Internal Medicine

A 45-year-old woman is brought to the emergency department by her husband due to progressive lethargy over the past 12 hours. The patient has a history of Crohn disease and has been experiencing severe, watery diarrhea for the past five days. Yesterday, she took multiple doses of a friend's prescription oxycodone to help manage her severe abdominal cramping. On physical examination, her temperature is 37.1°C (98.8°F), blood pressure is 105/65 mmHg, heart rate is 110/min, and respiratory rate is 8/min. She is somnolent but arouses to verbal stimuli. Mucous membranes are dry.

Laboratory studies show the following:

Based on the provided laboratory data, which of the following best characterizes this patient's acid-base status?

A $28$-year-old man is brought to the emergency department with a $4$-day history of progressively worsening right-sided abdominal pain, nausea, and multiple episodes of bilious vomiting. He reports an inability to pass flatus or stool for the past $24$ hours. The patient was diagnosed with Crohn's disease $6$ years ago, which had been previously well-controlled on adalimumab. However, he discontinued all medications $1$ year ago due to a loss of insurance coverage.

Vital signs show a temperature of $38.6^\circ\text{C}$ ($101.5^\circ\text{F}$), heart rate of $118/\text{min}$, blood pressure of $105/65\text{ mm Hg}$, and respiratory rate of $18/\text{min}$. Physical examination reveals dry mucous membranes. The abdomen is moderately distended with high-pitched, tinkling bowel sounds. There is marked tenderness and a palpable, tender fullness in the right lower quadrant. No diffuse rebound tenderness or abdominal rigidity is appreciated.

Laboratory studies show:
Leukocyte count: $16,500/\text{mm}^3$ (with $85\%$ neutrophils)
Hemoglobin: $11.2\text{ g/dL}$
Platelets: $450,000/\text{mm}^3$
C-reactive protein: $145\text{ mg/L}$ (Normal: $<5\text{ mg/L}$)
Lactate: $1.4\text{ mmol/L}$ (Normal: $0.5 - 2.2\text{ mmol/L}$)

Computed tomography (CT) of the abdomen and pelvis with intravenous contrast reveals dilated loops of small bowel measuring up to $4.5\text{ cm}$ in diameter. A distinct transition point is seen in the terminal ileum, which exhibits severe transmural wall thickening and mucosal hyperenhancement. Immediately adjacent to this strictured segment, there is a $5.5\text{ cm}$ well-circumscribed, rim-enhancing fluid collection containing several small locules of gas. There is no evidence of free intraperitoneal air.

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

A 62-year-old man presents to the emergency department with a 3-day history of progressive exertional dyspnea, chest tightness, and a near-syncopal episode while climbing stairs. He has a 40-pack-year smoking history and does not take any daily medications. His temperature is 37.1°C (98.8°F), blood pressure is 112/68 mmHg, pulse is 88/min, and respirations are 20/min. Pulse oximetry shows 95% on room air. Pulmonary auscultation reveals mild, bilateral end-expiratory wheezing. Cardiac examination demonstrates a prominent apical impulse and a grade 3/6 harsh systolic crescendo-decrescendo murmur heard best at the left lower sternal border. An electrocardiogram shows left ventricular hypertrophy and deep, narrow Q waves in leads I, aVL, V5, and V6. Suspecting an acute exacerbation of chronic obstructive pulmonary disease and possible cardiac ischemia, the physician administers nebulized albuterol and sublingual nitroglycerin. Twenty minutes later, the patient becomes lightheaded and lethargic. His blood pressure drops to 76/42 mmHg, and his heart rate increases to 128/min. Cardiac auscultation now reveals a significantly louder and longer systolic murmur. Which of the following is the most appropriate next step in the management of this patient's acute deterioration?

A 78-year-old woman is evaluated for sudden-onset severe shortness of breath. She was admitted to the hospital two days ago for symptomatic anemia secondary to a bleeding duodenal ulcer, which was successfully treated with endoscopic clipping. Two hours ago, she completed a transfusion of two units of packed red blood cells. She has a medical history of hypertension and chronic kidney disease. Her temperature is $37.1^\circ \text{C}$ ($98.8^\circ \text{F}$), blood pressure is $182/98\text{ mm Hg}$, pulse is $112/\text{min}$, and respiratory rate is $28/\text{min}$. Pulse oximetry shows an oxygen saturation of $86\%$ on room air. Physical examination reveals elevated jugular venous pressure and a prominent $S_3$ gallop. Pulmonary auscultation reveals bilateral crackles extending to the mid-lung fields.

Relevant laboratory results are shown below:

Arterial blood gas analysis on room air shows:

A portable chest radiograph demonstrates bilateral perihilar alveolar opacities and an enlarged cardiac silhouette.

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

Emergency medical services bring a 70-year-old female resident of an assisted living facility to the acute care unit with acute-onset lethargy and severe shivering. The patient's caregivers noted she was complaining of right-sided abdominal pain earlier in the day. Vital signs on arrival are: temperature 39.6°C (103.3°F), heart rate 128/min, respirations 22/min, and blood pressure 82/46 mm Hg. The patient is stuporous. Abdominal palpation elicits grimacing when the right subcostal region is pressed. Her skin and mucous membranes appear visibly jaundiced. Initial point-of-care testing reveals a marked leukocytosis of 22,000/mm³ and severe hyperbilirubinemia with a predominant conjugated fraction.

Arrange the following clinical interventions in the correct chronological order for managing this patient's condition.

A 68-year-old man presents to the clinic with a 3-month history of difficulty swallowing. Initially, he had trouble only with solid foods such as meat and bread, but recently he has also developed difficulty swallowing liquids. He reports an unintentional weight loss of 9 kg (20 lb) over this period. Medical history is significant for gastroesophageal reflux disease (GERD) and hypertension. He has a 40-pack-year smoking history. Vital signs are within normal limits. Physical examination reveals temporal wasting but is otherwise unremarkable.

Arrange the following steps in the most appropriate sequential order for the diagnostic evaluation, staging, and management of this patient's condition.

A 38-year-old woman comes to the office due to a 4-month history of worsening fatigue, generalized weakness, and a $5$-kg ($11$-lb) weight gain. She reports that her menstrual periods ceased 6 months ago; previously, her cycles were regular. She also complains of occasional dull, non-throbbing headaches. Her medical history is unremarkable, and she takes no medications. Vital signs show a temperature of $36.4^\circ$ C ($97.5^\circ$ F), blood pressure of $105/65$ mm Hg, and pulse of $56$/min. Physical examination reveals delayed relaxation of deep tendon reflexes, and pale, dry skin. There is no goiter. Visual fields are full to confrontation. A urine pregnancy test is negative.

Laboratory results show:

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

A 34-year-old woman, G1P0, at 30 weeks gestation is brought to the emergency department due to the sudden onset of severe shortness of breath, orthopnea, and a cough productive of pink, frothy sputum. She recently emigrated from Southeast Asia and has not received routine prenatal care. Her vital signs are temperature 37.0°C (98.6°F), blood pressure 105/65 mm Hg, heart rate 138/min and irregularly irregular, and respiratory rate 32/min. Pulse oximetry shows 87% on room air.

Physical examination reveals a distressed woman using accessory muscles of respiration. Lung auscultation demonstrates diffuse bilateral crackles extending to the apices and prominent expiratory wheezes. Cardiac auscultation reveals a loud $S_1$, a high-frequency sound shortly after $S_2$, and a low-pitched, rumbling mid-diastolic murmur heard best at the cardiac apex.

Laboratory results show:
Hemoglobin: 10.8 g/dL
Leukocyte count: 8,500/mm $^3$

Arterial blood gas on room air:
pH: 7.51
$PaCO_2$: 26 mm Hg
$PaO_2$: 54 mm Hg
$HCO_3^-$: 20 mEq/L

Which of the following is the most important primary pathophysiologic mechanism precipitating this patient's acute respiratory failure?

A 42-year-old woman is admitted to the hospital with a 1-day history of severe, unrelenting epigastric pain that radiates to her back. She also reports nausea and multiple episodes of nonbilious vomiting. Her temperature is 37.8°C (100°F), blood pressure is 110/70 mm Hg, pulse is 112/min, and respirations are 18/min. Physical examination shows marked epigastric tenderness with guarding but no rebound tenderness. Bowel sounds are decreased. Laboratory studies show:

Right upper quadrant ultrasound shows a distended gallbladder with multiple small echogenic foci and posterior acoustic shadowing. The common bile duct measures 4 mm in diameter, and no choledocholithiasis is visualized. Which of the following is the most appropriate next step in management?

Paramedics rush a 58-year-old man to the resuscitation bay after he experienced a sudden, agonizing, 'tearing' chest pain that radiated directly to his interscapular region. The patient is visibly distressed, diaphoretic, and clutching his chest. His spouse reports that he has a long history of medication nonadherence for hypertension. Initial vital signs reveal a temperature of 37.2°C (99.0°F), a right arm blood pressure of 220/125 mm Hg, a left arm blood pressure of 180/100 mm Hg, a heart rate of 124/min, and a respiratory rate of 24/min. Cardiac auscultation identifies a loud, early diastolic decrescendo murmur best heard at the right second intercostal space. A bedside portable chest radiograph displays significant widening of the superior mediastinum. Large-bore intravenous access is immediately established. Arrange the following critical interventions in the exact sequential order required for the optimal management of this patient, from immediate initial stabilization to definitive treatment.

During morning rounds, the internal medicine team evaluates a 58-year-old man who was admitted three days ago for management of tense ascites. He has a known history of alcohol-associated cirrhosis. On admission, he underwent a 7-liter therapeutic paracentesis.

Current vital signs include a blood pressure of 96/60 mm Hg, heart rate of 92/min, and temperature of 36.9°C (98.4°F).

Over the past 24 hours, his urine output has decreased to 320 mL. Laboratory studies show a progressive rise in serum creatinine from 1.1 mg/dL on admission to 2.8 mg/dL today. Blood urea nitrogen is 48 mg/dL. Urinalysis reveals no red blood cells, white blood cells, or cellular casts. The spot urinary sodium concentration is $< 10$ mEq/L.

Following these results, diuretic therapy was discontinued, and the patient received a 48-hour volume expansion challenge with intravenous albumin. However, a repeat serum creatinine this morning remains elevated at 2.9 mg/dL. A renal ultrasound demonstrates normal kidney size with no evidence of hydronephrosis.

Which of the following is the most appropriate next step in the pharmacologic management of this patient's acute kidney injury?

A 22-year-old woman is brought to the emergency department due to progressive confusion, nausea, and severe abdominal pain over the past 24 hours. She was diagnosed with type 1 diabetes mellitus during childhood. Vital signs show a blood pressure of 90/60 mm Hg, pulse of 124/min, and deep, rapid respirations at 26/min. Laboratory evaluation reveals a serum glucose of 560 mg/dL, arterial pH of 7.12, serum bicarbonate of 10 mEq/L, and significantly elevated serum ketones. Arrange the following interventions in the most appropriate chronological order for the acute management of this patient's condition.

Match each complication of decompensated cirrhosis to its most appropriate initial pharmacological or procedural management.

A 68-year-old man presents to a rural clinic with severe substernal chest pain. He is diagnosed with an acute ST-segment elevation myocardial infarction (STEMI). Due to limited resources and transport delays, definitive revascularization is significantly delayed, allowing the infarction to follow its natural clinical course. Arrange the following electrocardiographic (ECG) changes in the typical chronological order in which they appear during the evolution of an untreated acute transmural myocardial infarction.

A 57-year-old woman is admitted to the hospital due to a two-day history of diffuse abdominal pain, generalized weakness, and subjective fevers. Her past medical history is significant for alcohol-associated cirrhosis and esophageal varices. On physical examination, her temperature is 38.3°C (100.9°F), blood pressure is 105/65 mmHg, and heart rate is 102/min. Her abdomen is distended, tense, and diffusely tender to palpation, with shifting dullness present. Due to initial hypotension and concern for sepsis, she was empirically started on broad-spectrum coverage with intravenous piperacillin-tazobactam and daptomycin in the emergency department. A diagnostic paracentesis was also promptly performed, yielding cloudy fluid with an absolute neutrophil count of $750/mm^3$. It is now hospital day 3. The patient's fever has resolved and her abdominal pain has significantly improved. The ascitic fluid culture from admission now grows *Klebsiella pneumoniae*. Antimicrobial susceptibility testing indicates that the isolate is sensitive to ceftriaxone, cefepime, piperacillin-tazobactam, and meropenem. Which of the following is the most appropriate management of this patient's pharmacotherapy?

An endocrine evaluation is requested for a female patient aged $62$ who has been experiencing progressive, deep skeletal aching and difficulty rising from a seated position over the last half-year. Five years prior, the patient underwent bariatric surgery (Roux-en-Y bypass) to manage severe obesity, resulting in a weight loss of $45$ kg ($99$ lb). She admits to poor adherence with her prescribed postoperative vitamin regimen. Physical examination demonstrates a distinct waddling gait and marked tenderness upon palpation of the sternum, ribs, and anterior tibia. Proximal muscle strength is symmetrically reduced in the bilateral lower extremities.

Initial laboratory investigations reveal the following results:

Based on the patient's clinical presentation and laboratory findings, which of the following describes the most probable underlying histologic abnormality in this patient's skeletal system?

A 45-year-old man with a history of alcohol use disorder is admitted to the hospital with acute-onset, severe epigastric pain radiating to his back. His serum lipase is markedly elevated at $4,500 \text{ U/L}$. Over the next four weeks, his hospital course is complicated by the development of infected necrotizing pancreatitis. Based on the current standard of care and the evidence-based 'step-up approach' for necrotizing pancreatitis, arrange the following interventions in the most appropriate chronological sequence from his initial presentation to his definitive management.

A $68$-year-old male is evaluated in the intensive care unit for abrupt-onset severe respiratory distress and hypotension. Four days ago, he was admitted with an acute ST-segment elevation myocardial infarction involving the inferior leads; he subsequently received a drug-eluting stent to the right coronary artery. His medical history includes hypertension and a $40$-pack-year smoking habit. Vital signs are temperature $36.9^\circ\text{C}$ ($98.4^\circ\text{F}$), blood pressure $82/54\text{ mm Hg}$, heart rate $118\text{/min}$, and respirations $28\text{/min}$. Oxygen saturation is $84\%$ on a non-rebreather mask. Physical examination reveals cool, diaphoretic extremities and elevated jugular venous pressure. Auscultation of the chest demonstrates bilateral crackles extending halfway up the lung fields with scattered expiratory wheezes. A new, loud holosystolic murmur is heard best at the cardiac apex with radiation to the left axilla. Which of the following is the most likely cause of this patient's current clinical deterioration?

An $68$-year-old man is evaluated in the intensive care unit on hospital day $5$. He was originally admitted for severe sepsis secondary to a complicated intra-abdominal infection and underwent an emergency exploratory laparotomy. He remains on mechanical ventilation but his vasopressor requirements have resolved over the past $24$ hours. The medical team notes that he exhibits generalized edema and remains profoundly lethargic when sedation is paused. To evaluate his metabolic state, a thyroid panel is obtained, which reveals:

Thyroid-stimulating hormone (TSH): $0.2\text{ \mu U/mL}$ (Normal: $0.4-4.0\text{ \mu U/mL}$)
Free thyroxine (T4): $1.0\text{ ng/dL}$ (Normal: $0.8-2.7\text{ ng/dL}$)
Total triiodothyronine (T3): $45\text{ ng/dL}$ (Normal: $70-204\text{ ng/dL}$)

Which of the following is the most appropriate action regarding this patient's thyroid laboratory findings?

A 71-year-old man presents to the emergency department with rapidly worsening respiratory failure secondary to severe bilateral pneumonia. Despite a trial of non-invasive ventilation, his oxygenation continues to decline, and the decision is made to secure his airway. Arrange the following steps of rapid sequence intubation (RSI) in the correct chronological order.