The Science Journal of the American Association for Respiratory Care

2012 OPEN FORUM Abstracts

A COMPARISON OF LEAK COMPENSATION IN ACUTE CARE VENTILATORS DURING NON-INVASIVE VENTILATION; A LUNG MODEL STUDY.

Jun Oto, Andrew D. Marchese, Robert M. Kacmarek; Massachusetts General Hospital, Boston, MA

Background: Ventilators used for non-invasive ventilation (NIV) must be able to synchronize in the presence of system leaks. We compared the ability of 5 ventilators to compensate for leaks during NIV. Method: Using an ASL5000 lung simulator, the Maquet Servo-i, Drager V500, Covidien PB840, Respironics V60, and Hamilton C3 were compared during increasing (n=6) and decreasing leaks (n=6). Leak levels used were: BL (baseline 3-4L/min), L1 (9-10L/min), L2 (26-27L/min) and L3 (35-36L/min). Lung model inspiratory and expiratory resistance were 10, and 20 cmH2O/L/sec with compliance 60 ml/cmH2O (Obstructive model) and inspiratory and expiratory resistance 5, and 5 cmH2O/L/sec with compliance 20 ml/cmH2O (Restrictive model). Ventilator settings were non-invasive ventilation mode, pressure support, PEEP5, and 10 cmH2O and pressure support level 12 cmH2O. The number of breaths to synchronization was recorded for each leak scenario. Results: With the exception of the V500, all ventilators exhibited synchronization to increasing and decreasing leaks in both the obstructive and restrictive models. V500 could not synchronize to leaks L2 and L3. Number of breaths to synchronization for increasing leaks differed from decreasing leak with median breaths (25th, 75th) of 2 (1, 3) and 0 (0, 1) (p < 0.0001) respectively. Significant differences were observed for number of breaths to synchronization between the obstructive 2 (0, 3) and restrictive model 0 (0, 2) (p < 0.0001) and with PEEP 5 cmH2O 0 (0, 2) and 10 cmH2O 1 (0, 3) (p =0.002). PB840 required less breaths to synchronize to increasing and decreasing leaks in both obstructive and restrictive lung models and with PEEP 5 cmH2O and 10 cmH2O compared with all other ventilators (p < 0.0001). Conclusions: The leak compensation in non-invasive ventilation modes can correct partially or completely for leak interference within 4 breaths, but there are wide variations between ventilators. Grant support; COVIDIEN Inc, Boulder, CO Sponsored Research - Covidien Inc. Boulder CO