title: Low-intensity noninvasive ventilation: Lower pressure, more exacerbations of chronic respiratory failure.
abstract: BACKGROUND
  For patients with chronic respiratory failure (CRF) who are treated with noninvasive positive pressure ventilation (NPPV), a little is known regarding the effects of low-intensity NPPV (LI-NPPV) on the clinical course of CRF and the frequency of adjustments in these patients.
  
  
  OBJECTIVE
  This study investigated the effects of LI-NPPV on the clinical course of patients with CRF as compared with patients who were treated with conventional NPPV (C-NPPV) and determined how frequently NPPV was adjusted during therapy.
  
  
  METHODS
  Clinical data from 21 patients who received long-term NPPV were retrospectively analyzed. Patients were categorized into two groups based on the level of initial pressure support (PS): C-NPPV group (PS ≥ 10 cm H2O) and LI-NPPV group (PS < 10 cm H2O).
  
  
  RESULTS
  Patients in the LI-NPPV group had significantly more exacerbations of CRF (P < 0.05). There was no significant difference in the number of patients who required adjustments of NPPV settings between the two groups. There was no significant difference in PaCO2 levels 1 month after the start of NPPV between the two groups; however, PaCO2 levels were significantly lower after 1 year in the C-group (P < 0.001). Seventy-one percent of LI-NPPV patients and 43% of C-NPPV patients needed NPPV adjustments.
  
  
  CONCLUSIONS
  Attention should be paid to CRF patients who are initially administered LI-NPPV; they should be carefully observed because they can develop more exacerbations of CRF than patients undergoing C-NPPV. If possible, higher initial PS should be administered to prevent CRF exacerbations.
authors.affiliation: Department of Pulmonary Medicine, National Hospital Organization Matsue Medical Center, Matsue, Shimane, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kadowaki
authors.affiliation: Department of Pulmonary Medicine, National Hospital Organization Matsue Medical Center, Matsue, Shimane, Japan.
authors.forename: Kiryo
authors.initials: K
authors.lastname: Wakabayashi
authors.affiliation: Department of Pulmonary Medicine, National Hospital Organization Matsue Medical Center, Matsue, Shimane, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Department of Pulmonary Medicine, National Hospital Organization Matsue Medical Center, Matsue, Shimane, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Pulmonary Medicine, National Hospital Organization Matsue Medical Center, Matsue, Shimane, Japan.
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Ikeda
authors.affiliation: Department of Pulmonary Medicine, National Hospital Organization Matsue Medical Center, Matsue, Shimane, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yano
keywords: Adjustment; chronic respiratory failure; exacerbation; low-intensity noninvasive positive pressure ventilation; noninvasive positive pressure ventilation