Evaluating the Effectiveness of Dispatch‐assisted Cardiopulmonary Resuscitation Instructions

• Published in: Academic emergency medicine 2007-10, Vol.14 (10), p.877-883
• Main Authors: Vaillancourt, Christian, Verma, Aikta, Trickett, John, Crete, Denis, Beaudoin, Tammy, Nesbitt, Lisa, Wells, George A., Stiell, Ian G.
• Format: Article
• Language: English
• Subjects: cardiopulmonary resuscitation; emergency medical service communication systems; heart arrest
• ISSN: 1069-6563; 1553-2712
• DOI: 10.1197/j.aem.2007.06.021

Objectives: To determine the frequency of agonal breathing during cardiac arrest (CA), its impact on the ability of 9‐1‐1 dispatchers to identify CA, and the impact of dispatch‐assisted cardiopulmonary resuscitation (CPR) instructions on bystander CPR rates. Methods: A before‐after observational study enrolling out‐of‐hospital adult CA patients where resuscitation was attempted in a single city with basic life support with defibrillation/advanced life support tiered emergency medical services. Victim, caller, and system characteristics were measured during two successive nine‐month periods before (control group) and after (intervention group) the introduction of dispatch‐assisted CPR instructions. Results: There were 529 CAs between July 1, 2003, and December 31, 2004. Victim characteristics were similar in the control (n= 295) and intervention (n= 234) period; mean age was 68.3 years; 66.7% were male; 50.1% of CAs were witnessed; call‐to‐vehicle stop was 6 minutes, 37 seconds; ventricular fibrillation/ventricular tachycardia occurred in 29.9%; and the survival rate was 4.0%. Dispatchers identified 56.3% (95% confidence interval [CI] = 48.9% to 63.0%) of CA cases; agonal breathing was present in 37.0% (95% CI = 30.1% to 43.9%) of all CA cases and accounted for 50.0% (95% CI = 39.1% to 60.9%) of missed diagnoses. Callers provided ventilations in 17.2% and chest compressions in 8.3% of cases as a result of the intervention. Long time intervals were observed between call to diagnosis (2 minutes, 38 seconds) and during ventilation instructions (2 minutes, 5 seconds). Bystander CPR rates increased from 16.7% in the control phase to 26.4% in the intervention phase (absolute rate, 9.7%; 95% CI = 8.5% to 11.3%; p = 0.006). Conclusions: This trial demonstrates an increase in bystander CPR rate after the introduction of dispatch‐assisted CPR. Agonal breathing occurred frequently and had a negative impact on the recognition of CA. There were long time intervals between call initiation and diagnosis of CA and during mouth‐to‐mouth ventilation instructions.