RT Journal Article
SR Electronic
T1 Oxygen Supplementation in Noninvasive Home Mechanical Ventilation: The Crucial Roles of CO<sub>2</sub> Exhalation Systems and Leakages
JF Respiratory Care
FD American Association for Respiratory Care
SP 113
OP 120
DO 10.4187/respcare.02596
VO 59
IS 1
A1 Storre, Jan H
A1 Huttmann, Sophie E
A1 Ekkernkamp, Emelie
A1 Walterspacher, Stephan
A1 Schmoor, Claudia
A1 Dreher, Michael
A1 Windisch, Wolfram
YR 2014
UL http://rc.rcjournal.com/content/59/1/113.abstract
AB BACKGROUND: When supplemental oxygen is added to noninvasive ventilation using a non-ICU ventilator, it is usually introduced with a preset flow into the circuit near the ventilator; however, the impact of different CO2 exhalation systems and leaks on the actual FIO2 and gas exchange has not been elucidated. METHODS: In a randomized, open-label, 4-treatment (2-by-2), 4-period crossover design, 4 daytime measurements (60 min each) were performed in 20 subjects receiving home mechanical noninvasive ventilation plus supplemental oxygen (≥ 2 L/min) inserted near the ventilator: active valve circuit or leak port circuit with or without artificial leakage (4 mm inner diameter). Oxygen concentration near the ventilator, oxygen concentration at the mask, and blood gases were measured. RESULTS: Overall, oxygen concentration at the mask (29 ± 5%) was lower than oxygen concentration at the ventilator (34 ± 4%), with a mean difference of 5.1% (95% CI 4.2–5.9%, P &lt; .001)%. With the leak port circuit, oxygen concentration at the mask decreased by 3.2% (95% CI 2.6 to 3.9%, P &lt; .001), compared to the active valve circuit. When artificial leakage was introduced into the circuit, oxygen concentration at the mask decreased by 5.7% (95% CI 5.1 to 6.4%, P &lt; .001)%, PaO2 by 10.4 mm Hg (95% CI 3.1 to 17.7 mm Hg, P = .006), and PaCO2 increased by 1.8 mm Hg (95% CI 0.5 to 3.1 mm Hg, P = .008). CONCLUSIONS: The use of a leak port circuit and the occurrence of leak around the interface significantly reduced oxygen concentration at the mask and negatively impacted gas exchange in subjects receiving home noninvasive ventilation and supplemental oxygen. (German Clinical Trials Registry, www.drks.de, DRKS00000449).