Internal Medicine

A 38-year-old man is evaluated in the clinic for a 3-month history of episodic, severe headaches, excessive sweating, and palpitations. He reports that these spells occur spontaneously, last 15 to 20 minutes, and leave him feeling exhausted. During a recent episode, he checked his blood pressure at home, and it was 195/110 mm Hg. Today, he is asymptomatic. His temperature is 37.1°C (98.8°F), blood pressure is 142/90 mm Hg, and pulse is 82/min. Physical examination is unremarkable. The physician strongly suspects a catecholamine-secreting tumor.

Arrange the following steps in the most appropriate chronological order for the diagnostic workup and optimal management of this patient.

A 62-year-old man comes to the physician due to a 3-month history of progressive early satiety, postprandial epigastric pain, and an unintentional weight loss of 9 kg (20 lb). His past medical history is significant for a peptic ulcer associated with Helicobacter pylori infection treated 10 years ago. Vital signs are within normal limits. Physical examination reveals conjunctival pallor and mild epigastric tenderness on deep palpation, without rebound or guarding. Laboratory studies show a hemoglobin concentration of 9.2 g/dL and a mean corpuscular volume of 74 fL. Fecal occult blood testing is positive.

Arrange the following diagnostic and management steps in the most appropriate chronological order for this patient's suspected condition. Assume that each successive staging modality demonstrates localized, potentially curable disease without evidence of dissemination.

A 54-year-old woman with a history of metastatic breast cancer is brought to the emergency department due to progressive shortness of breath, generalized weakness, and lightheadedness over the past three days. She reports that she nearly fainted earlier today while walking to the bathroom. Her temperature is 37.1 C (98.8 F), blood pressure is 82/45 mm Hg, pulse is 122/min, and respirations are 24/min. Her systolic blood pressure decreases by 15 mm Hg during inspiration. Physical examination reveals markedly distended jugular veins. The lungs are clear to auscultation bilaterally. Cardiac auscultation demonstrates distant, muffled heart sounds. Which of the following is the most appropriate next step in the management of this patient?

A 56-year-old man with a history of alcohol use disorder and decompensated cirrhosis is admitted to the hospital with worsening lethargy and diffuse abdominal swelling over the past week. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $102/64 \text{ mm Hg}$, pulse is $108/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination reveals scleral icterus, shifting dullness to percussion, and bilateral pitting edema. Laboratory studies are obtained:

Assuming a normal reference serum albumin of $4.0 \text{ g/dL}$, what is this patient's albumin-corrected serum anion gap?

An occupational health physician evaluates a 28-year-old registered nurse who recently transitioned to working night shifts. She complains of persistent palpitations, a 4-kg (8.8-lb) weight loss over the past month, and severe anxiety. The patient states she has felt immense pressure to maintain a slim physique for an upcoming family event. Her temperature is 37.1°C (98.8°F), blood pressure is 138/78 mm Hg, and resting pulse is 112/min. On physical examination, her skin is warm and moist. Extraocular movements are intact, and there is no lid lag or proptosis. The thyroid gland is nonpalpable and non-tender. A fine tremor is noted when her arms are outstretched.

Initial laboratory testing demonstrates:

What is the most likely explanation for this patient's clinical and laboratory findings?

A 24-year-old woman presents to the outpatient clinic with a 3-month history of severe fatigue, symmetric pain in her bilateral wrists and metacarpophalangeal joints, and a photosensitive erythematous rash over her cheeks and nasal bridge. She is suspected of having a new-onset systemic autoimmune connective tissue disease. Arrange the following diagnostic and therapeutic steps in the appropriate clinical and chronological sequence for her suspected condition, starting from initial screening to the management of potential severe complications.

Match each esophageal motility disorder with its characteristic high-resolution manometry (HRM) findings according to the Chicago Classification.

A 22-year-old woman presents to the clinic for evaluation of easy bruising and prolonged bleeding following minor cuts. She reports a history of heavy menses since menarche, which occasionally requires iron supplementation. Her mother experiences similar mucosal bleeding symptoms. Physical examination reveals several small ecchymoses on her lower extremities but no petechiae. Vital signs are within normal limits. Arrange the following clinical steps in the most appropriate chronological sequence for the diagnostic workup and management of this patient's most likely condition.

An 81-year-old male resident of a skilled nursing facility is transported to the acute care unit following an episode of massive rectal bleeding. The nursing staff reports he passed several large clots of dark red blood and subsequently experienced presyncope. Upon arrival, he is pale, diaphoretic, and lethargic. Vital signs demonstrate a temperature of 36.1°C (97.0°F), a blood pressure of 78/42 mm Hg, and a pulse of 134/min. His medical history includes ischemic cardiomyopathy, chronic kidney disease, and advanced osteoarthritis, for which he takes daily naproxen and apixaban. Abdominal examination reveals normal bowel sounds and no guarding, rigidity, or focal tenderness. The rectal vault contains abundant fresh blood without palpable masses. Arrange the following interventions in the most appropriate sequential order for the management of this patient's acute presentation.

Match each classic peripheral manifestation of infective endocarditis with its correct clinical description.

An intensive care physician evaluates a 72-year-old male on his fourth day of hospitalization for severe community-acquired pneumonia complicated by septic shock. The patient is currently mechanically ventilated and receiving vasopressor support. His condition is slowly stabilizing, and the vasopressor requirements have decreased over the past $24\ \text{hours}$. His past medical history is notable for type 2 diabetes mellitus, hypertension, and benign prostatic hyperplasia. Current medications include continuous infusions of norepinephrine and propofol, subcutaneous insulin, and prophylactic enoxaparin. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $110/70\ \text{mmHg}$, and heart rate is $88/\text{min}$. A comprehensive metabolic panel and thyroid function tests are obtained as part of a routine morning evaluation. The thyroid panel reveals the following:

Serum thyroid-stimulating hormone (TSH): $1.1\ \mu\text{U/mL}$ (Normal: $0.4\text{--}4.2\ \mu\text{U/mL}$)
Free thyroxine ($\text{T}_4$): $1.2\ \text{ng/dL}$ (Normal: $0.8\text{--}2.7\ \text{ng/dL}$)
Total triiodothyronine ($\text{T}_3$): $45\ \text{ng/dL}$ (Normal: $80\text{--}200\ \text{ng/dL}$)

Which of the following is the most appropriate next step in management regarding this patient's thyroid laboratory findings?

A 58-year-old man presents to the emergency department complaining of sudden-onset, severe, crushing substernal chest pain that began 45 minutes ago and radiates to his left jaw. His blood pressure is 140/90 mmHg, heart rate is 92/min, respiratory rate is 16/min, and oxygen saturation is 98% on room air. Physical examination reveals an anxious, diaphoretic patient with normal heart sounds and clear lungs. Arrange the following initial management steps in the most appropriate chronological sequence for this patient.

Evaluate the provided arterial blood gas (ABG) and basic metabolic panel (BMP) profiles. Which clinical etiology most accurately corresponds to each laboratory pattern?

A 74-year-old woman is evaluated in the outpatient clinic for medical clearance 3 days prior to an elective right total hip arthroplasty. Her medical history includes well-controlled type 2 diabetes mellitus, essential hypertension, and osteoarthritis. She reports feeling well and explicitly denies fever, chills, flank pain, dysuria, or increased urinary frequency. Vital signs show a temperature of 37.1°C (98.8°F), blood pressure of 128/78 mmHg, and a pulse of 76/min. Physical examination is unremarkable with no costovertebral angle tenderness or suprapubic pain. As part of a preoperative protocol mandated by the surgical center, a urinalysis and urine culture are obtained. The urinalysis reveals a specific gravity of 1.018, pH of 6.5, positive leukocyte esterase, positive nitrites, and 45 white blood cells per high-power field. Two days later, the urine culture grows $>10^5$ CFU/mL of *Klebsiella pneumoniae*. Antimicrobial susceptibility testing indicates the isolate is susceptible to cephalexin, ciprofloxacin, and trimethoprim-sulfamethoxazole. Which of the following is the most appropriate management regarding the patient's urinary findings?

A 32-year-old man comes to the clinic for follow-up of a diarrheal illness. Three days ago, he developed fever, diffuse abdominal cramping, and multiple episodes of watery, non-bloody diarrhea after attending a family picnic. He was seen at an urgent care clinic yesterday where a stool culture was obtained and intravenous fluids were administered. Today, he reports that his fever has resolved and his diarrhea is beginning to improve, though he still has 2 to 3 loose stools per day. He is able to tolerate oral fluids and feels well-hydrated. His temperature is 37.1°C (98.8°F), blood pressure is 122/80 mmHg, and pulse is 76/min. The urgent care clinic forwards his stool culture results, which are positive for non-typhoidal *Salmonella enterica*. Susceptibility testing shows the isolate is pan-susceptible. Which of the following is the most appropriate antimicrobial management?

A 42-year-old man is hospitalized for community-acquired pneumonia. He has a 15-year history of ankylosing spondylitis. On admission two days ago, a sputum Gram stain and culture grew *Streptococcus pneumoniae* that is pan-sensitive to all standard antimicrobial agents, and he was appropriately started on targeted intravenous ceftriaxone. Over the past 48 hours, he has received 4 liters of intravenous crystalloid fluids. Today, he develops acute-onset severe shortness of breath and orthopnea. His temperature is $37.1^\circ$ C ($98.8^\circ$ F), blood pressure is $150/50$ mm Hg, pulse is 110/min, and respirations are 26/min. Pulse oximetry shows 86% on room air. Physical examination reveals an early blowing diastolic murmur best heard at the left lower sternal border. Pulmonary auscultation reveals bilateral crackles in the middle and lower lung fields. Laboratory studies show:

Thyroid-stimulating hormone (TSH): $2.5$ mU/L
Total T4: $4.1$ $\mu$ g/dL (Normal: $5.0$ - $12.0$ $\mu$ g/dL)

Arterial blood gas (room air):
pH: $7.48$
pCO $_2$: $30$ mm Hg
pO $_2$: $55$ mm Hg

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

A 42-year-old woman is evaluated for poorly controlled blood pressure despite adherence to a three-drug antihypertensive regimen consisting of amlodipine, lisinopril, and chlorthalidone. Her blood pressure is 162/98 mm Hg, and laboratory studies reveal a serum potassium level of 3.1 mEq/L. Primary hyperaldosteronism is suspected. She is an appropriate surgical candidate and wishes to pursue a definitive surgical cure if eligible. Assuming each test in the diagnostic pathway yields results consistent with a surgically correctable unilateral aldosterone-producing adenoma, arrange the following steps in the correct chronological order for her diagnostic workup and management.

A 68-year-old man is evaluated on postoperative day 6 following a sigmoid colectomy for colon adenocarcinoma. He reports sudden-onset shortness of breath and right-sided pleuritic chest pain. His past medical history includes chronic obstructive pulmonary disease and hypertension. His medications include subcutaneous unfractionated heparin, which was started on postoperative day 1. Temperature is 37.8°C (100.0°F), blood pressure is 128/82 mm Hg, pulse is 114/min, and respiratory rate is 24/min. Pulse oximetry is 90% on room air. Physical examination reveals decreased breath sounds at the right lung base and a swollen, tender right calf. Laboratory studies show:

Hemoglobin: 11.5 g/dL
Leukocyte count: 9,800/mm³
Platelet count: 52,000/mm³ (baseline was 260,000/mm³ prior to surgery)
Creatinine: 1.2 mg/dL

Arterial blood gas on room air:
pH: 7.32
PaCO2: 28 mm Hg
PaO2: 60 mm Hg
HCO3-: 14 mEq/L

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

An 82-year-old female resident of a skilled nursing facility is transported to the acute care clinic complaining of severe, crampy abdominal pain accompanied by intractable vomiting for the past 4 days. Her caregivers report that over the last 24 hours, her emesis has become dark brown with a distinct foul, fecal odor. She has not passed flatus or had a bowel movement for 48 hours. Medical history is significant for type 2 diabetes mellitus, coronary artery disease, and heart failure with preserved ejection fraction.

Vital signs include:
- Temperature: $37.9^\circ\text{C}$ ($100.2^\circ\text{F}$)
- Heart rate: $118/\text{min}$
- Blood pressure: $92/58\text{ mmHg}$
- Respiratory rate: $22/\text{min}$

Physical examination reveals a markedly distended, tympanic abdomen with high-pitched, tinkling bowel sounds. There is diffuse abdominal tenderness to palpation but no guarding or rigidity.

Laboratory studies demonstrate a leukocyte count of $15,200/\text{mm}^3$. A basic metabolic panel shows:
- $\text{Na}^+$: $134\text{ mEq/L}$
- $\text{K}^+$: $3.1\text{ mEq/L}$
- $\text{Cl}^-$: $92\text{ mEq/L}$
- $\text{HCO}_3^-$: $34\text{ mEq/L}$
- $\text{BUN}$: $48\text{ mg/dL}$
- $\text{Creatinine}$: $1.8\text{ mg/dL}$

Arterial blood gas on room air shows $\text{pH} = 7.50$ and $\text{pCO}_2 = 45\text{ mmHg}$.

An upright plain radiograph of the abdomen reveals dilated loops of small intestine with multiple air-fluid levels. Additionally, there are branching radiolucent lines seen over the right upper quadrant (overlying the liver shadow) and a distinct $3.5\text{-cm}$ radiopaque density projected in the right lower quadrant.

After initiating aggressive intravenous fluid resuscitation and placing a nasogastric tube, which of the following is the most appropriate next step in the management of this patient?

A 72-year-old woman presents to the emergency department with a 3-week history of severe aching and morning stiffness in her shoulders and hips that lasts for several hours. Over the past 3 days, she has developed a throbbing, new-onset right-sided headache and reports that her jaw aches and tires easily when she chews solid foods. Her temperature is 37.9°C (100.2°F), blood pressure is 138/85 mmHg, and heart rate is 88/min. Physical examination reveals scalp tenderness on the right side and prominent, rope-like temporal arteries. Neurologic examination is unremarkable, and visual acuity is currently intact. Laboratory studies show an erythrocyte sedimentation rate of 98 mm/h and a C-reactive protein of 45 mg/L. Which of the following is the most appropriate next step in the management of this patient?