Kim 2007.

Methods	Parallel‐group, randomized trial, November 2004 to February 2006, multicentre study
Participants	Total number of participants 125, mean age 66 years, 30% female, patients' average temperature at randomization: pre‐hospital cooling group 35.8°C, hospital cooling group: 35.5°C Inclusion criteria: out‐of‐hospital cardiac arrest cause of cardiac arrest: any primary rhythm: any unresponsive return of spontaneous circulation with palpable pulses age older than 17 years intubated and intravenous access available oesophageal temperature probe Exclusion criteria: already hypothermic (temperature < 34°C) cardiac arrest after trauma
Interventions	Pre‐hospital induction of cooling (32°C to 34°C): up to 2 L of 4°C normal saline after resuscitation Control: standard care with and without hypothermia
Outcomes	Primary: temperature differences field‐hospital Secondary: re‐arrests after randomization deaths before hospital admission in‐hospital death neurological outcome (severe neurological deficit) time to awakening, discharge, death safety data
Funding	This work was supported by a grant from the Medic One Foundation and National Institutes of Health grant HL04346 (F.K.)
Declarations of interest	None
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"...balanced blocks of 4"
Allocation concealment (selection bias)	Low risk	Paramedics called the emergency department physician at Harborview Medical Center to verify eligibility and to learn treatment assignment. The emergency room physician opened sequentially numbered envelopes that randomized participants to either receive or not receive cooling.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Treating ambulance and in‐hospital staff were not blinded
Blinding of outcome assessment (detection bias) Good neurological outcome	High risk	Study personnel during data collection and analysis could not be entirely unaware of treatment assignment
Blinding of outcome assessment (detection bias) Survival	Low risk	Lack of blinding of survival data considered 'low risk'
Blinding of outcome assessment (detection bias) Adverse events	Unclear risk	Not stated
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomized participants analysed for primary outcome
Selective reporting (reporting bias)	Unclear risk	Of participants discharged alive, only severe neurological deficit was reported, but not in detail (neurological scores missing)
Other bias	High risk	Of all 63 participants assigned to pre‐hospital cooling only 12 (20%) received full 2 L, 37 participants received between 500 mL and 2 L, 6 participants received 500 mL, 8 participants (13%) did not receive any fluid Primary endpoint of study was temperature differences on admission and not mortality Only 61% of all participants received in‐hospital cooling; it is unclear how many in which group No information on the conduct of temperature management in the hospital