title: Prone ventilation following witnessed pulmonary aspiration: the effect on oxygenation.
abstract: OBJECTIVE
  Pulmonary aspiration is a significant cause of admission to the ITU and is associated with significant morbidity and mortality. Aspiration in the supine position produces posterior collapse/consolidation, similar to that seen in ALI/ARDS patients. Prone positioning has been shown to improve oxygenation in ALI/ARDS, but no studies have been performed on pulmonary aspiration.
  
  
  METHODS
  A prospective crossover study.
  
  
  METHODS
  Twelve-bed ITU.
  
  
  METHODS
  Eleven patients admitted to ITU with respiratory failure secondary to witnessed pulmonary aspiration requiring ventilation and an FIO(2) >0.50 after 12 h.
  
  
  METHODS
  Patients were placed in a prone position for 8 h and then turned supine for 8 h. Prone positioning was repeated if the FIO(2) remained >0.50. Ventilator settings were not altered in the study period.
  
  
  RESULTS
  Arterial blood gas analysis was performed every 2 h. The PaO(2)/FIO(2) gradient was calculated. Oxygenation improved on turning prone, with a significant increase in the PaO(2)/FIO(2) ratio ( P<0.01). There was a fall in this gradient on return to the supine position. There was a significant improvement in oxygenation on turning prone for the second period ( P<0.01). Overall, there was a significant improvement in the PaO(2)/FIO(2) ratio in the final supine position when compared to the first ( P<0.05).
  
  
  CONCLUSIONS
  This study demonstrates a significant improvement in oxygenation in the prone position in pulmonary aspiration. Early prone positioning in patients with pulmonary aspiration requiring ventilation may improve oxygenation by altering V/Q relationships similarly to ARDS, but also may aid drainage of secretions, opening up alveoli and preventing progression to established pneumonitis.
authors.affiliation: Critical Care Service, The James Cook University Hospital, Middlesbrough, TS4 3BW, UK.
authors.forename: Jason
authors.initials: J
authors.lastname: Easby
authors.affiliation: Critical Care Service, The James Cook University Hospital, Middlesbrough, TS4 3BW, UK.
authors.forename: Babu K
authors.initials: BK
authors.lastname: Abraham
authors.affiliation: Critical Care Service, The James Cook University Hospital, Middlesbrough, TS4 3BW, UK. Steve.Bonner@btinternet.com.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Bonner
authors.affiliation: Critical Care Service, The James Cook University Hospital, Middlesbrough, TS4 3BW, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Graham
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000209:etiology / Q000628:therapy*; D016684:Prone Position; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial / Q000379:methods*