Acupressure and quality of recovery after surgery

Editor,

Noll et al.¹ are to be congratulated for their recently published work about the efficacy of acupressure on quality of recovery after surgery. However, a few clarifications would be helpful in case readers wish to repeat this study protocol or even should the authors themselves wish to extend their work further.

The study should have been performed and reported according to the Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA).² In the STRICTA checklist, the items 1 and 2 for acupuncture should be adapted for acupressure. The remaining four items (treatment regiment, other components, practitioner background and comparator interventions) may be used as reported.

The authors mention that patients were blind to group allocation. This is hard to understand, as the control group did not receive any kind of intervention. Thus, it is likely that the patients were aware of being ‘treated’ somehow or whether they served as a no treatment control.

As 10% of the general population are not responders to acupuncture, an active comparator (acupuncture) group would have been useful. Were all the patients scheduled for the morning list?

There are also some issues regarding the acupressure intervention. Usually, in comparative acupuncture studies, the sham points are located in different areas than the area of the active acupuncture. In the present study, the same acupressure points were serving as ‘active’ and as ‘sham’ points. It remains unclear whether the order of stimulation or simple touching of the three acupoints was always the same or whether it was based on a randomisation procedure. The pressure was applied for 2 min only. Can we assume that this is an adequately long, evidence-based duration, or was that an arbitrary choice? It is possible that longer application of acupressure could have given different results. Interestingly, in studies with acupressure on the Yintang acupoint (extra-1 point), pressure was applied for 10 min.^3–5 According to the traditional Chinese medicine, the time required for the onset of acupuncture analgesia is between 15 and 30 min. If the effect of acupressure behaves similarly to acupuncture, then its efficacy would require a longer period than just 2 min. Stimulation of different acupoints modulates neuronal signal transmissions via neural pathways related to nausea/vomiting, nociception, stress and anxiety. This modulation may be weaker, or inactive, in the presence of anaesthetic drugs. This may explain why pre-operative ‘acu-’ interventions are effective in contrast to interventions during or after anaesthesia.⁶ Thus, timing and duration of the acupressure may have influenced the results of the present study.

Finally, it remains unclear whether the presented results (primary and secondary outcomes, Figure 3 and Table 3) are from an intention-to-treat analysis or from the Adhere's analysis. The primary outcome was a composite endpoint. However, combining two or more events increases the overall outcome incidence with statistical power to be increased versus a single event. The statistically significant difference in patient satisfaction (single event) may be incidental, as satisfaction is hard to be defined and perhaps the numbers presented are not clinically significant.