Introduction: Cardiopulmonary bypass (CPB) is frequently associated with hemodynamic disorders caused by a whole blood inflammatory response. In particular vasoplegic syndrome occurs in the immediate postoperative time of patients who underwent normothermic CPB. Nitric oxide (NO) was described as an endothelium derived relaxing factor (EDRF). We report changes in NO concentration occurred in patients who experienced vasoplegic syndrome following CPB.
Materials and methods: We analyzed changes in NO concentration in 95 consecutive patients who underwent coronary artery bypass grafting under normothermic CPB. NO was measured as nitrite plasma level (NPL) by the Griess reaction.
Results: In all cases a significant NPL increase 30 minutes after starting CPB and 10 minutes after CPB interruption was observed (p<0.005). No significant differences were measured 60, 120 and 240 min after CPB interruption when compared with before CPB. Three patients experienced vasoplegic syndrome and NPL values measured at 60, 120 and 240 min after CPB interruption were still significantly increased when compared with before CPB (p<0.005).
Conclusion: NO plays a role in the CPB-related hemodynamic disorders. Use of NO synthase inhibitors could provide a better management of vasoplegic phenomenon following CPB.