title: High-frequency oscillation in adults: a utilization review.
abstract: OBJECTIVE
  High-frequency oscillation is used for adults with acute lung injury/acute respiratory distress syndrome. Given the uncertain benefits, our objective was to describe contemporary patient selection, high-frequency oscillation utilization, and outcomes.
  
  
  METHODS
  Utilization review.
  
  
  METHODS
  Ten academic centers (Ontario, Canada; January 1, 2005-January 31, 2007).
  
  
  METHODS
  We included 190 consecutive adults treated with high-frequency oscillation and retrospectively abstracted data on patient demographics, gas exchange, hemodynamics, settings during conventional ventilation and high-frequency oscillation, adjunctive therapies, and outcomes. We used logistic regression to explore associations with oxygenation response and hemodynamic and ventilatory complications (2 hrs after high-frequency oscillation initiation) and mortality. Continuous data are reported as mean (sd) or median (quartile 1, quartile 3).
  
  
  METHODS
  None.
  
  
  RESULTS
  Patients (60.0% male; mean age, 52; sd 17) had predominantly acute lung injury/acute respiratory distress syndrome (89.8%) and were severely ill (mean Acute Physiology and Chronic Health Evaluation II score, 28; sd, 9) and hypoxemic (mean Pao2/Fio2, 80; sd, 42). High-frequency oscillation was started a median of 2 (1, 8) days after intubation and continued for a median of 3 (2, 7) days. During high-frequency oscillation, adjunctive treatments (neuromuscular blockade, 75.6%; recruitment maneuvers, 49.5%; nitric oxide, 34.0%; steroids, 63.1%) and new barotrauma or chest tube placement (23.5%) were common. Ten patients (5.3%) had technical complications; five required a new ventilator. Reasons for stopping high-frequency oscillation included death or withdrawal of life support (39.1%), significant improvement in respiratory failure (37.6%), and inadequate improvement (23.3%). One hundred and twenty-eight of 189 patients died in hospital. Most (62.5%) had a positive oxygenation response after 2 hrs of high-frequency oscillation (mean absolute increase in PaO₂/FiO₂, 22 [SD, 54]; 95% confidence interval of mean 14-31). A minority had lower PaO₂/FiO₂ (32.5%) or a hemodynamic (27.5%) or ventilatory (30.5%) complication. Older age, Acute Physiology and Chronic Health Evaluation II score, and Paco2 before high-frequency oscillation were independently associated with mortality.
  
  
  CONCLUSIONS
  Most patients treated with high-frequency oscillation have acute respiratory distress syndrome and severe hypoxemia that modestly improves 2 hrs after high-frequency oscillation application. However, oxygenation worsens in some patients, complications are common, and mortality is high.
authors.affiliation: Department of Critical Care Medicine and the Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada. neill.adhikari@utoronto.ca
authors.forename: Neill K J
authors.initials: NK
authors.lastname: Adhikari
authors.forename: Abdel
authors.initials: A
authors.lastname: Bashir
authors.forename: François
authors.initials: F
authors.lastname: Lamontagne
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Mehta
authors.forename: Niall D
authors.initials: ND
authors.lastname: Ferguson
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhou
authors.forename: Lori
authors.initials: L
authors.lastname: Hand
authors.forename: Kasia
authors.initials: K
authors.lastname: Czarnecka
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Cook
authors.forename: John T
authors.initials: JT
authors.lastname: Granton
authors.forename: Jan O
authors.initials: JO
authors.lastname: Friedrich
authors.forename: Andreas
authors.initials: A
authors.lastname: Freitag
authors.forename: Irene
authors.initials: I
authors.lastname: Watpool
authors.forename: Maureen O
authors.initials: MO
authors.lastname: Meade
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D055371:Acute Lung Injury / Q000628:therapy; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006612:High-Frequency Ventilation / Q000009:adverse effects / Q000401:mortality / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D012119:Respiration; D012128:Respiratory Distress Syndrome / Q000628:therapy; D016896:Treatment Outcome