Electro-acupuncture modification of halothane anaesthesia in the dog

Acupuncture in Modern Medicine

Acupuncture, developed thousands of years ago in the Orient, is increasingly being integrated into modern Western Medicine. Its neurophysiological basis is partly understood, and controlled trials are demonstrating its efficacy and safety.

Narrative Review of Perioperative Acupuncture for Clinicians

Acupuncture is one of the oldest forms of the natural healing arts. The exact mechanisms of action are unknown at this time; however, current theories to explain the benefits experienced after acupuncture include Traditional Chinese Medicine and Western medicine concepts. Acupuncture may improve the quality of perioperative care and reduce associated complications. Perioperative acupuncture is apparently effective in reducing preoperative anxiety, postoperative nausea and vomiting, and postoperative pain. The Pericardium-6 (P-6; Nei Guan), Yintang (Extra 1), and Shenmen acupuncture points are the most studied and effective acupuncture points in reducing preoperative anxiety, postoperative nausea and vomiting, and postoperative pain experiences. Intraoperatively administered acupuncture may reduce immunosuppression in patients and lessen intraoperative anesthetic requirements, although the clinical usefulness of acupuncture in the intraoperative period remains inconclusive. Perioperative acupuncture is a promising intervention, but additional studies are needed to further understand and define acupuncture's role throughout the perioperative period and determine its clinical usefulness. The purpose of this article is to provide a brief clinical review concerning acupuncture and its application for common issues that occur in the perioperative period.

Impact of bilateral ST36 and PC6 electroacupuncture on the depth of sedation in general anaesthesia

OBJECTIVE

To investigate the impact of electroacupuncture (EA) at bilateral acupuncture points ST36 and PC6 on the level of sedation in general anaesthesia.

METHODS

40 patients undergoing abdominal surgery were randomly divided into two groups: EA combined with general anaesthesia (EA group, n=20) and general anaesthesia control group (n=20). The bilateral acupuncture points ST36 and PC6 were selected in both groups. Target-controlled infusion (TCI) of propofol was used for the induction and maintenance of general anaesthesia to reach an equilibrium state of Narcotrend Index (NT index). In the EA group, EA was performed with a Hans EA device. In the control group, general anaesthesia was performed without EA stimulation. In both groups, heart rate (HR), mean blood pressure (MAP) and NT index were recorded at corresponding time points up to 30 min after the end of acupuncture.

RESULTS

The NT indices of the EA group showed a downward trend after EA stimulation (p=0.01). From 15 min after the start of EA stimulation the NT indices of the EA group were significantly lower than those of the control group (p<0.05). HR and MAP of the two groups showed no significant differences at any time points (p≥0.05).

CONCLUSIONS

EA stimulation at bilateral ST36 and PC6 significantly deepens the sedation level of general anaesthesia in patients with propofol TCI, has little impact on haemodynamics and provides significant delayed sedation effects.

Comparisons of the effects of acupuncture, electroacupuncture, and transcutaneous cranial electrical stimulation on the minimum alveolar concentration of isoflurane in dogs

OBJECTIVE

To compare the effects of acupuncture (AP), electroacupuncture (EA), and transcutaneous cranial electrical stimulation (TCES) with high-frequency intermittent currents on the minimum alveolar concentration (MAC) of isoflurane and associated cardiovascular variables in dogs.

ANIMALS

8 healthy adult female Beagles.

PROCEDURE

Each dog was anesthetized with isoflurane on 4 occasions, allowing a minimum of 10 days between experiments. Isoflurane MAC values were determined for each dog without treatment (controls) and after treatment with AP and EA (AP points included the Large Intestine 4, Lung 7, Governing Vessel 20, Governing Vessel 14, San Tai, and Baihui) and TCES. Isoflurane MAC values were determined by use of noxious electrical buccal stimulation. Heart rate, mean arterial blood pressure (MAP), arterial blood oxygen saturation (Spo2) measured by use of pulse oximetry, esophageal body temperature, inspired and expired end-tidal isoflurane concentrations, end-tidal carbon dioxide concentration, and bispectral index (BIS) were monitored. Blood samples were collected for determination of plasma cortisol concentration.

RESULTS

Mean +/- SD baseline MAC of isoflurane was 1.19 +/- 0.1%. Acupuncture did not significantly change MAC of isoflurane. Treatments with EA and TCES significantly lowered the MAC of isoflurane by 10.1% and 13.4%, respectively. The Spo2, heart rate, MAP, BIS, esophageal body temperature, and plasma cortisol concentration were not significantly different after AP, EA, TCES, and control treatments at any time interval.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of EA and TCES decreased MAC of isoflurane in dogs without inducing adverse hemodynamic effects. However, the reduction in isoflurane MAC by EA andTCES treatments was not considered clinically relevant.

Effect of electroacupuncture on minimum alveolar concentration of isoflurane in dogs

The effect of electroacupuncture (EA) on minimum alveolar concentration (MAC) of isoflurane was evaluated in dogs. After determination of baseline MAC, EA was applied at each acupoints (LI-4, SP-6, ST-36 and TH-8) and nonacupoint for 30 min. MAC was determined again. EA at acupoints significantly lowered the MAC of isoflurane in dogs (17.5 +/- 3.1%, 21.3 +/- 8.0%, 21.2 +/- 7.5% and 15.4 +/- 3.1%, respectively). In control group and nonacupoint electrical stimulation group MAC were not decreased significantly. From these results, electroacupuncture at each acupoints used in the present study would have an advantage in isoflurane anesthesia with reducing its requirement.

The effect of auricular acupuncture on anaesthesia with desflurane

In most acupuncture studies it is difficult or even impossible to conduct a truly double-blind trial. However, this is possible when treatments are carried out on anaesthetised patients. Because acupuncture provides analgesia, we tested the hypothesis that needle stimulation of a combination of four ear acupoints would significantly reduce anaesthetic requirement. Ten healthy volunteers were anaesthetised with desflurane and randomly assigned to no treatment or acupuncture; the alternative treatment was given on a subsequent study day. Auricular acupuncture was performed with needles placed at the Shen Men, Thalamus, Tranquiliser and Master Cerebral Points on the right ear. Anaesthetic requirement, determined by the Dixon up-and-down method, was defined by the average desflurane concentration that prevented purposeful movement of the extremities in response to noxious electrical stimulation. Volunteers required a greater desflurane concentration to prevent movement on the control than on the acupuncture day: 4.9 (0.7; SD) vs. 4.4 (0.8) vol. %, p = 0.003. Acupuncture thus reduced anaesthetic requirement by 8.5 (7)%.

Electroacupuncture reduces morphine-induced emesis in ferrets: a pilot study

We treated morphine-induced emesis in ferrets with electroacupuncture (EA) for five minutes at the acupuncture point Neiguan (P6) using two different frequencies of stimulation: 1.0 Hz and 5.0 Hz (n = 5 ferrets per group). Both EA treatments reduced the number of emetic episodes (39% reduction of episodes, p < or = 0.05 at 1.0 Hz; 43% reduction of episodes, p < or = 0.05 at 5.0 Hz) and prolonged the onset time of emesis as compared with control receiving no EA. This model demonstrates that under these conditions EA is effective as an antiemetic against morphine in the ferret and may allow for further studies on the mechanisms of acupuncture and emesis.

Acupuncture analgesia

Acupuncture-produced surgical analgesia has been demonstrated in a wide variety of species under experimental and clinical circumstances. The main advantage is that no depressant drugs need to be used. The disadvantages of its use are unfamiliarity, the need for special equipment, inconsistent effects, and lack of restraint.

Electro-acupuncture and postoperative emesis

One hundred unpremedicated female patients of ASA grade 1 or 2 who underwent laparoscopy as outpatients were allocated randomly to one of four groups. All patients received general anaesthesia with fentanyl, thiopentone, halothane, nitrous oxide and oxygen; suxamethonium was given to facilitate tracheal intubation. In the recovery room, group 1 (control) received no treatment; group 2 received electro-acupuncture at the P6 point (Neiguan) on the right side for 15 minutes, group 3 received transcutaneous electrical nerve stimulation at the P6 point on the right side for 15 minutes and group 4 received prochlorperazine 5 mg intravenously. Any act of vomiting, including dry retching, during the first 3 postoperative hours was regarded as postoperative emesis. The incidence of postoperative emesis was 11/25 (44%) in group 1, 3/25 (12%, p less than 0.05) in group 2, 9/25 (36%) in group 3, and 3/25 (12%, p less than 0.05) in group 4. Our results suggest that electro-acupuncture is as effective as prochlorperazine, and may be better than transcutaneous electrical nerve stimulation, in reducing postoperative emesis.

Failure of narcotic antagonist to alter electroacupuncture modification of halothane anaesthesia in the dog

Sixteen dogs were used to study the analgesic effects of electroacupuncture. Electroacupuncture lowered halothane MAC significantly (1.21 +/- 0.04 to 1.05 +/- 0.05 per cent, p less than 0.005). Reversibility of this effect by narcotic antagonist was then studied, using naltrexone 5 mg . kg-1 injected intravenously (10 dogs) or 0.5 mg . kg-1 intrathecally (3 dogs). We failed to see any reversal of the effect of electroacupuncture on MAC. Narcotic antagonist reversibility of acupuncture effect is taken currently to imply endorphin mediation. Possible explanation for our result include an electroacupuncture analgesia not mediated by endorphins.