Cheng 2008.
| Methods | Randomized controlled trial conducted from July 2003 to July 2005 | |
| Participants | Inclusion criteria: women aged >18 years undergoing open hysterectomy or myomectomy. Exclusion criteria: history of tobacco use within the year prior to study entry, uncontrolled hypertension or other CVD, respiratory disease |
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| Interventions | Participants were anaesthetized with isoflurane or propofol. Within each anaesthetic group, the participants were further randomly assigned to receive nasal spray either nicotine 3 mg nasal spray or saline placebo once at the conclusion of surgery (postoperatively) | |
| Outcomes | Primary: pain at 60 minutes post‐surgery, pain at 24 hours post‐surgery, cumulative morphine at 60 minutes post‐surgery, cumulative morphine at 24 hours Secondary: sedation, nausea, vomiting |
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| Notes | Additional data provided by authors | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Method of sequence generation was not described as evidenced by the following quote from the paper: "Subjects were randomly assigned to receive one of two standard anaesthetic regimens", but method of sequence generation was not reported. "Subjects in both anaesthetic arms were further randomly assigned to receive a nasal spray containing either nicotine 3 mg or saline placebo at the conclusion of surgery" |
| Allocation concealment (selection bias) | Low risk | Quote: "The clinical anaesthesiologists was familiarized with both anaesthetic protocols by the research coordinator and then provided with a sealed envelope containing the general anaesthetic protocol assignment. Neither the patient nor the study coordinator was aware of the assignment" |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Outcome data were completely reported. Number and reason withdrawals were reported |
| Selective reporting (reporting bias) | Low risk | No evidenced of selective reporting in the paper. Quote: "The primary outcome variable was NAS [numerical analogue score]", which was reported |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Personnel and participants were blinded |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Quote: "Neither the patient nor the study coordinator was aware of the assignment," but it is unclear if the postoperative nurse was blinded |
| Other bias | Low risk | Described ITT analysis, withdrawals, baseline groups are similar, co‐interventions were avoided or similar, and timing of outcome assessments are similar |