title: Splanchnic oxygen transport after cardiac surgery: evidence for inadequate tissue perfusion after stabilization of hemodynamics.
abstract: OBJECTIVE
  To evaluate the adequacy of visceral oxygen transport and gastric pHi after open heart surgery in patients with stable hemodynamics.
  
  
  METHODS
  Nonrandomized control trial.
  
  
  METHODS
  A general intensive care unit in a tertiary care center.
  
  
  METHODS
  Sixteen postoperative cardiac surgery patients were studied after stabilization of systemic hemodynamics.
  
  
  METHODS
  The effect of dobutamine infusion (6 mu g kg-1 min-1) on systemic and regional oxygen transport was studied in ten patients, with six patients serving as controls. Systemic oxygen consumption was measured by indirect calorimetry and splanchnic and femoral blood flow, by continuous infusion of indocyanine green using regional catheters and gastric mucosal pHi by gastric tonometer.
  
  
  RESULTS
  Gastric mucosal acidosis was observed in half of the patients. Dobutamine increased cardiac output (3.2 +/- 0.6 vs 4.4 +/- 0.7 l x min-1 x min-2; P <0.05), splanchnic blood flow (0.68 +/- 0.28 vs 0.91 +/- 0.28 l x min-1 x m-2; p <0.05) and femoral blood flow (0.25 +/- 0.08 vs 0.32 +/- 0.11 l x min-1 x m-2; p <0.05). Changes in splanchnic oxygen delivery and consumption were parallel in the two study groups. In response to dobutamine, gastric pHi did not change (7.30 +/- 0.08 vs 7.31 +/- 0.06; NS), while in the control group, gastric pHi tended to decrease (7.32 +/- 0.04 vs 7.28 +/- 0.06; NS). Systemic oxygen consumption increased in response to dobutamine (141 +/- 11 vs 149 +/- 11 ml x min-1 x m-2; P <0.05) but did not change in the control group.
  
  
  CONCLUSIONS
  We conclude that a mismatch between splanchnic oxygen delivery and demand may be present despite stabilization of systemic hemodynamics after cardiac surgery. This is suggested by the parallel changes in splanchnic oxygen delivery and consumption. Dobutamine is likely to improve splanchnic tissue perfusion at this phase.
authors.affiliation: Department of Intensive Care, Kuopio University Hospital, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Uusaro
authors.forename: E
authors.initials: E
authors.lastname: Ruokonen
authors.forename: J
authors.initials: J
authors.lastname: Takala
mesh_terms: D000138:Acidosis; D000704:Analysis of Variance; D002316:Cardiotonic Agents / Q000494:pharmacology*; D001026:Coronary Artery Bypass; D004280:Dobutamine / Q000494:pharmacology*; D005260:Female; D005753:Gastric Mucosa; D006439:Hemodynamics; D006801:Humans; D000860:Hypoxia / Q000097:blood; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects*; D011184:Postoperative Period; D012039:Regional Blood Flow; D013152:Splanchnic Circulation / Q000187:drug effects*; D018709:Statistics, Nonparametric
chemical_list: D002316:Cardiotonic Agents; D004280:Dobutamine