A 64-year-old man is brought to the emergency department due to a 2-day history of progres… — USMLE Step 2 CK

A 64-year-old man is brought to the emergency department due to a 2-day history of progressively worsening shortness of breath and coughing up blood-tinged sputum. His past medical history is significant for chronic rhinosinusitis that has been poorly responsive to multiple courses of antibiotics, and migrating joint pains for the past 6 months. His temperature is $37.6^\circ\text{C}$ ( $99.7^\circ\text{F}$ ), blood pressure is $155/95\text{ mmHg}$ , pulse is $108/\text{min}$ , and respiratory rate is $26/\text{min}$ . Oxygen saturation is 88% on room air. Physical examination reveals a mild collapse of the nasal bridge. Lung auscultation reveals diffuse bilateral crackles. Heart sounds are normal with no murmurs, gallops, or jugular venous distention. There is trace bilateral lower extremity edema. Laboratory results show:

Hemoglobin: $9.2\text{ g/dL}$
Leukocyte count: $14,000/\text{mm}^3$
Platelet count: $410,000/\text{mm}^3$
Blood urea nitrogen: $42\text{ mg/dL}$
Serum creatinine: $2.8\text{ mg/dL}$ (baseline $1.0\text{ mg/dL}$ 6 months ago)
Urinalysis: 2+ protein, large blood, 20-30 red blood cells/hpf, presence of red blood cell casts.

A portable chest radiograph shows bilateral, patchy, diffuse alveolar infiltrates. An electrocardiogram shows normal sinus rhythm. Which of the following is the most appropriate initial step in the management of this patient's acute condition?

A
Intravenous furosemide
B
Computed tomography angiography of the chest
High-dose intravenous methylprednisoloneAnswer
D
Intravenous cyclophosphamide
E
Intravenous ceftriaxone and azithromycin

Answer

The most appropriate initial step is the administration of high-dose intravenous methylprednisolone.

This patient's presentation is classic for Granulomatosis with Polyangiitis (GPA), a small-vessel ANCA-associated vasculitis. The clinical triad includes upper respiratory tract involvement (chronic sinusitis, saddle-nose deformity from cartilage destruction), lower respiratory tract involvement (diffuse alveolar hemorrhage manifesting as hemoptysis, dyspnea, hypoxia, and bilateral infiltrates), and renal involvement (rapidly progressive glomerulonephritis indicated by elevated creatinine and red blood cell casts). When GPA presents as a life-threatening pulmonary-renal syndrome, immediate and aggressive immunosuppression is mandatory. High-dose "pulse" intravenous corticosteroids (e.g., methylprednisolone) are the most critical initial step because they act rapidly to reduce acute inflammation and halt the alveolar hemorrhage. Other immunosuppressive agents, such as cyclophosphamide or rituximab, are subsequently added for remission induction, and plasmapheresis may be utilized in severe cases, but steroids are the most immediate life-saving intervention.

Step-by-Step Solution

Analyze the clinical presentation to identify the unifying diagnosis.

The combination of chronic sinusitis, saddle-nose deformity, diffuse alveolar hemorrhage, and rapidly progressive glomerulonephritis points to Granulomatosis with Polyangiitis (GPA).

GPA is a small-vessel ANCA-associated vasculitis characterized by this classic clinical triad affecting the upper respiratory tract, lower respiratory tract, and kidneys.

Determine the severity and primary threat of the patient's current presentation.

The patient has severe hypoxia, hemoptysis, and acute renal failure, indicating a life-threatening pulmonary-renal syndrome.

Diffuse alveolar hemorrhage is an acute emergency requiring immediate medical intervention to halt the autoimmune destruction and prevent respiratory failure.

Select the most appropriate initial management for this life-threatening vasculitis flare.

High-dose intravenous methylprednisolone is chosen.

Pulse-dose corticosteroids act rapidly to suppress the acute inflammatory cascade, whereas other induction agents (like cyclophosphamide) take too long to exert their full effect in an acute crisis.

Key Concept

Acute management of Granulomatosis with Polyangiitis (GPA) presenting with pulmonary-renal syndrome (diffuse alveolar hemorrhage and rapidly progressive glomerulonephritis).

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