Gan 2004.
Methods | Parallel‐group randomized trial, conducted in United States. Study dates not reported. | |
Participants | 77 women undergoing major breast surgery. Exclusion: pregnancy, using permanent cardiac pacemaker, previous experience of acupuncture therapies, received any antiemetic medication or had nausea, vomiting or retching within 24 h of surgery. 2 women withdrew from study. | |
Interventions | Group 1: ondansetron 4 mg IV given at induction of anaesthesia and sham electro‐acupoint stimulation at P6 acupoints (30 ‐ 60 min before induction and continued to the end of surgery) (n = 25). Group 2: electro‐acupoint stimulation at P6 bilaterally (30 ‐ 60 min before induction and continued to the end of surgery) and saline IV given at induction of anaesthesia (n = 26). Group 3: sham electro‐acupoint stimulation at P6 bilaterally (30 ‐ 60 min before induction and continued to the end of surgery) and saline IV given at induction of anaesthesia (n = 24). |
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Outcomes | Nausea (0 ‐ 2 h), vomiting (0 ‐ 2 h), risk of rescue antiemetic drug, adverse effects. | |
Notes | Rescue antiemetic was dexamethasone 8 mg IV when participant's nausea score > 5 out of 10 for 15 min or longer, 2 emetic episodes within 15 min, or at participant's request. No redness residue on acupoint site in any groups. No details about funding source or any declarations of interest among authors. |
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Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | "Randomization was achieved using a random number generator..". |
Allocation concealment (selection bias) | Low risk | "...In a sealed envelope technique". "Study drugs were prepared by the pharmacists not directly involved in the study..". Comments: the authors appeared to take steps to minimize inadequate allocation concealment. |
Blinding of patients (performance bias) All outcomes | Low risk | "All patients were also told that the device produced an electrical current that they may or may not feel. The screen on the unit (measuring 4 x 2 cm) was covered with an opaque tape in all groups so that the clinicians and research personnel were unaware if the unit was on or off". |
Blinding of healthcare providers (performance bias) All outcomes | Low risk | "All patients were also told that the device produced an electrical current that they may or may not feel. The screen on the unit (measuring 4 x 2 cm) was covered with an opaque tape in all groups so that the clinicians and research personnel were unaware if the unit was on or off". |
Blinding of outcome assessor (detection bias) All outcomes | Low risk | "Postoperative data were collected by a separate research nurse not involved in the preoperative or intraoperative management of patients". |
Incomplete outcome data (attrition bias) All outcomes | Low risk | Reasons for withdrawals were given. No missing data reported for the 75 participants analysed. |
Selective reporting (reporting bias) | Low risk | All expected outcomes reported. |
Other bias | Low risk | Baseline characteristics were comparable. "There was no difference in patient demographics among the groups". |