Acupuncture vs Metoclopramide for Postoperative Gastroparesis Syndrome

Reference

Sun BM, Luo M, Wu SB, et al. Acupuncture versus metoclopramide in treatment of postoperative gastroparesis syndrome in abdominal surgical patients: a randomized controlled trial. J Chin Integr Med. 2010;8(7):641-644.

Design

This is a randomized controlled trial of 63 patients from the Eastern Hepatobiliary Surgical Hospital, Second Military Medical University, Shanghai, China, 2004–2007, with postoperative gastroparesis syndrome (PGS) treated with acupuncture or metoclopramide (Reglan). Acupuncture was given to 32 patients, of whom 22 were male and 10 female. Metoclopramide was given to 31 patients, of whom 24 were male and 7 female. The acupuncture points were CV/RN12 (zhongwan), and bilaterally ST36 (zusanli) treated with mild supplementation, P6 (neiguan) treated with stimulation, and SP6 (sanyinjiao) treated with reinforcing technique. All 7 needles were left in for 30 minutes once per day. Metoclopramide was given 20 mg IM tid. PGS was confirmed by meglumine diatrizoate radiographic visualization.

Outcome measures were gradations of improvement rated as:

• Recovery: no gastric juice outflow, no nausea or vomiting after stomach tube was removed, and the patient could consume semiliquid diet;
• Effective: decreased gastric juice volume, nausea without vomiting, stomach tube present; and
• Ineffective: No decrease in gastric juice volume, still has nausea and vomiting, stomach tube still present; PGS had been present 9–10 days + 6–7 days.

Baseline age, gastric volume and absence of diabetes were not significantly different between the treatment arms at the start of the trial.

Key Findings

Among the acupuncture patients, 29 were rated Recovered and 3 were rated Effective after a therapeutic treatment frequency of 6.58 + 4.26. Among the metoclopramide patients, 10 were rated Recovered, 12 were rated Effective, and 9 were rated Ineffective.

Prior Research

1. PGS is defined in China¹ using 7 diagnostic criteria:
2. Nausea, vomiting, distension, and succussion splash after a liquid or semiliquid diet
3. Stomach drainage fluid > 600 mL/d for 6 or more days
4. Absence of mechanical gastric obstruction
5. Decreased or absent gastrointestinal motility
6. Absence of water, electrolyte, and acid-base balance abnormalities
7. Absence of medication that adversely affects stomach muscle contraction
8. Absence of disease(s) that may cause PGS (eg, type 1 and 2 diabetes–induced neuropathy)

The acupuncture points chosen are clinically significant for stomach complaints—front-mu of the stomach, regulating stomach Qi and abdominal distention on the conception vessel meridian (CV/RN12); for calming shen (spirit/mood), sedating nausea and vomiting, and regulating Qi (PC6); 3 yin meridian crossing in the lower leg for transforming dampness, spreading Qi, regulating abdominal distention (SP6); and for control of stomach peristalsis at both the upper and lower end, and regulating Qi and blood in weak and deficient conditions (ST36).^2,3,4 The latter 3 points have been studied in several clinical studies and are commonly used in clinical practice. The use of CV/RN12 was unique to the current trial.

Two animal studies examined these points and the physiological mechanism. Hu et al (1996) gave big mice 654-2 solution (anisodamine) and showed that acupuncture of ST36 improved gastric motility while TFP (trifluoperazine) blocked this response.⁵ Needles manipulated for 5 minutes had little affect, but needles retained for 25 minutes improved gastric motility. Anisodamine is an anticholinergic, an alpha-1-adrenergic receptor agonist, and a tropane alkaloid from the Solanaceae used to treat circulatory shock in China.⁶ TFP is a schizophrenic, antipsychotic medication with central antiadrenergic, antidopaminergic, and mild anticholinergic effects used for agitation, severe nausea, and vomiting but with a risk of tardive dyskinesia. Ouyang et al. 2002 used PC6 and ST36 to study gastric motility in 7 female hound dogs implanted with eight pairs of electrodes in the gastric serosa and a duodenal cannula to assess gastric emptying.⁷ The researchers discovered that acupuncture of these 2 points bilaterally normalized gastric slow waves in the distal stomach, increased the spike bursts in the distal stomach, significantly increased vagal activity, and significantly decreased the sympathovagal balance. The improvement of gastric slow wave rhythmicity and antral contractile spike activity accelerated gastric emptying significantly at 15 minutes (P < 0.02), 45 minutes (P < 0.02), and 90 minutes (P < 0.04). Both of these animal studies confirmed the effect of acupuncture on gastric emptying and the ability of TFP to block the acupuncture response.

Four human studies have been done with diabetic gastroparesis. Zhang et al randomly divided 72 cases of diabetic gastroparesis into treatment with motilium 10 mg tid 30 minutes before meals or acupuncture.⁸ The points selected were LI11 (quchi), LI4 (hegu), CV12 (zhongwan), ST36 (zusanli), ST40 (fenglong), SP9 (yinlingquan), SP6 (sanyinjiao), SP10 (xuehai), and SP8 (diji) bid for 10 days. The effectiveness rate was 91% for acupuncture and 77% for the motilium control (P < 0.05). In 2007 Sun and Wang reported on 41 cases of PGS divided into 3 groups treated with 1) warming of the needles with moxibustion (n=17), 2) acupuncture plus auricular acupuncture (n=12), or 3) routine acupuncture.⁹ Each therapy was rated 100% successful, but the first group took 7.2 + 3.8, the second group 9.8 + 4.6, and the third group 15.2 + 3.8 treatments to achieve success in all patients. Thus needles with moxibustion warming needed the fewest treatments to be effective. In 2008, Wang et al reported on electroacupuncture (EA) of ST36 and LI4 or sham EA as the control in 19 randomized diabetic patients with symptoms of gastroparesis for over 3 months.¹⁰ The treatment, which consisted of 4 sessions over 2 weeks, significantly improved gastric emptying at the end of the trial and for the 2 weeks afterwards without significant adverse events or significant alteration of cholesterol and glucose laboratory findings. Zeng and Chai compared acupuncture and motilium in diabetic gastroparesis.¹¹ Needling was done on CV12 (zhongwan), ST36 (zusanli), PC6 (neiguan), and SP6 (sanyinjiao) daily for 2 weeks (n=30). Motilium (10 mg tid, 30 minutes before meals) was given for 2 weeks (n=30). Each group received the treatment for 2 courses (ie, 4 weeks). The effective rate was 93.3% in the acupuncture group and 73.3% in the motilium group (P < 0.05).

Zhang and Yan divided 102 cases equally and randomly into oral omeprazole (dose not stated) or danshen compound (Salvia miltrorrhiza) injected into ST36 (zusanli), and BL21 (weishu).¹² Acupoint injection was effective in 96% vs 76% for omeprazole (P < 0.01) after 2 weeks. The multiple constituents of the S. miltrorrhiza compound were not characterized.

Pfab et al (2011) compared acupuncture of PC6 (neiguan) to standard promotility medications (metoclopramide, cisapride, and erythromycin) in 30 mechanically ventilated ICU patients with a gastric residual volume (GRV) >500 mL for more than 2 days postoperatively.¹³ Success was defined as GRV < 200 mL per 24 hours. After 5 days, 80% of the acupuncture versus 60% of the medication group developed feeding tolerance. The medication group did not show an increase in feeding balance until day 6.

After 5 days, 80% of the acupuncture versus 60% of the medication group developed feeding tolerance.

Metoclopramide is an antiemetic and gastroprokinetic agent for facilitating gastric emptying in gastroparesis. The US Food and Drug Administration has approved it for short-term use (ie, 4–12 weeks), although it is often used longer in clinical practice. It binds to dopamine D2 receptors as a receptor antagonist and is a mixed 5-HT3 antagonist and 5-HT4 agonist. The D2 activity contributes to its prevention of nausea and vomiting in the central nervous system, and the 5-HT4 action may contribute to its antiemetic effect. Its prokinetic action increases peristalsis tone and amplitude of the jejunum and duodenum and relaxes the pyloric sphincter and duodenal bulb.¹⁴

Practice Implications

PGS is common after stomach, pancreas, duodenum, gallbladder, and/or liver resection(s), affecting 2–19% of patients. PGS will delay patient recovery, successful removal of the stomach tube and subsequent oral ingestion of food, and hospital discharge, thereby increasing healthcare costs, slowing patient recovery, and preventing adequate nutrition. Acupuncture, based on this moderate-sized study, was more effective than the conventionally prescribed metoclopramide.

Based on our current knowledge, use of bilateral acupuncture of ST36 alone or PC6 alone or in combination with such points as SP6, PC6, or CV/RN12, should yield patient benefit in postsurgical gastroparesis. All of these points are easily located and relatively safe to needle or otherwise stimulate. It also appears that needle retention for 30 minutes is more effective than the 5 minutes commonly used in current clinical practice.

Limitations

The current study did not define the method of randomization, each subject’s pre-existing clinical condition prior to gastric resection surgery, the exact number of days of either treatment prior to clinical outcome evaluations, or whether the reference index system had been previously validated. The qualifications and control for bias of those delivering treatment and making the clinical assessment was not described. Some of these details may have been lost in the translation from Chinese to English. The other significant difference in this study from clinical practice of traditional acupuncture is that tongue and pulse diagnosis and other patient clinical symptoms did not dictate point location; all patients in the treatment group received acupuncture at the same 7 points. The 2011 study performed in Germany used 3 standard medications and also showed greater and sooner benefit for acupuncture compared to conventional medications, confirming the results from the reviewed study.