A prospective manikin-based observational study of telephone-directed cardiopulmonary resuscitation

Abstract

Bystander cardiopulmonary resuscitation (CPR) significantly improves the outcome from sudden cardiac arrest (SCA) and is therefore encouraged by offering telephone instructions to the bystander. The effectiveness of this technique was examined in a manikin-based study. Subjects performed CPR on an instrumented adult manikin by following Advanced Medical Priority Dispatch System v11.1 (AMPDS) instructions given by telephone from a different room. Fifty-one volunteers (26 males, median age 56, range 27-76 years) with no previous experience of CPR were recruited. No volunteers followed the entire instructions correctly. Forty percent were unable to open the airway, only 18% achieved a median inspiration time of 2 s or greater and only 30% delivered tidal volumes within the range 700-1000 ml. Chest compressions were performed at a median rate of 52 min-1 with only 4% of subjects achieving a rate of 100 min-1. Depth of compression was also inadequate in 88% of subjects and hand positioning was incorrect in a third of subjects. The median duty cycle was 46% and there were significant delays between the commencement of the AMPDS protocol and the delivery of the first breath (123 s) and first chest compression (163 s). Few bystanders perform CPR satisfactorily and further work is necessary to improve the effectiveness of telephone CPR instructions.