Bowel ischaemia and organ impairment in elective abdominal aortic aneurysm repair

In 30 patients undergoing elective repair of abdominal aortic aneurysm the intramucosal pH (pHi) of the sigmoid colon was measured. Blood for endotoxin assay was taken at intervals before, during and after surgery. Daily measurements were made of liver transaminase activity and of arterial partial pressure of oxygen (PaO2). The mean(s.e.m.) peak systemic endotoxin concentration in those who developed intramucosal acidosis (pHibelow 7·00) was 90(14) pg/ml, compared with 42(5) pg/ml in those who did not (P< 0·01). In the 14 patients whose pHifell below 7·00, the mean(s.e.m.) postoperative rise in aspartate transaminase activity was 346(74) per cent, compared with 181(20) per cent in those whose pHiremained above this level (P< 0·05). The mean(s.e.m.) postoperative ratio of PaO2, to the fraction of inspired oxygen was 177(11) mmHg in those with intramucosal acidosis, compared with 260(24) mmHg in those whose pHiremained above 7·00 (P< 0·01). These results demonstrate a relationship between bowel ischaemia, endotoxaemia and organ impairment following elective aneurysm repair.