Unilateral pulmonary oedema after minimally invasive cardiac surgery via right anterolateral minithoracotomy.

Objectives: To investigate the incidence of unilateral pulmonary oedema after minimally invasive cardiac surgery (MICS) requiring unilateral lung collapse has been unknown until now.

Methods: We analysed the data of 484 consecutive patients undergoing minimally invasive cardiac surgery with unilateral lung collapse between January 2008 and December 2013. The clinical regimen was changed in 2010 to a single dose of dexamethasone (approximately 1 mg/kg body weight) administered after anaesthesia induction.

Results: Thirty-eight patients developed a radiographically evident unilateral pulmonary oedema within 24 h after surgery. Dexamethasone significantly reduced the incidence of this event [4.0 vs 12.9%; unadjusted odds ratio (OR) 0.28, 95% confidence interval (CI) 0.14-0.58, P < 0.001]. One patient with and six patients without dexamethasone were clinically symptomatic (P = 0.001). Logistic regression analysis identified four variables significantly associated with the development of a unilateral lung oedema: dexamethasone (OR 0.28, 95% CI 0.13-0.58, P = 0.001), diabetes mellitus (OR 3.17, 95% CI 1.04-9.63, P = 0.04), the level of mean pulmonary arterial pressure (OR 1.05 per mmHg, 95% CI 1.004-1.09, P = 0.03) and transfusion of fresh frozen plasma (OR 2.31, 95% CI 1.02-5.25, P = 0.045).

Conclusions: Our data revealed a 7.9% incidence of radiographically evident unilateral pulmonary oedema after MICS with intraoperative collapse of a lung. Of the total number of patients, 1.5% simultaneously developed clinical symptoms. The influence of corticosteroids, as well as the contribution of possible risk factors, needs further evaluation.