Internal Medicine

A 74-year-old woman presents to the emergency department with a two-day history of a severe, right-sided throbbing headache, jaw pain when chewing, and a recent episode of sudden, painless, temporary loss of vision in her right eye. Laboratory studies show an erythrocyte sedimentation rate of $105 \text{ mm/hr}$ and a C-reactive protein level of $45 \text{ mg/L}$. Arrange the following clinical steps in the most appropriate chronological sequence for the diagnosis and management of this patient's condition.

A $68$-year-old man is evaluated in the intensive care unit on day $6$ of a prolonged admission for severe lobar pneumonia complicated by septic shock. He remains mechanically ventilated and is currently receiving enteral nutrition and low-dose norepinephrine. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure is $105/65$ mm Hg, and pulse is $92$/min. Physical examination shows no goiter or anterior neck masses. A routine metabolic panel obtained this morning is largely unremarkable. Thyroid function tests, which were ordered due to the patient's persistent lethargy during sedation weaning, reveal the following:

Prior to admission, the patient had no history of thyroid disease and was not taking any thyroid-related medications. Which of the following is the most appropriate next step in management regarding his thyroid function?

Match each patient's laboratory profile with the most likely underlying clinical etiology.

Match each classic clinical presentation with its most likely esophageal diagnosis.

A 58-year-old man is evaluated in the hospital on the third day of admission for a catheter-related bloodstream infection. He initially presented to the emergency department with fever, chills, and hypotension during his outpatient hemodialysis session. At admission, blood cultures were drawn, his tunneled hemodialysis catheter was removed, and he was started on empiric intravenous vancomycin and cefepime. His past medical history is notable for end-stage renal disease, hypertension, and type 2 diabetes mellitus. His medical record indicates an allergy to amoxicillin, which caused a diffuse, non-pruritic maculopapular rash 15 years ago. Today, the patient is afebrile and hemodynamically stable. The blood cultures drawn at admission are growing *Staphylococcus aureus*.

Susceptibility testing results are as follows:

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

Connect the following antineoplastic agents with their most characteristic adverse effect that dictates specific clinical monitoring or preventive management.

A 42-year-old man presents to the clinic with a 3-month history of unintended weight loss, palpitations, excessive sweating, and frequent bowel movements. He also reports experiencing new-onset, intermittent frontal headaches over the same period. He has no significant past medical history and takes no medications. Blood pressure is $145/85 \text{ mm Hg}$ and pulse is $110/\text{min}$. Physical examination reveals a mild, diffuse enlargement of the thyroid gland without any palpable nodules. A fine resting tremor is present in both outstretched hands. Visual fields are full to confrontation.

Laboratory results are as follows:
Thyroid-stimulating hormone (TSH): $6.5 \text{ mIU/L}$ (Normal: $0.4 - 4.2 \text{ mIU/L}$)
Free thyroxine (T4): $3.2 \text{ ng/dL}$ (Normal: $0.8 - 1.8 \text{ ng/dL}$)
Free triiodothyronine (T3): $7.1 \text{ pg/mL}$ (Normal: $2.3 - 4.2 \text{ pg/mL}$)

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

A 45-year-old woman with a 15-year history of poorly controlled type 1 diabetes mellitus presents to the outpatient clinic with a three-month history of progressive early satiety, postprandial bloating, and intermittent vomiting of undigested food. Her vital signs are stable. Physical examination reveals a soft, non-tender abdomen with a distinct succussion splash on auscultation. Arrange the following diagnostic and therapeutic steps in the most appropriate chronological sequence for managing this patient's condition.

Hepatitis B virus (HBV) infection can present in various clinical phases, each characterized by a distinct serologic profile. Match each clinical status with its most representative hepatitis B serologic panel.

A 19-year-old man is brought to the emergency department due to abdominal pain, nausea, and vomiting for the past 2 days. He also reports increased thirst and frequent urination over the last week. His temperature is 37.1°C (98.8°F), pulse is 118/min, blood pressure is 90/60 mm Hg, and respirations are 26/min and deep. Mucous membranes are dry. Laboratory studies show:

Arterial blood gas shows a pH of 7.15.

Arrange the following steps in the optimal chronological sequence for the management of this patient's condition.

A 68-year-old man comes to the emergency department due to a 3-day history of worsening shortness of breath, increased cough, and a change in sputum color from clear to yellow-green. He has a history of severe chronic obstructive pulmonary disease (COPD) and ischemic cardiomyopathy with a left ventricular ejection fraction of 35%. His home medications include an albuterol inhaler, tiotropium, lisinopril, and carvedilol.

On presentation, his temperature is $38.0^\circ C$ ($100.4^\circ F$), blood pressure is 138/86 mm Hg, pulse is 98/min, and respirations are 24/min. Pulse oximetry is 92% on room air. Physical examination reveals a barrel chest, prolonged expiratory phase, and diffuse bilateral expiratory wheezes without crackles. Jugular venous pressure is 7 cm $H_2O$. There is trace bilateral lower extremity edema, which the patient states is his baseline.

Laboratory results show:
Leukocyte count: $11,500/mm^3$
B-type natriuretic peptide: 150 pg/mL

Arterial blood gas (room air):
pH: 7.36
$PaCO_2$: 52 mm Hg
$PaO_2$: 64 mm Hg
Calculated $HCO_3^-$: 28 mEq/L

A chest radiograph shows hyperinflated lungs with flattened diaphragms and no focal consolidations or pleural effusions. He is started on supplemental oxygen, nebulized albuterol and ipratropium, and systemic glucocorticoids.

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

A 62-year-old woman is brought to the emergency department with a 24-hour history of severe right upper quadrant abdominal pain, high fever, and confusion. Her blood pressure is 84/52 mmHg, heart rate is 118/min, and temperature is 39.5°C (103.1°F). Physical examination reveals scleral icterus and right upper quadrant guarding. Laboratory studies show a leukocyte count of 22,000/mm³, total bilirubin of 6.1 mg/dL, direct bilirubin of 4.8 mg/dL, and alkaline phosphatase of 510 U/L. Bedside ultrasound demonstrates a dilated common bile duct of 14 mm with echogenic debris and gallstones, but no pericholecystic fluid or gallbladder wall thickening.

Arrange the following clinical interventions in the most appropriate chronological sequence for the optimal management of this patient.

A $28$-year-old male medical resident is evaluated in the occupational health clinic immediately after sustaining a needlestick injury with a hollow-bore needle. The needle was just used to draw blood from a patient. The source patient is known to be positive for hepatitis B surface antigen (HBsAg) and negative for both HIV and hepatitis C virus. The resident is asymptomatic. A review of his employee health records indicates that he completed the standard hepatitis B vaccination series $4$ years ago. Blood is drawn from the resident, and laboratory studies show the following:

Hepatitis B surface antigen (HBsAg): Negative
Hepatitis B surface antibody (Anti-HBs): Positive ($150 \text{ mIU/mL}$)
Hepatitis B core antibody (Anti-HBc): Negative

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

A $65$-year-old man is evaluated in the clinic for severe, progressive fatigue, generalized weakness, and loss of appetite over the past $3$ weeks. He also reports a mild, constant, diffuse headache. The patient has a history of metastatic melanoma and has been receiving combination immunotherapy with nivolumab and ipilimumab for the past $4$ months. Blood pressure is $96/60$ mmHg while supine and $82/50$ mmHg while standing. Heart rate is $92$/min. Physical examination reveals vitiligo over the upper extremities. The thyroid gland is not palpable.

Laboratory studies show the following:

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

A 42-year-old woman comes to the outpatient clinic for evaluation of generalized muscle weakness and fatigue that have progressively worsened over the past three weeks. She also reports a history of recurrent flank pain, and her medical records indicate two previous emergency department visits for "calcium kidney stones." She has a long-standing history of dry eyes and a dry mouth, for which she uses artificial tears daily. She takes no medications other than an oral contraceptive pill. Vital signs are within normal limits. Physical examination reveals dry oral mucosa, bilateral conjunctival injection, and symmetric proximal muscle weakness (4/5 power). Laboratory studies show the following:

Which of the following is the most likely primary pathophysiologic mechanism for this patient's acid-base and electrolyte abnormalities?

A 24-year-old man with type 1 diabetes mellitus is brought to the emergency department by his roommate after a 2-day history of abdominal pain, nausea, vomiting, and profound weakness. The patient admits to missing several doses of his basal insulin due to a recent gastrointestinal illness. He appears lethargic and is using accessory muscles to breathe. Vital signs show a temperature of 37.6°C (99.7°F), blood pressure of 98/62 mm Hg, pulse of 124/min, and respiratory rate of 28/min with shallow breaths. Physical examination reveals dry mucous membranes and diffuse abdominal tenderness without guarding.

Laboratory evaluation shows:

Arterial blood gas analysis on room air:

Based on these findings, which of the following best describes this patient's acid-base status?

A 34-year-old woman presents to the emergency department with a 3-day history of profound fatigue, intermittent confusion, and easy bruising. Her temperature is 38.2°C (100.8°F), pulse is 105/min, and blood pressure is 110/70 mm Hg. Physical examination reveals scleral icterus and scattered petechiae on the lower extremities. Neurological examination reveals mild disorientation to time and place, but no focal motor or sensory deficits. Laboratory testing reveals the following:

A peripheral blood smear demonstrates numerous fragmented red blood cells and a paucity of platelets. Which of the following is the most appropriate next step in management for this patient?

A 52-year-old woman is evaluated in the emergency department for a fever of 38.8°C (101.8°F) and severe chills that began 2 hours ago. She was diagnosed with acute myeloid leukemia 3 weeks ago and is currently undergoing induction chemotherapy. She has an indwelling central venous catheter. Her blood pressure is 105/65 mm Hg, pulse is 110/min, and respirations are 18/min. Physical examination reveals a well-healed catheter site with no erythema or purulent drainage, and the remainder of the examination shows no obvious source of infection. A complete blood count reveals an absolute neutrophil count of 150/mm³. Arrange the following management steps in the most appropriate chronological order for this patient.

A $26$-year-old woman is brought to the emergency department after being found unresponsive. She has a history of type 1 diabetes mellitus. On presentation, she is lethargic and oriented only to person. Temperature is $36.8^\circ\text{C}$ ($98.2^\circ\text{F}$), blood pressure is $90/60\text{ mm Hg}$, heart rate is $135/\text{min}$, and respirations are $40/\text{min}$ and deep.

Initial laboratory and arterial blood gas (on room air) results show:

The patient is started on aggressive intravenous fluid resuscitation and an insulin infusion. One hour later, her respiratory effort diminishes significantly, and she becomes completely unresponsive (Glasgow Coma Scale score of 6). She undergoes rapid sequence intubation with etomidate and rocuronium.

Following intubation, she is placed on volume-assist control mechanical ventilation with the following settings:
- Tidal volume: $450\text{ mL}$ ($6\text{ mL/kg}$ ideal body weight)
- Respiratory rate: $14/\text{min}$
- FiO2: $100\%$
- PEEP: $5\text{ cm H}_2\text{O}$

Twenty minutes later, the ventilator alarms for low blood pressure. The patient's blood pressure has dropped precipitously to $62/40\text{ mm Hg}$, and her heart rate is $148/\text{min}$. A repeat arterial blood gas reveals:

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

A 28-year-old woman, gravida 1, para 0, at 14 weeks gestation presents to the emergency department with a 3-day history of shortness of breath, sharp right-sided chest pain that worsens with deep inspiration, and low-grade fever. She was diagnosed with systemic lupus erythematosus (SLE) 4 years ago and is currently taking hydroxychloroquine. Her temperature is $37.9^\circ \text{C}$ ($100.2^\circ \text{F}$), blood pressure is $122/76 \text{ mm Hg}$, pulse is $112/\text{min}$, and respirations are $24/\text{min}$. Pulse oximetry is $96\%$ on room air.

Physical examination reveals an erythematous rash over the cheeks and nasal bridge, as well as swelling, erythema, and tenderness in the metacarpophalangeal joints bilaterally. Lung auscultation reveals decreased breath sounds and dullness to percussion at the right lung base. Jugular venous pressure is $6 \text{ cm H}_2\text{O}$.

Laboratory studies show:
- Leukocytes: $4,200/\text{mm}^3$
- Hemoglobin: $10.5 \text{ g/dL}$
- Platelets: $130,000/\text{mm}^3$
- Creatinine: $0.7 \text{ mg/dL}$
- Urinalysis: Normal

A chest radiograph with abdominal shielding shows a small right-sided pleural effusion without focal airspace opacities. A ventilation-perfusion scan indicates a low probability of pulmonary embolism. An echocardiogram shows normal ventricular function and no pericardial effusion.

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