Abstract
Background: When supplemental oxygen is added to noninvasive positive pressure ventilation (NPPV) using non-ICU ventilators, it is usually introduced with a preset flow rate into the ventilatory circuit at a site next to the ventilator; however, the impact of different CO2 exhalation systems and leaks on actual inspired FiO2 and gas exchange has not been elucidated.
Methods: In a randomized, open-label, four-treatment (two-by-two), four-period crossover design, four daytime measurements (60 minutes each) were performed in 20 patients receiving home mechanical NPPV plus ≥2 L O2/min inserted proximally to the ventilator: active valve circuit or leak port circuit with or without artificial leakage (4mm I.D.). FiO2 at the ventilator, FiO2 at the mask, and blood gases were measured.
Results: Overall, FiO2-mask (29±5%) was lower compared to FiO2-ventilator (34±4%), with a mean (95%CI) difference of 5.1 (4.2 to 5.9, p<0.0001)%. With the leak port circuit, FiO2-mask decreased by 3.2 (2.6 to 3.9, p<0.0001)% when compared to the active valve circuit. When artificial leakage was introduced into the circuit, FiO2-mask decreased by 5.7 (5.1 to 6.4, p<0.0001)%, PaO2 by 10.4 (3.1 to 17.7, p=0.006) mmHg, and PCO2 increased by 1.8 (0.5 to 3.3, p=0.008) mmHg.
Conclusions: The use of leak port circuits and the occurrence of leakages around the interface significantly reduce FiO2-mask and negatively impact on gas exchange in patients receiving home mechanical NPPV and supplemental oxygen.
Registered at: German Clinical Trials Register (DRKS); www.drks.de
Registration number: DRKS00000449
- Chronic obstructive pulmonary disease
- mechanical ventilation
- chronic respiratory failure
- long-term oxygen therapy
- fraction of inspired oxygen
Footnotes
- Correspondence author information: Priv. Doz. Dr. Jan Hendrik Storre, M.D.; Department of Pneumology, Cologne-Merheim Hospital Kliniken der Stadt Köln gGmbH, Witten/Herdecke University Hospital; Ostmerheimer Strasse 200, D-51109 Cologne, Germany; Email: storrej{at}kliniken-koeln.de; Tel.: +49 221 890718344, Fax: +49 221 89078305.
Conflict of interest statements: JHS received speaking fees from the following companies: Breas Medical AB, Mölnlycke, Sweden; Respironics Inc., Pittsburgh, PA, USA; ResMed Germany Inc., Martinsried, Germany; Heinen und Löwenstein, Germany; Werner und Müller Medizintechnik; Keller Medical GmbH, Germany. JHS received also honorarium from Respironics, USA, and Boehringer Ingelheim Pharma GmbH & Co. KG, Germany, for expertise. JHS received travel funding for national and international research congresses from Breas Medical GmbH Germany, Heinen und Löwenstein, Germany; Respironics International, Respironics Germany, SenTec AG Switzerland, Vivisol Germany, Weinmann GmbH and Werner und Müller Medizintechnik. SEH received travel funding for national and international research congresses from Heinen und Löwenstein, Germany, and Boehringer Ingelheim Pharma GmbH & Co. KG, Germany. EE received travel funding for national and international research congresses from Vivisol Germany and ResMed Germany Inc. SW received speaking fees from Weinmann GmbH and travel funding for national and international research congresses from Vivisol Germany and GlaxoSmithKline. CS has no conflict of interest. MD has received speaking fees from VitalAire, ResMed, Drager Medical, and Respironics. MD received travel funding from ResMed and Vivisol. MD received funding for research and funding for a member of staff from ResMed. MD received consulting fees from Linde. WW was reimbursed by Maquet, Germany, for attending conferences on intensive care medicine. WW received speaking fees from the following companies: Dräger Medical, Germany; Heinen und Löwenstein, Germany; Respironics, USA; Weinmann, Germany; ResMed, Germany; Covedien, France; Linde, Germany; Maquet, Germany; Siare, Italy. WW received funds for research: Research grant from Respironics, USA, in 2008 (100.000 USD) and 60.000 Euro for 2009 and 2010, respectively; 310.000 Euro from Breas (1999-2009) and 75.000 Euro for 2010. WW received honoraria from Maquet, Germany, for having attended advisory board meetings.
All authors state that none of the discussed issues in the submitted manuscript was dependent or influenced on support and funding.
Funding information: The study group received an open research grant from Breas Medical AB, Möclnlycke, Sweden; Respironics Inc., Pittsburgh, PA, USA; and from ResMed Germany Inc., Martinsried, Germany. Study devices and consumables were supported by BREAS Medical AB, Sweden.
- Copyright © 2013 by Daedalus Enterprises Inc.
