Re-expansion pulmonary edema after routine use of cardiopulmonary bypass in cardiac surgery: Case report.

Background: Re-expansion pulmonary edema (REPE) is traditionally associated with the resolution of pneumothorax or pleural effusion. Its occurrence after routine cardiopulmonary bypass (CPB) in cardiac surgery is rare. The incidence of REPE after treatment of pneumothorax or pleural effusion is less than 1%, but it carries a mortality rate of up to 20%. Case Presentation: We present a case of REPE in a 64-year-old male undergoing elective coronary artery bypass grafting. Despite an uneventful surgery and standard perioperative management, the patient developed REPE, manifested with increased airway pressures, blood-tinged secretions, and compromised oxygenation post-CPB. Immediate intervention comprising mechanical ventilation adjustments, diuretics, and vasopressor support was initiated to facilitate recovery. The pulmonary edema resolved within 24 hours after the surgery, and the patient was transferred to the surgical high-dependency unit (HDU) on the third postoperative day. Discussion: This case reports a rare occurrence of REPE following routine CPB and highlights the multifactorial pathogenesis involving reperfusion injury and altered pulmonary physiology. Possible mechanisms include reperfusion injury from free radicals, cytokine release, and increased vascular permeability. The management of REPE requires prompt recognition and treatment and involves diuretics, ventilatory adjustments, and hemodynamic monitoring. Conclusion: REPE, though rare post-CPB, requires a high index of suspicion and prompt management to prevent adverse outcomes.