Effects of electroacupuncture on intraoperative and postoperative analgesic requirement

Abstract

Acupuncture has been shown to be effective in experimental and clinical acute pain settings. This study aims to evaluate the effect of preoperative electroacupuncture (EA) on intraoperative and postoperative analgesic (alfentanil and morphine) requirement in patients scheduled for gynaecologic lower abdominal surgery. Ninety patients were randomly assigned to one of three groups: Group I (control group) - received placebo EA for 45 minutes before induction of general anaesthesia (GA); Group II - preoperative EA instituted 45 minutes before induction of GA; Group III - 45 minutes of postoperative EA. The Bispectral Index monitor was used intraoperatively to monitor the hypnotic effect of anaesthetic drugs, and alfentanil was titrated to maintain the blood pressure and pulse rate within ±15% of basal values. Postoperative pain was managed by intravenous morphine via a patient-controlled analgesia (PCA) device. Patients in Group II (0.44 ± 0.15μg/kg/min) received less alfentanil than those in Group III (0.58 ± 0.22μg/kg/min) (p=0.024), but not significantly less than those in Group I (0.51 ± 0.21μg/kg/min) (p=0.472). Postoperative morphine consumption was numerically lower in Group II compared with the other groups; however, the difference was statistically significant only during the period of 6-12 hours between Group II [0.03 (0.05) mg/kg] and Group I [0.10 (0.11) mg/kg] (p=0.015), and Group II and Group III [0.08 (0.10) mg/kg] (p=0.010). The 24-hour cumulative morphine consumption for Group II (0.52 ± 0.19mg/kg) was less than that for either Group I (0.68 ± 0.38mg/kg) or Group III (0.58 ± 0.27mg/kg), but the difference did not reach significance. In conclusion, preoperative EA leads to a reduced intraoperative alfentanil consumption, though this effect may not be specific, and has a morphine sparing effect during the early postoperative period.