Internal Medicine

During morning rounds on the general medical ward, a physician evaluates a $68$-year-old man undergoing treatment for severe community-acquired pneumonia. The patient was admitted $3$ days ago with acute respiratory distress, fever, and a dense right lower lobe consolidation on chest radiography. Due to a history of a recent hospitalization $6$ weeks prior, he was started on empiric intravenous vancomycin and piperacillin-tazobactam.

The patient's condition has markedly improved over the past $48$ hours. He is now breathing comfortably on room air, and his cough is producing only minimal clear sputum. His temperature is $37.2^\circ$ C ($99.0^\circ$ F), blood pressure is $130/82$ mmHg, pulse is $78$/min, and respirations are $16$/min. Blood cultures drawn at the time of admission are now positive for *Streptococcus pneumoniae* in two out of two bottles. Antimicrobial susceptibility testing demonstrates that the isolate is sensitive to penicillin, amoxicillin, ceftriaxone, and linezolid, but resistant to azithromycin.

Which of the following is the most appropriate next step in this patient's pharmacotherapy?

A $58$-year-old man is brought to the emergency department by his wife due to severe headache, high fever, and confusion that started $12$ hours ago. On examination, his temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure is $110/70\text{ mmHg}$, and heart rate is $112\text{/min}$. The patient is lethargic and oriented only to his name. Nuchal rigidity is present. There are no focal neurologic deficits. The physician suspects acute bacterial meningitis.

Arrange the following steps in the most appropriate chronological order for the management of this patient.

A 32-year-old woman comes to the clinic for a routine follow-up. She has a history of Graves disease that was treated with radioactive iodine ablation 5 years ago, resulting in primary hypothyroidism. She has been well-maintained on a stable daily dose of $112 \mu g$ of levothyroxine. Eight weeks ago, she began taking combined oral contraceptive pills for dysmenorrhea. She currently reports feeling well, with no palpitations, fatigue, or weight changes. Her vital signs are within normal limits. Physical examination reveals a well-healed neck, no palpable goiter, and normal deep tendon reflexes.

Laboratory studies show:

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

A 52-year-old man with a history of obesity hypoventilation syndrome and type 2 diabetes mellitus is brought to the emergency department by his wife due to profound weakness and confusion. For the past 4 days, he has had severe, watery diarrhea with up to 10 bowel movements daily, accompanied by abdominal cramping. He has not been able to tolerate oral intake. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $90/60\text{ mm Hg}$, pulse is $112\text{/min}$, and respirations are $14\text{/min}$. Physical examination shows dry mucous membranes and decreased skin turgor. The patient appears somnolent but is arousable.

Laboratory studies show:
Serum sodium: $135\text{ mEq/L}$
Serum potassium: $3.2\text{ mEq/L}$
Serum chloride: $113\text{ mEq/L}$
Serum bicarbonate: $12\text{ mEq/L}$
Blood urea nitrogen: $42\text{ mg/dL}$
Serum creatinine: $1.6\text{ mg/dL}$
Serum albumin: $4.0\text{ g/dL}$

Arterial blood gas analysis on room air:
pH: $7.08$
$\text{PaCO}_2$: $42\text{ mm Hg}$
$\text{PaO}_2$: $65\text{ mm Hg}$

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

A 67-year-old woman is brought to the emergency department complaining of severe, unremitting abdominal pain and vomiting for the past 8 hours. Her medical history is notable for a total abdominal hysterectomy performed 10 years ago. She describes the pain as initially colicky but now constant and diffusely located across the lower abdomen. Her temperature is 39.1°C (102.4°F), blood pressure is 92/58 mm Hg, and pulse is 114/min. On physical examination, the abdomen is markedly distended and tympanic. There is severe, diffuse tenderness to palpation with involuntary guarding and rebound tenderness. Bowel sounds are absent. Laboratory studies reveal a leukocyte count of 19,500/mm³. An upright abdominal radiograph demonstrates multiple dilated small bowel loops with air-fluid levels and a paucity of gas in the colon.

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

An 82-year-old man is brought to the emergency department due to sudden-onset, severe abdominal pain. He has a history of hypertension, type 2 diabetes mellitus, and atrial fibrillation for which he takes apixaban; however, he admits to missing several doses over the past week. During transport, paramedics administered intravenous morphine for pain control. On arrival, he appears drowsy but is arousable. Temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $102/60\text{ mmHg}$, pulse is $118/\text{min}$ and irregular, and respiratory rate is $14/\text{min}$. The abdomen is slightly distended with absent bowel sounds, and there is minimal tenderness to palpation.

Laboratory results are as follows:

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

Match each clinical scenario describing a patient with newly detected hyponatremia to the most accurate expected pattern of laboratory findings, focusing on serum and urine osmolar characteristics.

A $48$-year-old man comes to the clinic due to worsening fatigue, feeling constantly cold, and a $6\text{-kg}$ ($13.2\text{-lb}$) weight gain over the past $5$ months. He also reports decreased libido and recent onset of erectile dysfunction. He has no significant past medical history and takes no medications. Blood pressure is $102/68 \text{ mm Hg}$, and pulse is $55/\text{min}$. Physical examination shows dry, pale skin and delayed relaxation of the deep tendon reflexes. Visual fields are full to confrontation. Laboratory studies show:

Serum sodium: $132 \text{ mEq/L}$
Thyroid-stimulating hormone (TSH): $1.6 \text{ mIU/L}$ (Normal: $0.5$ - $5.0 \text{ mIU/L}$)
Free thyroxine (T4): $0.4 \text{ ng/dL}$ (Normal: $0.9$ - $1.7 \text{ ng/dL}$)

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

A 68-year-old man is brought to the emergency department by his family due to a 24-hour history of high fever, severe generalized headache, and progressive confusion. His medical history is significant for type 2 diabetes mellitus and hypertension. On presentation, his temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure is $110/70\text{ mmHg}$, heart rate is $115/\text{min}$, and respiratory rate is $22/\text{min}$. The patient is somnolent and oriented only to person. Neurologic examination reveals marked nuchal rigidity. Fundoscopic examination demonstrates bilateral blurring of the optic disc margins.

Arrange the following steps in the most appropriate chronological order for managing this patient.

During morning rounds, the clinical team reviews the status of a patient who was hospitalized four days ago due to massive ascites and lower extremity edema. The patient has long-standing cirrhosis secondary to chronic hepatitis C virus infection. Despite medication compliance prior to admission, his weight had increased significantly over the preceding month. Current vital signs include a temperature of $36.9^\circ\text{C}$ ($98.4^\circ\text{F}$), blood pressure of $92/56\text{ mmHg}$, and heart rate of $94/\text{min}$. Physical examination reveals a tensely distended abdomen with a positive fluid wave and bilateral pitting edema extending to the thighs. The lungs are clear to auscultation. Recent laboratory values show a serum sodium of $131\text{ mEq/L}$, serum potassium of $4.2\text{ mEq/L}$, serum bicarbonate of $17\text{ mEq/L}$, blood urea nitrogen of $55\text{ mg/dL}$, and serum creatinine of $2.8\text{ mg/dL}$ (baseline was $1.0\text{ mg/dL}$ three weeks prior). A diagnostic paracentesis performed upon admission showed an absolute neutrophil count of $110/\text{mm}^3$. Urinalysis demonstrates no red blood cells, white blood cells, or casts, and the urine sodium concentration is $8\text{ mEq/L}$. Renal ultrasonography reveals normal renal architecture without obstruction. Over the past 48 hours, all diuretic therapy was withheld, and the patient was administered intravenous albumin at $1\text{ g/kg}$ per day. Today, his serum creatinine remains elevated at $2.9\text{ mg/dL}$. Which of the following is the most appropriate next step in management?

A 42-year-old woman is admitted to the intensive care unit with confusion, petechiae, and dark urine. Laboratory testing reveals a hemoglobin of $7.2 \text{ g/dL}$, a platelet count of $18,000/\mu\text{L}$, an elevated indirect bilirubin, and an elevated lactate dehydrogenase (LDH). Her prothrombin time and activated partial thromboplastin time are normal. You strongly suspect thrombotic thrombocytopenic purpura (TTP). Arrange the following steps in the most appropriate sequential order for the immediate diagnostic and therapeutic management of this patient.

Match each suspected endocrine disorder with the most appropriate confirmatory dynamic diagnostic test used to definitively establish the diagnosis.

Various chronic liver and biliary diseases have distinct clinical presentations and are confirmed using specific diagnostic tests or markers. Match each clinical description to the most appropriate diagnostic marker or imaging finding.

A 62-year-old woman is evaluated on the third day of hospitalization for a central line-associated bloodstream infection. She has been receiving total parenteral nutrition through a central venous catheter for short bowel syndrome. Three days ago, she experienced the sudden onset of rigors, a temperature of 39.2°C (102.6°F), and a blood pressure of 90/60 mmHg. Blood cultures drawn from both the central catheter and a peripheral vein revealed Gram-positive cocci in clusters. The catheter was promptly removed, and empiric intravenous vancomycin and cefepime were started. Today, she feels well and is afebrile with normal hemodynamics. Final blood culture results confirm the presence of Staphylococcus aureus in all bottles. Susceptibility testing indicates the isolate is resistant to penicillin but susceptible to oxacillin, cefazolin, and vancomycin. Which of the following is the most appropriate modification to her antimicrobial therapy?

Match the following clinical and serological profiles of patients with viral hepatitis to their most accurate diagnostic phase or infection state.

A 62-year-old man is brought to the emergency department by his family due to sudden-onset confusion, severe right upper quadrant abdominal pain, and high fever that began earlier today. His temperature is $39.4^\circ\text{C}$ ($102.9^\circ\text{F}$), blood pressure is $88/54\text{ mmHg}$, pulse is $118/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination reveals marked scleral icterus and significant right upper quadrant tenderness with guarding. Laboratory studies demonstrate a leukocyte count of $18,500/\text{mm}^3$, total bilirubin of $6.2\text{ mg/dL}$, direct bilirubin of $4.8\text{ mg/dL}$, and alkaline phosphatase of $450\text{ U/L}$. A right upper quadrant ultrasound shows a dilated common bile duct measuring $11\text{ mm}$ and multiple echogenic foci with posterior acoustic shadowing within the gallbladder. Arrange the following management steps in the most appropriate chronological order for this patient.

An inpatient infectious disease consultation is requested for a $54$-year-old man who has been hospitalized for the past $3$ weeks following an extensive bowel resection for acute mesenteric ischemia. Due to short bowel syndrome, he has been dependent on total parenteral nutrition administered via a right upper extremity peripherally inserted central catheter (PICC). Yesterday, the patient experienced a sudden onset of rigors and a temperature spike to $39.1^\circ\text{C}$ ($102.4^\circ\text{F}$). His blood pressure dropped to $105/65$ mm Hg with a pulse of $110$/min. Examination of the PICC insertion site revealed focal erythema and tenderness. The catheter was promptly removed, and empiric intravenous vancomycin and piperacillin-tazobactam were initiated. Today, the patient is afebrile and hemodynamically stable. Preliminary blood cultures from both the PICC tip and a peripheral draw are positive for *Staphylococcus aureus* in $4$ out of $4$ bottles. Final susceptibility results show the isolate is resistant to penicillin but susceptible to oxacillin, cefazolin, clindamycin, and vancomycin. Which of the following is the most appropriate next step in pharmacotherapy?

A 22-year-old man is brought to the emergency department by his roommate due to progressive lethargy, diffuse abdominal pain, and repeated vomiting for the past 24 hours. He has a history of type 1 diabetes mellitus but ran out of his insulin prescriptions three days ago. On examination, he is obtunded. Temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $86/54\text{ mm Hg}$, pulse is $128/\text{min}$, and respirations are $28/\text{min}$ and deep. Mucous membranes are extremely dry.

Arrange the following interventions in the most appropriate chronological sequence for the management of this patient.

A $48$-year-old patient who was admitted $3$ weeks ago with severe acute pancreatitis secondary to cholelithiasis now exhibits sudden clinical deterioration. The patient's temperature is $39.2^\circ \text{C}$ ($102.6^\circ \text{F}$) and white blood cell count is $22,000/\mu \text{L}$. An abdominal contrast-enhanced computed tomography scan demonstrates a large, encapsulated complex fluid collection replacing the pancreatic body, measuring $10 \times 8 \text{ cm}$, and notably containing multiple small gas bubbles. Arrange the following interventions in the most appropriate chronological sequence for managing this patient's current condition and preventing future recurrences.

A 52-year-old man is evaluated in the hospital on day 4 of admission. He originally presented with a 5-day history of high fever, chills, and severe right upper quadrant abdominal pain. His past medical history is notable for poorly controlled type 2 diabetes mellitus. On admission, a CT scan of the abdomen revealed a 6.2-cm solitary, rim-enhancing fluid collection in the right hepatic lobe. He immediately underwent CT-guided percutaneous catheter drainage and was started on empiric intravenous piperacillin-tazobactam.

Today, the patient feels significantly better. His temperature is 37.1°C (98.8°F), blood pressure is 128/82 mmHg, and pulse is 78/min. His leukocyte count has decreased from 21,000/mm³ on admission to 10,500/mm³. The percutaneous drain is outputting a small amount of serosanguinous fluid. Blood cultures from admission show no growth. The abscess fluid culture results have finalized as shown below:

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