Prevention of Reexpansion Pulmonary Edema and Ischemia-Reperfusion Injury in the Management of Diaphragmatic Herniation

Abstract

Before the 1980s, the veterinary literature reported a guarded prognosis for traumatic diaphragmatic herniation (TDH) in dogs and cats. In recent years, a better understanding of the pathophysiology of this condition has led to changes in the perioperative management of patients with TDH as well as significant improvements in patient outcome. Reexpansion pulmonary edema (RPE) and ischemia-reperfusion (IR) injury are now recognized as potentially fatal complications of surgical correction of TDH. Potentially fatal RPE appears to be a greater risk in patients with chronic lung collapse, and cats are affected more often than dogs. To prevent RPE, no attempt should be made to fully or rapidly reinflate collapsed lung lobes during surgery to minimize barotrauma. IR injury can occur when blood flow returns to previously strangulated and ischemic organs and may play a role in the development of RPE. Resection of ischemic tissue before reperfusion prevents metabolites of anaerobic metabolism from initiating a cascade of cellular injury and may be valuable in certain cases of abdominal organ entrapment occurring with diaphragmatic herniation. Research continues into effective strategies and medical therapies for prevention of RPE and IR injury.