Table 1 Characteristics of included studies
First author, publication year (site) [reference] | Timing of intervention | Primary cardiac rhythm | Cooling method (intervention) | Cooling methods in-hospital (intervention/control) | Outcome (efficacy and safety) | Outcome (pre-hospital safety) | ||
|---|---|---|---|---|---|---|---|---|
Bernard, 2002 (Australia) [6] | Post-arrest | VF | Application of ice packs to patient’s head and torso | Application of ice packs to patient’s head, neck, torso and limbs. When 33 °C temperature was achieved, ice packs were removed | No cooling implemented pre-hospital or in-hospital | Discharged directly to home or to a rehabilitation facility | Survival/favourable outcome at dischargea | N/A |
Bernard, 2010 (Australia) [17] | Post-arrest | VF | Infusion of up to 2 L of ice-cold lactated Ringer’s solution commenced at 100 ml/minute | Additional 10–20 ml/kg rapid infusion of ice-cold Ringer’s lactate, then surface cooling pads | Rapid infusion of 40 ml/kg of ice-cold Ringer’s lactate, then surface cooling pads | Discharged directly to home or to a rehabilitation facility | Survival/favourable outcome at discharge, temperature at admissiona | Pulmonary oedema |
Bernard, 2012 (Australia) [18] | Post-arrest | Asystole/PEA | Cooled intravenous fluids, ice packs and cooling blankets | Additional 40 ml/kg rapid infusion of ice-cold Hartmann’s solution, then surface cooling pads | 40 ml/kg rapid infusion of ice-cold Hartmann’s solution, then surface cooling pads | Discharged directly to home or to a rehabilitation facility | Survival/favourable outcome at discharge, temperature at admission, pre-hospital survivala | Pulmonary oedema |
Bernard, 2016 (Australia) [11] | Intra-arrest | VF, VT, Asystole, PEA | Infusion of 30 ml/kg cold saline (maximum 2 L) | N/A | N/A | Discharged directly to home or to a rehabilitation facility | Survival at hospital discharge, discharge to home from hospital, proportion of patients in shockable and non-shockable rhythms with ROSCa | Pulmonary oedema |
Castren, 2010 (multi-site) [23] | Intra-arrest | VF, VT, Asystole, PEA | Trans-nasal evaporative cooling | Cooled in hospital according to institutional standards | Cooled in-hospital according to institutional standards | CPC score 1 or 2 | Safety and efficacy of RhinoChill intra-nasal cooling system (BeneChill, San Diego, CA, USA), temperature at admission, ROSC, survival at discharge, neurological functiona | Pulmonary oedema, re-arrest, bleeding |
Debaty, 2014 (France) [22] | Intra-arrest | VF, VT, PEA, Asystole | Up to 2000 ml of ice-cold 0.9% saline solution at 100 ml/minute, then surface cooling using gel pads | Cooling continued with cold saline infusion, cooling mattress, cold air circulation and/or extracorporeal life support | Cooled with cold saline infusion, cooling mattress, cold air circulation and/or extracorporeal life support | CPC score 1 or 2 | Temperature at admission, ROSC, survival and neurological function (discharge/30 days/1 year) | Pulmonary oedema, bleeding, infection, arrhythmia |
Kamarainen, 2009 (Finland) [21] | Post-arrest | VF, VT, PEA, Asystole | 4 °C Ringer’s acetate at approximately 100 ml/minute | Cooling continued at the discretion of hospital physicians | Cooling initiated at the discretion of hospital physicians | CPC score 1 or 2 | Temperature at admission, survival at discharge, neurological functiona | Pulmonary oedema, re-arrest |
Kim, 2007 (United States) [20] | Post-arrest | VF, VT, PEA, Asystole | Up to 2 L of 4 °C normal saline solution | According to physician preferences | According to physician preferences | Absence of severe neurological deficit (undefined) | Temperature at admission, survival at dischargea | Pulmonary oedema, re-arrest |
Kim, 2014 (United States) [19] | Post-arrest | VF, VT, PEA, Asystole | Up to 2 L of 4 °C normal saline solution | Surface and intravascular cooling | Surface and intravascular cooling | Full neurological recovery/mild impairment | Survival at discharge,a neurological functiona and temperature at admission | Pulmonary oedema, re-arrest |
Scales, 2017 (Canada) [12] | Post-arrest | VF, VT, PEA, Asystole | Application of ice packs to neck, axillae and groins, and infusion of up to 2 L of cold saline (0.9% sodium chloride solution at approximately 4 °C) | According to physician preferences | According to physician preferences | mRS 0, 1 or 2 | Successful TTM,a survival to hospital discharge, good neurological outcome, temperature at admission | Pulmonary oedema, re-arrest |