An improved Boussignac device for the delivery of non-invasive CPAP: The SUPER-Boussignac

Description

Purpose: The purpose of this study is to describe and test a modified Boussignac system for non-invasive continuous positive airway pressure, aimed at reducing the decrease in inspiratory oxygen fraction (FiO2) with higher inspiratory peak flow rates. Methods: We modified a Boussignac circuit by inserting a T-piece between the Boussignac valve and the face mask. The T-piece was connected to a reservoir balloon receiving oxygen by an independent source. The system was tested in a bench study, consisting of five steps, with increasing inspiratory peak flow rates (Vinsp). Three levels of PEEP were tested: 7, 10 and 13 cmH2O. The following devices were tested: Boussignac, Boussignac with reservoir but without supplementary oxygen, Boussignac with reservoir and 10 (SUPER-Boussignac10) and 30 l/min (SUPER-Boussignac30) of supplementary oxygen. In each step we measured FiO2, tidal volumes, and airway pressure. Results: FiO2increased with PEEP and decreased at increasing Vinspwith all the systems. However, FiO2increased with SUPER-Boussignac10(7-10%) and with SUPER-Boussignac30(10-30%). Moreover, in the latter case, for Vinspvalues up to 60 l/min, FiO2became independent of Vinsp. The SUPER-Boussignac allowed also smaller drop in airway pressure during inspiration and higher tidal volumes. Conclusions: The SUPER-Boussignac represents a simple way to significantly improve the performance of the Boussignac device. © 2009 Springer-Verlag.

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