Influence of enoximone on systemic and splanchnic oxygen utilization and endotoxin release following cardiopulmonary bypass.
OBJECTIVE
We investigated whether the administration of enoximone during and after cardiopulmonary bypass (CPB) improves splanchnic oxygen utilization and thereby gut mucosal integrity in humans by its vasodilating and inotropic properties.


METHODS
Surgical intensive care unit (ICU) in a university hospital.


METHODS
21 patients (ASA III classification) scheduled for elective coronary artery bypass grafting were enrolled in the study. After induction of general anesthesia, patients were randomly assigned to received a bolus of 0.2 mg/kg enoximone, followed by 5 microg/kg per min (enoximone group), or followed by an equal volume of saline (NaCl group) during and 24 h after the surgical procedure. The following parameters were evaluated at different time intervals: systemic and pulmonary hemodynamics, blood gas analysis of arterial, mixed venous, and liver venous blood, venous and liver venous lactate level, venous and liver venous endotoxin level and intramucosal partial pressure of carbon dioxide for calculation of intramucosal pH (pHi).


RESULTS
Enoximone raised cardiac output and oxygen delivery to higher levels than those observed in the NaCl group. In both groups, gastric pHi fell continuously during the study period. The values were significantly decreased 12 h following admission to the ICU. Endotoxin was not detectable at baseline. Both groups showed increased endotoxin levels, with the highest values during the first 6 h postoperatively. The hepatic venous endotoxin level was almost doubled in the NaCl group in comparison to the enoximone group. Endotoxin levels differed in the two groups 6 and 12 h after admission to the ICU.


CONCLUSIONS
Improvement of oxygen delivery by enoximone did not prevent gastric mucosal acidosis following CPB. However, since the increase in endotoxin levels in liver venous blood was diminished by using enoximone, the drug seems to have a beneficial effect on tissue damage and barrier function of the gut.
Loick
H M
HM
Klinik und Poliklinik für Anästhesiologie und Operative Intensivmedizin, Westfälische Wilhelms-Universität Münster, Germany.
Möllhoff
T
T
Berendes
E
E
Hammel
D
D
Van Aken
H
H
D000368:Aged; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D002302:Cardiac Output / Q000187:drug effects; D002315:Cardiopulmonary Bypass; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004731:Endotoxins / Q000097:blood*; D017335:Enoximone / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects*; D011897:Random Allocation; D013152:Splanchnic Circulation / Q000187:drug effects*
D002316:Cardiotonic Agents; D004731:Endotoxins; D007773:Lactates; D017335:Enoximone