title: Positioning effects on arterial oxygen and relative pulmonary shunt in patients receiving mechanical ventilation after CABG.
abstract: OBJECTIVE
  To examine the effects of three different positions on arterial oxygen and relative pulmonary shunt in patients after coronary artery bypass graft (CABG) who are receiving mechanical ventilation with an effective tidal volume of 15 ml/kg and a minimum of 5 cm H2O positive end-expiratory pressure.
  
  
  METHODS
  Repeated measures, counterbalanced.
  
  
  METHODS
  Adult cardiovascular intensive care unit in a major tertiary referral hospital.
  
  
  METHODS
  Convenience sample of 30 patients who had undergone CABG, 90% of whom had postoperative atelectasis.
  
  
  METHODS
  Partial pressure arterial oxygen (PaO2) and relative pulmonary shunt (areas of low ventilation-perfusion ratio).
  
  
  METHODS
  Supine, right lateral, and left lateral positions with head of bed elevated 30 degrees.
  
  
  RESULTS
  No statistically significant differences in arterial oxygen and relative pulmonary shunt were found among the three positions.
  
  
  CONCLUSIONS
  For a selected cohort, positioning may not be an important consideration in arterial oxygenation in patients who have undergone CABG and are receiving mechanical ventilation with a high tidal volume and positive end-expiratory pressure.
authors.affiliation: Faculty of Nursing, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Chan
authors.forename: L
authors.initials: L
authors.lastname: Jensen
mesh_terms: D000328:Adult; D001784:Blood Gas Analysis; D015400:Clinical Nursing Research; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003422:Critical Care / Q000379:methods / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood*; D011182:Postoperative Care / Q000379:methods / Q000592:standards; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology / Q000451:nursing*; D011187:Posture; D001261:Pulmonary Atelectasis / Q000175:diagnosis / Q000209:etiology / Q000451:nursing*; D011659:Pulmonary Gas Exchange; D013902:Radiography, Thoracic; D012121:Respiration, Artificial / Q000451:nursing*; D014692:Ventilation-Perfusion Ratio
chemical_list: D010100:Oxygen