Postpneumonectomy pulmonary edema : A retrospective analysis of incidence and possible risk factors

To analyze the incidence of postpneumonectomy pulmonary edema (PPE) and to determine potential risk factors for PPE. A group of 197 patients was studied retrospectively, and the incidence of PPE was recorded over a 5-year period. Preoperative, perioperative, and postoperative clinical data were collected, and preoperative and postoperative chest radiographs were reviewed. A scoring system was used to distinguish between premanifest and manifest PPE. Postpneumonectomy patients with pulmonary edema, with no clinically evident cause, were considered to have PPE. The incidence of premanifest PPE was 12.2% (n = 24), and that of manifest PPE was 2.5% (n = 5). Mortality in the group of patients who developed manifest PPE was 100%. Two significant perioperative associations were found in the PPE group. One was the administration of fresh frozen plasma (FFP) transfusions (relative risk, 4.3; 95% confidence interval, 1.3 to 14.4 corrected for age and sex), while the other was higher mechanical ventilation pressures during surgery (relative risk, 3.0; 95% confidence interval, 1.2 to 7.3). Our data suggest that FFP transfusions form an important risk factor for PPE. The mechanism may be an increased permeability of the pulmonary vessels due to an immunologic reaction after multiple FFP transfusions. The significantly higher mechanical ventilation pressures we found in the PPE group may be explained as an early sign of the development of PPE.