By Carmen Tamayo, MD
Although postoperative nausea and vomiting (PONV) is less common now than when ether and cyclopropane were commonly used anesthetics, the overall incidence is about 30%, with up to 70% of high-risk patients experiencing PONV.1 Risk factors include being female, being a nonsmoker, having a history of motion sickness or PONV, and use of postoperative opioids.1 Type of surgery also affects risk: PONV is quite common after craniotomy, ear, nose and throat procedures, major breast procedures, strabismus surgery, laparoscopy, and laparotomy.1 Nitrous oxide, volatile inhalational agents, and intra-operative opioids also increase risk. PONV can lead to aspiration, dehydration, electrolyte disturbances, and disruption of the surgical site. PONV increases treatment costs and may be associated with increased anxiety, dissatisfaction with the surgical experience, and anticipatory nausea in the future.2 Although PONV rarely causes medically serious complications, patients feel that avoiding PONV is more important than avoiding postoperative pain.1
Acupuncture point stimulation has been assessed to prevent nausea and vomiting of various etiologies, including PONV. A MEDLINE search (1966-2002) of prospective randomized controlled trials of acupuncture or acupressure for nausea or emesis, supplemented by my own files, identified 23 trials of acupoint stimulation for postoperative nausea and vomiting in adults (see Table). Pediatric trials will not be covered here. Sixteen of 23 trials found a benefit for acupuncture stimulation for nausea and/or vomiting. Five trials were negative, and two trials reported mixed results.
Acupuncture points (or acupoints) can be stimulated by needles, pressure, heat, or transcutaneous electrical stimulation (TENS) devices. At least 11 trials tested acupressure bands, which are elastic bracelets with a button that presses on the P6 point, which is two thumb-widths proximal to the distal wrist crease, between the flexor carpi radialis and palmaris longus tendons. Acupressure band trials are easily controlled by misplacing the band on the wrist so that it doesn’t stimulate the P6 point; alternatively, a placebo band, lacking a button, may be used. All but two trials applied stimulation at the P6 acupoint; the Boehler trial tested acupressure "seeds" taped to a Korean hand acupressure point (K9, on the middle phalanx of the fourth finger), and the Kotani trial tested acupuncture at the bladder meridian point (about 2.5 cm from the spinal vertebrae).
No serious adverse events have been associated with acupressure bands; occasional wrist swelling has been noted. Several studies in which the bands were placed prior to anesthesia noted that the bands did not interfere with the insertion of intravenous lines into the same arm. Adverse events following acupuncture are rare (see Alternative Therapies in Women’s Health, July 2002).
Acupuncture and/or acupressure appear to be effective for PONV. Different methods of stimulating P6 (acupuncture, acupressure, electroacupuncture) appear to be equally effective, and all treatments appear to be benign.
Clinical trials of acupoint stimulation for PONV have used diverse populations and techniques. The wide variation in type of surgery, type of anesthesia, timing of administration of acupuncture or acupressure, duration of treatment, and duration of the study make it difficult to compare techniques and timing.
Future research evaluating acupoint stimulation should improve the quality of the existing evidence. Nevertheless, women undergoing surgery may consider acupressure bands, or other forms of acupoint stimulation, as a safe alternative or adjunct to pharmacological agents for preventing PONV.
Dr. Tamayo is Director, Division of Complementary and Alternative Medicine, Foresight Links Corp. in London, Ontario, Canada.
1. Gan TJ. Postoperative nausea and vomiting—Can it be eliminated? JAMA 2002;287:1233-1236.
2. Thompson HJ. The management of post-operative nausea and vomiting. J Adv Nurs 1999;29:1130-1136.
3. Boehler M, et al. Korean hand acupressure reduces postoperative nausea and vomiting after gynecological laparoscopic surgery. Anesth Analg 2002;94:872-875.
4. Kotani N, et al. Preoperative intradermal acupuncture reduces postoperative pain, nausea and vomiting, analgesic requirement, and sympathoadrenal responses. Anesthesiology 2001;95:349-356.
5. Ming JL, et al. Th efficacy of acupressure to prevent nausea and vomiting in post-operative patients. J Advanced Nurs 2002;39:343-351.
6. Agarwal A, et al. Acupressure wristbands do not prevent postoperative nausea and vomiting after urological endoscopic surgery. Can J Anaesth 2000;47: 319-324.
7. Harmon D, et al. Acupressure and prevention of nausea and vomiting during and after spinal anaesthesia for caesarean section. Br J Anaesth 2000;84:463-467.
8. Alkaissi A, et al. Effect and placebo effect of acupressure (P6) on nausea and vomiting after outpatient gynaecological surgery. Acta Anaesthesiol Scand 1999;43:270-274.
9. Harmon D, et al. Acupressure and the prevention of nausea and vomiting after laparoscopy. Br J Anaesth 1999;82:387-390.
10. al-Sadi M, et al. Acupuncture in the prevention of postoperative nausea and vomiting. Anaesthesia 1997;52: 658-661.
11. Yentis S, Vashisht S. The effect of timing of PC.6 acupuncture on post-operative vomiting following major gynaecological surgery. Acupuncture Med 1998; 16:10-13.
12. Fan CF, et al. Acupressure treatment for prevention of postoperative nausea and vomiting. Anesth Analg 1997;84: 821-825.
13. Stein DJ, et al. Acupressure versus intravenous metoclopramide to prevent nausea and vomiting during spinal anesthesia for cesarean section. Anesth Analg 1997;84:342-345.
14. Ho CM, et al. Effect of P-6 acupressure on prevention of nausea and vomiting after epidural morphine for post-cesarean section pain relief. Acta Anaesthesiol Scand 1996;40:372-375.
15. Ferrara-Love R, et al. Nonpharmacologic treatment of postoperative nausea. J Perianesth Nurs 1996;11:378-383.
16. Allen DL, et al. P6 acupressure and nausea and vomiting after gynaecological surgery. Anaesth Intensive Care 1994; 22:691-693.
17. Phillips K, Gill L. The use of simple acupressure bans reduces post-operative nausea. Complement Ther Med 1994;2:158-160.
18. Yang LC, et al. Comparison of P6 acupoint injection with 50% glucose in water and intravenous droperidol for prevention of vomiting after gynecological laparoscopy. Acta Anaesthesiol Scand 1993;37:192-194.
19. Gieron C, et al. Acupressure in the prevention of postoperative nausea and vomiting [in German]. Anaesthesist 1993; 42:221-226.
20. Barsoum G, et al. Postoperative nausea is relieved by acupressure. J R Soc Med 1990;83:86-89.
21. Rogers P. Using acupressure bands for postoperative nausea. Nurs Times 1990;86:52-53.
22. Dundee JW, et al. Traditional Chinese acupuncture: A potentially useful antiemetic. Br Med J 1986;3:583-584.
23. Ghaly RG, et al. Antiemetic studies with traditional Chinese acupuncture. A comparison of manual needling with electrical stimulation and commonly used antiemetics. Anaesthesia 1987;42:1108-1110.
24. Weightman WM, et al. Traditional Chinese acupuncture as an antiemetic Br Med J 1987;295:1379-1380.
25. Fry ENS. Acupressure and postoperative vomiting. Anaesthesia 1986;41:661-662.