Effect of electroacupuncture on sedation requirements during colonoscopy: a prospective placebo-controlled randomised trial

Introduction: Propofol provides excellent sedation during colonoscopy. However, its application, namely when used together with an opioid, is associated with cardiopulmonary depression. Acupuncture is used nowadays for the treatment of pain and anxiety, and also to induce sedation. We hypothesised that electroacupuncture (EA) during colonoscopy would have sedative effects, thereby reducing propofol requirements to achieve an adequate level of sedation. Method: The study was designed and conducted as a single centre, patient and observer blinded, sham- and placebo-controlled randomised trial. Patients scheduled for elective colonoscopy under deep propofol/alfentanil sedation were randomly assigned to receive unilateral EA, sham-acupuncture (SA) or placebo-acupuncture (PA) at ST36, PC6 and LI4. The primary outcome parameter was the total dosage of propofol. Secondary outcomes included the patients' and endoscopists' satisfaction levels evaluated by questionnaires. Results: The dosage of propofol required (median [IQR]) was not significantly different between the three groups (EA group 147 mu g/kg/min [109-193] vs SA group 141 mu g/kg/min [123- 180] vs PA group 141 mu g/kg/min [112-182]; P=0.776). There was also no significant difference in alfentanil consumption (P=0.634). Global satisfaction (median [IQR]) among patients (EA group 6.6 [6.0-7.0] vs SA group 6.8 [6.0-7.0] vs PA group 6.5 [6.0-7.0]; P=0.481) and endoscopists (6.0 [5.0-6.0] for all groups; P=0.773) did not significantly differ between the three groups. There was no significant difference in the number of cardiorespiratory events. Conclusion: For colonoscopy, the applied mode of EA did not show any propofol-sparing sedative effect compared with sham or placebo acupuncture.