Summary of findings 5.
Continous intravenous local anaesthetic infusion for the prevention of persistent pain after breast cancer surgery
| Should continuous intravenous local anaesthetic infusion or conventional pain control be used for the prevention of persistent pain after breast cancer surgery | ||||||
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Patient or population: women with breast cancer undergoing elective surgery Settings: university hospitals in Ireland and the USA Intervention: continuous intravenous local anaesthetic infusion Comparison: conventional pain control | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Control | Continous intravenous local anaesthetic infusion | |||||
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Persistent pain 3 to 6 months after breast cancer surgery (We defined persistent postsurgical pain as new pain that did not exist before the operation, measured using differences in scores based on validated pain scales; patient interview between 3 to 6 months after surgery.) |
Study population | OR 0.24 (0.08 to 0.69) | 97 (2 studies)1 | ⊕⊕⊕⊝ moderate1 | Event rates of persistent pain after breast cancer surgery ranged in this population between 20% to 40%. One in three women benefited on average from continuous intravenous infusion of local anaesthetics after breast cancer surgery. |
|
| 370 per 1000 | 123 per 1000 (45 to 288) | |||||
| Low | ||||||
| 200 per 1000 | 57 per 1000 (20 to 147) | |||||
| High | ||||||
| 600 per 1000 | 265 per 1000 (107 to 509) | |||||
| Adverse effects of continuous local anaesthetic infusion ‐ not reported | See comment | See comment | Not estimable | ‐ | See comment | Adverse effects of intravenous infusion of local anaesthetics after breast cancer surgery were not systematically reported and due to their low frequency are better investigated in registries. |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (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; OR: odds ratio | ||||||
| GRADE Working Group grades of evidence High quality: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of effect, but there is a possibility that it is substantially different. Low quality: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of effect, but there is a possibility that it is substantially different. Very low quality: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
1We downgraded quality of evidence by one level because conclusions may be considerably weakened by the small number of studies included. These two studies are however consistent and of high methodological quality. Still, meta‐analysis results based on small numbers tend to overestimate the effects.