Internal Medicine

A 60-year-old man suddenly collapses while walking in the hospital lobby. He is found to be unresponsive, pulseless, and apneic. Bystanders immediately begin high-quality chest compressions. An automated external defibrillator (AED) is attached, and the rhythm monitor displays ventricular fibrillation. Arrange the following subsequent interventions in the correct chronological order according to standard Advanced Cardiovascular Life Support (ACLS) guidelines.

Match the following sets of laboratory profiles to the most likely underlying pathophysiologic diagnosis. Assume all patients have normal renal function (serum creatinine 0.7-1.0 mg/dL). Reference ranges: Serum calcium 8.4-10.2 mg/dL; Serum phosphate 2.7-4.5 mg/dL; Intact PTH 10-65 pg/mL; 24-hr urine calcium 100-300 mg.

A series of patients undergo diagnostic paracentesis for newly developed or worsening ascites. Based on the provided laboratory and clinical findings, match each patient's ascitic fluid profile with the most accurate underlying pathophysiologic mechanism and diagnosis.

An otherwise healthy 29-year-old fitness instructor presents for medical evaluation due to a one-month history of a racing heart, heat intolerance, and shakiness. She notes that she has been taking multiple non-prescription nutritional supplements to accelerate fat loss for an upcoming bodybuilding competition. Vital signs demonstrate a blood pressure of 135/75 mm Hg and a heart rate of 112/min. Physical examination reveals a fine tremor in her outstretched hands, hyperreflexia, and warm, moist skin. There is no exophthalmos, and her thyroid gland is nonpalpable.

Laboratory studies show the following:

Which of the following is the most likely diagnosis?

A 52-year-old man is brought to the emergency department by ambulance after being found obtunded in his garage. His medical history is significant for major depressive disorder and alcohol use disorder. He is unresponsive to verbal stimuli but localizes to pain. Vital signs are within normal limits except for a respiratory rate of $24/\text{min}$. Laboratory evaluation reveals the following:

Arterial blood gas on room air shows a pH of $7.22$, $PCO_2$ of $26 \text{ mm Hg}$, and $PO_2$ of $92 \text{ mm Hg}$.

Based on these laboratory results, what is the patient's calculated serum osmolar gap?

A 66-year-old man presents to the emergency department with the sudden onset of severe, tearing chest pain that radiates to his back. He appears diaphoretic and in severe distress. Blood pressure is 188/112 mm Hg in the right arm and 156/94 mm Hg in the left arm. Pulse is 112/min and bounding. Cardiac auscultation reveals a new decrescendo diastolic murmur at the right upper sternal border. An electrocardiogram shows sinus tachycardia with no ST-segment or T-wave changes. Suspecting an acute aortic syndrome, the physician prepares to manage the patient.

Arrange the following next steps in the most appropriate chronological order for the initial stabilization and management of this patient.

A 55-year-old male with long-standing hepatic cirrhosis presents to the emergency department via ambulance due to a large episode of hematemesis. On arrival, his blood pressure is 88/50 mm Hg and pulse is 120/min. The physical examination reveals a distended abdomen with shifting dullness and prominent cutaneous telangiectasias. Arrange the following interventions in the correct chronological sequence for the management of this patient.

Emergency medical services bring a 65-year-old male to the resuscitation bay following the sudden onset of profound shortness of breath and altered mentation. The patient's wife states these symptoms began abruptly one hour ago while he was watching television. His medical history is notable for severe chronic obstructive pulmonary disease (COPD) managed with home oxygen therapy. Four days ago, he suffered an inferior ST-segment elevation myocardial infarction and was treated with percutaneous coronary intervention of the right coronary artery.

On physical examination, the patient is obtunded, diaphoretic, and using accessory muscles of respiration. Jugular venous pulsations are visible up to 11 cm $\text{H}_2\text{O}$. Auscultation of the chest reveals widespread coarse crackles and prolonged expiratory wheezing. Cardiac auscultation is significant for a hyperdynamic precordium and a new, loud, grade 4/6 holosystolic murmur heard loudest at the apex that radiates to the left axilla.

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

A 68-year-old man presents to the clinic with a 4-month history of progressive dysphagia to both solid foods and liquids. He reports frequent episodes of regurgitating undigested, bland-tasting food shortly after meals and occasionally wakes up coughing at night. He has experienced an unintentional weight loss of 13 kg (28.6 lb) during this period. Medical history is significant for hypertension and a 45-pack-year smoking history. Vital signs are within normal limits. Physical examination reveals temporal wasting but is otherwise unremarkable. A barium esophagram demonstrates significant dilation of the proximal and mid-esophagus with a smooth, tapering 'bird's beak' appearance at the lower esophageal sphincter. Esophageal manometry shows aperistalsis of the esophageal body and absent relaxation of the lower esophageal sphincter. Upper gastrointestinal endoscopy reveals a normal-appearing esophageal mucosa; however, the endoscopist encounters firm resistance at the esophagogastric junction, and the endoscope cannot be advanced into the stomach despite gentle pressure. Which of the following is the most appropriate next step in management?

A 62-year-old woman comes to the urgent care clinic complaining of worsening shortness of breath over the last 2 days. She has a 40-pack-year smoking history and was diagnosed with chronic obstructive pulmonary disease (COPD) 5 years ago. She uses a daily fluticasone/salmeterol inhaler and a tiotropium inhaler. Her home oxygen saturation is usually 93% on room air. Over the past 48 hours, she has noticed increased cough and a larger volume of sputum, which remains clear to white. She has had no fever, orthopnea, or lower extremity edema. Temperature is 37.0°C (98.6°F), blood pressure is 134/82 mm Hg, pulse is 96/min, and respirations are 22/min. Pulse oximetry is 91% on room air. Pulmonary examination shows a prolonged expiratory phase with scattered wheezes bilaterally. Cardiovascular examination is normal with no murmurs, gallops, or jugular venous distention. There is no peripheral edema. Which of the following is the most appropriate next step in management?

Emergency medical services bring a 69-year-old retired teacher to the resuscitation bay due to three days of worsening respiratory distress. She reports an increase in sputum production that has become dark yellow. Her medical history is significant for hypertension, diet-controlled type 2 diabetes, and a 45-pack-year smoking history.

On physical examination, she is alert and cooperative but visibly exhausted, sitting on the edge of the stretcher and leaning forward on her arms. Temperature is $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$), pulse is $112/\text{min}$, respirations are $28/\text{min}$, and blood pressure is $155/88\text{ mm Hg}$. Pulse oximetry shows an oxygen saturation of $85\%$ on room air. Jugular venous pulsation is visible $4\text{ cm}$ above the sternal angle. Chest auscultation reveals a prolonged expiratory phase with diffuse polyphonic wheezes and faint basilar crackles. Mild bilateral pitting edema is present at the ankles.

An electrocardiogram shows sinus tachycardia with right axis deviation and peaked P waves in lead II. A chest radiograph demonstrates hyperinflated lung fields, flattened hemidiaphragms, and enlarged central pulmonary arteries without focal consolidation.

Relevant laboratory results are as follows:

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

A $38$-year-old man is brought to the emergency department by emergency medical services after his roommate found him unresponsive. The roommate reports that the patient was severely depressed about a recent job loss and had been drinking a large amount of homemade, illicitly distilled liquor (moonshine). On arrival, the patient is difficult to arouse. His temperature is $36.5^\circ\text{C}$ ($97.7^\circ\text{F}$), blood pressure is $105/65$ mm Hg, pulse is $92$/min, and respiratory rate is $8$/min.

Laboratory results are as follows:
Sodium: $142$ mEq/L
Potassium: $4.8$ mEq/L
Chloride: $102$ mEq/L
Bicarbonate: $12$ mEq/L

Arterial blood gas analysis on room air reveals:
pH: $7.12$
$\text{PaO}_2$: $65$ mm Hg
$\text{PaCO}_2$: $38$ mm Hg

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

A 60-year-old man visits his primary care physician because of progressive fatigue, constipation, and an unintended weight gain of $5 \text{ kg}$ ($11 \text{ lbs}$) over the past eight months. He says he constantly feels cold, even when his house is well heated, and reports a recently decreased libido. He has no significant past medical history and takes no medications. Vital signs show a temperature of $36.2^\circ\text{C}$ ($97.2^\circ\text{F}$), blood pressure of $112/74 \text{ mmHg}$, and a heart rate of $54/\text{min}$. Physical examination reveals dry, coarse skin and a noticeable delay in the relaxation phase of the Achilles tendon reflexes. Laboratory studies show:

Thyroid-stimulating hormone (TSH): $0.2 \text{ } \mu\text{U/mL}$ (Normal: $0.5 - 5.0 \text{ } \mu\text{U/mL}$)
Free thyroxine (T4): $0.6 \text{ ng/dL}$ (Normal: $0.9 - 1.7 \text{ ng/dL}$)

Which of the following is the most likely mechanism underlying this patient's laboratory findings?

During a joint endocrinology and nephrology conference, participants are reviewing the diagnostic interpretation of polyuria. They are analyzing specific physiological responses to a carefully monitored water deprivation test, followed by the administration of exogenous subcutaneous desmopressin. Match each patient's physiological response pattern with the most accurate underlying diagnosis.

A 39-year-old man is evaluated in the hospital for the sudden onset of fever and progressive shortness of breath. He was admitted 11 days ago with a diagnosis of acute promyelocytic leukemia and was subsequently started on induction therapy with all-trans retinoic acid and arsenic trioxide. Over the past 24 hours, he has gained 4.5 kg (9.9 lb) and developed a persistent cough. His temperature is 38.8°C (101.8°F), blood pressure is 105/65 mm Hg, pulse is 114/min, and respirations are 26/min. Pulse oximetry shows 87% on room air. Physical examination reveals jugular venous distention and bilateral crackles at the lung bases. Laboratory studies show a leukocyte count of 28,000/mm³ (up from 3,200/mm³ at admission), a hemoglobin of 8.2 g/dL, and a platelet count of 45,000/mm³. A chest radiograph demonstrates bilateral interstitial opacities and moderate pleural effusions. He is currently receiving prophylactic fluconazole and acyclovir. Which of the following is the most appropriate next step in management?

An unresponsive 58-year-old man is brought to the emergency department by paramedics. His partner reports that the patient missed his last two scheduled hemodialysis sessions due to severe winter weather and transportation issues. Over the past 12 hours, he became progressively short of breath before losing consciousness. On arrival, he is in severe respiratory distress. His temperature is 36.8°C (98.2°F), blood pressure is 185/110 mmHg, pulse is 112/min, and respirations are 28/min and labored. Physical examination reveals prominent jugular venous distention and diffuse coarse crackles throughout both lung fields.

Laboratory evaluation reveals the following:

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

A 42-year-old parous female presents to the emergency department complaining of steady, severe pain in her right upper abdomen that radiates to her right scapula. The pain began 6 hours ago after she consumed a large, fatty meal. She reports nausea and two episodes of vomiting. Her temperature is 38.2°C (100.8°F), blood pressure is 130/80 mm Hg, and pulse is 98/min. Physical examination reveals focal tenderness with inspiratory arrest upon deep palpation of the right upper quadrant. Laboratory studies show a leukocyte count of 14,000/mm³ with a left shift, but normal liver chemistries and pancreatic enzymes.

Arrange the following management steps in the most appropriate sequential order for this patient.

A 72-year-old woman is brought to the emergency department due to severe, acute-onset shortness of breath. She has a history of essential hypertension, type 2 diabetes mellitus, severe obesity (BMI $44 \text{ kg/m}^2$), and a 40-pack-year smoking history.

On arrival, her blood pressure is $182/105 \text{ mmHg}$, heart rate is $115\text{/min}$, and respiratory rate is $28\text{/min}$. Oxygen saturation is $86\%$ on room air.

Physical examination shows a patient in severe respiratory distress, using accessory muscles. Lung auscultation reveals diffuse expiratory wheezing with a markedly prolonged expiratory phase. No crackles are auscultated. Heart sounds are distant; no gallops are appreciated. Jugular venous pressure cannot be assessed due to body habitus.

Laboratory studies show a B-type natriuretic peptide (BNP) level of $210 \text{ pg/mL}$ (normal $<100 \text{ pg/mL}$).

Arterial blood gas analysis on room air shows:

A chest radiograph demonstrates hyperinflated lung fields, cardiomegaly, and prominent upper lobe vessels, without distinct alveolar infiltrates.

The patient receives sublingual nitroglycerin and intravenous furosemide, which leads to a dramatic resolution of her wheezing and dyspnea within one hour.

Which of the following best explains the relatively modest elevation of the B-type natriuretic peptide level in this patient despite the severity of her acute presentation?

A 68-year-old man is evaluated in the intensive care unit for sudden-onset severe respiratory distress that began 30 minutes ago. He was admitted two days ago for a large anterior ST-elevation myocardial infarction. His medical history includes hypertension and severe chronic obstructive pulmonary disease (COPD). The patient is sitting upright on the edge of the bed, visibly diaphoretic, and using accessory muscles of respiration. Vital signs are temperature $37.1^\circ C$ ($98.8^\circ F$), blood pressure $165/95$ mm Hg, pulse $118$/min, and respirations $30$/min. Pulse oximetry shows an oxygen saturation of $84\%$ on room air. Physical examination reveals distended neck veins, a third heart sound (S3), and diffuse bilateral crackles on lung auscultation. An arterial blood gas on room air shows:

Which of the following are the most appropriate immediate medical interventions for this patient's acute respiratory failure? (Select all that apply)

A 72-year-old man is evaluated in the emergency department for severe, worsening shortness of breath that began two days ago. He reports waking up in the middle of the night gasping for air. His medical history includes ischemic heart disease, hypertension, and a 40-pack-year smoking history. Vital signs show a temperature of 37.1°C (98.8°F), blood pressure of 165/95 mmHg, pulse of 108/min, and respiratory rate of 24/min. Pulse oximetry is 90% on room air. The physician suspects acute decompensated heart failure rather than a chronic obstructive pulmonary disease exacerbation. Which of the following physical examination findings is most specific for confirming a cardiac etiology for this patient's dyspnea?