Effects Of Norepinephrine Or Phenylephedrine Combined With Restricted Infusion On Oxygen Metabolism In Elderly Patients Undergoing Elective Colorectal Resection

Objective:To compare the effects of norepinephrine or phenylephedrine combined with restrictive infusion on oxygen metabolism in elderly patients undergoing laparoscopic col-orectal resection;to discuss the advantages and disadvantages of the two drugs in restrictive infusion.Methods:Choose 60 elderly patients on colorectal resection selectively,aged 60or higher,ASA classⅡ-Ⅲ,BMI 18-24 kg/m²,without relative or absolute contraindica-tions.These patients weredivided into three groups:group A,group B and group C（n=20）。Group A was treated with phenylephedrine andpatients in this group were infused with phe-nylephedrine on 0.1-0.3ug/kg^-1·min^-1 intravenously after operation begin,remaining-MAP≥65mmHg;Group B was treated with norepinephrine andpatients in this group were infused with norepinephrine on 0.01-0.03ug/kg^-1·min^-1 intravenously after operation begin,remainingMAP≥65mmHg;Group C was routine infusion group andpatients in this group were infused with no vasoactive drugs,remainingMAP≥65mmHg.If necessary,pa-tients in group C were injected of ephedrine 6 mg per time.Extract venous blood and radial artery blood,record the arterial blood hemoglobin（Hb）and lactic acid（Lac）,calculate cen-tral venous blood oxygen saturation（ScvO₂）,oxygen index（DO₂I）,oxygen consumption index（VO₂I）,oxygen uptake rate（ERO₂）record hemodynamic parameters at four time points:before anesthesia induction（T0）,cut the skin（T1）,1 h after cut the skin（T2）,end of the surgery（T3）.Then compare the differences of each data among the three groups.Results:Compared with group C in group A and B,the datas of CI,Hb and DO₂I were increased during the operation,and datas of ERO₂ were decreased（P<0.05）,and the difference between group A and B was not statistically significant（P>0.05）.There was no statistically significant difference in tubal time,discharge time and gastrointestinal complications between the three groups（P>0.05）.Conclusion:Boththe applications of norepinephrine and deoxyepinephrine in restrictive infusion have beneficial effects on oxygen metabolism in elderly patients un-dergoing abdominal surgery,but the effects of phenylephedrine were more obvious.So it is better to use norepinephrine in restrictive infusion.