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 (FiO(2)) 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 [Formula: see text] Three levels of PEEP were tested: 7, 10 and 13 cmH(2)O. The following devices were tested: Boussignac, Boussignac with reservoir but without supplementary oxygen, Boussignac with reservoir and 10 (SUPER-Boussignac(10)) and 30 l/min (SUPER-Boussignac(30)) of supplementary oxygen.
In each step we measured FiO(2), tidal volumes, and airway pressure.
RESULTS:
FiO(2) increased with PEEP and decreased at increasing [Formula: see text] with all the systems. However, FiO(2) increased with SUPER-Boussignac(10) (7-10%) and with SUPER-Boussignac(30) (10-30%). Moreover, in the latter case, for [Formula: see text] values up to 60 l/min, FiO(2) became independent of [Formula: see text] 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.
2009-01-26
ENG.
Intensive care medicine
Department of Experimental Medicine (DIMS), University of Milan-Bicocca, Via Cadore 48, 20052, Monza (MI), Italy, giacomo.bellani1 [at] unimib.it.
Intensive Care Med. 24 Jan 2009
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