Randomised, controlled study of preoperative eletroacupuncture for postoperative pain control after cardiac surgery

Background This study aims to evaluate the effects of preoperative electroacupuncture (EA) on the need for opioids in the postoperative stage of conventional cardiac surgery. Methods A prospective, randomised and controlled study was conducted at Unimed Hospital Centre in Joinville, SC, Brazil. The day before the surgery, 32 patients undergoing cardiac surgery were randomised into two groups: patients from the treatment group received preoperative EA at bilateral points (LI4-LI11, LR3-ST36, PC6-TE5) for 30 min with alternating frequencies of 3 and 15 Hz. Patients from the control group received sham transcutaneous electrical nerve stimulation (TENS). Use of fentanyl during the postoperative period was measured. Results 10 patients were excluded because of hemodynamic and ventilatory instability leaving 13 (10 male) in the treatment group and 9 (4 male) in the control group. The average total doses of fentanyl given were 13.1+/-2.2 and 16.3+/-1.6 mu g/kg in the treatment and control groups respectively (p<0.002). The doses of patient controlled analgesia were 4.1+/-2.0 and 6.9+/-1.7 mu g/kg in the treatment and control groups respectively (p<0.003). The number of boluses issued also differed (treatment 13.9+/-7.0 vs control 24.8+/-7.0, p<0.002). Pain intensity scores differed between the groups (treatment 2.5+/-1.1 vs control 4.0+/-2.0, p<0.04). One patient from the control group experienced drowsiness that justified a change in fentanyl infusion, as decided by the anaesthetist. Conclusion Preoperative electro-acupuncture in conventional cardiac surgery may reduce the postoperative consumption of fentanyl.