Induction of therapeutic hypothermia by paramedics after resuscitation from out-of-hospital ventricular fibrillation cardiac arrest: a randomized controlled trial.
BACKGROUND
Therapeutic hypothermia is recommended for the treatment of neurological injury after resuscitation from out-of-hospital cardiac arrest. Laboratory studies have suggested that earlier cooling may be associated with improved neurological outcomes. We hypothesized that induction of therapeutic hypothermia by paramedics before hospital arrival would improve outcome.


RESULTS
In a prospective, randomized controlled trial, we assigned adults who had been resuscitated from out-of-hospital cardiac arrest with an initial cardiac rhythm of ventricular fibrillation to either prehospital cooling with a rapid infusion of 2 L of ice-cold lactated Ringer's solution or cooling after hospital admission. The primary outcome measure was functional status at hospital discharge, with a favorable outcome defined as discharge either to home or to a rehabilitation facility. A total of 234 patients were randomly assigned to either paramedic cooling (118 patients) or hospital cooling (116 patients). Patients allocated to paramedic cooling received a median of 1900 mL (first quartile 1000 mL, third quartile 2000 mL) of ice-cold fluid. This resulted in a mean decrease in core temperature of 0.8 degrees C (P=0.01). In the paramedic-cooled group, 47.5% patients had a favorable outcome at hospital discharge compared with 52.6% in the hospital-cooled group (risk ratio 0.90, 95% confidence interval 0.70 to 1.17, P=0.43).


CONCLUSIONS
In adults who have been resuscitated from out-of-hospital cardiac arrest with an initial cardiac rhythm of ventricular fibrillation, paramedic cooling with a rapid infusion of large-volume, ice-cold intravenous fluid decreased core temperature at hospital arrival but was not shown to improve outcome at hospital discharge compared with cooling commenced in the hospital.
Bernard
Stephen A
SA
The Intensive Care Unit, The Alfred Hospital, Commercial Rd, Prahran, VIC 3118, Australia. stephen.bernard@alfred.org.au
Smith
Karen
K
Cameron
Peter
P
Masci
Kevin
K
Taylor
David M
DM
Cooper
D James
DJ
Kelly
Anne-Maree
AM
Silvester
William
W
D000368:Aged; D001831:Body Temperature / Q000502:physiology; D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000639:trends; D004632:Emergency Medical Services / Q000379:methods* / Q000639:trends; D004634:Emergency Medical Technicians / Q000639:trends; D005260:Female; D006323:Heart Arrest / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D006760:Hospitalization / Q000639:trends; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods* / Q000639:trends; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000639:trends; D011446:Prospective Studies; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000150:complications / Q000503:physiopathology / Q000628:therapy*