Etiology of acute pulmonary edema during liver transplantation

Study objectives: To describe the clinical features of a group of patients who acutely developed pulmonary edema during orthotopic liver transplantation and to determine the nature (transudate vs exudate) of the edema. Design: Retrospective review of clinical records and radiographic studies. Setting: Operating room and ICU of a tertiary-care medical center hospital. Patients: End-stage liver disease patients undergoing orthotopic liver transplantation under general anesthesia. Interventions and measurements: Pulmonary edema fluid obtained from seven patients within 15 min of first appearance was analyzed for protein content and compared with the protein content of a simultaneously obtained plasma sample. Hemodynamic data, fluid administration totals, and length of postoperative intubation and ICU stay were also collected. Results: Eight patients were identified. Six of the seven patients whose edema fluid was analyzed had edema fluid/plasma protein ratios greater than or equal to 0.75, characteristic of increased permeability pulmonary edema (the one other patient had a ratio of 0.73). Hemodynamic monitoring at the time of onset of the edema effectively ruled out a cardiogenic etiology, One patient died intraoperatively; at autopsy, the cause of death was determined to be pulmonary fat embolization. In the other seven patients, production of edema fluid resolved within 6 h of admission to the ICU. The duration of ventilatory support ranged from 23 to 96 h, with a mean of 49 h. Conclusions: The most likely cause of the reaction is transfusion-related acute lung injury (TRALI). An incidence of TRALI that is higher than previously reported in this population indicates that other elements, such as reperfusion of the newly implanted liver, may be contributing factors.