Survival outcomes with the introduction of intravenous epinephrine in the management of out-of-hospital cardiac arrest.
OBJECTIVE
The benefit of epinephrine in cardiac arrest is controversial and has not been conclusively shown in any human clinical study. We seek to assess the effect of introducing intravenous epinephrine on the survival outcomes of out-of-hospital cardiac arrest patients in an emergency medical services (EMS) system that previously did not use intravenous medications.


METHODS
This observational, prospective, before-after clinical study constitutes phase II of the Cardiac Arrest and Resuscitation Epidemiology project. Included were all patients who are older than 8 years, with nontraumatic out-of-hospital cardiac arrest conveyed by the national emergency ambulance service. The comparison between the 2 intervention groups for survival to discharge was made with logistic regression and expressed in terms of the odds ratio (OR) and the corresponding 95% confidence interval (CI).


RESULTS
From October 1, 2002, to October 14, 2004, 1,296 patients were enrolled into the study, with 615 in the pre-epinephrine and 681 in the epinephrine phase. Demographic and EMS characteristics were similar in both groups. Forty-four percent of patients received intravenous epinephrine in the epinephrine phase. There was no significant difference in survival to discharge (pre-epinephrine 1.0%; epinephrine 1.6%; OR 1.7 [95% CI 0.6 to 4.5]; adjusted for rhythm OR 2.0 [95% CI 0.7 to 5.5]); return of circulation (pre-epinephrine 17.9%; epinephrine 15.7%; OR 0.9 [95% CI 0.6 to 1.2]), or survival to admission (pre-epinephrine 7.5%; epinephrine 7.5%; OR 1.0 [95% CI 0.7 to 1.5]). There was a minimal increase in scene time in the epinephrine phase (10.3 minutes versus 10.7 minutes; 95% CI of difference 0.02 to 0.94 minutes).


CONCLUSIONS
We were unable to establish a significant survival benefit with the introduction of intravenous epinephrine to an EMS system. More research is needed to determine the effectiveness of drugs such as epinephrine in resuscitation.
Ong
Marcus Eng Hock
ME
Department of Emergency Medicine, Singapore General Hospital, Singapore City, Singapore. marcus.ong.e.h@sgh.com.sg
Tan
Eng Hoe
EH
Ng
Faith Suan Peng
FS
Panchalingham
Anushia
A
Lim
Swee Han
SH
Manning
Peter George
PG
Ong
Victor Yeok Kein
VY
Lim
Steven Hoon Chin
SH
Yap
Susan
S
Tham
Lai Peng
LP
Ng
Kheng Siang
KS
Venkataraman
Anantharaman
A
D016001:Confidence Intervals; D004632:Emergency Medical Services / Q000379:methods* / Q000706:statistics & numerical data; D004837:Epinephrine / Q000008:administration & dosage*; D005260:Female; D006323:Heart Arrest / Q000188:drug therapy* / Q000401:mortality*; D006801:Humans; D007262:Infusions, Intravenous; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care; D011446:Prospective Studies; D012846:Singapore / Q000453:epidemiology; D016019:Survival Analysis; D014662:Vasoconstrictor Agents / Q000008:administration & dosage*
D014662:Vasoconstrictor Agents; D004837:Epinephrine