The effect of two modes of mechanical ventilation on cardiopulmonary function in pigs with or without acute lung injury: a comparison of pressure regulated biphasic positive airway pressure ventilation and airway pressure release ventilation / 解放军医学杂志

ABSTRACT

Objective To compare the effect of pressure regulated biphasic positive airway pressure ventilation(BiPAP) and airway pressure release ventilation(APRV) on cardiopulmonary function of pigs with or without acute lung injury. Methods after anaesthesia, 18 healthy pigs were given BiPAP or APRV ventilation through tracheotomy. Inspiration pressure and expiration pressure in BiPAP equal to APRV. Inspiration time and expiration time is 1.5/2.5s in BiPAP and 4.0/2.0s, 4.5/1.5s, 5.0/1.0s, 5.5/0.5s in APRV respectively. Respiration dynamics, hemodynamics, blood gases and oxygen metabolize scales were measured during two mechanical ventilatory modalities pigs acquired from Swam-gans catheter in internal jugular vein and from catheter in femoral artery. Then oleic-induced acute lung injury model was made, modalities pigs were distributed to BiPAP group (n=9) and APRV group (n=8) randomly. Forenamed scales were repeat measured. Results BiPAP has not difference with APRV on respiration dynamics, hemodynamics, blood gases and oxygen metabolize during normal condition, BiPAP has higher cardiac output (CO) and lower oxygen extraction ratio (O2ER) compare with APRV in ALI pigs. If expiration time is short to 0.5s in APRV, it would represent intrinsic peak end-expiratory (PEEPi), heart rate (HR), mean pulmonary arterial pressure (MPAP) and systemic vascular resistance (SVR) increased and CO decreased. Conclusion Both BiPAP and APRV are beneficial in ALI, but BiPAP has fewer side-effect compared with APRV in early ALI.