Impact of average volume-assured pressure-support mode on the management of obesity hypoventilation syndrome

Abstract

Background
The mode of average volume-assured pressure support (AVAPS) was considered as a newly developed noninvasive ventilation mode that measures the tidal volume of the patient at multiple respiratory cycles and estimates the varieties in positive airway pressure during inspiration to reach to the target tidal volume for the patient.


Objectives
The present prospective observational randomized study’s goal is to evaluate the advantages of new spontaneous timed/AVAPS mode compared with the conventional spontaneous/timed mode as a noninvasive ventilation for management of obesity hypoventilation syndrome regarding daytime hypercapnea, body activities, and quality of life related to health.


Patients and methods
Our study included 40 patients with a syndrome of obesity hypoventilation and were classified into group I: 20 patients received positive airway pressure by bilevel positive pressure ventilation/spontanous timed (BPV/ST) mode and group II: 20 patients ST/AVAPS mode. Clinical assessment with gasometric measurements and severe respiratory-insufficiency questionnaire were performed to all studied participants.


Results
PaCO2 significantly decreased at 48 h during spontaneous/timed mode of noninvasive ventilation by 62.93 ± 10.19 mmHg, but significantly decreased earlier at 12 h during spontaneous/timed-AVAPS mode of noninvasive ventilation by 55.10 ± 5.75 mmHg. After 6 weeks, the exhaled volume was higher significantly, also, the leak volume tended to be less significantly during spontaneous/timed-AVAPS group with improvement of severe respiratory-insufficiency summary-scale score.


Conclusions
AVAPS/ST mode provided additional benefits on BPV/ST mode, including earlier and higher decrease in PaCO2 level with more tolerability and lower leaks.