Susanne Eberl

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Chapter 12

gastrointestinal procedures that is greater than sham-acupuncture and similar to

premedication with a combination of an opioid and a benzodiazepine.

This result is

supported by three other trials that found a significant effect of acupuncture on reducing

the necessary dosage of sedative drugs and pain during colonoscopy.

28-30

Ng et al.

used in

128 patients patient-controlled analgo-sedation with propofol and alfentanil. In the studies

of Ni et al.

(n= 60 patients) and Fanti et al. (n=30 patients)

midazolam was given on

demand if the patient was complaining pain or felt uncomfortably. Both studies used mild

or moderate sedation aiming for a conscious patient. Additionally, electro-acupuncture was

started 20-45 minutes before start of the procedure.

Besides the used drug, the method and start of drug administration, and therefore the

corresponding level of sedation and analgesia were different compared with our trial. All

groups in our study were sedated with propofol by specialised sedation nurses showing

a NRS score of 0 (0-2) and an OAAS score of 1 (0-1), which means patients were deeply

sedated with marginal reaction to mild or even aching prodding and shaking. Additionally,

we started EA together with propofol sedation.

Leung et al. could show that the time point of acupuncture in relation to the start of sedation

or procedure is important. Their group found that in blood samples of EA-treated patients

45 minutes after start of the electro-acupuncture beta-endorphins were significantly higher

than in the SA group.

It might therefore be necessary to start EA 20-45 minutes pre-

procedural to allow reaching the maximum level of endogenous opioids before starting

sedation or colonoscopy, respectively.

During electro-acupuncture, serotonin pathways at the central insula, and mood and

affection in higher cortical centres are modulated. This was demonstrated by Chu et al.

using functional magnet resonance imaging (MRI) during CT colonography in completely

awake patients without any form of sedation or analgesia, except for acupuncture. It might

be possible that brain reactions on noxious stimuli triggered by colonoscopy, and the

interaction of these stimuli with the acupuncture-evoked effect are inhibited in deeply

sedated patients. These two aspects could be the reasons why we did not see any effect of

EA in our trial.

Limitations

General

Our study was designed as single centre trial in the Academic Medical Centre, an academic

teaching hospital treating highly complex patients out of the region of Amsterdam. Besides

experienced gastroenterologists, residents in training examined the patients, probably

resulting in longer lasting and more complex procedures with the need of deep sedation

to facilitate the procedure, but counteracting possible effect of electro-acupuncture.