Internal Medicine

A 74-year-old woman is evaluated in the emergency department for the sudden onset of extensive ecchymoses over her trunk and a large, expanding hematoma on her right thigh. She has no prior personal or family history of bleeding disorders. Her past medical history is significant for rheumatoid arthritis. Vital signs are within normal limits. Laboratory studies reveal a hemoglobin of 9.4 g/dL, platelet count of 250,000/mm³, prothrombin time (PT) of 12.5 seconds (normal: 11-15 sec), and activated partial thromboplastin time (aPTT) of 78 seconds (normal: 25-35 sec). Thrombin time is normal.

Arrange the following diagnostic steps in the correct chronological sequence required to definitively diagnose and fully characterize this patient's underlying hemostatic disorder.

During morning rounds on the inpatient hematology unit, a resident assesses a 38-year-old male who was admitted four days ago with a new diagnosis of acute promyelocytic leukemia. He was immediately started on targeted induction therapy including a vitamin A derivative. Over the last 12 hours, the patient has developed a fever, progressive shortness of breath, and a weight gain of $3.5\text{ kg}$. Temperature is $38.5^\circ\text{C}$ ($101.3^\circ\text{F}$), blood pressure is $105/65\text{ mmHg}$, pulse is $118/\text{min}$, and respiratory rate is $26/\text{min}$. Pulse oximetry shows $89\%$ on ambient air. Physical examination reveals elevated jugular venous pressure and diffuse bilateral crackles on lung auscultation. Laboratory studies show a leukocyte count of $28,000/\mu\text{L}$, which has increased from $4,500/\mu\text{L}$ on admission. A chest radiograph demonstrates bilateral interstitial opacities and a small right-sided pleural effusion. Which of the following is the most appropriate next step in management?

A 67-year-old retired mechanic is evaluated in the emergency department for severe shortness of breath that has progressively worsened over the past 48 hours. He has a medical history of heart failure with reduced ejection fraction (ejection fraction 40%), atrial fibrillation, and severe chronic obstructive pulmonary disease (COPD) due to a 50 pack-year smoking history. Upon arrival, his temperature is $36.4^\circ\text{C}$ ($97.5^\circ\text{F}$), blood pressure is $148/86\text{ mm Hg}$, heart rate is $102/\text{min}$, respiratory rate is $28/\text{min}$, and oxygen saturation is $85\%$ on room air. The patient is lethargic but arousable and is using accessory muscles of respiration. Physical examination reveals a prolonged expiratory phase with diffuse polyphonic wheezing bilaterally. There are no crackles. The jugular venous pressure is $6\text{ cm H}_2\text{O}$. Cardiac examination shows an irregularly irregular rhythm without murmurs. Bilateral lower extremities have trace pitting edema that the patient states is his baseline. A portable chest radiograph shows hyperinflated lung fields and flattened diaphragms, without focal opacities or pleural effusions. Arterial blood gas analysis on room air reveals:

$pH$: $7.24$
$PaCO_2$: $68\text{ mm Hg}$
$PaO_2$: $54\text{ mm Hg}$
$HCO_3^-$: $28\text{ mEq/L}$

Recent outpatient laboratories from one week ago showed a thyroid-stimulating hormone (TSH) of $1.1\text{ }\mu\text{U/mL}$ (normal: 0.5-5.0) and a free T4 of $0.6\text{ ng/dL}$ (normal: 0.9-1.7). Which of the following is the most appropriate initial step in the management of this patient's acute respiratory distress?

A 28-year-old man comes to the physician because of a 5-day history of right knee swelling, left heel pain, and redness in both eyes. He reports no recent trauma. Four weeks ago, he had a diarrheal illness that resolved spontaneously after $3$ days. His temperature is $37.2^{\circ}\text{C}$ ($99.0^{\circ}\text{F}$), blood pressure is $122/78$ mmHg, and pulse is 84/min. Physical examination shows a moderately effused, warm, and tender right knee. There is marked tenderness to palpation at the insertion of the left Achilles tendon. The conjunctivae are injected bilaterally. Arthrocentesis of the right knee yields synovial fluid with a leukocyte count of $22,000/\text{mm}^3$ ($75\%$ neutrophils). Gram stain of the fluid shows no organisms, and polarized light microscopy reveals no crystals. Which of the following is the most appropriate initial pharmacotherapy for this patient's current symptoms?

A 32-year-old man comes to the emergency department due to severe right upper quadrant abdominal pain and progressive fatigue over the past week. He also reports that his urine has occasionally appeared unusually dark, particularly in the morning. He has no significant past medical history and takes no medications. His temperature is 37.2°C (99.0°F), blood pressure is 128/82 mm Hg, and pulse is 98/min. Physical examination reveals scleral icterus, pale conjunctivae, and right upper quadrant abdominal tenderness with hepatomegaly.

Laboratory studies show:

Doppler ultrasound of the abdomen demonstrates absent blood flow in the hepatic veins.

Which of the following is the most appropriate next step to confirm the underlying cause of this patient's findings?

A $38$-year-old man is evaluated in the emergency department for progressive fatigue, severe epistaxis, and bleeding from his gums over the past two days. He has no significant past medical history and takes no medications. Vital signs are: Temperature $37.6^\circ\text{C}$ ($99.7^\circ\text{F}$), Blood pressure $100/60 \text{ mm Hg}$, Heart rate $112/\text{min}$, Respiratory rate $18/\text{min}$. Physical examination reveals marked mucosal pallor, continuous gingival oozing, and extensive coalescing petechiae and purpura over the trunk and bilateral lower extremities. Laboratory studies show:

Leukocyte count: $2,800/\text{mm}^3$
- Neutrophils: $15\%$
- Lymphocytes: $25\%$
- Atypical cells: $60\%$
Hemoglobin: $7.4 \text{ g/dL}$
Platelet count: $15,000/\text{mm}^3$
Prothrombin time: $24 \text{ seconds}$
Partial thromboplastin time: $54 \text{ seconds}$
Fibrinogen: $65 \text{ mg/dL}$ (Normal: $150-400 \text{ mg/dL}$)
D-dimer: $8,500 \text{ ng/mL}$ (Normal: $< 500 \text{ ng/mL}$)

Peripheral blood smear demonstrates predominant cells with bilobed nuclei and dense, coarse azurophilic granules. Several of these cells contain bundles of red-staining, needle-like cytoplasmic inclusions. Which of the following is the most appropriate initial step in the management of this patient?

An essential skill in hematology is interpreting coagulation panels to diagnose bleeding disorders. Match each underlying hematologic disorder with its most characteristic laboratory profile.

A 32-year-old man presents to the emergency department triage desk with a 4-week history of severe cough, low-grade fevers, and drenching night sweats. He recently returned from a prolonged trip to a region where tuberculosis is highly endemic. He is currently sitting in the crowded main waiting room. Arrange the following steps in the correct chronological order for managing this patient's suspected infection.

A 64-year-old man with a 15-year history of poorly controlled type 2 diabetes mellitus is evaluated in the outpatient clinic for a chronic ulcer on the plantar surface of his right foot. He first noticed the ulcer 8 weeks ago. He has established peripheral neuropathy and reports no pain at the site. His temperature is 37.1°C (98.8°F), blood pressure is 135/82 mmHg, and pulse is 78/min. Physical examination reveals a 2.5-cm, full-thickness ulcer under the first metatarsal head. The ulcer base is composed of pale granulation tissue. There is no surrounding erythema, warmth, fluctuance, or purulent discharge. A sterile, blunt stainless-steel probe easily reaches the underlying bone. Pedal pulses are palpable bilaterally. Laboratory studies show a leukocyte count of $7,500/\mu L$ and an erythrocyte sedimentation rate of $65 \text{ mm/h}$. A plain radiograph of the right foot demonstrates cortical erosion and periosteal elevation at the first metatarsal head. Which of the following is the most appropriate next step in management?

Match each peripheral blood smear description or characteristic laboratory finding with the most likely underlying hematologic disorder.

A 54-year-old man is reviewed by the medical team during his inpatient hospitalization. He was admitted 72 hours ago after presenting to the emergency department with an acutely painful, erythematous, and swollen right knee accompanied by shaking chills. Initial arthrocentesis yielded turbid synovial fluid containing $85,000 \text{ leukocytes}/\mu L$ with $92\%$ neutrophils. Following the procedure, he was empirically started on intravenous vancomycin and piperacillin-tazobactam. Today, his temperature has improved to $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$), blood pressure is $128/82 \text{ mmHg}$, and pulse is $84/\text{min}$. The right knee shows decreased swelling and erythema. Blood cultures and synovial fluid cultures obtained on admission are both positive for *Staphylococcus aureus*. Antimicrobial susceptibility testing reveals the following:

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

A $61$-year-old male landscape architect presents to the emergency department in coastal Connecticut during early September. His wife reports that he has had $4$ days of high-grade fever, drenching sweats, profound fatigue, and progressive confusion. His medical history is significant for a splenectomy at age $25$ following blunt abdominal trauma, and essential hypertension. Vital signs show a temperature of $39.8^\circ\text{C}$ ($103.6^\circ\text{F}$), blood pressure of $88/54 \text{ mm Hg}$, heart rate of $126/\text{min}$, and respiratory rate of $28/\text{min}$. Oxygen saturation is $88\%$ on room air. Physical examination reveals marked scleral icterus and pale conjunctivae. Auscultation of the lungs reveals bibasilar crackles.

Laboratory evaluation shows the following:

A peripheral blood smear demonstrates numerous intraerythrocytic pleomorphic ring forms and occasional tetrad structures. Quantitative analysis reveals a parasitemia level of $16\%$.

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

A 42-year-old woman is evaluated on the medical floor for ongoing management of a bloodstream infection. She was admitted three days ago with a high fever and localized erythema surrounding a peripheral intravenous catheter site. Blood cultures were drawn, the catheter was removed, and she was started on empiric intravenous vancomycin and intravenous cefepime. The patient is currently afebrile and her localized erythema has resolved. Today, the initial blood cultures are finalized, showing growth of Staphylococcus aureus. Susceptibility testing reveals the organism is resistant to penicillin but susceptible to oxacillin, cefazolin, and vancomycin. Repeat blood cultures drawn 48 hours after admission show no growth. Which of the following is the most appropriate next step in the antibiotic management of this patient?

Match each specific autoantibody profile with its most strongly associated clinical presentation or syndrome.

A $62$-year-old man is hospitalized on the general medical ward for a severe exacerbation of chronic obstructive pulmonary disease and suspected superimposed pneumonia. He is prescribed a new regimen of intravenous piperacillin-tazobactam. $10$ minutes into the first infusion, the rapid response team is called because the patient suddenly develops diffuse urticaria, facial swelling, a high-pitched inspiratory noise, and profound shortness of breath. His vital signs reveal a blood pressure of $80/45$ mm Hg, a heart rate of $128$/min, and an oxygen saturation of $88\%$ on room air. Arrange the following acute management steps in the most appropriate chronological sequence according to established life-support guidelines.

A 52-year-old man is recovering on the surgical ward following an extensive bowel resection for ischemic colitis. On postoperative day 2, his hemoglobin is found to be 6.5 g/dL, and a transfusion of packed red blood cells is initiated. Approximately 25 minutes after the transfusion begins, the patient suddenly develops severe chills, a temperature of 39.2°C (102.6°F), and worsening right flank pain. His blood pressure drops to 90/60 mm Hg, and his heart rate increases to 118/min. A Foley catheter placed in the operating room now drains dark, reddish-brown urine. Which of the following is the most appropriate initial step in management?

A 62-year-old man is evaluated in the intensive care unit for antimicrobial management. He was admitted 8 days ago after a severe motor vehicle collision resulting in multiple rib fractures and a pulmonary contusion. He has required mechanical ventilation since admission. On hospital day 6, he developed a new fever, increased purulent endotracheal secretions, and a right lower lobe consolidation on chest radiography. He was empirically started on intravenous vancomycin and piperacillin-tazobactam for suspected ventilator-associated pneumonia.

Today (hospital day 8), his temperature is 37.6°C (99.7°F), blood pressure is 122/78 mmHg, and heart rate is 84/min. Endotracheal aspirate cultures obtained on day 6 now show $>10^5$ CFU/mL of *Enterobacter cloacae*. Blood cultures remain sterile. Antimicrobial susceptibility testing for the *E. cloacae* isolate is reported below:

Which of the following is the most appropriate modification to this patient's pharmacotherapy?

A $62$-year-old woman is evaluated in the clinic for bilateral knee pain that has progressively worsened over the past $2$ years. The pain is exacerbated by walking and relieved by rest. She reports no morning stiffness. Her body mass index is $33 \text{ kg/m}^2$. Physical examination reveals bony enlargement and crepitus in both knees without significant warmth or erythema. Radiographs demonstrate asymmetric joint space narrowing and osteophyte formation. Arrange the following therapeutic interventions in the most appropriate stepwise sequence for managing this patient's condition, progressing from initial first-line management to definitive end-stage therapy.

Match each clinical presentation of an immunocompromised patient with advanced HIV infection to the most appropriate initial targeted pharmacologic therapy.

A $68$-year-old woman is brought to the emergency department by her family due to a $24$-hour history of severe generalized headache, high fever, and progressive confusion. Her temperature is $39.2^\circ\text{C}$ ($102.6^\circ\text{F}$), blood pressure is $110/70 \text{ mmHg}$, pulse is $115/\text{min}$, and respirations are $18/\text{min}$. On physical examination, the patient is lethargic and oriented only to her name. She exhibits nuchal rigidity. There are no focal neurologic deficits, and funduscopic examination reveals no papilledema. Which of the following represents the most appropriate sequence of steps in the management of this patient?