Identification of agonal breathing by dispatchers to improve the detection and treatment of cardiac arrest

Background

In as many as 40% of applicable out-of-hospital cardiac arrest (OOHCA) cases, bystanders do not receive instructions over the telephone from public safety dispatchers to perform cardiopulmonary resuscitation (CPR) because the bystanders report that the patient is 'breathing' due to the presence of agonal respirations.

Objective

To determine whether a new dispatcher assessment protocol could better identify agonal breathing and thus more cases of OOHCA that might benefit from CPR instructions.

Methods

Study of all dispatcher-assisted OOHCA cases in a large municipality (population 1.2 million) for the 8 months before and 4 months after protocol implementation (November 2003). In the protocol, the call-taker asks about gasping defined as either 'slow, barely breathing' or 'slow, noisey/gurgling'. If unsure, the caller places the telephone near the patient's mouth and the dispatcher listens for breathing, or the bystander is asked to state each time the patient takes a breath.

Results

Among 962 consecutive patients identified as having OOHCA (57% male, 43% female; mean age 63 ± 17 years, range 17–106), the presenting rhythm was ventricular fibrillation or pulseless electrical activity in 85% of those identified with agonal breaths versus 46% without them (P = 0.002) and such presentations had a higher rate of survival to hospital admission (P < 0.0001). After protocol introduction, the percentage of OOHCA patients thought to be 'breathing' normally fell from 28% (168/599) to 19% (68/362; P = 0.0012). Also, in the 8 months before the protocol, no patient had their agonal respirations detected compared with 22 patients detected in the 4 months afterwards (P < 0.0001). No adverse problems were reported from the subsequent performance of CPR in these agonal breathing cases.

Conclusion

Introduction of a supplemental dispatcher assessment protocol (that includes questioning about agonal respirations) can significantly increase cardiac arrest detection over the telephone, thus increasing the opportunity for dispatchers to provide CPR instructions for those very patients who, in fact, may a higher propensity for survival than the average OOHCA patient (i.e. those with agonal respirations).