title: Efficacy of nocturnal nasal positive pressure ventilation in hypercapnic patients with severe obstructive lung diseases.
abstract: BACKGROUND
  The study objective was to investigate the efficacy of 6 months of nocturnal nasal positive pressure ventilation (NNPPV) on arterial blood gas, exercise capacity, respiratory muscle function, and the frequency of hospital admission in hypercapnic patients with severe obstructive lung diseases.
  
  
  METHODS
  This was a prospective, randomized, controlled study. Twenty-seven patients with hypercapnic obstructive lung diseases were randomized to either the NNPPV group (N = 13) or the control group (N = 14). Arterial blood gas, exercise capacity and respiratory muscle function were measured before and after 6 months of NNPPV intervention. The number of hospital admissions and the length of stay during the 6-month period before and after NNPPV intervention were recorded.
  
  
  RESULTS
  Subjects in the NNPPV group showed a significant reduction in arterial carbon dioxide partial pressure (PaCO2). bicarbonate (HCO3-), and base excess (BE), compared with those before intervention and of the control group. Six-minute walk distance (6MWD) also increased significantly from 232.2 +/- 79.3 m to 333.4 +/- 81.3 m in the NNPPV group after 6 months of intervention. The maximum voluntary ventilation (MVV) also increased significantly after NNPPV intervention. Moreover, the NNPPV group had significantly lower frequency of admission and fewer days of hospital stay during the intervention period compared with those before intervention and of the control group.
  
  
  CONCLUSIONS
  Six months of NNPPV improved the arterial blood gas, increased exercise capacity and respiratory muscle endurance, and helped to reduce the frequency and the length of hospitalization in hypercapnic patients with severe obstructive lung disease.
authors.affiliation: School of Respiratory Therapy, Taipei Medical University, Taiwan 333, ROC.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Chiang
authors.forename: Chien-Ying
authors.initials: CY
authors.lastname: Liu
authors.forename: Shu-Chuan
authors.initials: SC
authors.lastname: Ho
authors.forename: Te-Fang
authors.initials: TF
authors.lastname: Sheng
authors.forename: Chih-Teng
authors.initials: CT
authors.lastname: Yu
authors.forename: Horng-Chyuan
authors.initials: HC
authors.lastname: Lin
authors.forename: Han-Pin
authors.initials: HP
authors.lastname: Kuo
mesh_terms: D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000150:complications*; D007902:Length of Stay; D008173:Lung Diseases, Obstructive / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011175:Positive-Pressure Respiration / Q000379:methods*; D011446:Prospective Studies; D012132:Respiratory Muscles / Q000502:physiology; D013995:Time
chemical_list: D010100:Oxygen