Table 5
Author, date and countryPatient groupStudy type (level of evidence)OutcomesKey resultsStudy weaknesses
Bernard SA et al, 1997, Australia22 adults who remained unconscious after return of spontaneous circulation after out of hospital cardiac arrestProspective study with historical control group.Good neurological recovery (Glasgow outcome scale 1 or 2)Hypothermia gp 11/22 versus Normothermia gp 3/22, p<0.05Prospective study with 22 historical controls rather than a randomised control trial
Hypothermia group cooled to 33°C for 12 h and rewarmed over 6 h to 36°CSurvivalHypothermia gp 12/22 versus Normothermia gp 5/22, p<0.05
Yanagawa Y et al, 1998, Japan13 adults with out of hospital cardiac arrest and return of spontaneous circulationProspective studyGood neurological recovery (GOS 1)Hypothermia gp 3/13 versus Normothermia gp 1/15Historical controls rather than randomised study
Core temperature 33–34°C for 48 h. Rewarmed to 37°C at 1 °C/day.SurvivalHypothermia gp 7/13 versus Normothermia gp 5/15, p = 0.27
Control group 15 patients treated before the hypothermia protocol was started
Bernard SA et al, 2002, Australia77 adults who remained unconscious after resuscitation from out of hospital cardiac arrestRandomised control trialGood neurological recovery (GOS 1–2)Hypothermia gp 21/43 versus normothermia gp 9/34, p = 0.046Odd and even day prehospital randomisation
hypothermia to 33°C for 12 h versus normothermiaSurvivalHypothermia gp 21/43 versus normothermia 11/34, p = 0.145
The Hypothermia after Cardiac Arrest Study Group, 2002, Europe275 adults with out of hospital cardiac arrest and return of spontaneous circulationRandomised controlled trial with blinded assessment of outcome.Good neurological outcome at 6 months (GOS 1 or 2)Hypothermia gp 75/136 versus normothermia gp 54/137, p  = 0.009Enrolment rate slower than expected. Study ended when funds ran out
Hypothermia to 32–34°C for 24 h then passive rewarming over 8 h versus normothermiaSurvival at 6 months80/136 versus normothermia gp 61/137, p = 0.02