title: Intra-breath arterial oxygen oscillations detected by a fast oxygen sensor in an animal model of acute respiratory distress syndrome.
abstract: BACKGROUND
  There is considerable interest in oxygen partial pressure (Po2) monitoring in physiology, and in tracking Po2 changes dynamically when it varies rapidly. For example, arterial Po2 ([Formula: see text]) can vary within the respiratory cycle in cyclical atelectasis (CA), where [Formula: see text] is thought to increase and decrease during inspiration and expiration, respectively. A sensor that detects these [Formula: see text] oscillations could become a useful diagnostic tool of CA during acute respiratory distress syndrome (ARDS).
  
  
  METHODS
  We developed a fibreoptic Po2 sensor (<200 µm diameter), suitable for human use, that has a fast response time, and can measure Po2 continuously in blood. By altering the inspired fraction of oxygen ([Formula: see text]) from 21 to 100% in four healthy animal models, we determined the linearity of the sensor's signal over a wide range of [Formula: see text] values in vivo. We also hypothesized that the sensor could measure rapid intra-breath [Formula: see text] oscillations in a large animal model of ARDS.
  
  
  RESULTS
  In the healthy animal models, [Formula: see text] responses to changes in [Formula: see text] were in agreement with conventional intermittent blood-gas analysis (n=39) for a wide range of [Formula: see text] values, from 10 to 73 kPa. In the animal lavage model of CA, the sensor detected [Formula: see text] oscillations, also at clinically relevant [Formula: see text] levels close to 9 kPa.
  
  
  CONCLUSIONS
  We conclude that these fibreoptic [Formula: see text] sensors have the potential to become a diagnostic tool for CA in ARDS.
authors: Nuffield Department of Clinical Neurosciences, Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK federico.formenti@ndcn.ox.ac.uk.
authors: F
authors: F
authors: Formenti
authors: Nuffield Department of Clinical Neurosciences, Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
authors: R
authors: R
authors: Chen
authors: Nuffield Department of Clinical Neurosciences, Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
authors: H
authors: H
authors: McPeak
authors: School of Veterinary Sciences, University of Bristol, Bristol, UK.
authors: P J
authors: PJ
authors: Murison
authors: Biomedical Centre, Charles University in Prague, Faculty of Medicine in Pilsen, alej Svobody 80, 304 60 Pilsen, Czech Republic First Medical Department, Charles University in Prague, Faculty of Medicine in Pilsen, alej Svobody 80, 304 60 Pilsen, Czech Republic.
authors: M
authors: M
authors: Matejovic
authors: Nuffield Department of Clinical Neurosciences, Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
authors: C E W
authors: CE
authors: Hahn
authors: Nuffield Department of Clinical Neurosciences, Nuffield Division of Anaesthetics, University of Oxford, Oxford, UK.
authors: A D
authors: AD
authors: Farmery
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005336:Fiber Optic Technology; D010100:Oxygen / Q000097:blood*; D012128:Respiratory Distress Syndrome / Q000097:blood*; D013552:Swine
chemical_list: D010100:Oxygen
keywords: acute respiratory distress syndrome; arterial oxygen monitoring; cyclical atelectasis; fibreoptic sensor
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