Use of noninvasive mechanical ventilation with pressure support guaranteed with average volume in de novo hypoxaemic respiratory failure. A pilot study

Background: 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 novo hypoxaemic respiratory failure. Methods: This is a prospective study that includes subjects with de novo hypoxaemic 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. Results: 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. Conclusion: 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.Background: This study was designed to determine the results associated with the use of noninvasive mechanicalventilation (NIV) using the BiPAP S/T-AVAPS ventilation strategy in subjects with mild to moderate de novo hypoxaemicrespiratory failure. Methods: This is a prospective study that includes subjects with de novo hypoxaemic respiratory failure (not producedby 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 200mm Hg (moderate ARDS) or between 200 and 300 mm Hg (mild ARDS) (both groups were ventilated with the BiPAPS/T-AVAPS strategy). Results: A total of 38 subjects were analysed in this study. The total rate of intubation was 34.2% while the mortalityrate was 28.9%. Significant differences were observed when comparing success versus failure in exhaled tidalvolumes heart rate (P = 0.04), peak inspired pressure (P &lt; 0.001), PaO2 (P &lt; 0.001), SaO2 (P &lt; 0.002), PaO2/FiO2 (P &lt;0.002), arterial blood pressure (P &lt; 0.001), HR (P &lt; 0.001), and inspiratory time (P = 0.029) measured at baseline andat 12-hour, 24-hour and 48-hour intervals. Conclusion: The BiPAP S/T-AVAPS ventilatory mode can be used in subjects with de novo hypoxaemic respiratoryfailure with special vigilance concerning exhaled tidal volumes and inspired pressure