Ketamine and the coagulation response during and after cardiopulmonary bypass

Introduction

The inflammatory response and the coagulation-fibrinolytic cascades are closely interconnected. Vascular injury following cardiopulmonary bypass (CPB) may result in uncontrolled platelet activation, thrombin generation, and disseminated intravascular coagulation. Many of the anesthetic agents posses immunomodulatory effects. The clinical implications of such effects in the context of CPB remain unknown. Ketamine attenuates IL-6 response and production of the superoxide anion by neutrophils after CPB, and reduces coronary uptake of neutrophils following myocardial ishemia and reperfusion. We studied the effect of small-dose ketamine on the coagulation response (antithrombin III, fibrinogen, D-dimers, platelets) during and after CPB.

Methods

In the preliminary prospective study report, we randomized 30 patients who underwent open heart surgery into two groups: K-group (n = 15), which received 0.5 mg/kg ketamine; and P-group (n = 15), which received placebo. Serum samples were collected before starting the operation (T0), after aorta clamp releasing (T1), 30 min (T2), 2 hours (T3), 6 hours (T4), 12 hours (T5), 24 hours (T6), and 48 hours (T7) after weaning from CPB. Data (mean ± standard deviation) were tested by variance analysis.

Results

Both groups were comparable for age, sex, and body surface area. Differences of operative data (CPB and aorta cross-clamping time) and postoperative data (ventilatory support, ICU stay, blood transfusion) between groups were not significant. Furthermore, there was no statistical significance between all other collected data in this study.

Conclusion

In this preliminary study, findings suggest that small doses of ketamine do not possess any effect on the coagulation response during and after CPB.