The effect of pulmonary static inflation with sevoflurane during cardiopulmonary bypass on lung function in patients undergoing cardiac valve replacement surgery

Objective: To assess the phenomenon of lung injury after cardiopulmonary bypass (CPB) and the effects of pulmonary static inflation with sevoflurane during CPB on lung function in patients undergoing cardiac valve replacement surgery.

Methods: Sixty adult patients (ASA II or III, aged 20-59 years) were randomly assigned to two groups, control group (n=30): pulmonary static inflation during CPB, no sevoflurane inhaled, sevoflurane group (n=30): pulmonary static inflation with 1.0 MAC sevoflurane during CPB. The pressure of pulmonary static inflation was maintained at 5 cm H2O in both groups. Arterial blood gas analysis was performed at time of operation starting (To)0 1, 3, 6 h after CPB (T1, TZ,2T3). The values of alveolar-arterial oxygen pressure difference ED[A-a)O2)2]respiratory index [RI, D(A-a)O2/2aO2)2and oxygenation index (OI, PaOz/2iOz)2were calculated respectively.

Results: Compared with control group, D(A-a)Oz,2RI and OI were not different in sevoflurane group at any stage; Compared with the baseline (To) in both groups, D (A-a)O2 2nd RI increased after CPB, and OI decreased (P < 0.05 or 0.01), the peak of them occurred at 3 h after CPB.

Conclusions: The impact of pulmonary function usually occur after cardiopulmonary bypass (CPB)in patients undergoing cardiac valve replacement surgery, of which peak injury within 6 h presents at 3 h after CPB. Static pulmonary inflation with 1.0 MAC sevoflurane during CPB shows no beneficial effects on lung function in patients undergoing cardiac valve replacement surgery.