Internal Medicine

A 62-year-old man is evaluated in the intensive care unit on day 6 of mechanical ventilation. He was initially intubated for acute respiratory distress syndrome (ARDS) secondary to severe influenza A pneumonia. Over the past 48 hours, he has developed worsening hypoxemia, increased purulent endotracheal secretions, and a new fever of 38.8°C (101.8°F). His medical history includes moderate chronic obstructive pulmonary disease (COPD) and heart failure with preserved ejection fraction.

Current ventilator settings in volume-control mode are:
Fraction of inspired oxygen (FiO2): 0.60
Positive end-expiratory pressure (PEEP): 14 cm H2O
Tidal volume: 6 mL/kg of predicted body weight
Respiratory rate: 24/min

Arterial blood gas analysis shows:
pH: 7.28
pCO2: 54 mm Hg
pO2: 68 mm Hg
HCO3-: 24 mEq/L

A chest radiograph reveals a new focal consolidation in the right lower lobe, superimposed on bilateral diffuse alveolar opacities. Two days ago, when the fever began, he was empirically started on intravenous vancomycin and cefepime. Today, the bronchoalveolar lavage quantitative culture grows Streptococcus pneumoniae that is susceptible to ceftriaxone, levofloxacin, and linezolid.

Which of the following are appropriate interventions for this patient's ongoing management? (Select all that apply)

A 64-year-old man presents to the outpatient clinic reporting a 2-month history of retrosternal chest tightness. The discomfort occurs predictably after walking two blocks and resolves completely with 5 minutes of rest. He has a history of type 2 diabetes mellitus, hyperlipidemia, and hypertension. Current medications include lisinopril and metformin. Vital signs are within normal limits. Physical examination is unremarkable. A resting 12-lead electrocardiogram shows normal sinus rhythm without ST-segment or T-wave abnormalities.

Arrange the following steps in the most appropriate sequential order for the optimal long-term evaluation and management of this patient's condition, assuming each successive step reveals findings that appropriately warrant further escalation of care.

An otherwise healthy $28$-year-old female patient presents to the urgent care clinic complaining of a sudden onset of sharp, right-sided chest pain that worsens with deep inspiration. She returned from a long-haul international flight two days ago. Her vital signs are stable, including a heart rate of $82$/min and oxygen saturation of $99\%$ on room air. The physical examination, including lung auscultation and lower extremity inspection, shows no abnormalities. The physician suspects a pulmonary embolism. Arrange the following clinical actions in the most appropriate chronological order to accurately evaluate and manage this patient.

A rapid response is called for a $70$-year-old woman admitted to the medical ward who has developed worsening respiratory distress. She was admitted two days ago for acute pyelonephritis and has been receiving intravenous piperacillin-tazobactam and vancomycin. Her medical history includes diet-controlled type 2 diabetes mellitus, Hashimoto thyroiditis, and severe chronic obstructive pulmonary disease.

Currently, she is confused and lethargic. Her temperature is $38.4^\circ\text{C}$ ($101.1^\circ\text{F}$), blood pressure is $92/58\text{ mmHg}$, pulse is $118/\text{min}$, and respiratory rate is $28/\text{min}$. Pulse oximetry shows $86\%$ on $4\text{ L/min}$ oxygen via nasal cannula.

Physical examination reveals coarse rhonchi and decreased breath sounds bilaterally, with no jugular venous distention. The point-of-care echocardiogram demonstrates a normal left ventricular ejection fraction ($60\%$) and no significant valvular abnormalities.

Laboratory results are as follows:
Leukocyte count: $16,500/\text{mm}^3$
Serum sodium: $138\text{ mEq/L}$
Serum potassium: $4.1\text{ mEq/L}$
Serum chloride: $102\text{ mEq/L}$
Serum bicarbonate: $14\text{ mEq/L}$
Blood urea nitrogen: $32\text{ mg/dL}$
Serum creatinine: $1.8\text{ mg/dL}$
Thyroid-stimulating hormone (TSH): $0.2\text{ }\mu\text{U/mL}$ (normal: $0.4-4.0$)
Free T4: $0.6\text{ ng/dL}$ (normal: $0.9-1.7$)

Arterial blood gas analysis on room air:
pH: $7.28$
pCO $_2$: $30\text{ mmHg}$
pO $_2$: $54\text{ mmHg}$

Blood cultures drawn on admission are negative, but urine cultures have grown $>100,000\text{ CFU/mL}$ of *Escherichia coli*. The isolate is resistant to ampicillin but susceptible to ceftriaxone, cefepime, and piperacillin-tazobactam.

The patient is urgently intubated for hypoxic respiratory failure. Following stabilization of her airway, which of the following is the most appropriate next step in the pharmacologic management of this patient?

A 32-year-old woman presents to the clinic complaining of a $6$-month history of fatigue, abdominal bloating, and frequent, bulky, foul-smelling bowel movements. She has not traveled recently and reports no blood in her stool. Her past medical history is notable for type 1 diabetes mellitus. Vital signs are within normal limits. Physical examination reveals mild conjunctival pallor but is otherwise unremarkable. Laboratory studies show a hemoglobin of $10.4 \text{ g/dL}$ and a mean corpuscular volume of $74 \text{ fL}$. Which of the following is the most appropriate next step in diagnosis?

A $74$-year-old woman is brought to the emergency department by ambulance due to severe shortness of breath that awoke her from sleep $2$ hours ago. She has a history of chronic obstructive pulmonary disease (COPD), essential hypertension, and osteoarthritis. Her home medications include a daily tiotropium inhaler and amlodipine. She reports a dry cough but denies fever, chills, or changes in sputum production. She appears in severe respiratory distress, sitting upright and using accessory muscles of respiration. Vital signs are temperature $37.0^{\circ}C$ ($98.6^{\circ}F$), blood pressure $182/105$ mm Hg, pulse $112$/min, and respirations $28$/min. Pulse oximetry is $88\%$ on room air. Jugular venous pressure is $10$ cm $H_2O$. Lung auscultation demonstrates diffuse expiratory wheezes and a prolonged expiratory phase; no crackles are appreciated. Cardiac examination reveals a regular tachycardia with a faint, high-frequency presystolic sound at the apex. There is no peripheral edema. Arterial blood gas analysis on room air reveals a pH of $7.28$, $PaCO_2$ of $60$ mm Hg, $PaO_2$ of $55$ mm Hg, and $HCO_3^-$ of $27$ mEq/L. A bedside chest radiograph shows hyperinflated lungs, prominent upper lobe vessels, and peribronchial cuffing, without distinct alveolar infiltrates. Electrocardiogram shows sinus tachycardia and voltage criteria for left ventricular hypertrophy. Which of the following is the most appropriate next step in management?

A $68$-year-old man with a history of prior myocardial infarction and ischemic cardiomyopathy is brought to the emergency department after a witnessed episode of near-syncope at home. Upon arrival, he appears pale and lethargic but withdraws to painful stimuli. His vital signs show a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), a heart rate of $188\text{ /min}$, a blood pressure of $78/50\text{ mmHg}$, and a respiratory rate of $22\text{ /min}$. Continuous cardiac monitoring reveals a regular, wide-complex tachycardia. His oxygen saturation is $94\%$ on room air.

Based on the Advanced Cardiovascular Life Support (ACLS) guidelines, arrange the following acute management steps in the correct sequential order for this patient.

A $70$-year-old man comes to the emergency department due to severe shortness of breath that has worsened over the past $24$ hours. He reports waking up multiple times during the night gasping for air and had to sleep sitting up in a recliner. His medical history includes chronic obstructive pulmonary disease (COPD), hypertension, and type 2 diabetes mellitus. His current medications include inhaled tiotropium, oral amlodipine, and metformin. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $168/94\text{ mm Hg}$, pulse is $108/\text{min}$, and respiratory rate is $26/\text{min}$. Pulse oximetry is $88\%$ on room air. Physical examination reveals jugular venous distention to $11\text{ cm H}_2\text{O}$ above the sternal angle. Pulmonary auscultation reveals bibasilar crackles and diffuse expiratory wheezes. He has $2+$ pitting edema in both lower extremities. Which of the following is the most appropriate initial pharmacologic therapy for this patient?

A $68$-year-old male is brought to the emergency department due to progressive somnolence and worsening dyspnea over the past $24$ hours. His medical history is significant for severe chronic obstructive pulmonary disease (COPD) requiring $2\text{ L/min}$ of home oxygen. Upon arrival, he is obtunded and using accessory muscles of respiration. Vital signs are temperature $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure $145/85\text{ mm Hg}$, pulse $112/\text{min}$, and respiratory rate $28/\text{min}$. An initial arterial blood gas analysis on ambient air reveals:

The patient is immediately intubated for hypercapnic respiratory failure and inability to protect his airway. He is placed on volume-assist control mechanical ventilation with a tidal volume of $450\text{ mL}$ ($8\text{ mL/kg}$ of ideal body weight), respiratory rate of $20/\text{min}$, $\text{FiO}_2$ of $0.40$, and positive end-expiratory pressure (PEEP) of $5\text{ cm H}_2\text{O}$.

Forty-five minutes after the initiation of mechanical ventilation, the cardiac monitor displays sustained ventricular tachycardia, and the patient's blood pressure drops to $70/40\text{ mm Hg}$. A repeat arterial blood gas analysis drawn just prior to the arrhythmic event shows a $pH$ of $7.54$, $\text{PaCO}_2$ of $40\text{ mm Hg}$, and $\text{HCO}_3^-$ of $33\text{ mEq/L}$. Serum potassium is currently $2.8\text{ mEq/L}$ (baseline $4.1\text{ mEq/L}$ upon admission).

Which of the following initial management strategies would most likely have prevented this patient's current hemodynamic collapse?

During a scheduled winter visit to his primary care provider, a 64-year-old male patient reports a 72-hour history of escalating dyspnea and cough. He mentions that his usual morning sputum has become significantly more voluminous and opaque yellow in color over the past few days. His medical history is notable for severe chronic obstructive pulmonary disease (COPD) requiring daily maintenance inhalers, and he has a 45-pack-year smoking history. At triage, his vital signs include a temperature of 37.3°C (99.1°F), a heart rate of 102/min, a blood pressure of 138/82 mm Hg, and a respiratory rate of 22/min. Room air oxygen saturation is 93%. Pulmonary auscultation reveals globally decreased breath sounds with prominent expiratory wheezing. The cardiac exam is unremarkable, with no elevated jugular venous pressure, normal heart sounds, and an absence of peripheral edema. Chest radiography confirms pulmonary hyperinflation without new infiltrates or effusions. Which of the following pharmacological interventions should be initiated as part of this patient's acute management plan? (Select all that apply.)

Emergency medical services bring a $22$-year-old university student to the resuscitation bay after her roommates found her profoundly lethargic. According to the roommates, she has complained of diffuse abdominal discomfort, nausea, and excessive thirst over the preceding $48$ hours. She has a known medical history of type 1 diabetes mellitus. Upon arrival, the patient is minimally responsive, localizing only to painful stimuli.

Evaluation reveals a blood pressure of $92/58\text{ mm Hg}$, a pulse of $126\text{/min}$, and deep, rapid respirations at a frequency of $36\text{/min}$. Pulse oximetry indicates $99\%$ oxygen saturation on ambient air. Physical examination is notable for severely parched oral mucosa and a distinct fruity odor on exhalation.

Stat laboratory testing reveals:
Serum sodium: $134\text{ mEq/L}$
Serum potassium: $4.8\text{ mEq/L}$
Serum chloride: $98\text{ mEq/L}$
Serum bicarbonate: $9\text{ mEq/L}$
Blood glucose: $680\text{ mg/dL}$

Due to her rapidly declining sensorium and inability to protect her airway, the care team proceeds with endotracheal intubation. Following the procedure and administration of continuous sedation, she is placed on volume-assist/control mechanical ventilation. The initial settings include a tidal volume of $450\text{ mL}$ (approximately $8\text{ mL/kg}$ of predicted body weight), a mandatory rate of $12\text{ breaths/min}$, a positive end-expiratory pressure of $5\text{ cm H}_2\text{O}$, and a fraction of inspired oxygen of $0.40$.

An arterial blood gas is drawn $30$ minutes post-intubation, demonstrating:
pH: $6.96$
PaCO2: $44\text{ mm Hg}$
PaO2: $135\text{ mm Hg}$

Which of the following is the most appropriate immediate intervention?

A 38-year-old man presents to the clinic with a 3-month history of persistent epigastric pain and dyspepsia. He has no alarm symptoms such as unintended weight loss, gastrointestinal bleeding, early satiety, or dysphagia. You decide to employ a 'test-and-treat' strategy for suspected Helicobacter pylori infection. Arrange the following steps in the most appropriate chronological order for the diagnosis, treatment, and follow-up of this patient.

An ICU team is managing a $53$-year-old male patient who remains profoundly hypoxemic $24$ hours after being intubated for viral pneumonia-induced acute respiratory distress syndrome (ARDS). Arrange the following management strategies in the standard sequential order of escalation for progressive, refractory hypoxemia, from foundational standard of care to the final salvage therapy.

A 64-year-old man is brought to the emergency department due to sudden-onset, excruciating chest pain that radiates to his back. His blood pressure is 210/120 mm Hg in the right arm and 185/105 mm Hg in the left arm. Heart rate is 118/min. Physical examination reveals a bounding pulse and a new early diastolic decrescendo murmur at the right upper sternal border. Electrocardiogram shows sinus tachycardia and left ventricular hypertrophy. The physician strongly suspects an acute aortic dissection and prepares to manage the patient. Arrange the following diagnostic and therapeutic interventions in the most appropriate sequential order for this patient.

An emergency medical team brings a female in her early thirties to the resuscitation bay following a brief loss of consciousness at her workplace. Upon arrival, the patient is lethargic and complains of profound weakness, lightheadedness, and difficulty breathing. She reports recovering from a severe viral upper respiratory tract infection two weeks ago but otherwise has no chronic medical conditions.

Her temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), pulse is $128$/min, respirations are $26$/min, and blood pressure is $78/48$ mmHg. When assessed during normal inhalation, her systolic blood pressure drops to $62$ mmHg.

Physical evaluation reveals marked distension of the external jugular veins while she is positioned at a $45$-degree angle. Auscultation of the chest demonstrates clear lung fields bilaterally without rhonchi or crepitations. Cardiac auscultation reveals a regular, rapid rhythm with significantly distant and muffled heart sounds. An electrocardiogram shows sinus tachycardia with low-voltage QRS complexes and beat-to-beat variation in QRS amplitude.

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

A $71$-year-old woman who resides in a skilled nursing facility is evaluated for the sudden onset of severe, foul-smelling, watery diarrhea. She reports having up to eight bowel movements per day for the last $48$ hours, accompanied by mild abdominal cramping. Three weeks prior, she completed a $10$-day course of oral clindamycin for a tooth abscess. Her temperature is $38.2^\circ\text{C}$ ($100.8^\circ\text{F}$), blood pressure is $112/70\text{ mmHg}$, and pulse is $98/\text{min}$. Abdominal examination reveals hyperactive bowel sounds and diffuse mild tenderness, but the abdomen is soft and non-distended. Laboratory testing shows a serum leukocyte count of $18,500/\text{mm}^3$. Stool polymerase chain reaction testing is positive for *Clostridioides difficile* toxin genes. Which of the following is the most appropriate initial pharmacotherapy for this patient?

Match each structural or valvular heart pathology with its most characteristic physical examination or auscultatory finding.

Identify the correct inherited gastrointestinal syndrome that corresponds to each set of clinical findings.

Match the following physical examination findings of cardiac murmurs with their most likely underlying pathophysiology or structural etiology.

A 24-year-old man is brought to the emergency department after a severe motor vehicle collision. He is in profound respiratory distress. Vital signs show a heart rate of 135/min, blood pressure of 75/40 mm Hg, and oxygen saturation of 82% on room air. Physical examination reveals distended neck veins, marked tracheal deviation to the left, and completely absent breath sounds over the right hemithorax. The clinical diagnosis of a right-sided tension pneumothorax is made. Arrange the following management steps in the correct chronological sequence for this patient.