Quality of on-site performance in prehospital advanced cardiac life support (ACLS)

Abstract

The aim of our prospective study was to assess the structural and procedural quality of an urban emergency medical services (EMS) system providing prehospital basic and advanced cardiac life support (BLS/ACLS), to compare the onsite performance of physicians and non-physicians in ECG diagnosis and defibrillation, and to identify incidence and causes of avoidable delays in the initial treatment sequences. Methods: Between 1 February 1991 and 1 July 1992, 162 on-line tape recordings of prehospital cardiopulmonary resuscitation (CPR) efforts performed by the staff of the EMS system of the city of Mainz were evaluated. After arrival at the patient's side, time intervals to initial ACLS steps (first ECG-diagnosis, first defibrillation, endotracheal intubation, first epinephrine administration) were measured. Times to rhythm identification and countershock by EMT-Ds vs. physicians were compared (Mann-Whitney U- test). Time intervals are presented as median values. One-hundred sixty-two adult patients with out-of-hospital cardiac arrests (ventricular fibrillation [VF] or ventricular tachycardia [VT], 72; asystole or electromechanical dissociation [EMD], 90) receiving CPR by EMTs, EMT-Ds, and physicians of the Mainz EMS were included. Patients with arrests due to non-cardiac aetiologies were excluded. Results: After arrival at the patient's side, for patients with VF/VT, the EMT-Ds took 1:36 min and the physicians took 1:00 min to obtain the first ECG diagnosis ( P = 0.004). The first countershock was delivered within 1:42 min by both EMT-Ds and physicians of the mobile intensive care unit (MICU). After diagnosis was established, the EMT-Ds took 0:08 min to defibrillate, whereas the physicians took 0:36 min ( P = 0.0001). Endotracheal intubation was performed within 3:30 min, and epinephrine was administered within 3:56 min. In patients with asystole or EMD, the first ECG-diagnosis was obtained within 0:48 min by both EMT-Ds and physicians. Patients were intubated within 2:44 min, and received epinephrine within 3:24 min. Conclusions: Since there is no consensus yet about the methods of EMS evaluation and comparison of ACLS time intervals, reliable reference data are lacking. Yet we found that in cases of VF/VT, physicians equipped with manual defibrillators obtain the diagnosis earlier than EMT-Ds equipped with semi-automatic devices, but deliver the first shock later. Another delay manifested itself in cases of asystole or EMD, between ECG-diagnosis and intubation or epinephrine administration. Possible causes for such delays in ACLS sequences are problems in communication between physicians and EMTs. As a result of this study, our EMS system has implemented rehearsals of taped real codes in our megacode training.