Influence of Hematocrit and Pump Prime on Cerebral Oxygen Saturation in On-Pump Coronary Revascularization
Background: The couplings between cerebral oxygenation (rSO2), on-pump hematocrit and circuit prime are explored in this study.
Methods: Thirty-eight consecutive patients undergoing coronary revascularization with cardiopulmonary bypass (CPB) were matched on preoperative hematocrit <40% and >40% (n = 16). Similarly, six blood prime patients were matched with six crystalloid prime patients. Hematocrit and rSO2 levels were then compared on CPB.
Results: The pre-operative hematocrit >40% group retained higher levels on pump run (p <0.01) and significantly higher rSO2 prior to CPB (64.8±9.6 versus 73.2±7.3), and on and off CPB (61.1±8.8 versus 67.4±6.4). Blood priming increased absolute rSO2 (2.3±6.3 versus −10.9±5.9) and % rSO2 (4.7±11.8 versus −14.2±7.4%) in the low hematocrit group.
Conclusion: Blood primes are instrumental in high-risk and low preoperative hematocrit patients in preventing cerebral oxygen desaturation during initiation and maintenance of CPB.
