title: Combining high-frequency oscillatory ventilation and recruitment maneuvers in adults with early acute respiratory distress syndrome: the Treatment with Oscillation and an Open Lung Strategy (TOOLS) Trial pilot study.
abstract: OBJECTIVE
  To determine the safety, feasibility, and lung-recruitment efficacy of an explicit ventilation protocol combining high-frequency oscillatory ventilation and recruitment maneuvers.
  
  
  METHODS
  Prospective, multiple-center, single-intervention pilot study.
  
  
  METHODS
  Four university-affiliated intensive care units.
  
  
  METHODS
  Twenty-five patients with early acute respiratory distress syndrome and severe oxygenation failure.
  
  
  METHODS
  Patients were transitioned from standardized conventional ventilation to high-frequency oscillatory ventilation beginning with an initial cycle of up to three sustained inflation recruitment maneuvers (40 cm H2O x 40 secs), followed by a decremental titration of Fio2 and then mean airway pressure. Recruitment maneuvers were repeated for hypoxemia and routinely at least twice daily if the Fio2 was >0.4. A specific protocol was used for weaning high-frequency oscillatory ventilation, for transitioning to conventional ventilation, and for judging intolerance of conventional ventilation whereby patients should be put back on high-frequency oscillatory ventilation.
  
  
  RESULTS
  Patients (median [interquartile range] Acute Physiology and Chronic Health Evaluation II, 24 [19-32]; age, 50 [41-64]) were enrolled after 13 (range, 6-51) hrs of conventional ventilation. Following the initial cycle of recruitment, the mean (+/-sd) Pao2/Fio2 increased significantly compared with standardized conventional ventilation (200 +/- 117 vs. 92 +/- 36 mm Hg, p < .001). After a mean of 12 hrs of high-frequency oscillatory ventilation, the mean Fio2 was significantly reduced compared with prestudy levels (0.5 +/- 0.2 vs. 0.9 +/- 0.1, p < .001). A median of seven (four to 11) recruitment maneuvers was performed per patient over the study period, with only eight of 244 (3.3%) being aborted. Six of 19 patients transitioned to conventional ventilation (32%) were deemed intolerant and were switched back to high-frequency oscillatory ventilation. Protocol adherence was excellent with documented rates >90%.
  
  
  CONCLUSIONS
  The combination of high-frequency oscillatory ventilation and recruitment maneuvers resulted in rapid and sustained improvement in oxygenation, likely through lung recruitment. This explicit high-frequency oscillatory ventilation protocol appears well tolerated, feasible, and physiologically sound.
authors.affiliation: Department of Medicine, Division of Respirology, and the Interdepartmental Division of Critical Care Medicine, University Health Network and Mount Sinai Hospital, University of Toronto, Toronto, Canada.
authors.forename: Niall D
authors.initials: ND
authors.lastname: Ferguson
authors.forename: Jean-Daniel
authors.initials: JD
authors.lastname: Chiche
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kacmarek
authors.forename: David C
authors.initials: DC
authors.lastname: Hallett
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Mehta
authors.forename: George P
authors.initials: GP
authors.lastname: Findlay
authors.forename: John T
authors.initials: JT
authors.lastname: Granton
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Slutsky
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Stewart
mesh_terms: D000328:Adult; D002985:Clinical Protocols; D005260:Female; D006439:Hemodynamics; D006612:High-Frequency Ventilation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D010865:Pilot Projects; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D018709:Statistics, Nonparametric
chemical_list: D010100:Oxygen