title: Epidemiology of noninvasive mechanical ventilation in acute respiratory failure--a retrospective population-based study.
abstract: BACKGROUND
  Noninvasive mechanical ventilation (NIV) is a front-line therapy for the management of acute respiratory failure (ARF) in the intensive care units. However, the data on factors and outcomes associated with the use of NIV in ARF patients is lacking. Therefore, we aimed to determine the utilization of NIV for ARF in a population-based study.
  
  
  METHODS
  We conducted a populated-based retrospective cohort study, where in all consecutively admitted adults (≥18 years) with ARF from Olmsted County, Rochester, MN, at the Mayo Clinic medical and surgical ICUs, during 2006 were included. Patients without research authorization or on chronic NIV use for sleep apnea were excluded.
  
  
  RESULTS
  Out of 1461 Olmsted County adult residents admitted to the ICUs in 2006, 364 patients developed ARF, of which 146 patients were initiated on NIV. The median age in years was 75 (interquartile range, 60-84), 48% females and 88.7% Caucasians. Eighteen patients (12%) were on Continuous Positive Airway Pressure (CPAP) mode and 128 (88%) were on noninvasive intermittent positive-pressure ventilation (NIPPV) mode. Forty-six (10%) ARF patients were put on NIV for palliative strategy to alleviate dyspnea. Seventy-six ARF patients without treatment limitation were given a trial of NIV and 49 patients succeeded, while 27 had to be intubated. Mortality was similar between the patients initially supported with NIV versus invasive mechanical ventilation (33% vs 22%, P=0.289). In the multivariate analysis, the development of acute respiratory distress syndrome (ARDS) and higher APACHE III scores were associated with the failure of initial NIV treatment.
  
  
  CONCLUSIONS
  Our results have important implications for a future planning of NIV in a suburban US community with high access to critical care services. The higher APACHE III scores and the development of ARDS are associated with the failure of initial NIV treatment.
authors.affiliation: Department of Medicine, Guang An Men Hospital, China Academy of Chinese Medical Science, Beijing, China.
authors.forename: Shihan
authors.initials: S
authors.lastname: Wang
authors.forename: Balwinder
authors.initials: B
authors.lastname: Singh
authors.forename: Lin
authors.initials: L
authors.lastname: Tian
authors.forename: Michelle
authors.initials: M
authors.lastname: Biehl
authors.forename: Ivaylo L
authors.initials: IL
authors.lastname: Krastev
authors.forename: Marija
authors.initials: M
authors.lastname: Kojicic
authors.forename: Guangxi
authors.initials: G
authors.lastname: Li
mesh_terms: D018806:APACHE; D055371:Acute Lung Injury / Q000453:epidemiology; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure / Q000706:statistics & numerical data*; D004417:Dyspnea / Q000453:epidemiology / Q000628:therapy; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D007362:Intensive Care Units; D007385:Intermittent Positive-Pressure Ventilation / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D015999:Multivariate Analysis; D010166:Palliative Care / Q000706:statistics & numerical data; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology; D012128:Respiratory Distress Syndrome / Q000453:epidemiology; D012131:Respiratory Insufficiency / Q000453:epidemiology / Q000628:therapy*; D012189:Retrospective Studies