Background: In our recent study professional rescuers only delivered chest compressions 39% of the available time before intubation during out-of-hospital cardiac arrest.1 We have investigated if this could be explained by the time used for two ventilations in a 15:2-pattern with bag-valve-mask (BVM).Methods: Quality of CPR was registered by a modified defibrillator in 284 cardiac arrest episodes between 2002 and 2004 in the Akershus, London and Stockholm ambulance services following 2000 guidelines. All pauses between compressions before intubation were studied.Results: In 710 (30%) of 2338 compression pauses we found two ventilations with mean of the mean pause duration in each episode 6 ± 3 s. In 415 (18%) pauses one ventilation was given, in 455 (20%) pauses zero ventilations, and in 216 (9%) pauses more than two (range; 3 – 16), while 542 (23%) pauses included additional interventions such as defibrillations and rhythm analyses.Conclusions: While lay rescuers required 14 ± 1 s for two ventilations during single rescuer CPR,2 professional rescuers delivered two BVM ventilations during compression pauses close to the recommended four seconds, but only 30% of the pauses were used for ventilations in a 15:2-pattern. Most of the no-flow time during CPR was due to pauses with other activities and pauses with an insufficient/excessive number of ventilations.References: 1. Kramer-Johansen, Wik L, Steen PA. Advanced cardiac life support before and after tracheal intubation – direct measurements of quality. Resuscitation 2005;68:61-9. 2. Heidenreich JW, Higdon TA, Kern KB et al. Single-rescuer cardiopulmonary resuscitation: “Two quick breaths” – an oxymoron. Resuscitation 2004;62:283-9.