Background:

Colonoscopy is often regarded as a painful and unpleasant procedure. Electroacupuncture (EA) has been used successfully to treat pain of various origins, but few good-quality studies have evaluated its role in treating pain and anxiety during colonoscopy.

Objective:

To investigate the efficacy of EA in reducing procedure-related pain and the consumption of sedatives/analgesics during colonoscopy.

Design:

Prospective, randomized, double-blind, sham-controlled study.

Subjects:

One hundred and twenty eight consecutive patients undergoing first-time elective day-case colonoscopy without previous experience of acupuncture will be recruited.

Interventions:

Patients will be randomized to receive either 45 minutes of EA or sham acupuncture (SA) before colonoscopy. The acupoints relevant to the treatment of abdominal pain, including Zusanli, Hegu, and Neiguan will be used. For the SA group, blunt-tip needles will be placed (without skin penetration) 15 mm away from the acupoints. Foam blocks will be used to stabilize the needles and to blind the patients and endoscopists to the treatment allocation. EA and SA will be continued throughout colonoscopy. A mixture of Propofol and Alfentanil, delivered by a patient-controlled syringe pump, will be used for sedation/analgesia in both groups.

Outcome measures:

Primary outcome: doses of patient-controlled sedation/analgesia consumed. Secondary outcomes: pain and satisfaction scores according to a visual analog scale, cecal intubation rate/time, and episodes of hypotension/desaturation.

Inclusion criteria:

• Consecutive patients (aged between 18 and 60 years) undergoing first-time elective day-case colonoscopy
• Patients with American Society of Anesthesiologists (ASA) grading I-II
• Informed consent available

Exclusion criteria:

• Patients with previous experience of acupuncture
• Patients with previous history of colorectal surgery
• Patients who are diagnosed with irritable bowel syndrome according to Rome III criteria
• Patients with chronic pain syndrome
• Patients with psychiatric disorder
• Patients with poor cognitive function
• Patients with renal impairment
• Patients with obstructive sleep apnea syndrome
• Patients with cardiac arrhythmias
• Patients with cardiac pacemaker
• Patients who are pregnant
• Patients who are allergic to the acupuncture needles or Propofol/Alfentanil