Dopexamine and dopamine in the prevention of low gastric mucosal pH following cardiopulmonary by-pass.
The effect of low-dose dopexamine and dopamine on gastric intramucosal pH (pHi) during cardiac surgery and 16 hours postoperatively was studied in 35 adults patients (coronary artery bypass grafting and/or valve replacement). The patients were assigned randomly to treatment groups with either dopexamine (1 microgram.kg-1.min-1 (n = 12), dopamine 2.5 micrograms.kg-1.min-1 (n = 11) or to a control group (n = 12). The infusions were started after induction of anaesthesia and were continued until 16 hours after CPB. pHi and arterial pH (pHa) did not differ between groups and remained unchanged during cardiopulmonary by-pass and for the first four postoperative hours. Both the carbon dioxide tension of arterial blood (PaCO2) and of the saline in the tonometer (PtonCO2) changed in parallel with a decrease during CPB and an increase after CPB and surgery with maximal values 12 hours after termination of CPB. A significant correlation was noted between pHi and pHa and between arterial and tonometric PCO2. It is concluded that low dose dopexamine and dopamine have no influence on pHi during and after cardiac surgery. The observed changes in pHi and PtonCO2 were due to changes in pHa and in PaCO2 and not a sign of gastric mucosal ischemia.
Gårdebäck
M
M
Department of Cardiothoracic Anaesthetics and Intensive Care, Karolinska Hospital, Stockholm, Sweden.
Settergren
G
G
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000368:Aged; D002245:Carbon Dioxide / Q000097:blood; D002315:Cardiopulmonary Bypass; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005745:Gastric Acidity Determination; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008875:Middle Aged
D000318:Adrenergic beta-Agonists; D002245:Carbon Dioxide; C046318:dopexamine; D004298:Dopamine