Summary of findings 7. Opioid antagonists compared to placebo for preventing nausea and vomiting.
| Opioid antagonists compared to placebo for preventing nausea and vomiting | ||||||
| Patient or population: preventing nausea and vomiting Setting: in women undergoing regional anaesthesia for caesarean section Intervention: opioid antagonists Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with opioid antagonists | |||||
| Nausea ‐ intraoperative | Study population | ‐ | (0 studies) | ‐ | ||
| see comment | see comment | |||||
| Vomiting ‐ intraoperative | Study population | ‐ | (0 study) | ‐ | ||
| see comment | see comment | |||||
| Nausea ‐ postoperative | Study population | RR 0.75 (0.39 to 1.45) | 120 (1 RCT) | ⊕⊕⊝⊝ LOW 1 | ||
| 267 per 1000 | 200 per 1000 (104 to 387) | |||||
| Vomiting ‐ postoperative | Study population | RR 1.25 (0.35 to 4.43) | 120 (1 RCT) | ⊕⊕⊝⊝ LOW 2 | ||
| 67 per 1000 | 83 per 1000 (23 to 295) | |||||
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio. | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
1 Downgrade 2 for imprecision. Only 28 events out of 120 women in one study. Wide CI crossing line of no difference.
2 Downgrade 2 for imprecision. Only 9 events out of 120 women in one study. Wide CI crossing line of no difference.