Internal Medicine

A 64-year-old man is evaluated in the intensive care unit for increasing respiratory effort. He was admitted $48$ hours ago for severe left lower lobe community-acquired pneumonia and sepsis. Blood cultures obtained at admission have since grown *Streptococcus pneumoniae* sensitive to ceftriaxone, and he is currently receiving targeted therapy with intravenous ceftriaxone.

Over the last few hours, he has become increasingly lethargic and is using accessory muscles of respiration. Vital signs are:
- Temperature: $38.1^\circ\text{C}$ ($100.6^\circ\text{F}$)
- Blood pressure: $95/60\text{ mm Hg}$
- Pulse: $118\text{/min}$
- Respirations: $34\text{/min}$
- Pulse oximetry: $90\%$ on a high-flow nasal cannula.

Laboratory and arterial blood gas analysis reveals:

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

Match each clinical presentation with its corresponding classic arterial blood gas and basic metabolic panel profile.

A 35-year-old woman is evaluated in the hospital on day 3 of admission for acute pyelonephritis. She originally presented to the emergency department with a 2-day history of fever, chills, right-sided flank pain, and intractable vomiting. At that time, she was febrile to 39.2°C (102.6°F) and hypotensive. After initial fluid resuscitation, she was empirically started on intravenous vancomycin and piperacillin-tazobactam. Today, her temperature is 37.1°C (98.8°F), blood pressure is 120/78 mm Hg, and pulse is 82/min. Her flank pain has significantly improved, but she continues to experience severe nausea and vomits immediately after attempting to drink any liquids. Blood and urine cultures from admission are now growing *Proteus mirabilis*. Susceptibility testing shows the isolate is intrinsically resistant to nitrofurantoin but susceptible to ampicillin, ceftriaxone, piperacillin-tazobactam, and ciprofloxacin. Which of the following is the most appropriate next step in pharmacotherapy?

During cardiovascular physiology rounds, a medical student is asked to interpret the central venous pressure waveforms of various patients. Match each specific jugular venous pulsation (JVP) waveform abnormality with the underlying cardiac pathology that most commonly produces it.

A $72$-year-old man is evaluated in the intensive care unit due to rapidly worsening abdominal distension and hemodynamic instability. He was admitted $8$ days ago for severe community-acquired pneumonia, which was treated with a $5$-day course of intravenous levofloxacin. On hospital day $5$, he developed frequent, foul-smelling, watery stools. Today, the nursing staff notes that his diarrhea abruptly ceased over the last $12$ hours, but he has become progressively lethargic. His temperature is $39.1^\circ\text{C}$ ($102.4^\circ\text{F}$), pulse is $132\text{/min}$, blood pressure is $82/48\text{ mm Hg}$, and respirations are $26\text{/min}$. Physical examination reveals a markedly distended abdomen that is tympanitic to percussion and diffusely tender with guarding. Bowel sounds are absent. Laboratory studies show a leukocyte count of $34,500\text{/mm}^3$ and a serum lactate of $4.6\text{ mmol/L}$. Plain abdominal radiography demonstrates colonic dilation with a transverse colon diameter of $10.2\text{ cm}$, loss of haustral markings, and no evidence of pneumoperitoneum. In addition to aggressive fluid resuscitation and urgent surgical consultation, which of the following is the most appropriate pharmacotherapy?

A 68-year-old man is brought to the emergency department by his daughter due to a 2-day history of fever, severe right upper quadrant abdominal pain, and yellowing of his eyes. Today, he became increasingly confused and lethargic. His temperature is 39.4°C (102.9°F), blood pressure is 82/50 mmHg, pulse is 124/min, and respirations are 22/min. Physical examination reveals scleral icterus and marked tenderness in the right upper quadrant without rebound or guarding. Laboratory studies show a leukocyte count of 18,500/mm³, total bilirubin of 6.2 mg/dL, and alkaline phosphatase of 450 U/L.

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

A 45-year-old woman is evaluated in the outpatient clinic for a 6-month history of progressive exertional dyspnea and fatigue. She has no history of smoking, cardiac disease, or venous thromboembolism. Vital signs are within normal limits. Physical examination reveals a loud pulmonic component of the second heart sound (P2) and a right ventricular heave. Lungs are clear to auscultation bilaterally. Electrocardiography shows right axis deviation and right ventricular hypertrophy. Pulmonary function tests are normal. A chest radiograph reveals enlarged central pulmonary arteries. Arrange the following diagnostic modalities in the most appropriate chronological sequence for the evaluation of this patient's suspected condition.

An emergency medical services team brings a 71-year-old male to the resuscitation bay following 48 hours of progressively worsening shortness of breath, rapid heart rate, and increased production of thick, yellowish sputum. He has a documented medical history of chronic obstructive pulmonary disease (COPD), essential hypertension, and major depressive disorder. Current home pharmacological therapies consist of amlodipine, a combined fluticasone-salmeterol inhaler, and citalopram.

Initial vital signs obtained upon arrival demonstrate a temperature of $37.6^\circ\text{C}$ ($99.7^\circ\text{F}$), blood pressure of $128/78\text{ mm Hg}$, heart rate of $138/\text{min}$, and respiratory rate of $26/\text{min}$. Pulse oximetry indicates an oxygen saturation of $85\%$ while breathing ambient air.

Physical assessment highlights a barrel-shaped chest with prominent utilization of accessory muscles of respiration. Thoracic auscultation reveals global expiratory wheezing intermixed with coarse rhonchi. Evaluation of the cardiovascular system demonstrates a tachycardic, irregularly irregular rhythm featuring variable intensity of the first heart sound (S1); no S3 gallop or murmurs are appreciated. The jugular venous pressure is measured at $8\text{ cm H}_2\text{O}$. Trace bilateral lower extremity edema is noted.

A 12-lead electrocardiogram (ECG) reveals an irregularly irregular rhythm with narrow QRS complexes. Closer inspection of lead II identifies varying PR intervals and at least three distinct P-wave morphologies preceding the QRS complexes. The calculated QTc interval is $460\text{ ms}$.

Arterial blood gas parameters on room air are as follows:

Which of the following interventions represents the most appropriate initial management step for this patient's specific cardiac rhythm abnormality?

A 47-year-old previously healthy man visits his primary care provider reporting a gradual decline in peripheral vision over the past several months. He explains that he recently sideswiped a parked vehicle because he did not see it. He also reports decreased energy levels, a diminished interest in sexual activity, and difficulty achieving an erection for the past year. Vital signs are within normal limits. Confrontation visual field testing reveals bitemporal hemianopsia. Brain magnetic resonance imaging demonstrates a $3.5 \text{ cm}$ mass in the sella turcica with suprasellar extension and compression of the optic chiasm. Laboratory evaluation shows:

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

A $24$-year-old woman is brought to the emergency department by her roommate due to severe, progressive muscle weakness, dizziness, and palpitations over the past $3$ days. She has a history of generalized anxiety disorder. She takes no prescribed medications but admits to using over-the-counter supplements to help with weight loss. She denies any recent vomiting, diarrhea, or illicit drug use. On physical examination, her body mass index is $18.2$ kg/m $^2$. Blood pressure is $98/60$ mm Hg while supine and $82/50$ mm Hg upon standing. Pulse is $105$/min supine and $125$/min standing. Respiratory rate is $12$/min. Her mucous membranes are dry, and skin turgor is decreased. Neurologic examination reveals symmetrical $3/5$ strength in the proximal upper and lower extremities with diminished deep tendon reflexes.

Laboratory results are as follows:
Serum sodium: $135$ mEq/L
Serum potassium: $2.2$ mEq/L
Serum chloride: $84$ mEq/L
Serum bicarbonate: $38$ mEq/L
Blood urea nitrogen: $35$ mg/dL
Serum creatinine: $1.2$ mg/dL

Arterial blood gas (room air):
pH: $7.52$
pCO $_2$: $49$ mm Hg
pO $_2$: $92$ mm Hg

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

Match each distinct arterial pulse contour abnormality observed on physical examination to its most closely associated underlying cardiovascular pathology.

A 71-year-old man with a 40-pack-year smoking history and diet-controlled type 2 diabetes mellitus arrives at the emergency department with a 3-day history of progressively worsening shortness of breath. He reports a dry cough that frequently awakens him from sleep. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $165/95\text{ mmHg}$, pulse is $110/\text{min}$, and respiratory rate is $28/\text{min}$. Pulse oximetry shows $89\%$ on room air. Physical examination reveals diffuse expiratory wheezing, a prolonged expiratory phase, and an elevated jugular venous pressure. The physician suspects that an acute cardiovascular condition may be mimicking a primary pulmonary process. Which of the following additional findings would be most specific for confirming an acute cardiogenic etiology for this patient's respiratory distress rather than an exacerbation of chronic obstructive pulmonary disease?

A 58-year-old man is admitted to the medical ward due to a 2-day history of severe right knee pain, swelling, and subjective fevers. He has a history of type 2 diabetes mellitus and essential hypertension. His temperature is 38.8°C (101.8°F), blood pressure is 132/82 mmHg, and pulse is 108/min. Physical examination reveals a large, erythematous, and exquisitely tender right knee effusion with significantly limited range of motion. There are no overlying skin lacerations or prior joint surgeries. Diagnostic arthrocentesis yields turbid fluid with a leukocyte count of 92,000/mm³ (94% neutrophils). Gram stain of the synovial fluid demonstrates Gram-positive cocci in clusters. The patient is promptly started on empiric intravenous vancomycin and ceftriaxone, and he undergoes urgent arthroscopic irrigation and debridement. Forty-eight hours later, he reports decreased joint pain and his temperature has normalized. Blood and synovial fluid cultures both grow Staphylococcus aureus that is resistant to penicillin but susceptible to oxacillin, cefazolin, and vancomycin. Which of the following is the most appropriate next step in targeted pharmacotherapy?

An outpatient clinic evaluates a 24-year-old male who reports a 5-day history of fatigue, severe sore throat, and a newly developed diffuse maculopapular rash. He discloses having unprotected sexual intercourse with a new partner two weeks ago. Clinical suspicion for acute human immunodeficiency virus (HIV) infection is high. Assuming his initial screening test is reactive, but his antibody levels remain undetectable due to the recent exposure, arrange the following diagnostic and management steps in the appropriate chronological sequence according to the current testing algorithm.

Match the following endocrine laboratory profiles with their most likely underlying pathophysiologic diagnosis.

A 28-year-old otherwise healthy man is evaluated in an urgent care clinic for a 2-day history of frequent, watery diarrhea, abdominal cramping, and nausea. He states that his symptoms began approximately 24 hours after consuming homemade chicken salad at a community picnic. He has not noticed any blood or mucus in his stool. His past medical history is unremarkable, and he takes no medications. His temperature is 37.7°C (99.9°F), blood pressure is 118/76 mm Hg, pulse is 88/min, and respiratory rate is 14/min. Physical examination reveals slightly dry oral mucosa. The abdomen is soft and non-distended with mild, diffuse tenderness to palpation but no guarding or rebound. Bowel sounds are hyperactive. A rapid stool multiplex polymerase chain reaction panel is positive for *Salmonella enterica*. Which of the following is the most appropriate next step in management?

Match each clinical presentation to the most likely hepatobiliary or metabolic liver diagnosis.

A 34-year-old woman is brought to the emergency department by her husband due to severe agitation, confusion, and high fever. She has a history of Graves disease but stopped taking her prescribed antithyroid medications 3 months ago. Her temperature is 39.8°C (103.6°F), blood pressure is 160/90 mmHg, pulse is 145/min and irregular, and respiratory rate is 24/min. Physical examination reveals an enlarged, non-tender goiter, marked fine resting tremor, and profound diaphoresis. An electrocardiogram demonstrates atrial fibrillation with a rapid ventricular response. A diagnosis of thyroid storm is made. Supportive measures, including cooling blankets and intravenous fluids, are initiated.

Arrange the following targeted therapies in the correct chronological sequence for the optimal management of this patient's condition, from first intervention to final definitive treatment.

Match each clinical presentation with the most appropriate, guideline-directed primary antimicrobial therapy.

A $45$-year-old man with a history of severe alcohol use disorder is brought to the emergency department after $3$ days of intractable vomiting and generalized weakness. On physical examination, he appears lethargic and has dry mucous membranes with decreased skin turgor. Vital signs show a blood pressure of $95/60 \text{ mmHg}$, heart rate of $118/\text{min}$, and respiratory rate of $24/\text{min}$. Laboratory evaluation reveals the following:

- Serum sodium: $138 \text{ mEq/L}$
- Serum potassium: $3.2 \text{ mEq/L}$
- Serum chloride: $86 \text{ mEq/L}$
- Serum bicarbonate: $10 \text{ mEq/L}$
- Blood urea nitrogen: $42 \text{ mg/dL}$
- Serum creatinine: $1.9 \text{ mg/dL}$
- Plasma beta-hydroxybutyrate: elevated

Based on the provided laboratory values, the physician suspects a mixed acid-base disorder and decides to calculate the delta-delta (corrected) bicarbonate. Assuming a normal anion gap of $12 \text{ mEq/L}$, what is the patient's calculated delta-delta bicarbonate level?