ASSESSMENT OF NEONATAL VENTILATOR PERFORMANCES

Objective: To analyze efficiency and reliability of 4 modern neonatal ventilators;under difficult test conditions. The ventilators tested we re: Babylog 8000 (Drager Medical), BP 2001 (Bear Medical Systems), Sec hrist IV 100 B (Sechrist Industries), Infant Star (Infrasonics INC). M easurements and results: Gas flow generation was tested by comparison of preset flow values with no resistance in the circuit to flow values obtained during interposition of a resistance in the inspiratory circ uit. A decrease in gas flow was observed when interposition of a resis tance in the inspiratory circuit increased peak inspiratory pressure t o 60 cmH(2)O (gas flow decreased by 8% to 24% depending on the ventila tor tested). The pressure limiting valve and the positive end-expirato ry pressure valve were also evaluated in order to test their behaviour under different flow conditions. Flow-dependence of the pressure was noted for all ventilators except Babylog 8000. Assessment of the relia bility of pressure monitoring revealed either 'under' or 'over' estima tion of peak inspiratory pressure and positive end-expiratory pressure depending on the ventilator tested. Conclusion: For the best clinical use of mechanical ventilators, neonatologists should be aware of thes e limitations. Therefore a regular assessment of ventilator performanc e and monitoring reliability is recommended.