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A PROSPECTIVE PLACEBO-CONTROLLED RANDOMISED TRIAL
12
Acupuncture Points
In our trial, we used the three acupuncture points (P6, ST36, and LI4) unilaterally. Ni et al.
29
and Fanti et al.
28
employed four more points, which were accessed bilaterally: Stomach 37
(ST37), Spleen 6 (SP6), Spleen 9 (SP9) and the auricular acupuncture point Shen Men. We
cannot exclude that this extended approach might have had induced additional synergistic
effects on gastrointestinal symptoms, leading to a reduction of pain and anxiety.
Electrical stimulation
Another point of discussion could be the time adaption of the electrical stimulator. The
cited studies differ in choosing frequency of stimulation from low frequency (e.g. 2 Hz) to
high frequency (e.g. 100 Hz). Low frequency EA seams to involve other central pathways
than high frequency EA.
33
Therefore, different patterns of frequency might have different
effects on usage of sedatives. Leung et al. showed that the level of beta-endorphins declined
after reaching the abovementioned peak value at 25-30 minutes of treatment.
34
In our trial
we used a constant stimulation frequency (1-10 Hz) of the electrical stimulator during the
entire procedure, which eventually can lead to a habituation to the stimulus.
Strength
Including n=153 patients, we performed one of the largest prospective, observer and patient
blinded, randomised studies with three comparable groups in baseline characteristics.
Using sham and placebo groups, we also excluded the placebo effect
35
of acupuncture and
non-specific effects of puncturing the skin by use of Streitberger placebo needles.
In contrast to other studies, we used validated questionnaires to evaluate patient and
endoscopist satisfaction level and their experiences with sedation. Satisfaction level of both,
patients and endoscopists, were high in all three groups, probably due to the effect of deep
sedation.
26
Furthermore, we integrated acupuncture in daily sedation practice – without
using extra time- making it feasible for clinical use.
Future
For further studies it would be interesting to use the functional MRI approach of Chu et al.
32.
to evaluate if there is a modified brain reaction on noxious stimuli and acupuncture-evoked
effect in deeply sedated patients.