title: Predicting duration of mechanical ventilation in patients with carbon monoxide poisoning: a retrospective study.
abstract: OBJECTIVE
  Patients with severe carbon monoxide (CO) poisoning may develop acute respiratory failure, which needs endotracheal intubation and mechanical ventilation (MV). The objective of this study was to identify the predictors for duration of MV in patients with severe CO poisoning and acute respiratory failure.
  
  
  METHODS
  This is a retrospective observational study of 796 consecutive patients diagnosed with acute CO poisoning that presented to the emergency department. Patients who received MV were divided into 2 groups: the early extubation (EE) consisting of patients who were on MV for less than 72 hours and the nonearly extubation (NEE) consisting of patients who were on MV for more than 72 hours. Demographic and clinical data of the two groups were extracted for analysis.
  
  
  RESULTS
  The intubation rate of all CO-poisoned patients was 23.4%. A total of 168 patients were enrolled in this study. The main source of CO exposure was intentional CO poisoning by charcoal burning (137 patients). Positive toxicology screening result was found in 104 patients (61.9%). The EE group had 105 patients (62.5%). On arriving at the emergency department, high incidence of hypotension; high white blood cell count; and elevation of blood urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase, creatine kinase, and troponin-I levels were statistically significant in the NEE group (P < .05). Positive toxicology screening result was statistically significant in the EE group (P < .05). In a multivariate analysis, elevation of troponin-I level was an independent factor for NEE (odds ratio, 1.305; 95% confidence interval, 1.024-1.663; P = .032). Positive toxicology screening result was an independent factor for EE (odds ratio, 0.222; 95% confidence interval, 0.101-0.489; P = .001).
  
  
  CONCLUSIONS
  A positive toxin screen predicts extubation within the first 72 hours for patients with severe CO poisoning and acute respiratory failure. On the other hand, elevation of initial troponin-I level is a predictor for a longer duration of MV.
authors.affiliation: Hyperbaric Oxygen Therapy Center, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chih-Hao
authors.initials: CH
authors.lastname: Shen
authors.affiliation: Hyperbaric Oxygen Therapy Center, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Chung-Kan
authors.initials: CK
authors.lastname: Peng
authors.affiliation: School of Public Health, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Chou
authors.affiliation: Graduate Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Ke-Ting
authors.initials: KT
authors.lastname: Pan
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Shun-Cheng
authors.initials: SC
authors.lastname: Chang
authors.affiliation: Hyperbaric Oxygen Therapy Center, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
authors.forename: Shan-Yueh
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Hyperbaric Oxygen Therapy Center, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Graduate Institute of Aerospace and Undersea Medicine, National Defense Medical Center, Taipei, Taiwan. Electronic address: kun@mail.ndmctsgh.edu.tw.
authors.forename: Kun-Lun
authors.initials: KL
authors.lastname: Huang
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D060666:Airway Extubation / Q000706:statistics & numerical data; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D002249:Carbon Monoxide Poisoning / Q000097:blood / Q000150:complications* / Q000628:therapy; D005260:Female; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial / Q000706:statistics & numerical data*; D012131:Respiratory Insufficiency / Q000097:blood / Q000209:etiology / Q000628:therapy*; D012189:Retrospective Studies; D013624:Taiwan; D013997:Time Factors; D019210:Troponin I / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019210:Troponin I
keywords: Benzodiazepine; Carbon monoxide; Extubation; Mechanical ventilation; Toxicology screen; Troponin-I