Internal Medicine

Paramedics bring a 68-year-old male patient to the emergency department for the acute onset of severe breathlessness and right-sided chest discomfort that worsens with deep inspiration. The symptoms began abruptly 2 hours ago. His medical history is significant for metastatic pancreatic adenocarcinoma, for which he is currently receiving palliative chemotherapy. He has no other known medical conditions.

Temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $82/50 \text{ mm Hg}$, pulse is $128/\text{min}$, and respirations are $30/\text{min}$. Pulse oximetry shows an oxygen saturation of $85\%$ on room air. The patient appears diaphoretic and in severe respiratory distress. Jugular venous distension is present. Cardiac examination reveals tachycardia, a prominent right ventricular heave, and an accentuated pulmonic component of the second heart sound. The lungs are clear to auscultation bilaterally. The right calf is swollen, warm, and tender to palpation.

Arterial blood gas analysis on room air shows:
$pH$: $7.54$
$PaCO_2$: $26 \text{ mm Hg}$
$PaO_2$: $54 \text{ mm Hg}$
$HCO_3^-$: $22 \text{ mEq/L}$

An electrocardiogram demonstrates sinus tachycardia with a new right bundle branch block.

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

A $56$-year-old man is evaluated in the hospital for a $5$-day history of fever, severe right-sided pleuritic chest pain, and a cough productive of foul-smelling sputum. He has a history of severe alcohol use disorder and was admitted after being found intoxicated. On examination, his temperature is $38.8^\circ\text{C}$ ($101.8^\circ\text{F}$), blood pressure is $112/72$ mm Hg, pulse is $108$/min, and respirations are $24$/min. Oxygen saturation is $93\%$ on room air. Physical examination reveals decreased breath sounds and dullness to percussion at the right lung base. Chest radiography demonstrates a right lower lobe consolidation with a moderate-sized, free-flowing right pleural effusion. Diagnostic thoracentesis yields turbid yellow fluid. Pleural fluid analysis shows:

Gram stain of the fluid shows abundant neutrophils but no organisms. A concurrently drawn arterial blood gas reveals a pH of $7.38$. He is currently receiving intravenous ceftriaxone and azithromycin. Which of the following is the most appropriate next step in management?

A $44$-year-old woman comes to the clinic due to a $6$-month history of profound fatigue, generalized weakness, and amenorrhea. She previously had regular, $28$-day menstrual cycles. Over this period, she has had an unintentional weight loss of $5$ kg ($11$ lbs). Her blood pressure is $90/60$ mmHg, and her pulse is $58$/min. Physical examination shows pale skin without hyperpigmentation, a delay in the relaxation phase of the deep tendon reflexes, and decreased axillary and pubic hair. Laboratory studies show the following:

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

Progressive respiratory distress over the past 72 hours brings a retired teacher to the emergency department. The 72-year-old man reports that he cannot sleep flat in bed due to a suffocating sensation, which is accompanied by a cough producing frothy sputum. He has a 45-pack-year history of smoking, hypertension, and type 2 diabetes mellitus. His daily medications are amlodipine and metformin. Vital signs include a temperature of 37.1°C (98.8°F), blood pressure of 162/94 mm Hg, heart rate of 108/min, and respiratory rate of 26/min. Pulse oximetry on ambient air indicates an oxygen saturation of 88%. On physical examination, the jugular veins are distended to 10 cm H2O above the sternal angle. Auscultation of the lungs reveals widespread expiratory wheezes and fine crackles at both lung bases. Cardiac examination shows a regular, rapid rhythm with a distinct third heart sound (S3). Examination of the lower extremities shows bilateral 1+ pitting edema. Electrocardiography shows sinus tachycardia without ischemic changes. Chest radiography is pending. Which of the following is the most appropriate next step in management?

A 25-year-old woman with a history of type 1 diabetes mellitus presents to the emergency department with generalized weakness, nausea, and abdominal pain for the past 24 hours. She has been unable to eat and has missed her last two doses of insulin. Her blood pressure is 110/70 mm Hg, pulse is 115/min, and respirations are 24/min. Physical examination shows dry mucous membranes and a fruity odor to her breath.

Laboratory studies show:
Serum sodium: 140 mEq/L
Serum potassium: 4.8 mEq/L
Serum chloride: 104 mEq/L
Serum bicarbonate: 12 mEq/L
Blood urea nitrogen: 28 mg/dL
Serum creatinine: 1.2 mg/dL
Plasma glucose: 450 mg/dL

Arterial blood gas analysis on room air:
pH: 7.25
pCO2: 26 mm Hg
pO2: 95 mm Hg

Which of the following best describes this patient's acid-base status?

A 72-year-old man is evaluated in the hospital for acute-onset shortness of breath. He is currently on postoperative day 3 following an open partial colectomy for colon cancer. He has a history of hypertension, type 2 diabetes mellitus, and chronic kidney disease. Two hours ago, routine laboratory studies were obtained:

Due to the symptomatic anemia, a transfusion of packed red blood cells was initiated. Forty-five minutes into the transfusion, the patient develops severe dyspnea and a nonproductive cough.

His temperature is $38.1^\circ\text{C} (100.6^\circ\text{F})$, blood pressure is $178/96 \text{ mmHg}$, pulse is $115/\text{min}$, and respirations are $28/\text{min}$. Pulse oximetry is $87\%$ on room air.

Physical examination reveals a patient in acute respiratory distress. The jugular veins are distended to the angle of the mandible while sitting at 45 degrees. Cardiac auscultation reveals a regular tachycardia with a prominent $S_{3}$ gallop. Pulmonary auscultation reveals bilateral basilar crackles.

An arterial blood gas on room air shows:
pH: $7.49$
pCO2: $30 \text{ mmHg}$
pO2: $56 \text{ mmHg}$
HCO3: $23 \text{ mEq/L}$

The blood transfusion is immediately stopped, and supplemental oxygen is provided. Which of the following is the most appropriate next step in management?

A $74$-year-old man is evaluated on the postoperative wards on hospital day $5$ following an urgent open reduction and internal fixation of a right femoral neck fracture. For the past $3$ days, he has experienced progressive abdominal distension, nausea, and a failure to pass flatus or stool. $48$ hours ago, all opioid analgesics were discontinued, and he was placed on bowel rest with nasogastric tube decompression and intravenous fluid support. Despite these measures, his symptoms have worsened. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), pulse is $88/\text{min}$, blood pressure is $138/82 \text{ mmHg}$, and respirations are $16/\text{min}$. The abdomen is massively distended and tympanitic to percussion. It is mildly tender diffusely, but there is no guarding, rigidity, or rebound tenderness. Bowel sounds are absent. Laboratory studies show a leukocyte count of $8,000/\text{mm}^3$, potassium of $4.2 \text{ mEq/L}$, and magnesium of $2.1 \text{ mEq/L}$. An electrocardiogram shows normal sinus rhythm. Computed tomography of the abdomen and pelvis with intravenous contrast reveals marked dilation of the colon extending from the cecum to the splenic flexure, with a maximal cecal diameter of $11.8 \text{ cm}$. There is no discrete transition point, obstructing mass, or pneumoperitoneum. Which of the following is the most appropriate next step in management?

A 58-year-old man with a history of chronic alcohol use disorder is brought to the emergency department due to profound weakness and a four-day history of intractable vomiting. He reports being unable to keep any food or fluids down. On physical examination, he appears lethargic and has dry mucous membranes with decreased skin turgor.

Laboratory studies reveal the following:

Serum:
Sodium: 140 mEq/L
Potassium: 3.1 mEq/L
Chloride: 88 mEq/L
Bicarbonate: 14 mEq/L
Blood urea nitrogen: 35 mg/dL
Creatinine: 1.6 mg/dL

Arterial blood gas on room air reveals a pH of 7.32 and a $pCO_2$ of 29 mm Hg. The physician suspects a complex mixed acid-base disorder driven by alcoholic ketoacidosis and protracted emesis.

Assuming a baseline normal anion gap of 12 mEq/L and a baseline normal serum bicarbonate of 24 mEq/L, what is the calculated delta-delta ratio ($\Delta AG / \Delta HCO_3^-$) for this patient?

An oncology consultation is requested for a 34-year-old man admitted to the intensive care unit due to profound pancytopenia and severe watery diarrhea. The patient has a history of classical Hodgkin lymphoma, for which he completed systemic chemotherapy three months ago. Two weeks prior to this admission, he presented to an outpatient clinic with symptomatic anemia and received two units of packed red blood cells donated by his healthy biological brother. Over the last four days, he has developed a diffuse, erythematous maculopapular rash involving the palms and soles, abdominal cramping, and jaundice. Vital signs reveal a temperature of $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure of 105/65 mmHg, and heart rate of 115/min. Laboratory studies show:

Which of the following pre-transfusion blood product modifications would have most likely prevented this patient's current condition?

During morning rounds in the intensive care unit, a 54-year-old woman experiences a sudden respiratory decompensation. She was intubated and mechanically ventilated three days prior due to acute respiratory distress syndrome (ARDS) secondary to severe influenza pneumonia. Over the past 5 minutes, the ventilator's high peak airway pressure alarm has activated repeatedly. Concurrently, her oxygen saturation has rapidly declined from $94\%$ to $82\%$, and her blood pressure has fallen from $110/70\text{ mmHg}$ to $85/50\text{ mmHg}$. Her heart rate is $128/\text{min}$. Arrange the following steps in the most appropriate sequential order for evaluating and managing this patient's acute deterioration.

A 62-year-old woman is evaluated in the hospital for sudden-onset right leg pain and swelling. She was admitted 6 days ago for a pulmonary embolism and has been receiving a continuous intravenous infusion of unfractionated heparin. Today, her platelet count is 65,000/mm³, representing a significant drop from her admission baseline of 240,000/mm³. Lower extremity venous Doppler ultrasound reveals a new acute deep vein thrombosis in the right femoral vein. The 4Ts score is calculated and indicates a high clinical probability of heparin-induced thrombocytopenia (HIT).

Arrange the following steps for the diagnosis and long-term management of this patient in the most appropriate chronological order.

A 67-year-old male is brought to the emergency department by his daughter due to a three-day history of progressively worsening shortness of breath. The patient reports that his typical morning cough has worsened, producing a larger volume of thick, yellowish-green sputum. His past medical history is significant for chronic obstructive pulmonary disease and hypertension. Current vital signs reveal a temperature of 37.3°C (99.1°F), blood pressure of 138/86 mm Hg, heart rate of 98/min, and a respiratory rate of 22/min. Pulse oximetry shows an oxygen saturation of 91% on ambient air. Physical examination demonstrates a prolonged expiratory phase with diffuse bilateral wheezing. There is no jugular venous distention, and the lower extremities are free of edema. Which of the following interventions are indicated in the initial management of this patient's current condition? (Select all that apply.)

A 45-year-old man with newly diagnosed acute myeloid leukemia is hospitalized for induction chemotherapy. On day 10 of his hospital stay, he develops a new-onset fever. He reports feeling mildly fatigued but denies cough, shortness of breath, dysuria, or abdominal pain. Temperature is 38.8°C (101.8°F), blood pressure is 122/78 mm Hg, heart rate is 98/min, and respiratory rate is 16/min. Physical examination reveals clear lungs, normal bowel sounds, and no skin rashes. His totally implantable venous access port in the right upper chest is clean, with no surrounding erythema, induration, or tenderness. Laboratory studies show a leukocyte count of 400/mm³ with an absolute neutrophil count of 100/mm³. Blood and urine cultures are obtained. Which of the following is the most appropriate next step in the pharmacologic management of this patient?

An emergency department physician evaluates a 73-year-old man who experienced a sudden, painless loss of vision in his right eye 3 hours ago. He notes that over the preceding 3 weeks, he has suffered from persistent right-sided head pain, profound fatigue, and intense cramping in his jaw muscles during meals. Physical examination reveals visual acuity limited to light perception in the right eye. The right temporal artery is visibly prominent, nodular, and exquisitely tender to palpation. Fundoscopic examination of the right eye shows a pale, swollen optic disc with blurred margins.

Arrange the following clinical actions in the most appropriate chronological sequence for the immediate and long-term management of this patient's condition.

A 68-year-old woman is evaluated in the hospital on the third day of admission for acute pyelonephritis. She initially presented with fever, right-sided flank pain, nausea, and vomiting. She was empirically started on intravenous piperacillin-tazobactam. Today, the patient reports feeling much better. Her temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $126/82\text{ mm Hg}$, heart rate is $78\text{/min}$, and respiratory rate is $14\text{/min}$. Physical examination shows resolution of costovertebral angle tenderness. She is tolerating a regular diet without nausea.

The urine culture obtained on admission has finalized, showing $>10^5\text{ CFU/mL}$ of *Escherichia coli*. Susceptibility testing results are as follows:

Blood cultures obtained on admission show no growth to date.

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

While recovering from an extensive bowel resection, a 76-year-old man requires blood product replacement due to a postoperative hemoglobin of $6.4 \text{ g/dL}$. His past medical history is notable for ischemic cardiomyopathy with a baseline ejection fraction of $40\%$. Approximately one hour after the second unit of packed red blood cells is initiated, the nursing staff urgently calls the physician to the bedside. The patient reports sudden, severe shortness of breath and a pounding headache. Vital signs are temperature $37.7^\circ\text{C}$ ($99.9^\circ\text{F}$), blood pressure $188/96 \text{ mmHg}$, heart rate $115/\text{min}$, and respiratory rate $28/\text{min}$. Oxygen saturation is $85\%$ on room air. Physical examination reveals prominently distended neck veins while sitting upright. Auscultation of the lungs demonstrates diffuse crackles up to the mid-lung fields bilaterally. A third heart sound ($S_3$) is present. The transfusion is immediately halted and supplemental oxygen is provided. Which of the following is the most appropriate next step in the management of this patient?

An elderly woman is evaluated in the emergency department for a new, excruciating headache localized to her right temple that began $48$ hours ago. The $72$-year-old patient reports that earlier today, she lost all vision in her right eye for approximately $10$ minutes before it fully returned. Over the past month, she has struggled to get out of bed due to profound stiffness in her shoulders and hips that lasts until mid-day. Additionally, she notes that chewing food has recently become quite painful, prompting her to eat softer meals. Her temperature is $37.9^\circ\text{C}$. On physical examination, her right temporal scalp is exquisitely tender to touch. Initial laboratory evaluation shows an erythrocyte sedimentation rate of $98$ mm/h.

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

An elderly male patient, aged 72, comes to the clinic reporting a four-week history of profound fatigue, night sweats, and unintentional weight loss. He notes that these symptoms began roughly two weeks after he underwent a transurethral resection of the prostate for benign prostatic hyperplasia. His temperature in the clinic is 38.2°C (100.8°F), blood pressure is 134/68 mm Hg, and pulse is 96/min. Cardiovascular auscultation reveals a new early diastolic decrescendo murmur best heard at the left third intercostal space. Physical examination also demonstrates nontender, erythematous macules on the palms and soles. Transesophageal echocardiography confirms a mobile, 1.1-cm vegetation on the right coronary cusp of the aortic valve. Two days later, all three sets of blood cultures are positive for *Enterococcus faecalis*. Antimicrobial susceptibility testing indicates that the isolate is susceptible to ampicillin and vancomycin. However, high-level resistance to both gentamicin and streptomycin is detected. Renal function is within normal limits. Which of the following is the most appropriate definitive intravenous antibiotic regimen for this patient?

Patients with various rheumatologic and autoimmune conditions are frequently managed with long-term immunosuppressive therapies, each carrying a unique adverse effect profile. Match each clinical scenario describing an adverse drug effect or mandatory screening requirement to the corresponding disease-modifying antirheumatic drug (DMARD) or immunosuppressant.

A 26-year-old woman, G1P0 at 16 weeks gestation, is brought to the emergency department with a 4-day history of progressively worsening shortness of breath, orthopnea, and severe bilateral leg swelling. She has a 4-year history of systemic lupus erythematosus (SLE) but stopped taking hydroxychloroquine and azathioprine 6 months ago because she wanted a "natural pregnancy." Her temperature is 37.6°C (99.7°F), blood pressure is 165/105 mmHg, pulse is 112/min, and respirations are 28/min. Pulse oximetry shows 89% on room air. Physical examination reveals prominent jugular venous distention. Lung auscultation demonstrates bilateral bibasilar crackles and scattered expiratory wheezes. Cardiac examination shows an S3 gallop. There is 3+ pitting edema extending to the mid-thighs.

Laboratory results are as follows:

Arterial blood gas on room air:
pH: 7.30
pCO₂: 30 mmHg
pO₂: 60 mmHg
HCO₃⁻: 14 mEq/L

Urinalysis shows 4+ protein, numerous red blood cells, and red blood cell casts. Sputum Gram stain reveals rare epithelial cells and no organisms. Chest radiograph with abdominal shielding demonstrates bilateral diffuse alveolar opacities and prominent pulmonary vasculature.

Which of the following is the most appropriate next step in the management of this patient's acute respiratory distress?