Bag-Valve-Mask Ventilation and Survival From Out-of-Hospital Cardiac Arrest: A Multicenter Study

Abstract

Background: Few studies have measured ventilation during early cardiopulmonary resuscitation (CPR) before advanced airway placement. Resuscitation guidelines recommend pauses after every 30 chest compressions to deliver ventilations. The effectiveness of bag-valve-mask ventilation delivered during the pause in chest compressions is unknown. We sought to determine: (1) the incidence of lung inflation with bag-valve-mask ventilation during 30:2 CPR; and (2) the association of ventilation with outcomes after out-of-hospital cardiac arrest. Methods: We studied patients with out-of-hospital cardiac arrest from 6 sites of the Resuscitation Outcomes Consortium CCC study (Trial of Continuous Compressions versus Standard CPR in Patients with Out-of-Hospital Cardiac Arrest). We analyzed patients assigned to the 30:2 CPR arm with ≥2 minutes of thoracic bioimpedance signal recorded with a cardiac defibrillator/monitor. Detectable ventilation waveforms were defined as having a bioimpedance amplitude ≥0.5 Ω (corresponding to ≥250 mL V T ) and a duration ≥1 s. We defined a chest compression pause as a 3- to 15-s break in chest compressions. We compared the incidence of ventilation and outcomes in 2 groups: patients with ventilation waveforms in <50% of pauses (group 1) versus those with waveforms in ≥50% of pauses (group 2). Results: Among 1976 patients, the mean age was 65 years; 66% were male. From the start of chest compressions until advanced airway placement, mean±SD duration of 30:2 CPR was 9.8±4.9 minutes. During this period, we identified 26861 pauses in chest compressions; 60% of patients had ventilation waveforms in <50% of pauses (group 1, n=1177), and 40% had waveforms in ≥50% of pauses (group 2, n=799). Group 1 had a median of 12 pauses and 2 ventilations per patient versus group 2, which had 12 pauses and 12 ventilations per patient. Group 2 had higher rates of prehospital return of spontaneous circulation (40.7% versus 25.2%; P <0.0001), survival to hospital discharge (13.5% versus 4.1%; P <0.0001), and survival with favorable neurological outcome (10.6% versus 2.4%; P <0.0001). These associations persisted after adjustment for confounders. Conclusions: In this study, lung inflation occurred infrequently with bag-valve-mask ventilation during 30:2 CPR. Lung inflation in ≥50% of pauses was associated with improved return of spontaneous circulation, survival, and survival with favorable neurological outcome.

Increasing ventilation in drowning resuscitation − A cross-over randomized simulation study of ventilation during automated external defibrillator analysis pauses

“…This, in addition to increasing the total volume of air without affecting the compression variables, could have an impact on increasing the likelihood of survival and favourable neurological outcome. 17 …”

“… 3 Additionally, providing effective ventilations is not always easy, as there are numerous factors that can influence poor quality (lack of experience, pre-fatigue after a rescue, or prolonged CPR). 17 , 18 Increasing the number of ventilations without affecting the other elements of BLS may compensate, maintain, or increase the success rate of ventilations delivered in prolonged basic life support.…”

A new physiological manikin to test and compare ventilation devices during cardiopulmonary resuscitation

“… 2 Regarding ventilation, areas of uncertainty persist, 3 due to the complex interactions between ventilation and circulation. 2 , 4 A recent study from Idris et al showed that bag valve mask ventilation was often ineffective before advanced airway placement, 5 while a protective ventilation strategy could be preferred to prevent hyperventilation after intubation. 6 Over the years, several CPR ventilation strategies and new medical devices have been proposed, some of them interacting directly with circulation.…”

“Hard and Fast” Resuscitation Guidelines May Need a Bit of “Breathing” Room

“…Although the CCC trial ultimately concluded that continuous chest compressions did not provide significantly higher rates of survival or favorable neurologic function than standard 30:2 CPR, Idris and colleagues in this issue of Circulation demonstrate valuable dividends drawn from the trial’s ambitious methodology. 8 Returning to retained CCC monitor defibrillator data, the authors extracted thoracic bioimpedance signals incorporated into 2 of 3 commercially available monitor defibrillators used in the CCC trial. Using novel, validated technology, these changes in electrical resistance occurring as a victim’s chest expands and contracts during chest compressions can now be used to quantify both the frequency and the volume of ventilation.…”