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

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

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.

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).

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.