Mesure sur banc d'essai des FIO 2 délivrées par la CPAP Boussignac alimentée en oxygène pur

Abstract

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 FIO 2 is available. Objective. – To measure the FIO 2 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 FIO 2 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·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 cmH 2O EPAP, the required oxygen flow is ≤ 30 l min –1. Measured FIO 2 ranges from 70 to 100 vol %, for a volume per minute ≤ 15 l min –1 except for a EPAP at 2.5 cmH 2O with a rate = 10 c min –1 and a tidal volume (VT) at 1500 ml where the measured FIO 2 is 60 vol %. For a volume per minute > 15 l min –1 and < 20 l min –1, measured FIO 2 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 FIO 2 , 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.