title: Cerebral and somatic oxygen saturations after repair of tetralogy of Fallot: effects of extubation on regional blood flow.
abstract: BACKGROUND
  After repair of tetralogy of Fallot, some patients experience a low cardiac output state owing to right ventricular diastolic failure. Negative-pressure ventilation has been shown to improve cardiac output in these patients. What has not been evaluated is the effect of extubation and loading of the respiratory muscles on the distribution of cardiac output after repair of tetralogy of Fallot.
  
  
  METHODS
  In 23 consecutive patients undergoing repair of tetralogy of Fallot, standard hemodynamic variables, central venous oxygen saturations, and near infrared spectroscopy of the brain, mesenteric, and renal circulations were monitored for 30 minutes before and after extubation.
  
  
  RESULTS
  With extubation, the systolic blood pressure increased significantly from 96 ± 11 to 106 ± 15 mm Hg (p = 0.002) while the heart rate remained unchanged. With extubation, the central venous oxygen saturation increased significantly from 65% ± 7% to 70% ± 10% (p = 0.003). Cerebral oxygen saturations increased significantly from 67% ± 10% to 72% ± 9% (p = 0.0001), whereas mesenteric oxygenation fell significantly from 74% ± 15% to 72% ± 15% (p = 0.04). Renal oxygenation was unaffected by extubation.
  
  
  CONCLUSIONS
  Cardiac output and cerebral oxygenation increased significantly during spontaneous respiration, the latter suggesting that the brain was in or approaching an oxygen supply-dependent state before extubation. Despite the increase in cardiac output, the presumed increase in respiratory pump perfusion, as well as the concurrent increase in cerebral perfusion, came at the expense of mesenteric perfusion. Renal oxygenation remained unchanged with extubation.
authors.affiliation: Division of Pediatric Critical Care Medicine, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas 77037, USA. bronicki@bcm.edu
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Bronicki
authors.forename: Paul A
authors.initials: PA
authors.lastname: Checchia
authors.forename: Nick G
authors.initials: NG
authors.lastname: Anas
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Adams
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Penny
authors.forename: Mark S
authors.initials: MS
authors.lastname: Bleiweis
authors.forename: Lara S
authors.initials: LS
authors.lastname: Shekerdemian
mesh_terms: D060666:Airway Extubation; D001921:Brain / Q000378:metabolism*; D002302:Cardiac Output; D006801:Humans; D007223:Infant; D010100:Oxygen / Q000378:metabolism*; D011184:Postoperative Period; D011446:Prospective Studies; D012039:Regional Blood Flow; D013771:Tetralogy of Fallot / Q000601:surgery*
chemical_list: D010100:Oxygen