Abstract 14195: Physiological Ventilation Volume Improves Return of Spontaneous Circulation in a Pig Model of Eight-minute Untreated Cardiac Arrest
Background: It is not known whether the duration of cardiac arrest affects the ventilatory requirements during CPR.
Hypothesis: For prolonged cardiac arrest, current recommended ventilation pattern is nonideal for satisfactory results during CPR.
Methods: In 32 pigs (intubated and ventilated with a tidal volume of 10 mL/kg and a frequency which maintained PETCO2 between 35 and 40 mmHg), ventricular fibrillation (VF) was induced and chest compressions (CC) were started after 4min or 8min. Sixteen pigs of 4min VF randomly received mechanical ventilation with a tidal volume of 7 mL/kg and a frequency of 10/min (Guideline-4, n=8) or the same tidal volume and frequency as baseline (Baseline-4, n=8). Sixteen pigs of 8min VF had similar groups (Guideline-8 and Baseline-8). Following 10min uninterrupted CC and mechanical ventilation, up to three defibrillations was administered. Measurements were taken at baseline, 5th and 10th minute of CC.
Results: Ventilation in Baseline-4 (minute ventilation 5.7±1.0 L/min) resulted in higher PHa, PaO2, mean airway pressure, and lower PaCO2, SvO2, and PETCO2 than Guideline-4 (2.3±0.4 L/min) both at the 5th and 10th minute of CC (p<0.05). Higher cerebral blood flow and coronary perfusion pressure were observed in Guideline-4 only at the 5th minute of CC (p<0.05). Return of spontaneous circulation (ROSC) rates (100%) were the same in two groups of 4min VF. Ventilation in Baseline-8 (6.1±1.0 L/min) resulted in higher PHa, PaO2, PHv, mean airway pressure, and lower PaCO2 and PvCO2 than Guideline-8 (2.4±0.5 L/min) both at the 5th and 10th minute (p<0.05).
Hemodynamic parameters were not statistically different between two groups of 8min VF (p<0.05). Higher ROSC was observed in Baseline-8 than Guideline-8 (87.5% vs 37.5%, p=0.039).
Conclusions: For 4min VF pig models, guideline-based ventilation was proper during CPR, however, physiological ventilation volume resulted in higher ROSC during CPR for 8min VF.
Author Disclosures: D. Tan: None. Y. Fu: None. S. Shao: None. F. Sun: None. J. Xu: None. H. Zhu: None. X. Yu: None.
- © 2016 by American Heart Association, Inc.