[Laboratory testing measurement of FIO2 delivered by Boussignac CPAP system with an input of 100% oxygen].

INTRODUCTION: CPAP (Continuous Positive Airway Pressure) is one of the treatments of the cardiogenic acute pulmonary edema (cAPE). Among the out-of-hospital used devices, Boussignac CPAP (Vygon) shows a good technical usability, but no analysis of delivered FIO2 is available.
OBJECTIVE: To measure the FIO2 delivered to patient, using Boussignac CPAP with an input of 100 vol % oxygen. Type of study. - Measurement in a laboratory testing. MATERIAL AND
METHOD: Measurement of delivered FIO2 in a three parameters environment: expiratory positive airway pressure (EPAP), respiratory rate (RR) and required oxygen flow (ROF). Laboratory test: 100 vol % oxygen input, with a ball-type flow regulator for oxygen 0-30 l x min(-1) (Mediline), Boussignac CPAP valve with manometer (Vygon), Michigan test lung, ventilator César (Taema), oxygen analysis (Servomex) with paramagnetic sensor, with a response time < 10 s, pneumotachographe (Fleisch v 2).
RESULTS: Under 10 cmH2O EPAP, the required oxygen flow is < or = 30 l x min(-1). Measured FIO2 ranges from 70 to 100 vol %, for a volume per minute < or = 15 l x min(-1) except for a EPAP at 2.5 cmH2O with a rate = 10 c min(-1) and a tidal volume (VT) at 1500 ml where the measured FIO2 is 60 vol %. For a volume per minute > 15 l x min(-1) and < 20 l x min(-1), measured FIO2 ranges from 59 to 83 vol % depending on the variations of RR and VT.
CONCLUSION: Boussignac CPAP with 100 vol % oxygen input, delivers high levels of FIO2, especially for volume per minute values usually met in cAPE. The needed oxygen flow is lower than what is usually required by other CPAP flow generators using the venturi effect that may be used in out-of-hospital medical care.