Hypertonic saline during CPR: Feasibility and safety of a new protocol of fluid management during resuscitation

BACKGROUND AND PURPOSE: In experimental studies infusion of hypertonic saline during cardiopulmonary resuscitation (CPR) increased resuscitation success rate and improved myocardial and cerebral reperfusion during CPR. We tested the feasibility and the safety of this new therapeutic measure in a randomised, preclinical pilot study. METHODS: The study was performed in the EMS system of Bonn after approval of the local ethical committee. Study inclusion criteria were out-of-hospital cardiac arrest (CA) of non-traumatic origin, age > or =18 years, application of adrenaline (epinephrine) during CPR, duration of CA < or = 15 min, and estimated body weight < or = 125 kg. Patients randomly received 2 ml/kg/10 min HHS (7.2% NaCl with 6% hydroxy ethyl starch 200,000/0.5 [HES]) or HES alone. Haemoglobin, blood gases, plasma sodium and potassium concentrations were measured before and 10 min after infusion, and after admission to hospital. Feasibility and safety of the new fluid management was evaluated by looking for side effects and determination of resuscitation success and admission rates. RESULTS: Sixty-six patients were included. After infusion of HHS, plasma sodium concentration increased to 168+/-29 mmol/l at 10 min after application but already decreased to near normal (147+/-5.5 mmol/l) at admission to hospital. Patients receiving HHS showed a trend to higher resuscitation success and hospital admission rates (ROSC: HHS 66.7%, HES 51.5%, p = 0.21; admission: HHS 57.6%, HES 39.4%, p = 0.14). The benefit of HHS was more pronounced if duration of untreated CA was >6 min or if initial rhythm was asystole or pulseless electrical activity (PEA). Negative side-effects were not observed after HHS. CONCLUSIONS: HHS after CA is feasible and safe and might improve short term survival after CPR. However, whether giving HHS could be a useful measure to increase resuscitation success after out-of-hospital CA requires a larger preclinical trial.