Use of noninvasive mechanical ventilation with pressure support guaranteed with average volume in de novo hypoxaemic...

This study was designed to determine the results associated with the use of noninvasive mechanical ventilation (NIV) using the BiPAP S/T-AVAPS ventilation strategy in subjects with mild to moderate de novohypoxaemicrespiratory failure.

This is a prospective study that includes subjects with de novohypoxaemic respiratory failure (not produced by acute exacerbations of COPD, chronic lung disease, or congestive heart failure) with mild to moderate PaO₂/FiO₂, who were admitted to the Intensive Care Unit (ICU) of Santa Maria Clinic in Guayaquil, Ecuador. Subjects were divided into two groups and compared according to their PaO₂/FiO₂: higher than 100 and up to 200 mm Hg (moderate ARDS) or between 200 and 300 mm Hg (mild ARDS) (both groups were ventilated with the BiPAP S/T-AVAPS strategy). A value of P < 0.05 was considered significant.

A total of 38 subjects were analysed in this study. The total rate of intubation was 34.2% while the mortality rate was 28.9%. Significant differences were observed when comparing success versus failure in exhaled tidal volumes (P = 0.04), peak inspired pressure (P < 0.001), PaO₂ (P < 0.001), SaO₂ (P < 0.002), PaO₂/FiO₂ (P < 0.002), RR (P < 0.001), HR (P < 0.001), and inspiratory time (P = 0.029) measured at baseline and at 12-hour, 24-hour and 48-hour intervals.

The BiPAP S/T-AVAPS ventilatory mode can be used in subjects with de novo hypoxaemic respiratory failure with special vigilance concerning exhaled tidal volumes and inspired pressure.