Abstract P18: Automated High Frequency Ventilation During Experimental CPR: A New Approach to Resuscitation
Purpose: Experimental and clinical studies suggest manual over-ventilation during cardiopulmonary resuscitation (CPR) is common and reduces maximum obtainable ‘cardiac output’ from chest compressions. Automated ventilation during CPR has not been previously tested.
Methods: This study compared hemodynamic (using solid state Millar transducers), gas exchange, and ventilation parameters during experimental CPR using 100% O2 and manual bag ventilation (6 – 8 breaths/min) compared to automated ventilation using a compressed gas powered, non-electronic, pressure limited, pressure and flow triggered device (Oxylator, CPR Medical Devices) set at maximum inspiratory pressure of 12 mmHg, PEEP = 1.5 mmHg, max flow 30 L/min. The device automatically delivers inhalations when airway pressure falls to 1.5 mmHg and stops when pressure reaches 12 mmHg, delivering 1 breath for every decompression during manual chest compression. Twelve pigs underwent 5 min of electrically induced, untreated ventricular fibrillation (VF). They were randomly assigned to CPR using manual or automated ventilations (n = 6 each), together with continuous manual chest compressions at 95 – 110/min, 3 – 5 cm depth. Carotid artery flow was measured using a Doppler flow probe. All measures were made after 2 min of CPR.
Results: Ventilatory and hemodynamic parameters for manual vs. automated ventilation during CPR
Conclusion: Automated high frequency, low pressure ventilation during experimental CPR is associated with hemodynamics and gas exchange similar to that achieved with guideline recommended manual ventilation and avoids the risk of over-ventilation and barotrauma.