title: Long-term non-invasive ventilation to manage persistent ventilatory failure after COPD exacerbation.
abstract: OBJECTIVE
  Patients with ventilatory failure at discharge from hospital following an exacerbation of COPD (ECOPD) have increased work of breathing and reduced inspiratory muscle strength compared with those with a normal arterial carbon dioxide tension (PaCO(2)). They also have a significantly worse prognosis. Long-term non-invasive positive pressure ventilation (NIPPV) may offer a treatment strategy but benefits have not been established.
  
  
  METHODS
  We examined the outcomes of 35 patients, with a PaCO(2) >7.5 kPa and normal pH, following hospital admission with an ECOPD. Patients were initiated on long-term NIPPV. Our aims were to establish if NIPPV was tolerated and to describe the effects on ventilatory parameters.
  
  
  RESULTS
  Daytime arterial blood gases and nocturnal ventilatory parameters improved significantly on NIPPV. Diurnal PaO(2), self-ventilating, rose from (mean (SD)) 7.3 (1.8) to 8.1 (0.9) kPa (P = 0.005) and PaCO(2) fell from 8.8 (1.3) to 7.3 (0.8) kPa (P <or= 0.001). Mean overnight oxygen saturations increased from 82% (7%) to 89% (2%) (P <or= 0.001) and mean overnight transcutaneous carbon dioxide fell from 7.6 (1.3) to 5.6 (1.7) kPa (P <or= 0.001). Similar changes were seen in a group of stable COPD patients, who initiated NIPPV without a preceding exacerbation, suggesting improvements were not solely due to recovery from exacerbation. Acceptance (89%) and compliance (8.4 (3.5) h/day) with domiciliary treatment were good. Median survival was 28.6 months (95% CI: 10.9-46.8).
  
  
  CONCLUSIONS
  NIPPV was well tolerated in this group and appears to improve ventilation. Our preliminary data support further investigation of NIPPV in patients who remain hypercapnic after hospital admission with ECOPD.
authors.affiliation: Respiratory Support and Sleep Centre, Papworth Hospital NHS Foundation Trust, Cambridge, UK. nickoscroft@doctors.org.uk
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Oscroft
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Quinnell
authors.forename: John M
authors.initials: JM
authors.lastname: Shneerson
authors.forename: Ian E
authors.initials: IE
authors.lastname: Smith
mesh_terms: D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000097:blood / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010349:Patient Compliance; D011175:Positive-Pressure Respiration; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality / Q000628:therapy*; D012131:Respiratory Insufficiency / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen