Bennett 1994.
| Methods | Design: RCT Operative phase: intraoperative Withdrawals: none Setting: 1 centre (UK) Sample size: 45 Funding: Augustine Medical donated the Bair Hugger blankets and Mallinkrodt the Mono‐therm temperature probes |
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| Participants | Age (mean): 71 years (range 59 – 88) Gender (M/F): 30/15 ASA grade: not stated Surgery type: elective (hip arthroplasty) Surgery duration (mean): > 2 hrs (2 ‐ 2½ hrs) Anaesthesia type: general |
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| Interventions |
Intervention (ABSW): n = 15 Convective warm air blanket (Bair Hugger®, Augustine Medical, USA) Duration: after induction until end of surgery Temperature (max.) at 43°C Body area covered: spread over the trunk, upper limbs and head Control 1: n = 15 Metallized plastic garment (Thermolire®, Techstyles, USA) Duration: after induction until end of surgery Body area covered: head, upper limbs, exposed part of trunk and the non‐operated lower limb Control 2: n = 15 "No form of intraoperative warming" Co‐interventions: all participants received an IV infusion of Hartmann's solution (at ambient temperature) at a rate of 6ml/ Kg/1h. Blood was warmed to 37ºC before infusion Room temperature: 19° to 21ºC |
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| Outcomes | Blood transfusions (ml) N of participants transfused (The paper states that "no complications with FAW were observed") |
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| Notes |
Comparison 1 The two control groups have been merged in the analysis leaving 1 single comparison |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Not reported |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Not reported |
| Baseline comparability of groups | Low risk | To a high extent according to Table 1 |
| Co‐interventions equal between groups | Low risk | Not reported |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | All randomized participants were analysed |
| Selective reporting (reporting bias) | Unclear risk | We did not have access to the protocol, therefore we cannot exclude risk of selective reporting. |
| Other bias | Low risk | |