The present study was a single-blind clinical trial comprised of three groups. The study population included all children aged five to 12 years undergoing tonsillectomy and referred to the Amiralmomenin Hospital in the city of Rasht in 2017 - 2018. The sample size was determined by 48 individuals in each group and a total number of 144 patients based on the results of the study by Lin et al. (the final row in the data in
Table 2), considering 95% confidence level and 80% power. The sampling started in early November 2017 and lasted until late April 2018. We used random blocks to assign children equally to each three groups. We used the Random List software and samples assigned in three groups with three in one block allocations (the so-called block size is three) that were generated by the computer software. The children and their parents in this study were not aware of their allocation to the three groups. As well, the type of surgery for all children was the same in terms of surgical techniques and general anesthesia procedures.
In this study, acupressure was considered as the independent variable, and the dependent variables included heart rate, respiratory rate, and levels of arterial oxygen saturation. The inclusion criteria in this study were children aged five to 12 years undergoing tonsillectomy, and the exclusion criteria included post-operative severe pain preventing children from participating in the study, the existence of coagulation disorders, as well as skin diseases or skin burns in the pressure points wherein acupressure could be applied. The data collection instruments in this study included (A) a demographic characteristics information form accompanied by a recording log for heart rate and levels of arterial oxygen saturation in children during three phases of intervention one hour, two to four hours, and six to eight hours following a tonsillectomy whose validity was determined through content (logical) validity; (B) a pulse oximetry (with the brand name of Nomentrix) manufactured in the United States with a child-specific probe to measure their heart rate and levels of arterial oxygen saturation; and (C) a chronometer watch branded as Orient made in Japan.
To determine the reliability of the given device, its confirmation and control were conducted by the manufacturer and the relevant engineer; moreover, the device was used for three consecutive times on a child and showed fixed numbers. Since changes are unlikely to be seen in electronic devices like digital pulse oximetry if they are not connected to multiple patients and considering the fact that two pulse oximetry were available in each hospital ward and the number of surgeries did not exceed two cases per shiftwork in the study context, the probe of the device was only connected from onset until the end of the work to one child and it was re-calibrated at the end of work, thereby its validity was confirmed.
To commence the study, first, we get permission from the hospital principal, matron, and Deputy of Research and Technology of Gilan University of Medical Sciences. Then, we visited the mother of the children, and full explanations were given to them, and their written informed consent was acquired.
In this study, acupressure intervention was performed in three phases (one hour, two to four hours, and six to eight hours after surgery).To this end, acupressure was applied to three points of LI4 (Hego) located at the interface between the thumb and the index finger of the hand, ST-44 (Neiting) located above the edge of the curtains between the second and third toes of the foot, and ST-36 (Zusanli) located at the width of the four toes under the knee joint and the width of one toe outside the lower edge of the tibia bone protuberance in the pediatric patients in the intervention group. Considering the placebo group, the pressure was solely applied to the pressure points in close proximity to the given acupressure points, but the main difference was that the pressures had no therapeutic effects and they were very superficial. The third group, as the control one, received no intervention and they were only provided with routine care services.
The heart rate, respiratory rate, and levels of arterial oxygen saturation were evaluated for three minutes before the intervention using the pulse oximetry for parents and children one, two to four, and six to eight hours after the tonsillectomy when the children were in their beds. To decrease anxiety and also to attract the children to cooperate, firstly, the researcher connected the pulse oximetry to her finger and that of mothers; then, she connected the probe of the device to the child’s finger after providing a complete description and winning their confidence. In the intervention (experimental) group receiving acupressure; heart rate, respiratory rate, and levels of arterial oxygen saturation were controlled and recorded using the pulse oximetry and a chronometer watch two minutes before the intervention. Immediately after the intervention, heart rate and levels of arterial oxygen saturation were measured and recorded. All the steps above were also followed in the placebo and control groups, except that acupressure was applied to sham acupressure points in the placebo group. Finally, the data collected were entered into the SPSS Statistics (version 21) and analyzed using descriptive and inferential tests (Wilcoxon signed-rank test, analysis of variance (ANOVA), and Kruskal-Wallis test). The significance level of the test was considered by P < 0.05. Furthermore, this study was approved by the Ethics Committee of Gilan (Shahid Beheshti) University of Medical Sciences (IR.GUMS.REC.1396.229) receiving the registration number from the Iranian Registry of Clinical Trials (IRCT2017100836651N1).