Summary of findings for the comparisons
| Ketamine compared with opioids for prehospital pain management | ||||||
| Patient or population: prehospital pain management setting: prehospital setting in the USA and Vietnam Intervention: ketamine Comparison: opioids | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with opioids | Risk with ketamine | |||||
| Change in pain score assessed with VAS | The mean change in the pain score was 3.1 | The mean change in the pain score in the intervention group was 0.4 less (0.8 less to 0) | – | 308 (1 RCT) | ⨁⨁⨁◯ Moderate † | |
| Change in pain score assessed with NRS scale from: 1 to 10 | The mean change in the pain score was 2.5 | The mean change in pain score in the intervention group was 3 less (3.86 less to 2.14 less) | – | 158 (1 observational study) | ⨁⨁◯◯ Low | |
| Serious adverse events | 51 per 1000 | 0 per 1000 (0 to 0) | Not estimable | 158 (1 observational study) | ⨁⨁◯◯ Very ‡low | |
| Nausea and vomiting | 194 per 1000 | 47 per 1000 (21 to 101) | RR 0.24 (0.11 to 0.52) | 308 (1 RCT) | ⨁⨁⨁◯ Moderate † | |
| Agitation | 14 per 1000 | 112 per 1000 (27 to 474) | RR 7.81 (1.85 to 32.97) | 308 (1 RCT) | ⨁⨁⨁◯ Moderate † | |
| Ketamine and morphine compared with only morphine for prehospital pain management | ||||||
| Patient or population: prehospital pain management setting: prehospital setting in Sweden, France and Australia Intervention: ketamine and morphine Comparison: only morphine | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with only morphine | Risk with ketamine and morphine | |||||
| Change in pain scores Scale from: 1 to 10 | The mean change in pain scores was 3.5 | Mean 1.51 lower (3.36 lower to 0.33 higher) | – | 135 (2 RCTs) | ⨁⨁◯◯ Low§ ‡ | |
| Change in pain scores Scale from: 1 to 10 | The mean change in pain score was 3.1 | Mean 1.3 lower (2.95 lower to 0.35 higher) | – | 27 (1 observational study) | ⨁◯◯◯ Very low§ | |
| Serious adverse events | Not reported | Not estimable | – | – | None of the two studies reported any serious adverse events | |
| Total number of adverse events | 165 per 1 000 | 468 per 1 000 (289 to 764) | RR 2.84 (1.75 to 4.63) | 200 (2 RCTs) | ⨁⨁⨁◯ Moderate¶ | |
| Continuous administration of ketamine compared with ketamine given as a bolus for prehospital pain management | ||||||
| Patient or population: prehospital pain management setting: prehospital setting in France Intervention: continuous administration of ketamine Comparison: ketamine given as a bolus | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with ketamine given as a bolus | Risk with the continuous administration of ketamine | |||||
| Change in pain scores. Scale from 0 to 10 | The mean change in the pain score was 3.1 | The mean change in pain score in the intervention group was 0.6 less (1.84 less to 0.64 more) | – | 63 (1 RCT) | ⨁⨁◯◯ Low** | |
| Serious adverse events | – | – | Not estimable | (One study) | – | No serious events were reported |
| Nausea and vomiting | 91 per 1000 | 0 per 1000 (0 to 0) | Not estimable | 63 (1 RCT) | ⨁⨁◯◯ Very low†† | |
| Ketamine and nitrous oxide compared with only nitrous oxide for prehospital pain management | ||||||
| Patient or population: prehospital pain management setting: prehospital setting in Canada Intervention: ketamine and nitrous oxide Comparison: only nitrous oxide | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with only nitrous oxide | Risk with ketamine and nitrous oxide | |||||
| ≥2 point reduction in pain, 15 min | 350 per 1 000 | 634 per 1 000 (427 to 931) | RR 1.81 (1.22 to 2.66) | 120 (1 RCT) | ⨁⨁⨁◯ Moderate‡‡ | |
| ≥2 point reduction in pain, 30 min | 407 per 1 000 | 758 per 1 000 (534 to 1 000) | RR 1.86 (1.31 to 2.66) | 108 (1 RCT) | ⨁⨁⨁◯ Moderate ‡‡ | |
| Serious adverse events | 0 per 1 000 | 0 per 1 000 (0 to 0) | Not estimable | (1 RCT) | – | |
| Total number of adverse events | 233 per 1 000 | 866 per 1 000 (541 to 1 000) | RR 3.71 (2.32 to 5.31) | 120 (1 RCT) | ⨁⨁⨁◯ Moderate‡‡ | |
| Number of patients with adverse events | 200 per 1 000 | 616 per 1 000 (358 to 1 000) | RR 3.08 (1.79 to 5.31) | 120 (1 RCT) | ⨁⨁⨁◯ Moderate‡‡ | |
*The risk in the intervention group (and its 95% CI) assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). GRADE Working Group grades of evidence: high certainty: we are very confident that the true effect is similar to that of the estimated 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 estimated effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimated effect.
†Downgraded one level for high risk of bias,.
‡Downgraded one level for imprecision, Only four events and all four of them in the same group. There were no events in the other group and therefore RR cannot be estimated.
§Downgraded one level for imprecision, This cohort only has 27 patients included.
¶ Downgraded one level for risk of bias due to unclear randomisation and open label design.
** Downgraded one level for imprecision, one study included with 63 patients.
††Downgraded one level for imprecision, Only three events.
‡‡Downgraded one level for imprecision, only one study with a total of 120 patients. There are also large effects, but with unclear blinding we do not upgrade.
NRS, numeric pain rating scale; RCT, randomised controlled trial; VAS, visual analogue scale.