Internal Medicine

An $81$-year-old woman is brought to the emergency department from a skilled nursing facility due to the sudden onset of severe, unrelenting abdominal pain that began $4$ hours ago. The facility staff reports that she has become progressively lethargic and confused over the past hour. Her past medical history is significant for heart failure with preserved ejection fraction, hypertension, and paroxysmal non-valvular atrial fibrillation. She has not taken her prescribed apixaban for the last three weeks due to an insurance coverage issue.

Her temperature is $38.4^\circ\text{C}$ ($101.1^\circ\text{F}$), pulse is $132/\text{min}$ and irregularly irregular, blood pressure is $82/48\text{ mmHg}$, and respirations are $26/\text{min}$. Pulse oximetry shows $94\%$ on ambient air. She is diaphoretic and writhing in bed. Cardiopulmonary examination reveals an irregular heartbeat with no murmurs, and the lungs are clear to auscultation. The abdomen is rigid and distended. There is diffuse, severe tenderness to palpation with marked involuntary guarding and rebound tenderness in all four quadrants. Bowel sounds are absent. Digital rectal examination yields grossly normal-appearing stool that is positive for occult blood.

Laboratory studies are as follows:

Arterial blood gas analysis on room air shows a pH of $7.18$ and a $\text{pCO}_2$ of $28\text{ mmHg}$.

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

An 82-year-old woman is evaluated in the hospital on the day of her planned discharge. She was admitted 4 days ago for an acute exacerbation of heart failure, which has now resolved with intravenous diuresis. An indwelling urinary catheter was placed on admission to closely monitor her urine output. Today, the nursing staff reports that her urine appears cloudy and has a strong malodorous scent. The patient feels well, has no new complaints, and is eager to return home. Her temperature is 37.1 C (98.8 F), blood pressure is 126/78 mm Hg, and pulse is 76/min. Physical examination reveals clear lungs, normal heart sounds, and no suprapubic or costovertebral angle tenderness. A urinalysis shows 15-20 white blood cells/hpf and positive nitrites. Urine culture from a sample taken from the catheter port grows >100,000 CFU/mL of Escherichia coli. Which of the following is the most appropriate next step in management?

A $32$-year-old man is brought to the emergency department by paramedics following a generalized tonic-clonic seizure. His roommate witnessed the event, reporting that the seizure lasted for approximately $10$ minutes before stopping on its own. On arrival, the patient is deeply lethargic and only withdraws to painful stimuli. His temperature is $37.2^\circ C$ ($99.0^\circ F$), blood pressure is $118/76$ $mmHg$, pulse is $110/min$, and respiratory rate is $8/min$. Pulse oximetry shows $92\%$ on room air.

Laboratory results are as follows:
Sodium: $140$ $mEq/L$
Potassium: $4.5$ $mEq/L$
Chloride: $100$ $mEq/L$
Bicarbonate: $12$ $mEq/L$
Blood urea nitrogen: $16$ $mg/dL$
Serum creatinine: $1.2$ $mg/dL$

An arterial blood gas drawn on room air reveals:
pH: $7.15$
pCO $_2$: $40$ $mmHg$
pO $_2$: $65$ $mmHg$

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

A 24-year-old primigravida at 28 weeks gestation presents to the obstetrical triage unit complaining of worsening shortness of breath and a cough that is occasionally productive of blood-streaked sputum. She immigrated to the United States two years ago and has had limited prior medical care. The patient notes that her breathing is significantly worse when she attempts to lie flat in bed. Temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $108/68\text{ mmHg}$, pulse is $118/\text{min}$ and regular, and respirations are $26/\text{min}$. Pulse oximetry ($SpO_2$) is $92\%$ on room air. Physical examination shows jugular venous distention. Lung auscultation reveals bilateral crackles in the lower lung fields. Cardiac auscultation in the left lateral decubitus position demonstrates a prominent first heart sound ($S_1$) and a low-pitched, mid-diastolic rumble at the apex. Which of the following is the most appropriate next step in patient care?

A $64$-year-old man comes to the clinic for a routine follow-up. He has a $15$-year history of type 2 diabetes mellitus, hypertension, and hyperlipidemia. His current medications include lisinopril, amlodipine, atorvastatin, and insulin glargine. Blood pressure is $138/86 \text{ mm Hg}$, and pulse is $76\text{/min}$. Physical examination reveals decreased sensation to monofilament testing in the bilateral feet. Laboratory studies show the following:

Which of the following is the most likely primary mechanism responsible for this patient's laboratory findings?

A 68-year-old woman is brought to the emergency department by her family due to sudden-onset, severe shortness of breath that awoke her from sleep 2 hours ago. She reports feeling as though she is "drowning" and has a prominent cough producing frothy sputum. Her medical history is significant for long-standing bronchial asthma, poorly controlled essential hypertension, and osteoarthritis. Current medications include inhaled budesonide-formoterol, amlodipine, and diclofenac. Upon arrival, her blood pressure is 225/120 mm Hg, heart rate is 118/min, respiratory rate is 32/min, and oxygen saturation is 84% on room air. The patient is diaphoretic, sitting bolt upright, and using accessory muscles of respiration. Lung auscultation reveals diffuse, loud expiratory wheezing bilaterally with faint crackles at the lung bases. Cardiac examination is notable for regular tachycardia and an S4 gallop; an S3 gallop is not appreciated due to the loud breath sounds. A bedside point-of-care ultrasound reveals bilateral B-lines in all lung zones. Electrocardiogram shows sinus tachycardia and voltage criteria for left ventricular hypertrophy. Which of the following is the most appropriate initial pharmacological therapy for this patient?

A hospital medicine team is evaluating a 65-year-old woman on the third day of her admission for acute cholangitis. On presentation to the hospital, she had a temperature of 39.2°C (102.6°F), pronounced scleral icterus, and right upper quadrant abdominal tenderness. Two sets of blood cultures were drawn, and empiric intravenous piperacillin-tazobactam was initiated. Later that same day, she underwent an uncomplicated endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and successful extraction of a 1.5-cm common bile duct stone.

Today, the patient is clinically much improved. Her temperature is 37.1°C (98.8°F), her abdominal pain has entirely resolved, and her leukocyte count has decreased from 18,000/mm³ on admission to 8,500/mm³. The admission blood cultures are now growing *Escherichia coli* in both sets. The laboratory's antimicrobial susceptibility report indicates the isolate is resistant to ampicillin but susceptible to ceftriaxone, ciprofloxacin, meropenem, and piperacillin-tazobactam.

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

An internal medicine team evaluates a patient ready for transfer out of the acute care unit. The patient, a resident of an assisted living facility, presented 72 hours ago with profound chills, vomiting, and right-sided back pain. She was hemodynamically stable but highly symptomatic, prompting the initiation of empiric intravenous piperacillin-tazobactam. Currently, she has been afebrile for 24 hours, her vital signs are within normal limits, and she is comfortably eating a regular diet. Microbiological analysis of both blood and urine samples collected on admission reveals heavy growth ($>10^5 \text{ CFU/mL}$) of *Enterococcus faecalis*. Susceptibility testing confirms the isolate is susceptible to ampicillin, amoxicillin, vancomycin, and nitrofurantoin. Which of the following is the most appropriate next step in pharmacotherapy?

Match each characteristic urinalysis sediment finding with its most likely underlying renal pathology.

A 68-year-old man is brought to the emergency department by his son following two days of progressively worsening breathlessness. The patient describes a new onset of coughing that yields thick, yellowish mucus. He has a known history of severe chronic obstructive pulmonary disease (COPD), hypertension, and a myocardial infarction three years ago. His daily medications include an inhaled long-acting muscarinic antagonist, as-needed inhaled short-acting beta-agonists, and low-dose aspirin.

Vital signs show a temperature of 37.6°C (99.7°F), blood pressure of 145/88 mmHg, pulse of 112/min, and respirations of 26/min. Pulse oximetry reveals an oxygen saturation of 87% while breathing ambient air.

On physical examination, the patient appears visibly anxious and is using accessory muscles of respiration. Assessment of the neck shows a jugular venous pressure of 9 cm $H_2O$. Auscultation of the chest reveals widespread expiratory wheezes and a significantly prolonged expiratory phase, with no audible crackles. Cardiac examination shows a regular rhythm with no murmurs. Trace pitting edema is noted in both lower extremities.

Laboratory analysis reveals:
Leukocyte count: 11,200/mm³
Thyroid-stimulating hormone (TSH): 0.2 $\mu U/mL$ (normal: 0.4–4.0 $\mu U/mL$)
Free T4: 1.1 ng/dL (normal: 0.9–1.7 ng/dL)
Total T3: 55 ng/dL (normal: 80–200 ng/dL)

An arterial blood gas sample obtained on room air demonstrates the following values:
pH: 7.27
$PaCO_2$: 65 mmHg
$PaO_2$: 54 mmHg
$HCO_3^-$: 29 mEq/L

A portable chest radiograph displays hyperlucency of the lung fields and flattened hemidiaphragms, with no evidence of focal consolidation or vascular congestion.

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

A 32-year-old woman comes to the clinic reporting a 5-month history of worsening fatigue, generalized weakness, and a $5\text{-kg}$ ($11\text{-lb}$) weight gain. She also notes new-onset cold intolerance and states she has not had a menstrual period since the birth of her second child $14$ months ago. Her delivery was complicated by severe uterine atony requiring emergency blood transfusions. Blood pressure is $92/58\text{ mm Hg}$ and pulse is $56\text{/min}$. Physical examination reveals pale, dry skin, delayed relaxation of deep tendon reflexes, and diminished pubic and axillary hair.

Laboratory studies show:
Thyroid-stimulating hormone (TSH): $1.5\text{ \mu U/mL}$ (normal: $0.4-4.0\text{ \mu U/mL}$)
Free thyroxine (T4): $0.5\text{ ng/dL}$ (normal: $0.9-1.7\text{ ng/dL}$)

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

A gastroenterology clinic regularly screens and evaluates patients for viral hepatitis. Proper interpretation of Hepatitis B serologic panels is critical for determining the phase of infection and appropriate management. Match each of the following patient Hepatitis B serologic profiles with the most appropriate clinical interpretation.

A 71-year-old man is brought to the emergency department by his wife due to sudden-onset severe shortness of breath that awoke him from sleep. He reports feeling as though he is suffocating and has coughed up pink-tinged, frothy sputum. His past medical history is significant for a myocardial infarction 3 years ago, essential hypertension, and a 45-pack-year smoking history. Upon arrival, his temperature is 37.0°C (98.6°F), blood pressure is 180/105 mmHg, pulse is 118/min, and respirations are 32/min. Oxygen saturation is 84% on room air. He is diaphoretic and sitting upright, leaning forward. Lung auscultation reveals diffuse expiratory wheezing and bilateral crackles extending to the mid-lung fields. Cardiac auscultation demonstrates a regular tachycardia with a prominent S3 gallop. An arterial blood gas on room air shows:

$pH$: 7.22
$PaCO_2$: 65 mmHg
$PaO_2$: 50 mmHg
$HCO_3^-$: 26 mEq/L

Which of the following is the most appropriate initial pharmacologic intervention for this patient?

Match the following classic electrocardiographic (ECG) findings with their most likely underlying structural or electrophysiologic pathology.

A genetics consultation service is reviewing several patient charts for familial endocrine disorders. Based on the clinical descriptions provided below, match each patient's presentation with the most likely underlying genetic syndrome.

A 55-year-old man with a history of decompensated alcohol-related cirrhosis is evaluated on hospital day 3. He initially presented to the emergency department with a temperature of 38.2°C (100.8°F), diffuse abdominal pain, and worsening lethargy. A diagnostic paracentesis performed on admission yielded ascitic fluid with a neutrophil count of $650/\text{mm}^3$. Due to a history of multiple recent hospitalizations, he was empirically started on intravenous meropenem. Today, his mental status has returned to baseline, his abdominal pain has markedly improved, and he is afebrile. Ascitic fluid cultures obtained on admission have finalized, growing *Escherichia coli*. Susceptibility testing indicates the organism is susceptible to cefotaxime, ceftriaxone, and ciprofloxacin, but resistant to trimethoprim-sulfamethoxazole. Which of the following is the most appropriate next step in the pharmacologic management of this patient?

During morning rounds in the intensive care unit, the medical team evaluates a patient who was intubated seven days ago for airway protection following a subarachnoid hemorrhage. The patient has developed a new fever of $38.9^\circ \text{C}$ ($102.0^\circ \text{F}$) and thick, purulent endotracheal secretions. His oxygenation has deteriorated, requiring an increase in fractional inspired oxygen ($\text{FiO}_2$) from $0.30$ to $0.55$. Morning laboratory results show a leukocyte count of $18,500/\text{mm}^3$. A bedside chest radiograph confirms a new lobar infiltrate in the left lung base. Suspecting a nosocomial respiratory infection, the team prepares to intervene. Arrange the following steps in the optimal chronological sequence for managing this patient's suspected complication.

An emergency medical services team brings a $73$-year-old man to the acute care bay with severe respiratory distress that began abruptly two hours ago. The patient is visibly agitated, diaphoretic, and cannot speak in full sentences. His wife reports that he has a history of essential hypertension, osteoarthritis, a $40$-pack-year smoking habit, and treatment-resistant depression for which a new medication (phenelzine) was initiated three weeks ago.

Vital signs:
Temperature: $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$)
Blood pressure: $192/108\text{ mm Hg}$
Heart rate: $118\text{/min}$
Respiratory rate: $28\text{/min}$
Oxygen saturation: $86\%$ on room air

Physical examination reveals prominent jugular venous distention. Lung auscultation yields diffuse, high-pitched expiratory wheezing bilaterally with prolonged expiratory phases. Cardiac examination reveals a regular tachycardia with a prominent extra heart sound heard just after $\text{S}_2$ at the cardiac apex. The abdomen is distended with a palpable liver edge $4\text{ cm}$ below the right costal margin.

Arterial blood gas analysis on room air shows:
$\text{pH}$: $7.49$
$\text{pCO}_2$: $29\text{ mm Hg}$
$\text{pO}_2$: $54\text{ mm Hg}$
$\text{HCO}_3^-$: $22\text{ mEq/L}$

Chest radiography reveals bilateral perihilar opacities and blunting of the costophrenic angles.

Which of the following is the most appropriate initial pharmacological intervention for this patient?

A $68$-year-old woman is admitted to the hospital with a $48$-hour history of colicky abdominal pain, severe nausea, and repeated episodes of bilious vomiting. She has not passed flatus or had a bowel movement for $3$ days. Her past surgical history is significant for an open hysterectomy performed $10$ years ago. On initial evaluation, she was afebrile and hemodynamically stable. Her abdomen was distended and tympanic, with mild diffuse tenderness but no guarding or rebound. An initial plain abdominal radiograph demonstrated multiple dilated loops of small bowel with prominent air-fluid levels and a paucity of gas in the colon. She was admitted for conservative management with intravenous fluid resuscitation, bowel rest, and nasogastric tube decompression.

Twelve hours after admission, the patient reports a sudden worsening of her abdominal pain, which is now constant and severe. Her temperature is $39.1^\circ\text{C}$ ($102.4^\circ\text{F}$), blood pressure is $92/58 \text{ mmHg}$, pulse is $122/\text{min}$, and respiratory rate is $22/\text{min}$. Physical examination now reveals a rigid abdomen with marked diffuse tenderness, involuntary guarding, and rebound tenderness. Bowel sounds are absent. Laboratory studies demonstrate a leukocyte count of $22,000/\text{mm}^3$ with a left shift, and a serum lactate level of $4.2 \text{ mmol/L}$.

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

A 64-year-old man is evaluated on hospital day 4 for ongoing management of vertebral osteomyelitis. He initially presented with severe mid-back pain, fever, and focal spinal tenderness. Magnetic resonance imaging of the thoracic spine at admission demonstrated T8-T9 discitis and adjacent vertebral body osteomyelitis without an epidural abscess. Blood cultures drawn prior to antibiotic administration have now finalized, showing heavy growth of *Streptococcus agalactiae*. Susceptibility testing indicates the organism is sensitive to penicillin, ceftriaxone, cefepime, and vancomycin. He was empirically started on intravenous vancomycin and piperacillin-tazobactam. Currently, his temperature is 37.1°C (98.8°F), blood pressure is 128/82 mmHg, and pulse is 78/min. His back pain has improved, and his neurologic examination remains unremarkable. Which of the following is the most appropriate next step in pharmacotherapy?