Background: Severe pulmonary injury with the development of ARDS is a poten
tial complication of cardiac surgery and cardiopulmonary bypass (CPB).
Study objectives: This retrospective, case-control study was designed to de
termine the incidence and mortality of ARDS after cardiac surgery and CPB,
as well as to identify preoperative and perioperative predisposing factors
of this complication.
Methods: Of 3,278 patients who underwent cardiac surgery and CPB between Ja
nuary 1995 and December 1998, 13 patients developed ARDS during the postope
rative period. Each patient was matched with four or five control subjects
who had the same type of surgery on the same day but did not develop postop
erative respirator 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 th
e control group (p < 0.002). During the postoperative period, ARDS patients
received more blood products (4 +/- 5 vs 2 +/- 3; p < 0.01) and developed
shock more frequently (31% vs 5%; p < 0.02) than patients in the control gr
oup. Multivariate regression analysis identified previous cardiac surgery,
shock, and the number of transfused blood products as significant independe
nt predictors for ARDS, with odds ratios of 31.5 (p = 0.015), 10.8 (p = 0.0
3), and 1.6 (p = 0.03), respectively.
Conclusions: ARDS following cardiac surgery and CPB was a rare complication
that carried a 15% mortality rate. Previous cardiac surgery, shock, and nu
mber of blood products received are important predicting factors for this c
omplication.