Effects of dexmedetomidine on oxygen supply-demand balance in patients un-dergoing off-pump coronary artery bypasss grafting surgery

Zhang Hui; Zhang Tao-yuan; Wang Miao; Lei Chong; Hou Li-hong; Zhi Wei-wei; Chen Wei

doi:10.13498/j.cnki.chin.j.ecc.2017.02.06

Abstract：Objective To observe the effects of the dexmedetomidine on oxygen supply-demand balance in patients undergoing off-pump coronary artery bypass grafting surgery ( OP-CABG) . Methods 40 patients with ASA grade II-III coronary artery disease planned to be corrected with OP-CABG surgery were randomly divided into D group and C group, 20 cases in each group. In D group, dexmedetomidine was infused 0.5 μg/( kg·h) from 10 min before anesthesia induction until the end of surgery, and C group received equal volume of normal saline. We documented the basic information of all the patients, time of anesthesia and surgery, the dosage of norepinephrine during induction and maintenance, the dosage of propofol and sufentanial during anesthesia, the inotrope score during surgery, the number of revascularized vessels, mechanical ventilation time, CCU stay, in-hospital stay. Hemodynamic parameters were recorded at the following 10 time points:before the anesthesia induction ( baseline, T0) , before intubation ( T1) , three minutes after intubation ( T2) , initiation of surgery ( T3) , after the sternotomy ( T4) , after dissection of internal mammary artery ( T5) , at anasto-mosis of circumflex coronary artery or diagonal artery ( T6 ) , after the anastomosis of distal vessels ( T7 ) , 5 minutes after revascularization ( T8) and end of surgery ( T9) . Cardiac output ( CO) , cardiac index ( CI) , systemic vascular resistance ( SVR) and pulmonary vascular resistance ( PVR) were recorded from T3 to T9. Oxygen supply ( DO2 ) and oxygen consumption ( VO2 ) were re-corded from T3 to T4 and from T6 to T9. The postoperative complications in both groups were also recorded. Results Compared with C group, the dosage of propofol ( P =0.01), and sufentanil in D group were less ( P =0.04), The dosage of norepinephrine during the anesthesia maintenance in D group was much higher than that in C group ( P =0.032) . Heart rate and mean arterial pressure were significantly reduced in D group from T0 to T9. SVR and PVR were remarkably decreased from T3 to T9. VO2 in D group were much less from T3 to T4 and from T6 to T9. No significant changes were found in the other endpoints. Conclusion Dexmedetomidine infu-sion at the rate of 0.5 μg/( kg·h) from 10 min before anesthesia induction until the end of surgery can reduce anesthetics consump-tion, maintain stable hemodynamics during the anesthesia and can improve the oxygen supply-demand balance with depressed oxygen consumption while maintaining the oxygen supply, which can be safely used in the patients undergoing OP-CABG surgery.