title: Low-tidal volume mechanical ventilation in patients with acute respiratory distress syndrome caused by pandemic influenza A/H1N1 infection.
abstract: OBJECTIVE
  Low-tidal volume (TV) mechanical ventilation is an important manipulation in managing patients with acute respiratory distress syndrome (ARDS). However, there is no definite evidence to support the use of this intervention in patients with viral etiologies.
  
  
  METHODS
  A retrospective observational study of 104 patients with ARDS caused by pandemic influenza A/H1N1 infection admitted to 28 intensive care units (ICUs) in Korea was performed. Patients were categorized into 3 groups according to the TV they received: TV less than or equal to 7 mL/kg, TV greater than 7 mL/kg but less than or equal to 9 mL/kg, or TV greater than 9 mL/kg.
  
  
  RESULTS
  The mean age was 55.1 years, and 55.8% were male (n = 58). Patients with TV greater than 9 mL/kg showed higher 28-day ICU mortality than the 2 other groups (vs TV < 7 mL/kg, P = .007 and vs 7 mL/kg < TV ≤ 9 mL/kg, P = .004, respectively). Patients with TV less than or equal to 7 mL/kg required ventilators, ICU admissions, and hospitalizations for fewer days than those with TV greater than 7 mL/kg (11.4 vs 6.1 days for 28-day ventilator-free days, 9.7 vs 4.9 days for 28-day ICU-free days, and 5.2 vs 2.4 days for 28-day hospital-free days, respectively). Tidal volume greater than 9 mL/kg (hazard rate, 2.459; P = .003) and Sequential Organ Failure Assessment score (hazard rate, 1.158; P = .014) were significant predictors of 28-day ICU mortality.
  
  
  CONCLUSIONS
  Low-TV mechanical ventilation still benefits patients with ARDS caused by viral pneumonia.
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan, College of Medicine, Seoul 138-736, Republic of Korea.
authors.forename: Dong Kyu
authors.initials: DK
authors.lastname: Oh
authors.forename: Myung Goo
authors.initials: MG
authors.lastname: Lee
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Choi
authors.forename: Jaemin
authors.initials: J
authors.lastname: Lim
authors.forename: Hyun-Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Seok Chan
authors.initials: SC
authors.lastname: Kim
authors.forename: Chae-Man
authors.initials: CM
authors.lastname: Lim
authors.forename: Younsuck
authors.initials: Y
authors.lastname: Koh
authors.forename: Sang-Bum
authors.initials: SB
authors.lastname: Hong
mesh_terms: D016009:Chi-Square Distribution; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy* / Q000821:virology*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D056910:Republic of Korea / Q000453:epidemiology; D012121:Respiration, Artificial / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy* / Q000821:virology*; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric; D015996:Survival Rate; D013990:Tidal Volume; D016896:Treatment Outcome
keywords: Acute respiratory distress syndrome (ARDS); Influenza A virus; Mechanical ventilators; Tidal volume