title: Improved oxygenation 24 hours after transition to airway pressure release ventilation or high-frequency oscillatory ventilation accurately discriminates survival in immunocompromised pediatric patients with acute respiratory distress syndrome*.
abstract: OBJECTIVE
  Children with an immunocompromised condition and requiring invasive mechanical ventilation have high risk of death. Such patients are commonly transitioned to rescue modes of nonconventional ventilation, including airway pressure release ventilation and high-frequency oscillatory ventilation, for acute respiratory distress syndrome refractory to conventional ventilation. Our aim was to describe our experience with airway pressure release ventilation and high-frequency oscillatory ventilation in children with an immunocompromised condition and acute respiratory distress syndrome refractory to conventional ventilation and to identify factors associated with survival.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Tertiary care, university-affiliated PICU.
  
  
  METHODS
  Sixty pediatric patients with an immunocompromised condition and acute respiratory distress syndrome refractory to conventional ventilation transitioned to either airway pressure release ventilation or high-frequency oscillatory ventilation.
  
  
  METHODS
  None.
  
  
  RESULTS
  Demographic data, ventilator settings, arterial blood gases, oxygenation index, and PaO(2)/FIO(2) were recorded before transition to either mode of nonconventional ventilation and at predetermined intervals after transition for up to 5 days. Mortality in the entire cohort was 63% and did not differ between patients transitioned to airway pressure release ventilation and high-frequency oscillatory ventilation. For both airway pressure release ventilation and high-frequency oscillatory ventilation, improvements in oxygenation index and PaO(2)/FIO(2) at 24 hours expressed as a fraction of pretransition values (oxygenation index(24)/oxygenation index(pre) and PaO(2)/FIO(224)/PaO(2)/FIO(2pre)) reliably discriminated nonsurvivors from survivors, with receiver operating characteristic areas under the curves between 0.89 and 0.95 (p for all curves < 0.001). Sensitivity-specificity analysis suggested that less than 15% reduction in oxygenation index (90% sensitive, 75% specific) or less than 90% increase in PaO(2)/FIO(2) (80% sensitive, 94% specific) 24 hours after transition to airway pressure release ventilation were the optimal cutoffs to identify nonsurvivors. The comparable values 24 hours after transition to high-frequency oscillatory ventilation were less than 5% reduction in oxygenation index (100% sensitive, 83% specific) or less than 80% increase in PaO(2)/FIO(2) (91% sensitive, 89% specific) to identify nonsurvivors.
  
  
  CONCLUSIONS
  In this single-center retrospective study of pediatric patients with an immunocompromised condition and acute respiratory distress syndrome failing conventional ventilation transitioned to either airway pressure release ventilation or high-frequency oscillatory ventilation, improved oxygenation at 24 hours expressed as PaO(2)/FIO(224)/PaO(2)/FIO(2pre) or oxygenation index(24)/oxygenation indexpre reliably discriminates nonsurvivors from survivors. These findings should be prospectively verified.
authors.affiliation: 1Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA. 2Division of Pediatric Critical Care Medicine, Department of Pediatrics and Public Health Science, Penn State Hershey Children's Hospital, Hershey, PA. 3Division of Critical Care Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO.
authors.forename: Nadir
authors.initials: N
authors.lastname: Yehya
authors.forename: Alexis A
authors.initials: AA
authors.lastname: Topjian
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Thomas
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Friess
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D002648:Child; D002675:Child, Preschool; D045422:Continuous Positive Airway Pressure; D005260:Female; D006612:High-Frequency Ventilation; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D008297:Male; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012128:Respiratory Distress Syndrome / Q000097:blood* / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D010100:Oxygen