and non-tender.

Laboratory studies show:
Leukocyte count: 1,100/µL
Absolute neutrophil count: 350/µL
Hemoglobin: 11.2 g/dL
Platelets: 145,000/µL
Blood urea nitrogen: 14 mg/dL
Serum creatinine: 0.8 mg/dL
Hepatic function panel: Normal

Chest radiograph shows no infiltrates. Urinalysis is unremarkable. The patient is able to tolerate oral fluids in the emergency department without nausea.

Which of the following is the most appropriate disposition for this patient?

A 58-year-old man is evaluated in the hospital for a 5-day history of fever, nonproductive cough, and right-sided pleuritic chest pain. He underwent a deceased-donor renal transplantation eight months ago and is maintained on a daily immunosuppressive regimen of tacrolimus, mycophenolate mofetil, and low-dose prednisone. Vital signs are temperature $38.6^\circ\text{C}$ ($101.5^\circ\text{F}$), pulse $108/\text{min}$, respirations $20/\text{min}$, and blood pressure $138/82\text{ mm Hg}$. Chest computed tomography reveals a dense right upper lobe nodule with a surrounding halo of ground-glass attenuation. Serum galactomannan assay is strongly positive, and bronchoscopy with bronchoalveolar lavage confirms the diagnosis of invasive pulmonary aspergillosis. The medical team decides to initiate the standard first-line targeted intravenous antifungal therapy for this condition. Which of the following concurrent pharmacologic interventions is most appropriate for this patient?

A 68-year-old man is preparing for discharge to a subacute rehabilitation facility following a prolonged hospitalization for acute decompensated heart failure and superimposed hospital-acquired pneumonia. His clinical course necessitated numerous changes to his baseline diuretic, antihypertensive, and diabetic regimens. The discharging physician is executing the formal medication reconciliation process to ensure safe continuity of care and prevent adverse drug events during this care transition. Arrange the following fundamental steps of the standardized medication reconciliation process in the correct chronological sequence.

A $28$-year-old man is admitted to the intensive care unit with diabetic ketoacidosis. He is initially started on a continuous intravenous regular insulin infusion and $0.9\%$ normal saline. Over the next several hours, his blood glucose decreases from $550$ mg/dL to $220$ mg/dL. However, his calculated anion gap remains elevated at $18$ mEq/L, and his serum bicarbonate is $14$ mEq/L. He is clinically stable, and his mental status is improving.

Arrange the following subsequent management and monitoring steps in the correct chronological order to safely resolve the ketoacidosis and transition his therapy.

Assign the most appropriate guideline-directed next step in the diagnostic sequence for each of the following patients presenting with clinical indicators of secondary hypertension.

A 74-year-old man is evaluated in the intensive care unit 24 hours after admission for a head injury sustained in a ground-level fall. His past medical history is significant for paroxysmal atrial fibrillation, heart failure with preserved ejection fraction, hypertension, and osteoarthritis. His home medications include dabigatran, amiodarone, lisinopril, and meloxicam.

On arrival yesterday, his Glasgow Coma Scale (GCS) score was 14. A noncontrast CT of the head revealed a 6-mm acute right-sided subdural hematoma without midline shift. Initial laboratory studies showed an activated partial thromboplastin time (aPTT) of 68 seconds (reference: 25-35 seconds) and a serum creatinine of 1.6 mg/dL (baseline 1.1 mg/dL). He was promptly administered 5 g of intravenous idarucizumab. A repeat head CT performed 6 hours post-admission showed no expansion of the hematoma.

Currently, the patient is alert and oriented (GCS 15) with no focal neurological deficits. His blood pressure is 132/84 mm Hg, and his pulse is 72/min and irregularly irregular.

Morning laboratory results are as follows:
Hemoglobin: 12.1 g/dL (unchanged from admission)
Platelet count: 185,000/mm³
Serum creatinine: 1.4 mg/dL
Prothrombin time: 13 seconds
Activated partial thromboplastin time (aPTT): 46 seconds

Which of the following is the most appropriate next step in the management of this patient's anticoagulation status?

Review the following four patients currently undergoing evaluation in the emergency department. Utilizing standard objective clinical risk stratification pathways, match each patient's clinical presentation to their most appropriate initial disposition.