title: A randomised crossover trial comparing volume assured and pressure preset noninvasive ventilation in stable hypercapnic COPD.
abstract: Recent randomised controlled trials suggest non-invasive ventilation may offer benefit in the long-term management of ventilatory failure in stable COPD. The best mode of ventilation is unknown and newer volume assured modes may offer advantages by optimising ventilation overnight when treatment is delivered. This study compares volume assured with pressure preset non-invasive ventilation. Randomised crossover trial including twenty five subjects previously established on long-term non-invasive ventilation to manage COPD with chronic ventilatory failure. Two 8-week treatment periods of volume assured and pressure preset non-invasive ventilation. The primary outcomes were daytime arterial blood gas tensions and mean nocturnal oxygen saturation. Secondary outcomes included lung function, exercise capacity, mean nocturnal transcutaneous carbon dioxide, health status and compliance. No significant differences were seen in primary or secondary outcomes following 8 weeks of treatment when comparing volume assured and pressure preset ventilation. Primary outcomes assessed: mean (standard deviation) PaO(2) 7.8 (1.2) vs 8.1(1) kPa, PaCO(2) 6.7 (1.1) vs 6.3 (1.2) kPa and mean nocturnal oxygenation 90 (4) vs 91 (3)% volume assured versus pressure preset, respectively. Volume assured and pressure preset non-invasive ventilation appear equally effective in the long-term management of ventilatory failure associated with stable COPD.
authors.affiliation: Respiratory Support and Sleep Centre, Papworth Hospital NHS Foundation Trust, Papworth Everard, Cambridge, UK CB23 3RE. nickoscroft@doctors.net.uk
authors.forename: Nicholas Stephen
authors.initials: NS
authors.lastname: Oscroft
authors.forename: Masood
authors.initials: M
authors.lastname: Ali
authors.forename: Atul
authors.initials: A
authors.lastname: Gulati
authors.forename: Michael Gordon
authors.initials: MG
authors.lastname: Davies
authors.forename: Timothy George
authors.initials: TG
authors.lastname: Quinnell
authors.forename: John Michael
authors.initials: JM
authors.lastname: Shneerson
authors.forename: Ian Edward
authors.initials: IE
authors.lastname: Smith
mesh_terms: D000368:Aged; D001785:Blood Gas Monitoring, Transcutaneous; D018592:Cross-Over Studies; D017079:Exercise Tolerance; D006304:Health Status; D006801:Humans; D006935:Hypercapnia / Q000628:therapy; D008875:Middle Aged; D010147:Pain Measurement; D011175:Positive-Pressure Respiration / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*; D012129:Respiratory Function Tests; D012890:Sleep