IMPROVED VENTILATORY FUNCTION IN BURN PATIENTS USING VOLUMETRIC DIFFUSIVE RESPIRATION

BACKGROUND: Volumetric diffusive respiration (VDR) offers theoretical advantages over conventional mechanical ventilation (CV) by using lowe r airway pressures, recruiting alveoli, and mobilizing secretions. STU DY DESIGN: Forty-eight thermally injured pediatric patients with faili ng respiratory status were changed from CV to VDR. Data were obtained just before transition for CV and after stabilization on VDR, within s ix hours of transition. RESULTS: Both ventilation and oxygenation were significantly improved with PaCO2 decreasing from 47+/-3 to 39+/-11 m m Hg and PaO2 increasing from 105+/-8 to 171+/-12 mm Hg after transiti on to VDR. Treatment with the VDR ventilator also resulted in a signif icant decrease in peak inspiratory pressures (PIP) from 52+/-2 to 38+/ -2 cm H2O. The PaO2 to FiO(2) ratio increased from 189+/-16 using CV, to 329+/-21 using VDR, suggesting an improvement in the ventilation an d perfusion matching. Ventilatory efficiency, measured by the PaO2/FiO (2)/PIP ratio, greatly improved after transition from CV to VDR with f raction of inspired oxygen increasing from 3.9+/-0.4 to 10.3+/-1.0. He modynamic function (blood pressure and pulse rate) were not adversely affected by VDR. CONCLUSIONS: The VDR ventilator is more effective tha n conventional ventilation for maintaining optimal gas exchange at low er airway pressures in thermally injured pediatric patients.