Re-expansion Pulmonary Edema

History of present illness: A 95-year-old male with history of atrial fibrillation presented to the emergency department for shortness of breath for one week. A chest X-ray showed a large right-sided pleural effusion. Given the unknown etiology of the effusion, and the patient’s dyspnea, a thoracentesis was performed. Under ultrasound guidance, 2.9 liters of cloudy yellow fluid was removed. The patient tolerated the procedure well and a post procedural chest X-ray was performed, which is noted below. A few hours later, the patient became tachypneic and oxygenation saturation dropped from 100% to 91%-92% on room air, and was found to have decreased breath sounds on the right. An additional chest X-ray was performed which showed pulmonary re-expansion edema and patient was subsequently admitted for observation. Significant findings: Initial chest X-ray (chest X-ray 1) showed a right-sided pleural effusion with compressive atelectasis of the mid to lower right lung. Repeat chest X-ray immediately after evacuation (chest X-ray 2) shows improvement of the pleural effusion and a new trace apical right pneumothorax measuring 6.7 mm. When the patient became tachypneic, a third X-ray (chest X-ray 3) showed persistent trace apical right pneumothorax measuring 6.7 mm. Discussion: Re-expansion pulmonary edema (RPE) is a rare complication that can occur following thoracentesis of a pleural effusion or chest tube drainage of pneumothorax, and is a potentially fatal complication due to the resulting abrupt reduction in pleural pressure.1,2 RPE pathophysiology is not fully understood; however, risk factors include presence of pleural effusion in conjunction with pneumothorax, young patients (