title: Application of a new method for analysis of exhaled gas in critically ill patients.
abstract: OBJECTIVE
  Application of a new method for analysis of exhaled gas in critically ill patients.
  
  
  METHODS
  Open study.
  
  
  METHODS
  Surgical intensive care unit of an university hospital.
  
  
  METHODS
  Thirty-seven consecutive, critically ill, mechanically ventilated patients.
  
  
  METHODS
  None.
  
  
  RESULTS
  Chemical analysis of the patient's exhaled gas was based upon substance adsorption and concentration onto activated charcoal, microwave desorption and gas chromatographic separation. Patients with acute respiratory distress syndrome (ARDS) exhaled less isoprene than those without ARDS [9.8 (8.2-21.6) vs 21.8 (13.9-41.4) nmol/m2 per min [median (95% confidence interval)], p = 0.04]. In patients who developed pulmonary infection, pentane elimination increased from 0.4 (0.0-5.4) to 2.7 (0.6-6.1, p = 0.05) nmol/m2 per min and isoprene elimination decreased from 5.2 (0-33) to 5.0 (0-17, p = 0.05) nmol/m2 per min, resulting in a significant increase in pentane/isoprene ratio from 0.1 (0-0.3) to 0.4 (0-15, p = 0.007) when compared to patients without pulmonary infection.
  
  
  CONCLUSIONS
  The new method allows quantitative analysis of human gas samples with low substance concentrations and is well suited for clinical studies which involve the investigation of metabolic processes in the lung and the body.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital of Freiburg, Germany. schubert@ana1.ukl.uni-freiburg.de
authors.forename: J K
authors.initials: JK
authors.lastname: Schubert
authors.forename: W P
authors.initials: WP
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Benzing
authors.forename: K
authors.initials: K
authors.lastname: Geiger
mesh_terms: D000328:Adult; D000368:Aged; D001944:Breath Tests / Q000295:instrumentation / Q000379:methods*; D002138:Calibration; D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D016638:Critical Illness; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000378:metabolism*; D015203:Reproducibility of Results; D012128:Respiratory Distress Syndrome / Q000378:metabolism*; D018709:Statistics, Nonparametric