The optimal tidal volume (VT) during Cardio-Pulmonary Resuscitation (CPR) remains unknown. Capnogram could permit to detect ventilation induced harmful effect. The objectives of the present study were to describe the impact of different VT on hemodynamics during CPR; and to evaluate whether capnogram analysis can assess the influence of ventilation on circulation. Eighteen pigs had five minutes of untreated ventricular fibrillation followed by CPR with automated continuous chest compressions and ventilation settings randomly combining VT 6, 10 or 14ml/kg. Capnograms were recorded to determine thoracic distension patterns. After return of spontaneous circulation (ROSC), all surviving animals were ventilated 2h and lungs were withdrawn for histological analysis. VT was associated with differences in the hemodynamic parameters studied. VT at 6 or 14ml/kg graphically showed poorer cerebral and coronary perfusion pressures and mean arterial pressure than a VT at 10ml/kg. The capnogram could distinguish three levels of thoracic distension. Thoracic distension was associated with differences in the hemodynamic parameters studied. Animals with either low or high distension showed poorer cerebral and coronary perfusion pressures and mean arterial pressure than those with moderate distension. ROSC was obtained in 13 (72%) animals. Histology showed that both low and high VT was associated with a trend towards higher lung damage. In this animal study, a U-shaped relationship observed with VT suggests that both small and large VT may impair circulation. Capnogram analysis could contribute to identify ventilation settings associated with hemodynamic compromise.

To investigate the association between barriers reported by cardiac arrest team members and chest compression quality during in-hospital cardiac arrest (IHCA) cardiopulmonary resuscitation (CPR) attempts. This is a mixed-methods prospective cohort study. We sent post-event debriefing surveys to cardiac arrest team members following resuscitation attempts across four hospitals from 2017 to 2022. Likert-scale ratings and qualitative analysis of free-text comments were used to categorize events as having barriers present. We investigated the association between barriers and key chest compression quality metrics measured from defibrillators. The association was further examined for three predefined barrier categories: CPR quality, teamwork and communication. We included 313 IHCAs with complete defibrillator and survey data, of which 133 (42.5%) events had barriers reported. The odds ratio (OR) of having a CCF ≥80% was 0.55 (95% CI: 0.35-0.89) when barriers were reported. IHCAs with any reported barriers had an increase in the longest pause duration of 3.21s (95% CI: -1.91 to 8.38) compared to IHCAs without reported barriers, while the OR for guideline-compliant compression rate was 1.02 (95% CI: 0.64-1.62). Communication barriers, but not teamwork and CPR quality barriers, were associated with lower odds of guideline-compliant chest compression rates (OR=0.53; 95% CI: 0.29-0.95). Barriers were frequently reported during IHCA and were associated with a significantly lower odds for a CCF ≥80% but not significantly associated with the longest pause duration and guideline-compliant chest compression rates. The category of communication barriers appeared to be the main driver of associations with chest compression quality metrics.