Research of hemodynamic change and oxygen metabolism during anesthesia of off-pump coronary artery bypass grafting (OPCABG)

Objectives: The purpose of this study is to evaluate the anesthesia methods by observing hemodynamic changes, oxygen supply and demand balance in order to provide the reference for the Off-Pump Coronary Artery Bypass Grafting (OPCABG) anesthesia management level during OPCABG. Methods: Thirty patients scheduled for elective OPCABG were premedicated with intramuscular scopolamine 0.3 mg/kg and morphine 0.15 mg, 30 min before anesthesia. Artery blood pressure was monitored through radial artery catheter. Hemodynamic and oxygen metabolism index was recorded respectively at preoperative (T1), after the sternal incision (T2), LAD anastomosis (T3), CX/DIA anastomosis (T4), RCA anastomosis (T5) and the end of the operation (T6). Results: The preload parameters change significantly at T1 and T5. Compared to T1, CVP and RVEDV decrease significantly at T4 (P<0.05), PCWP increase significantly at T5 (P<0.05). The afterload parameters change at T3 and T5. SVR and SVRI decrease significantly at T3 (P<0.01). SVRI decreases significantly at T5 (P<0.05). The cardiac systolic function was mainly influenced at T3, T4 and T5. Compared to T1, RVEF, CCO and CCI increase significantly (P<0.05), SV and SVI decreased significantly (P<0.01), RVEF increase significantly at T3 (P<0.05). The pressure related parameters change at T4 and T5. CVP decreases significantly at T4 (P<0.05), while PCWP increase significantly at T5 (P<0.05). Oxygen supply and demand balance parameters change at T2, T3, T4 and T5. O2ER and O2EI decrease significantly (P<0.01), Ca-vO2 decrease significantly at T2 (P<0.05). SvO2 increase significantly at T3 (P<0.01), increase relative slightly at T2 and decrease significantly compared to T1. DO2 and DO2I increase significantly (P<0.05), PvO2 increase significantly until T5 (P<0.01), but the lactic acid level decrease significantly (P<0.05). Conclusion: During the management of OPCABG anesthesia, maintaining the stable hemodynamic may ensure oxygen supply, demand balance and make the operation safe.