Randomised, controlled study of preoperative electroacupuncture 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 μg/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 μg/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.