title: The use of noninvasive mechanical ventilation in COPD with severe hypercapnic acidosis.
abstract: OBJECTIVE
  To compare the effect of noninvasive mechanical ventilation (NIV) in severely acidotic with mildly acidotic patients with acute hypercapnic chronic obstructive lung disease (COPD).
  
  
  METHODS
  Comparison of NIV in consecutively enrolled patients with acute hypercapnic COPD with mild (pH 7.25-7.35) or severe (pH<7.25) acidosis on time to normalise pH and improve PaCO(2), duration of NIV treatment, length of stay in hospital and survival. Results (meadian (IQR)): Twenty-nine patients had 36 episodes of acute hypercapnic respiratory failure: Seventeen with pH<7.25 and 19 with pH 7.25-7.34. Compared with the mildly acidotic group, the severely acidotic group took a similar length of time for pH to normalise and PaCO(2) improve (12 (6-34) vs 12 (4-28)h, respectively, P=0.42), with similar duration of NIV treatment (60 (35-96) vs 68 (36-48)h, respectively, P=0.25) and hospital length of stay (8 (7-18) vs 9 (5-17) days, respectively, P=0.61). Overall survival was 89%, with 95% in the mild and 82% in the severely acidotic groups.
  
  
  CONCLUSIONS
  Noninvasive ventilation is effective in the treatment of patients with severe acidosis due to acute hypercapnic COPD.
authors.affiliation: Department of Allergy, Immunology and Respiratory Medicine, Alfred Hospital, Prahran, Victoria, Melbourne, Victoria, Australia.
authors.forename: Fionnuala
authors.initials: F
authors.lastname: Crummy
authors.forename: Catherine
authors.initials: C
authors.lastname: Buchan
authors.forename: Belinda
authors.initials: B
authors.lastname: Miller
authors.forename: Jo
authors.initials: J
authors.lastname: Toghill
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Naughton
mesh_terms: D000142:Acidosis, Respiratory / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D000208:Acute Disease; D000368:Aged; D001784:Blood Gas Analysis; D016009:Chi-Square Distribution; D006801:Humans; D006935:Hypercapnia / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D007902:Length of Stay; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D012121:Respiration, Artificial; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome