Summary of findings 1. Automated mandatory bolus versus basal infusion for maintenance of epidural analgesia in labour.
| Automated mandatory bolus versus basal infusion for maintenance of epidural analgesia in labour | |||||
| Patient or population: term, pregnant women (nulliparous, or combination of nulli‐ and muliparous) requesting for labour epidural analgesia Setting: labour ward Intervention: programmed intermittent boluses (after initiation with combined spinal‐epidural, or epidural alone) Comparison: continuous infusion (after initiation with combined spinal‐epidural, or epidural alone) | |||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | |
| Risk with basal infusion | Risk with automated mandatory boluses | ||||
| Breakthrough pain assessed with: need for anaesthetic intervention during labour epidural analgesia | Study population | RR 0.71 (0.55 to 0.91) | 1528 (16 RCTs) | ⊕⊕⊕⊝ Moderatea | |
| 285 per 1000 | 202 per 1000 (157 to 259) |
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| Caesarean delivery during labour epidural analgesia | Study population | RR 0.85 (0.69 to 1.06) | 1735 (16 RCTs) | ⊕⊕⊕⊝ Moderateb | |
| 173 per 1000 | 147 per 1000 (120 to 184) |
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| Instrumental delivery during labour epidural analgesia | Study population | RR 0.85 (0.71 to 1.01) | 4550 (17 RCTs) | ⊕⊕⊕⊝ Moderateb |
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| 95 per 1000 | 81 per 1000 (68 to 96) |
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| Duration of labour analgesia in minutes | The mean duration of labour in min ranged from 186.3 to 689.9 min | MD 8.81 min lower (19.38 lower to 1.77 higher) | — | 4544 (17 RCTs) | ⊕⊕⊕⊝ Moderateb |
| Local anaesthetic consumption per hour (mg/hr)c during labour epidural analgesia | The mean local anaesthetic consumption per hour ranged from 3.0 mg to 16.2 mg | MD 0.84 mg/h lower (1.29 lower to 0.38 lower) | — | 1642 (16 RCTs) | ⊕⊕⊕⊝ Moderatec,d |
| Maternal satisfaction following fetal delivery | Eight studies (five reported dichotomous data, three reported ordinal data) reported increased maternal satisfaction with automated mandatory boluses compared to basal infusion, while six studies found no difference between the groups. | 14 RCTs | ‐ | ||
| Apgar scores at 1‐ and 5‐minutes following fetal delivery | None of the studies reported any significant difference in Apgar scores | 14 RCTs | ‐ | ||
| *The risk in the intervention group (AMB) (and its 95% confidence interval) is based on the assumed risk in the comparison group (BI) and the relative effect of the intervention (and its 95% CI). Assumed comparator risks for dichotomous outcomes were derived from the median outcome incidence in patients receiving basal infusion within the studies included in this systematic review. AMB: automated mandatory bolus; CI: confidence interval; MD: mean difference; 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. | |||||
a Downgraded one level due to high statistical heterogeneity for this outcome, i.e. I2 = 57%.
b Downgraded one level due to imprecision, i.e. the wide range from upper to lower confidence limits and the 95% CI overlaps no effect.
c Converted into bupivacaine equivalents to account for variation in the type of local anaesthetic utilised.
d Downgraded one level due to high statistical inconsistency for this outcome, i.e. I2 = 87%.