The use of tonometry to predict mortality in patients undergoing abdominal aortic aneurysm repair.
OBJECTIVE
To assess the reliability of intramucosal pH (pHi) of the sigmoid colon, IL-6 concentration and the APACHE II score in predicting outcome in patients undergoing elective abdominal aortic aneurysm repair.


METHODS
Prospective study.


METHODS
In 42 patients, measurements were made of the sigmoid pHi with the silicone tonometer and plasma IL-6 by enzyme linked immuno-sorbent assay (ELISA). The daily postoperative APACHE II scores were also calculated. In 29 patients a preoperative left ventricular ejection fraction was determined by gated radionuclide angiography.


RESULTS
Four out of 42 patients who were studied died. The lowest perioperative pHi, the peak postoperative IL-6 concentration and APACHE II scores were significantly different in the survivors in comparison to the non-survivors. In the non-survivors, the fall in pHi preceded the time of patient's demise by at least 4 days. Significant correlations were observed between changes in pHi, IL-6 and APACHE II. Using receiver operating characteristic curves, pHi was shown to be the most predictive of mortality compared to the other variables. The simplicity, speed and practicality of using the tonometer adds to its superiority over the latter measurements. No relationship was found between ventricular ejection fraction, pHi and outcome.


CONCLUSIONS
Although the number of patients is small, these results support pHi as a valuable predictor of outcome and also suggest a role for the gut in initiating the IL-6 and physiological responses.
Soong
C V
CV
Vascular Surgery Unit, Royal Victoria Hospital, Queen's University of Belfast, Northern Ireland, U.K.
Halliday
M I
MI
Hood
J M
JM
Rowlands
B J
BJ
Barros D'Sa
A A
AA
D018806:APACHE; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000401:mortality* / Q000601:surgery*; D012809:Colon, Sigmoid / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015850:Interleukin-6 / Q000097:blood; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D012372:ROC Curve; D013318:Stroke Volume; D015996:Survival Rate
D015850:Interleukin-6