EFFECT OF LOW-DOSE DOPAMINE ON SIGMOID COLONIC INTRAMUCOSAL PH IN PATIENTS UNDERGOING ELECTIVE ABDOMINAL AORTIC-ANEURYSM REPAIR

The effect of low-dose dopamine administration on intramucosal pH (pH( i)) of the sigmoid colon and on postoperative function of various orga ns in patients undergoing elective abdominal aortic aneurysm repair wa s examined. Nineteen patients were randomized to two groups; nine rece ived dopamine at a rate of 3 mu g per kg per min for 24 h from inducti on of anaesthesia and ten control patients received fluids without dop amine. pH(i) was measured with a silicone tonometer and daily samples of blood were taken for measurement of liver transaminase activity, ar terial oxygen saturation and creatinine concentration. Mean(s.e.m.) pH (i) fell to a significantly lower minimum value in those receiving dop amine compared with control patients (6.86(0.10) versus 7.11(0.08), P < 0.05). Five of the nine patients given dopamine developed intramucos al acidosis compared with only one of the ten control patients (P=0.06 ). After operation the mean(s.e.m.) aspartate transaminase concentrati on in patients given dopamine rose from 33(2) to 80(17) units/l (P< 0. 01); in control patients it rose from 32(3) to 59(16) units/l (P=0.054 ). No difference between the groups was observed in the postoperative ratio of arterial oxygen saturation to inspired oxygen fraction or cre atinine concentrations. These results indicate that dopamine has no be neficial effect on bowel mucosal oxygenation and function of the vario us organs in patients undergoing aortic aneurysm repair.