Incidence and Predictors of ARDS After Cardiac Surgery

Background:

Severe pulmonary injury with thedevelopment of ARDS is a potential complication of cardiac surgery and cardiopulmonary bypass (CPB).

Study objectives:

Thisretrospective, case-control study was designed to determine theincidence and mortality of ARDS after cardiac surgery and CPB, as wellas to identify preoperative and perioperative predisposing factors of this complication.

Methods:

Of 3,278 patients whounderwent cardiac surgery and CPB between January 1995 and December1998, 13 patients developed ARDS during the postoperative period. Eachpatient was matched with four or five control subjects who had the sametype of surgery on the same day but did not develop postoperativerespiratory complications.

Results:

The incidence of ARDS was 0.4%, with an ARDS mortality of 15%. In the ARDS group, 38%had previous cardiac surgery, as compared to 3.5% in the control group(p < 0.002). During the postoperative period, ARDS patients receivedmore blood products (4 ± 5 vs 2 ± 3; p < 0.01) and developedshock more frequently (31% vs 5%; p < 0.02) than patients in thecontrol group. Multivariate regression analysis identified previouscardiac surgery, shock, and the number of transfused blood products assignificant independent predictors for ARDS, with odds ratios of 31.5(p = 0.015), 10.8 (p = 0.03), and 1.6 (p = 0.03),respectively.

Conclusions:

ARDS following cardiacsurgery and CPB was a rare complication that carried a 15% mortalityrate. Previous cardiac surgery, shock, and number of blood productsreceived are important predicting factors for thiscomplication.