title: Helmet noninvasive mechanical ventilation in patients with acute postoperative respiratory failure.
abstract: BACKGROUND
  The physiological and clinical effects of noninvasive ventilation (NIV) on acute postoperative respiratory failure are relatively unknown. The aim of this study was to determine the prediction factors for failure in the use of NIV with a helmet in this context.
  
  
  METHODS
  This was a prospective observational study. The use of NIV was assessed for a period of 2 years in a postoperative ICU. Demographic data were collected, as well as acute respiratory failure (ARF) and arterial gas readings. Hemodynamic changes were assessed using pulse contour cardiac output  technology, and the clinical development of subjects was recorded. All subjects who developed ARF were treated using NIV as their primary care, depending on whether the technique was successful or the subject required intubation. The risk factors that determined failure in the application  of NIV were subsequently determined.
  
  
  RESULTS
  Of the 99 subjects presenting with postoperative ARF treated with NIV using a helmet, 74 did not require intubation (74.7%). Following a multivariate analysis using logistic regression, we determined that there are 3 independent risk factors for  the failure of NIV. Three factors were associated with respiratory failure: ARDS, pneumonia, and lack of improvement with NIV in 1 hour (increase in the P(aO(2))/F(IO(2))).
  
  
  CONCLUSIONS
  NIV using a helmet could provide an effective alternative to conventional  ventilation in selected patients with postoperative ARF.
authors.affiliation: Department of Anesthesiology and Critical Care, Hospital General Universitario de Ciudad Real, Ciudad Real, Spain. ardredondo@hotmail.com
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Redondo Calvo
authors.forename: Maria
authors.initials: M
authors.lastname: Madrazo
authors.forename: Fernando
authors.initials: F
authors.lastname: Gilsanz
authors.forename: Rafael
authors.initials: R
authors.lastname: Uña
authors.forename: Rubén
authors.initials: R
authors.lastname: Villazala
authors.forename: Ginés
authors.initials: G
authors.lastname: Bernal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006260:Head Protective Devices; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011143:Polyvinyl Chloride; D011183:Postoperative Complications; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000295:instrumentation*; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D012307:Risk Factors; D017211:Treatment Failure
chemical_list: D011143:Polyvinyl Chloride