title: Pre-operative tonometry is predictive for mortality and morbidity in high-risk surgical patients.
abstract: OBJECTIVE
  To determine whether a) pre-operative measurement of gastric intramucosal pHi is predictive for mortality and morbidity in high-risk surgical patients and b) peri-operative improvement of global oxygen delivery (DO2) with fluids and dopexamine leads to increased gastric pHi and c) either improved global perfusion or improved splanchnic perfusion is related to the prevention of multiple organ failure (MOF).
  
  
  METHODS
  Retrospective analysis of a double-blind, placebo-controlled, randomised study.
  
  
  METHODS
  General intensive care units from 14 hospitals.
  
  
  METHODS
  Two hundred eighty-six high-risk surgical patients.
  
  
  METHODS
  Swan-Ganz and tonometer catheter placement; patients were stabilised pre-operatively using fluids, blood and/or oxygen to preset goals before receiving placebo or two doses of dopexamine (0.5 or 2.0 microg.kg.min) peri-operatively.
  
  
  RESULTS
  Haemodynamic assessment (including DO2 and oxygen consumption (VO2)) was performed together with measurement of gastric mucosal pHi pre-operatively and directly, 2, 6, 12, 24 and 36 h post-operatively. Retrospectively, patients were divided pre-operatively into two sub-groups based on the optimal cut-off value for mortality of the first pHi measurement after induction of anaesthesia as calculated by a receiver operator characteristic (ROC) curve analysis --low pHi group (< 7.35) and normal pHi (> or =7.35). Mortality in the low pHi, was higher than in the normal pHi, group (16.8 vs 2.3%; p = 0.0001). In the normal pHi group dopexamine, which was given prior to the first pHi measurement, had no effect on pHi, while DO2 increased significantly. In this group MOF score and number of patients with MOF remained similar for the treatment sub-groups. In the low pHi group gastric pHi increased significantly during dopexamine infusion (p = 0.008), despite the lack of an increase in DO2 and VO2. In this group the MOF score and the number of patients developing MOF decreased significantly with the use of dopexamine (p = 0.04). In both groups bicarbonate levels remained similar for the treatment subgroups.
  
  
  CONCLUSIONS
  In high-risk surgical patients pre-operative measurement of pHi was predictive for mortality. The peri-operative response of pHi to dopexamine seemed to be dependent on pre-operative gastric pHi.
authors.affiliation: Department of Surgery, University Hospital Maastricht, The Netherlands. m_poeze@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Poeze
authors.forename: J
authors.initials: J
authors.lastname: Takala
authors.forename: J W
authors.initials: JW
authors.lastname: Greve
authors.forename: G
authors.initials: G
authors.lastname: Ramsay
mesh_terms: D000704:Analysis of Variance; D002407:Catheterization, Swan-Ganz; D004298:Dopamine / Q000031:analogs & derivatives / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005440:Fluid Therapy; D005745:Gastric Acidity Determination; D005753:Gastric Mucosa / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000503:physiopathology; D010100:Oxygen / Q000378:metabolism; D011300:Preoperative Care; D012372:ROC Curve; D012044:Regression Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013152:Splanchnic Circulation; D014665:Vasodilator Agents / Q000627:therapeutic use
chemical_list: D014665:Vasodilator Agents; C046318:dopexamine; D010100:Oxygen; D004298:Dopamine