Internal Medicine

A 38-year-old man is brought to the emergency department by his partner due to severe headache, confusion, and fever for the past 24 hours. His medical history is significant for HIV, but he has not taken antiretroviral therapy for over a year. His last known CD4 cell count was 85/mm $^3$. His temperature is 39.2°C (102.6°F), blood pressure is 110/70 mmHg, and heart rate is 115/min. He is lethargic but arousable to physical stimuli. Neurologic examination reveals marked nuchal rigidity. Funduscopic examination shows blurring of the optic disc margins bilaterally. Arrange the following diagnostic and therapeutic steps in the most appropriate chronological sequence for the immediate management of this patient.

A 68-year-old woman is brought to the emergency department by her family due to a 24-hour history of fever, severe headache, and progressively worsening confusion. She has a medical history of rheumatoid arthritis and is currently on chronic immunosuppressive therapy with methotrexate and prednisone. On physical examination, her temperature is 39.2°C (102.6°F), blood pressure is 105/65 mmHg, and heart rate is 118/min. She is lethargic, oriented only to her own name, and exhibits marked nuchal rigidity. There are no clear focal neurologic deficits, but a thorough neurologic examination is limited by her altered mental status. Based on her clinical presentation and risk factors, arrange the following management steps in the most appropriate chronological sequence.

A $68$-year-old man is brought to the emergency department by his daughter due to a $3$-day history of progressively worsening headache, blurred vision, and confusion. He also reports having two episodes of severe epistaxis earlier in the week. Over the past several months, he has experienced fatigue and a $4.5\text{ kg}$ ($10\text{ lb}$) weight loss. His temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $145/85\text{ mm Hg}$, heart rate is $92/\text{min}$, and respiratory rate is $16/\text{min}$. Physical examination reveals bilateral cervical lymphadenopathy. Funduscopic examination shows dilated, tortuous retinal veins with scattered retinal hemorrhages. Neurologic examination shows an oriented but lethargic patient with no focal motor or sensory deficits. Laboratory studies show the following:

Serum protein electrophoresis demonstrates a prominent monoclonal spike in the gamma-globulin region. Quantitative immunoglobulins reveal a markedly elevated IgM level. Which of the following is the most appropriate next step in management?

A 32-year-old woman comes to the clinic due to profound fatigue, generalized weakness, and amenorrhea. She delivered her first child 6 months ago. The delivery was complicated by a severe postpartum hemorrhage that required an emergent transfusion of $4$ units of packed red blood cells. Since the delivery, she has been unable to breastfeed her infant and her menses have not resumed. She reports frequent dizzy spells, especially when standing. Her blood pressure is $90/60 \text{ mm Hg}$ seated and $78/50 \text{ mm Hg}$ upon standing. Her pulse is $64/\text{min}$. Physical examination shows loss of pubic and axillary hair, and a delayed relaxation phase of the deep tendon reflexes.

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

A 52-year-old man is brought to the emergency department by emergency medical services after his daughter found him lethargic and confused in his apartment. The daughter reports that the patient has a history of severe osteoarthritis, major depressive disorder, and alcohol use disorder. He recently lost his job and has been drinking heavily for the past week. His current medications include fluoxetine and several over-the-counter pain relievers. On physical examination, the patient is difficult to arouse but withdraws from painful stimuli. His mucous membranes are dry.

Vital signs are as follows:
Temperature: 37.4°C (99.3°F)
Blood pressure: 105/65 mmHg
Heart rate: 112/min
Respiratory rate: 26/min
Oxygen saturation: 98% on room air

Laboratory studies reveal the following:

Serum chemistry:
Sodium: 142 mEq/L
Potassium: 3.4 mEq/L
Chloride: 106 mEq/L
Bicarbonate: 12 mEq/L
Blood urea nitrogen: 24 mg/dL
Creatinine: 1.2 mg/dL
Glucose: 88 mg/dL

Arterial blood gas (on room air):
pH: 7.44
PaCO $_2$: 18 mmHg
PaO $_2$: 102 mmHg

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

Match each patient's clinical presentation and laboratory profile, obtained during an episode of documented fasting hypoglycemia, to the most accurate pathophysiologic description of the underlying etiology.

A $22$-year-old man with a history of type 1 diabetes mellitus is brought to the emergency department due to lethargy, abdominal pain, and recurrent vomiting for the past $24$ hours. He recently had a viral respiratory tract infection. Vital signs show a temperature of $37.2^{\circ}\text{C}$ ($99.0^{\circ}\text{F}$), blood pressure of $90/60$ mm Hg, pulse of $122$/min, and respirations of $28$/min with deep, sighing breathing. Point-of-care blood glucose is $520$ mg/dL. Intravenous access is established. Arrange the following acute management steps in the most appropriate chronological order.

A 23-year-old man comes to the office to evaluate a progressively enlarging lump on the right side of his neck that he first noticed 6 weeks ago. He also reports drenching night sweats and a 6-kg (13-lb) unintentional weight loss over the past 2 months. His temperature is 37.8°C (100.0°F), blood pressure is 118/76 mm Hg, pulse is 84/min, and respirations are 14/min. Physical examination reveals a 4.5-cm, firm, non-tender, rubbery lymph node in the right supraclavicular region. There is no other cervical, axillary, or inguinal lymphadenopathy. The liver and spleen are not palpable. Complete blood count and comprehensive metabolic panel are within normal limits. Arrange the following steps in the most appropriate chronological order for the evaluation and initial management of this patient's condition.

A 22-year-old woman with a history of type 1 diabetes mellitus presents to the emergency department with a 1-day history of nausea, vomiting, and diffuse abdominal pain. She missed several doses of her insulin because she was not feeling well. Her temperature is $37.2^\circ C$ ($99.0^\circ F$), blood pressure is $105/65$ mmHg, heart rate is $118/min$, and respiratory rate is $26/min$. Physical examination reveals dry mucous membranes and diffuse abdominal tenderness without rebound or guarding.

Which of the following is the expected arterial partial pressure of carbon dioxide ($pCO_2$) if appropriate respiratory compensation has occurred in this patient?

A 68-year-old man presents to the emergency department with progressively worsening shortness of breath over the past 3 days. He has a history of ischemic cardiomyopathy with a reduced ejection fraction and severe chronic obstructive pulmonary disease. The patient reports waking up in the middle of the night gasping for air and has required three pillows to sleep comfortably. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure is $155/90$ mm Hg, pulse is $110$/min, and respirations are $24$/min. Oxygen saturation is $91\%$ on room air. Physical examination reveals an elevated jugular venous pressure, an S3 gallop, and diffuse bilateral crackles at the lung bases. There is 3+ bilateral pitting edema up to the mid-calves. Laboratory testing demonstrates a brain natriuretic peptide (BNP) level of $950$ pg/mL (normal: $<100$ pg/mL). Which of the following is the most appropriate next step in management?

A 72-year-old man is brought to the emergency department by emergency medical services due to severe, progressive shortness of breath over the past 48 hours. He also reports a cough productive of clear sputum and difficulty sleeping unless propped up on three pillows. His medical history is significant for severe chronic obstructive pulmonary disease (COPD), ischemic cardiomyopathy with a left ventricular ejection fraction of 35%, and hypothyroidism. He admits to missing his medications for the past two weeks.

Vital signs are temperature 37.1 °C (98.8 °F), blood pressure 162/94 mm Hg, pulse 115/min, and respirations 28/min. Oxygen saturation is 85% on room air.

Physical examination shows a patient in acute respiratory distress, using accessory muscles of respiration. Jugular venous distention is present up to 10 cm H2O. Lung auscultation reveals diffuse, bilateral expiratory wheezing and scattered crackles at the lung bases. Cardiovascular examination demonstrates a regular tachycardia with a prominent S3 gallop. There is 2+ bilateral lower extremity pitting edema.

Laboratory and diagnostic studies show:
Leukocyte count: 8,200/mm³
Thyroid-stimulating hormone (TSH): 0.3 µU/mL (Normal: 0.5–5.0 µU/mL)
Free T4: 0.8 ng/dL (Normal: 0.9–1.7 ng/dL)
Sputum culture (obtained 3 days ago at an outpatient clinic for a mild cough): heavy growth of *Streptococcus pneumoniae*, susceptible to amoxicillin.

Arterial blood gas analysis on room air:
$pH$: $7.29$
$pCO_2$: $56$ mm Hg
$pO_2$: $52$ mm Hg
$HCO_3^-$: $26$ mEq/L

A portable chest radiograph shows cardiomegaly, bilateral perihilar alveolar opacities, and prominent interlobular septa.

Which of the following is the most appropriate initial step in the management of this patient's respiratory distress?

A $22$-year-old man with type $1$ diabetes mellitus is brought to the emergency department due to nausea, vomiting, and confusion for the past $24$ hours. He has not taken his insulin for $2$ days. Vital signs show blood pressure $90/60$ mm Hg, heart rate $124$/min, and respiratory rate $26$/min with deep, sighing breaths. Laboratory evaluation reveals a serum glucose of $580$ mg/dL, potassium of $4.9$ mEq/L, bicarbonate of $11$ mEq/L, and an arterial pH of $7.18$. Serum ketones are strongly positive. Arrange the following steps in the most appropriate sequence for the acute management and resolution of this patient's condition.

Jugular venous pulse (JVP) analysis provides critical insights into right-sided heart hemodynamics and can distinguish between several life-threatening and chronic cardiovascular pathologies. Match each of the following abnormal JVP waveform findings with the specific clinical condition it most classically represents.

A series of patients present to the primary care clinic for routine health screening and evaluation of liver function. As part of their workup, Hepatitis B serologic testing is performed. Match the following Hepatitis B serologic profiles with their most accurate clinical interpretation.

Match each patient's clinical presentation with the most likely corresponding liver biopsy finding.

A 22-year-old man with type 1 diabetes mellitus is brought to the emergency department due to lethargy, nausea, vomiting, and diffuse abdominal pain for the past 24 hours. He recently had a viral upper respiratory infection. Temperature is 37.2°C (99.0°F), blood pressure is 90/60 mmHg, pulse is 125/min, and respirations are 28/min and deep. Mucous membranes are dry and capillary refill is prolonged. Laboratory studies show:

Urine ketones are strongly positive.

Arrange the following management steps in the correct chronological order of administration for this patient according to standard diabetic ketoacidosis (DKA) protocols.

Match each patient's clinical presentation with the most likely acid-base and electrolyte profile expected on their laboratory evaluation.

A 68-year-old man is evaluated in the intensive care unit for altered mental status and respiratory distress. He was admitted 2 days ago for severe community-acquired pneumonia. He has a history of severe chronic obstructive pulmonary disease (COPD) with a baseline $FEV_1$ of 30% of predicted. Upon admission, he was started on intravenous ceftriaxone and azithromycin. Sputum cultures from admission are currently growing *Streptococcus pneumoniae* susceptible to ceftriaxone, and azithromycin has been discontinued. Over the last 3 hours, he has become increasingly lethargic and confused.

Temperature is 38.6°C (101.5°F), heart rate is 122/min, blood pressure is 84/52 mm Hg, and respiratory rate is 32/min. Oxygen saturation is 89% on 6 L/min via nasal cannula. The patient is diaphoretic with warm extremities. Lung auscultation reveals right lower lobe bronchial breath sounds and diffuse scattered expiratory wheezes. Cardiac examination reveals a regular tachycardia with no murmurs, rubs, or gallops. Jugular venous pressure is normal.

Laboratory results are as follows:
Leukocytes: $18,000/mm^3$
Serum lactate: $6.2$ mmol/L

Arterial blood gas (on 6 L/min $O_2$):
pH: $7.18$
$PaCO_2$: $38$ mm Hg
$PaO_2$: $58$ mm Hg
$HCO_3^-$: $14$ mEq/L

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

A 54-year-old man with decompensated cirrhosis secondary to alcohol use disorder and chronic hepatitis C infection is admitted to the hospital with a 2-day history of increasing confusion and progressive abdominal distension. He has a known history of esophageal varices for which he takes nadolol. Other home medications include spironolactone and lactulose.

On physical examination, temperature is 37.9°C (100.2°F), pulse is 92/min, and blood pressure is 98/60 mmHg. He appears lethargic but arousable, and is oriented to person only. Asterixis is present. The abdomen is markedly distended and non-tender, with shifting dullness and a positive fluid wave. There is 2+ pitting edema of the lower extremities.

A diagnostic paracentesis yields cloudy yellow fluid. Ascitic fluid analysis shows:

The patient is started on intravenous cefotaxime. Which of the following is the most appropriate additional step in the management of this patient?

A 54-year-old woman is brought to the emergency department due to 3 days of fever, worsening abdominal pain, and profound lethargy. She has a history of Crohn's disease and underwent an extensive ileal resection two years ago. For the past week, she has had severe, voluminous watery diarrhea and has been unable to tolerate oral fluids. Her temperature is 38.9°C (102.0°F), blood pressure is 86/50 mm Hg, pulse is 122/min, and respirations are 24/min. Physical examination shows dry mucous membranes, decreased skin turgor, and diffuse abdominal tenderness with guarding.

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