Abstract 16231: Respiratory Failure After Cardiac Surgery: Evidence of Cardiopulmonary Bypass and Transfusion Interaction
Background: Respiratory Failure is an unpredictable complication of cardiac surgery with cardiopulmonary bypass (CPB) strongly implicated in its pathogenesis. Nearly half of CPB patients will receive perioperative transfusion of which a substantial fraction is intraoperative (i-XFN) - in particular when CPB duration is prolonged. How CPB and transfusion interact to contribute to respiratory failure is incompletely elucidated.
Methods: We studied 8,475 consecutive cardiac surgery patients [1992-2006, 64±11yrs] in whom a protocol for weaning from mechanical ventilation was uniformly applied. Respiratory failure was quantified in terms of two factors: 1) prolonged mechanical ventilation >24 hours (ProlVent) and 2) significant pulmonary edema on X-Ray with/without acute respiratory distress syndrome (PE/ARDS). Adjusted odds ratios were derived by multivariate logistic regression [AOR (95% confidence Interval)].
Results: CPB duration varied widely among patients (96±47min), and i-XFN was less frequent in off-pump (n=437) patients (11.2% vs. 28.5%; P4 hours). Incidence of respiratory failure was 884 ProlVent (10.4%), 256 PE (3.02%) and 89 ARDS (1.05%). Respiratory failure was increased systematically with CPB (overlapping decile sub-cohorts) but both of the ProlVent and PE/ARDS increasing relations were attenuated in patients that did not receive iXFN.[Figure] Both outcomes were predicted by longer CPB [AOR(per 60 min )= 1.42(1.30-1.54) ProlVent; and 1.24 (1.12-1.36) PE/ARDS] and in case of iXFN [AOR=3.02(2.56-3.57) ProlVent; and 2.53(1.95-3.27) PE/ARDS].
Conclusion: Both increased CPB duration and i-XFN contribute to the development of respiratory failure after cardiac surgery. These results lend support to a multi-hit model of transfusion related respiratory failure in cardiac surgery where CPB acts like a priming pro-inflammatory state that leads to a greater risk of lung injury when accompanied or followed with early transfusion.
- © 2013 by American Heart Association, Inc.