Table 1 Characteristics of the included trials
| Â | Duration | Participants | Experimental intervention | Control intervention | Inclusion criteria | Exclusion criteria | Follow-up time | Patients screened (n) | Patients included (n) |
|---|---|---|---|---|---|---|---|---|---|
Mori 2000 (abstract) [20] | Not reported | OHCA patients with GCS <8 | MIH to 32–34 °C for 72 h, method of cooling not described, rewarming rate not reported | 36 °C for 72 h, method of temperature control not described | OHCA and GCS <8 | Not defined | 1 month | Not reported | 54 |
Hachimi-Idrissi 2001 [22] | 6 months | Unconscious OHCA patients, cardiac cause of arrest, initial rhythm asystole of PEA | Helmet cooling to 34 °C, when temperature of 34 °C achieved or more than 4 h elapsed from start of cooling, passive rewarming for 8 h | Standard ICU care, acetaminophen if temperature over 38 °C | OHCA of cardiac origin asystole or PEA as initial rhythm, >18 years, temp >30 °C, GCS <7 | Pregnancy, coagulopathy, CNS antidepressant medication before CA, cardiogenic shock (MAP <60), GCS ≥7 | 14 days | Not reported | 30 |
HACA 2002 [7] | 65 months | Unconscious CA patients, cardiac cause of arrest, initial rhythm VF or non-perfusing VT | Air cooling induced hypothermia to 33 °C for 24 h, passive rewarming for 8 h | Standard ICU care, no temperature control | Witnessed CA of cardiac origin, VF or non-perfusing VT as initial rhythm, 18–75 years, 5–15 min from arrest to CPR and <60 min to ROSC | <30 °C, coma because of drugs before CA, pregnancy, response to verbal command, MAP <60 for >30 min, hypoxemia >15 min, terminal illness, factors making follow-up unlikely, coagulopathy, other study, CA after arrival of medical personnel | 6 months | 3551 | 275 |
Bernard 2002 [6] | 33 months | Unconscious OHCA patients, cardiac cause of arrest, initial rhythm VF or VT | Ice-pack induced hypothermia to 33 °C for 12 h (started prior to hospital admission), active rewarming for 6 h | Standard ICU care, no temperature control | OHCA with VF as initial rhythm, persistent coma | <18 years for men, <50 years for women, cardiogenic shock <90 SBP despite epinephrine, other causes of coma than CA, no available ICU bed | Hospital discharge | Not reported (84 eligible) | 77 |
Laurent 2005 [21] | 23 months | Unconscious OHCA patients, cardiac cause of arrest, initial rhythm VF or asystole | CVVH to 32–33 °C (CVVH for 8 h and surface cooling for 16 h), passive rewarming | CVVH maintaining 37 °C for 8 h, thereafter no temperature control | OHCA of cardiac origin, VF of asystole, 18–75 years, <10 min to start of CPR, <50 min to ROSC | Pregnancy, response to verbal command, terminal illness before CA | 6 months | 244 | 42 |
Nielsen 2013 [11] | 27 months | OHCA patients with GCS <8 | Ice-cold fluids, ice packs, and intravascular or surface temperature-management devices induced hypothermia to 33 °C for 28 h, gradual rewarming to 37 °C in hourly increments of 0.5 °C, <37.5 °C for unconscious patients until 72 hours after CA | Ice-cold fluids, ice packs, and intravascular or surface temperature-management devices induced hypothermia to 36 °C for 28 h, gradual rewarming to 37 °C in hourly increments of 0.5 °C, <37.5 °C for unconscious patients until 72 hours after CA | OHCA of cardiac origin, GCS <8, >18 years, >20 min of spontaneous circulation after resuscitation | An interval from the ROSC to screening >240 min, unwitnessed arrest with asystole as the initial rhythm, suspected or known acute intracranial haemorrhage or stroke, <30 °C | 180 days | 950 | 939 |