title: Computed tomographic assessment of airflow obstruction in smoke inhalation injury: Relationship with the development of pneumonia and injury severity.
abstract: OBJECTIVE
  The prediction of pulmonary deterioration in patients with smoke inhalation injury is important because this influences the strategy for patient management. We hypothesized that narrowing of the luminal bronchus due to bronchial wall thickening correlates to respiratory deterioration in smoke inhalation injury patients.
  
  
  METHODS
  In a prospective observational study, all patients were enrolled at a single tertiary trauma and critical care center. In 40 patients, chest computed tomographic images were obtained within a few hours after smoke inhalation injury. We assessed bronchial wall thickness and luminal area % on chest computed tomographic images. Airway wall thickness to total bronchial diameter (T/D) ratio, percentage of luminal area, and clinical indices were compared between patients with smoke inhalation injury and control patients.
  
  
  RESULTS
  The T/D ratio of patients with smoke inhalation was significantly higher than that of control patients (p<0.001), and the luminal area of these patients was significantly smaller than that of control patients (p<0.001). The number of mechanical ventilation days correlated with the initial infusion volume, T/D ratio, and luminal area %. ROC analysis showed a cut-off value of 0.26 for the T/D ratio, with a sensitivity of 79.0% and specificity of 73.7%, and a value of 23.4% for luminal area %, with a sensitivity of 68.4% and specificity of 84.2%.
  
  
  CONCLUSIONS
  These data revealed the utility of computed tomography scanning on admission to show that the patients with smoke inhalation injury had airway wall thickening compared to control patients without smoke inhalation injury. Airflow narrowing due to airway wall thickening was related to the development of pneumonia and the number of mechanical ventilation days in patients with smoke inhalation injury. Airflow narrowing is one important factor of respiratory deterioration in smoke inhalation injury.
authors.affiliation: Department of Critical Care Medicine, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abenoku, Osaka City 545-8585, Osaka, Japan. Electronic address: yamamura@med.osaka-cu.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamamura
authors.affiliation: Department of Critical Care Medicine, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abenoku, Osaka City 545-8585, Osaka, Japan.
authors.forename: Takasei
authors.initials: T
authors.lastname: Morioka
authors.affiliation: Department of Critical Care Medicine, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abenoku, Osaka City 545-8585, Osaka, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Hagawa
authors.affiliation: Department of Critical Care Medicine, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abenoku, Osaka City 545-8585, Osaka, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Critical Care Medicine, Graduate School of Medicine, Osaka City University, 1-4-3 Asahimachi, Abenoku, Osaka City 545-8585, Osaka, Japan.
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Mizobata
mesh_terms: D000328:Adult; D000368:Aged; D001980:Bronchi / Q000473:pathology; D002056:Burns / Q000000981:diagnostic imaging; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D015601:Injury Severity Score; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000000981:diagnostic imaging / Q000209:etiology*; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity; D015208:Smoke Inhalation Injury / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
keywords: Airflow narrowing; Bronchial wall thickness; Computed tomography; Luminal area; Pneumonia; Smoke inhalation injury