Abstract 36: Professional Rescuers provide two Bag-Valve-Mask Ventilations within the Time recommended by Guidelines during Out-Of-Hospital Cardiac Arrest
Aims: The quality of CPR performed by professional rescuers during out-of-hospital cardiac arrest has been found substandard in several studies. In particular, the time without chest compressions (no flow time) has been too long and it has been higher before the time of intubation. In manikin-studies lay rescuers need approximately 15 seconds to deliver two ventilations. It is not known how long time professional rescuers use for two ventilations and we hypothesized that time used for two ventilations with a bag-valve-mask device before endotracheal intubation is longer than recommended, and that the extended time contributes to the high no flow time.
Methods: Quality of CPR was available for analysis in 628 cases of out-of-hospital cardiac arrest in the ambulance service in Oslo, Akershus, London, and Stockholm from 2002–2005. The 2000 Guidelines was used as reference. Ventilations were registered via changes in transthoracic impedance as measured via the standard defibrillation pads. We only included episodes with CPR with a 15:2 pattern for at least one minute and registered all pauses between chest compressions before intubation.
Results: In 172 (27%) episodes we identified 3097 chest compression pauses. In 1587 (51%) of the pauses we identified two ventilations and a mean pause length for each episode was calculated. The median of these means was 5.5 s (IQR; 4.5, 7). These pauses comprised only a median 14% (IQR 6%, 30%) of the no flow time before intubation in these episodes. In 892 (29%) of the pauses we identified a different number of ventilations, or other interventions in addition to ventilation. In the remaining 618 pauses (20 %) no ventilations were registered.
Conclusions: It is achievable to deliver two bag-valve-mask ventilations close to the recommended 5 seconds during out-of-hospital cardiac arrest for professional rescuers. However, only half of the pauses were used for two ventilations in accordance with Guidelines. Excessive time for ventilation can not explain the high no flow time during CPR by professional rescuers before intubation.