title: Patient-ventilator asynchrony in a traumatically injured population.
abstract: BACKGROUND
  Prolonged mechanical ventilation, longer hospital stay, and a lower rate of home discharge have been reported with patient-ventilator asynchrony in medical patients. Though commonly encountered, asynchrony is poorly defined within the traumatically injured population.
  
  
  METHODS
  Mechanically ventilated trauma patients at an urban, level-1 center were enrolled. Breath waveforms were recorded over 30 min within the first 48 hours following intubation. Asynchronous breaths were defined as ineffective patient triggering, double-triggering, short-cycle breaths, and long-cycle breaths. Asynchronous subjects were defined as having asynchrony in ≥ 10% of total breaths. Demographic, injury, sedation/delirium scores, and clinical and discharge outcomes were prospectively collected.
  
  
  RESULTS
  We enrolled 35 subjects: median age 47 y, 77.1% male, 28.6% with penetrating injuries, 16% with a history of COPD, median (IQR) Injury Severity Score 22 (17-27), and median (IQR) chest Abbreviated Injury Scale score 2 (0-6). We analyzed 15,445 breaths. Asynchrony was present in 25.7% of the subjects. No statistical differences between the asynchronous and non-asynchronous subjects were found for age, sex, injury mechanism, COPD history, delirium/sedation scores, PaO2/FIO2, PEEP, blood gas values, or sedative, narcotic, or haloperidol use. Asynchronous subjects more commonly used synchronized intermittent mandatory ventilation (SIMV) (100% vs. 38.5%, P = .002) and took fewer median spontaneous breaths/min: 4 breaths/min (IQR 3-8 breaths/min) vs. 12 breaths/min (IQR 9-14 breaths/min) (P = .007). SIMV with set breathing frequencies of ≥ 10 breaths/min was associated with increased asynchrony rates (85.7% vs. 14.3%, P = .02). We found no difference in ventilator days, ICU or hospital stay, percent discharged home, or mortality between the asynchronous and non-asynchronous subjects.
  
  
  CONCLUSIONS
  Ventilator asynchrony is common in trauma patients. It may be associated with SIMV with a set breathing frequency of ≥ 10 breaths/min, though not with longer mechanical ventilation, longer stay, or discharge disposition. (ClinicalTrials.gov NCT01049958).
authors.affiliation: Division of Trauma and Critical Care, Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio.
authors.forename: Bryce Rh
authors.initials: BR
authors.lastname: Robinson
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Blakeman
authors.forename: Peter
authors.initials: P
authors.lastname: Toth
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Hanseman
authors.forename: Eric
authors.initials: E
authors.lastname: Mueller
authors.forename: Richard D
authors.initials: RD
authors.lastname: Branson
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007362:Intensive Care Units; D007385:Intermittent Positive-Pressure Ventilation / Q000379:methods*; D007902:Length of Stay / Q000639:trends; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D009820:Ohio / Q000453:epidemiology; D011379:Prognosis; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D015996:Survival Rate / Q000639:trends; D012122:Ventilators, Mechanical; D014939:Work of Breathing / Q000502:physiology*; D014947:Wounds and Injuries / Q000150:complications / Q000401:mortality / Q000628:therapy*
keywords: asynchrony; critical care; mechanical ventilation; trauma