Pit 1996.

Methods	Single‐centre Dutch study
Participants	59 men (mean age 72 years) undergoing transurethral resection of the prostate under spinal anaesthesia
Interventions	Room temperature irrigation fluid (n = 31): resection time 30 minutes Isothermic irrigation fluid (n = 28): resection time 28 minutes
Outcomes	Rectal temperature, preoperative and postoperative haemoglobin concentrations and subjective participant assessment
Notes	No exclusion criteria were described. The data were not useable, as differences between lowest temperature and starting temperature were recorded rather than serial temperature measurements, postoperative haemoglobin rather than estimated blood loss and subjective feeling of cold rather than shivering Volumes irrigated were not stated As a result of the proximity of the rectum and prostate, core temperature measurements at the rectum may be inaccurate
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	'Randomized selection'
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	'The patient was not aware of the temperature treatment he had received until the second post‐operative day'; it was not described whether the investigator was blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not described
Selective reporting (reporting bias)	Low risk	No evidence of this
Other bias	Low risk	None