title: High frequency oscillation and airway pressure release ventilation in pediatric respiratory failure.
abstract: BACKGROUND
  Airway pressure release ventilation (APRV) and high frequency oscillatory ventilation (HFOV) are frequently used in acute lung injury (ALI) refractory to conventional ventilation. Our aim was to describe our experience with APRV and HFOV in refractory pediatric ALI, and to identify factors associated with survival.
  
  
  METHODS
  We analyzed 104 patients with hypoxemia refractory to conventional ventilation transitioned to either APRV or HFOV. Demographics, oxygenation index (OI), and PaO2 /FiO2 (PF ratio) were recorded before transition to either mode of nonconventional ventilation (NCV) and for every 12 hr after transition.
  
  
  RESULTS
  Relative to APRV, patients on HFOV were younger and had more significant lung disease evidenced by higher OI (28.5 [18.6, 36.2] vs. 21.0 [15.5, 30.0], P = 0.008), lower PF ratios (73 [59,94] vs. 99 [76,131], P = 0.002), and more frequent use of inhaled nitric oxide. In univariate analysis, HFOV was associated with more frequent neuromuscular blockade. Forty-one of 104 patients died on NCV (39.4%). Survivors demonstrated improvement in OI 24 hr after transition to NCV, whereas non-survivors did not (12.9 [8.9, 20.9] vs. 28.1 [17.6, 37.1], P < 0.001). After controlling for immunocompromised status, number of vasopressors, and OI before transition, mode of NCV was not associated with mortality.
  
  
  CONCLUSIONS
  In a heterogeneous PICU population with hypoxemia refractory to conventional ventilation transitioned to NCV, improvement in oxygenation at 24 hr was associated with survival. Immunocompromised status, number of vasopressor infusions, and the OI before transition to NCV were independently associated with survival.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Nadir
authors.initials: N
authors.lastname: Yehya
authors.forename: Alexis A
authors.initials: AA
authors.lastname: Topjian
authors.forename: Richard
authors.initials: R
authors.lastname: Lin
authors.forename: Robert A
authors.initials: RA
authors.lastname: Berg
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Thomas
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Friess
mesh_terms: D055371:Acute Lung Injury / Q000150:complications* / Q000401:mortality; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D005260:Female; D006612:High-Frequency Ventilation; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D007223:Infant; D008297:Male; D012131:Respiratory Insufficiency / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: acute lung injury; acute respiratory distress syndrome; airway pressure release ventilation; high frequency oscillatory ventilation; mechanical ventilation; pediatric