Acupoint injection with 0.9% saline for the prevention of nausea and vomiting after total abdominal hysterectomy : a randomized, double blinded, placebo controlled trial

Abstract

Objective: To study the effectiveness of acupoint injection with 0.9% saline at the four acupoints for the prevention of nausea and vomiting after total abdominal hysterectomy under general anesthesia. Design: A randomized, double-blinded, placebo controlled trial. Setting: King Chulalongkorn Memorial Hospital, Thai Red Cross Society. Participants: Sixty-five female ASA physical status I-III adult patients who underwent Total Abdominal Hysterectomy (TAH) under General Anesthesia (GA) were enrolled in the study, while 4 cases were excluded. Patients (n=61) were double-blind randomized into two groups. Intervention: The eligible patitnes were allocated into two groups by block randomization. At the end of hysterectomy and after the muscle relaxant was reversed but before the patient was fully alert, the patient in the study group received acupoint injection with 0.9% saline at four acupuncture points (both sides of PC-6 and ST-36) while the control group did not get acupoint injection. Outcome measures: Efficacy was assessed by measuring complete response rate of PONV (no nausea, no retching, no vomiting, no rescue antiemetics) in both groups for the first 24 hours after the operation as main outcome. At the same time, the number of retching and vomiting as well as antiemetic rescue used within 24 hours in both groups were be recorded as secondary outcomes. Results: 1. There was no statistical significant difference in the complete response rate (%) between the two groups (43.3% in acupoint group, 35.5% in control group with 95% CI of the difference: -16.7% to 32.3%). 2. The number of vomiting was significantly less in acupoint group compared to control group (P=0.024) in 24 hours after operation, especially during 6-24 hours (P=0.005). 3. The patients who got retching were all in control group, with none in the acupoint group and the patients who got more 5 times vomiting in 24 hours were also in the control group. 4. There was no significant difference in times of nausea, nausea score and rescue using in both groups. 5. There was no incidence of adverse events in both groups. Conclusion: Acupoint injection with normal saline does not reduce the overall incidence of nausea and vomiting in 24 hours after total abdominal hysterectomy under general anesthesia. However, it does reduce the frequency (number) of retching and vomiting during 24 hours after the operation.