A bench evaluation of fraction of oxygen in air delivery and tidal volume accuracy in home care ventilators available for hospital use.

BACKGROUND

Turbine-powered ventilators are not only designed for long-term ventilation at home but also for hospital use. It is important to verify their capabilities in delivering fraction of oxygen in air (FO) and tidal volume (V).

METHODS

We assessed the FO accuracy and the V delivery in four home care ventilators (HCV) on the bench. The four HCV were Astral 150, Elisée 150, Monnal T50 and Trilogy 200 HCV, which were connected to a lung model (ASL 5000). For assessing FO accuracy, lung model was set to mimic an obstructive lung and HCV were set in volume controlled mode (VC). They supplied with air, 3 or 15 L/min oxygen and FO was measured by using a ventilator tester (Citrex H4). For the V accuracy, the lung model was set in a way to mimic three adult configurations (normal, obstructive, or restrictive respiratory disorder) and one pediatric configuration. Each HCV was set in VC. Two V (300 and 500 mL) in adult lung configuration and one 50 mL V in pediatric lung configuration, at two positive end expiratory pressures 5 and 10 cmHO, were tested. V accuracy was measured as volume error (the relative difference between set and measured V). Statistical analysis was performed by suing one-factor ANOVA with a Bonferroni correction for multiple tests.

RESULTS

For Astral 150, Elisée 150, Monnal T50 and Trilogy 200, FO averaged 99.2%, 93.7%, 86.3%, and 62.1%, respectively, at 15 L/min oxygen supplementation rate (P<0.001). Volume error was 0.5%±0%, -38%±0%, -9%±0%, -29%±0% and -36%±0% for pediatric lung condition (P<0.001). In adult lung configurations, Monnal T50 systematically over delivered V and Trilogy 150 was sensitive to lung configuration when V was set to 300 mL at either positive end-expiratory pressure (PEEP).

CONCLUSIONS

HCV are different in terms of FO efficiency and V delivery.