Q&A Medicine>>>>>Pulmonology
Question 14#

A 46-year-old man with a history of ulcerative colitis is admitted to the hospital with abdominal pain and heavy rectal bleeding. Initial laboratory samples are drawn, and his hemoglobin is measured at 6 g/dL. He is given IV methylprednisolone and 2 units of packed red blood cells. Three hours later, the patient complains of shortness of breath and is given supplemental oxygen at an FiO2 of 30%. He appears anxious and is gasping for breath while speaking. There is no jugular venous distention or murmurs on cardiac examination. An arterial blood gas shows a PaO2 of 55 mmHg and a PaCO2 of 36 mmHg. A chest x-ray shows fluffy opacities in both lung fields with a normal cardiac silhouette

What intervention should be performed next?

A. Transfuse more units of packed red blood cells
B. Diuresis with furosemide
C. Intubation and positive end-expiratory pressure (PEEP)
D. Plasmapheresis

Correct Answer is C

Comment:

Intubation and positive end-expiratory pressure (PEEP). A PaO2/FiO2 ratio ≤200 with pulmonary edema that is noncardiogenic – no jugular venous distention or elevated pulmonary capillary wedge pressure (PCWP) – meets criteria for acute respiratory distress syndrome (ARDS). The most common causes of ARDS are pneumonia, sepsis, and aspiration. The pathophysiology involves alveolar and capillary endothelial injury, which causes a strong inflammatory response and leakage of fluid into the lungs. This patient developed ARDS within 6 hours of a transfusion, making the most likely diagnosis transfusion-related acute lung injury (TRALI). Despite the name, TRALI can present with acute lung injury or ARDS. The management of ARDS involves intubation with mechanical ventilation targeting low tidal volumes and increased PEEP to help prop open alveoli for gas exchange.

(A) This patient suffered TRALI and therefore no more transfusions should be given at this time. However, patients that experience one episode of TRALI are not necessarily at an increased risk of TRALI in the future. (B) Hypervolemia can increase fluid leakage from damaged capillaries in the lung during ARDS. This patient is likely hypovolemic due to the heavy blood loss from ulcerative colitis, and therefore diuresis is not a good answer choice. (D) There is no role for plasmapheresis in ARDS or TRALI specifically.