Time to give the first medication during resuscitation in out-of-hospital cardiac arrest.

OBJECTIVE There is no evidence showing an impact from any advanced cardiac life support (ACLS) medications on patient survival following cardiac arrest. One potential reason for a lack of such benefit may be medication timing. We formed the hypothesis that medications are given late after rescuer arrival, limiting any benefit. We performed a meta-analysis to determine the time from emergency medical services (EMS) dispatch to first medication administration, regardless of route, during out-of-hospital cardiac arrest (OOHCA). Then, the mean time and ranges of reported study medication delivery in clinical trials where medication was the experimental intervention was determined. METHODS We conducted a comprehensive literature review between January 1990 and August 2005 in MEDLINE using the following MeSH headings: cardiopulmonary resuscitation, cardiac arrest, heart arrest, EMS, EMT, ambulance, and the names of all ACLS medications. We reviewed the abstracts of 632 studies and full manuscripts of 248 published papers. We eliminated the following articles from further analysis: non-peer reviewed; all without human primary data (includes review articles, guidelines or consensus manuscripts, editorials, or simulation studies); animal data; case reports. We used no language restriction. From this search, our independent reviewers found 17 papers that contained information on time to medication administration. RESULTS We analyzed reporting of drug delivery time to 7617 patients in 32 different emergency medical services systems. Time to first medication delivery by any route was a mean of 17.7 min (range 10.0-25.0; 95% CI around mean 10.6, 24.8). Time to intravenous experimental medication administration was a mean of 19.4 min (range 13.3-25.0; 95% CI around mean 12.8, 25.9). CONCLUSIONS Medications are given late during out-of-hospital cardiac arrest, even in cohorts where drug delivery is a key study intervention.