Feasibility and Efficacy of Pulsed-Dose Oxygen Delivery During Noninvasive Ventilation.

BACKGROUND: It is difficult to apply noninvasive ventilation (NIV) simultaneously with pulsed-dose oxygen delivery. We evaluated the feasibility and efficacy of pulsed-dose oxygen delivery during NIV. METHODS: A bench study was conducted using a simulated lung during NIV, with a breathing frequency of 10 or 20 breaths/min and 3 oxygen injection sites (site A on face mask, site B proximal to face mask, and site C at the ventilator outlet) with continuous flow oxygen delivery of 1, 3, or 5 L/min) or pulsed-dose oxygen delivery (numerical settings of 1, 3, or 5 representing the oxygen pulse characteristics). FIO2 under different experimental conditions and the influence of mode of oxygen delivery on NIV (compared to baseline and continuous flow oxygen delivery vs pulsed-dose oxygen delivery) were compared. In the clinical study, we enrolled 10 subjects with COPD exacerbation who received NIV with either continuous flow oxygen delivery or pulsed-dose oxygen delivery. Under the same targeted pulse oxygen saturation (88–92%), the numerical settings of different modes of oxygen delivery were titrated, and the clinical parameters during the different modes of oxygen delivery were compared. RESULTS: In the bench study, the ratio of the FIO2 with pulsed-dose oxygen delivery to the FIO2 with continuous flow oxygen delivery at the same numerical setting was 0.94 ± 0.15. The oxygen injection site had a significant influence on FIO2 in pulsed-dose oxygen delivery or continuous flow oxygen delivery mode (P .05 or changes .05). CONCLUSIONS: Integration of pulsed-dose oxygen delivery into NIV could achieve efficacy similar to that achieved with continuous flow oxygen delivery.