# 2263 Prediction of Anastomotic Complications Following Oesophageal
Resection Using Automated Measurement of Gastroplasty Carbon
Dioxide GAP.
Peter C. Roberts, Angela McLuckie, William J. Owen, Richard J Beale,
Robert C Mason, London, United Kingdom
Background: Gastric mucosal perfusion can be assessed tonometrically by
measuring the intra-mucosal pH (pHi) and CO2 gap (tonometer pCO2-arterial
pCO2) and its ability to predict outcome following surgery has been demonstrated
in previous studies. This study employed automated gas tonometry
to measure gastric CO2 gap and pHi following oesophagectomy to test
the predictive ability of the technique for anastomotic complications.
Method: Gastric tonometers were placed in the gastric tubes of 30 consecutive
patients undergoing oesophageal resection and pro-peristaltic tubular
gastroplasty. These were connected to a Tonocap analyser (Datex-
Engstrom Division, Instrumentarium Corporation, Helsinki, Finland). The
gastric CO2 gap and pHi were calculated at 12 hourly intervals up to 48
hours post-operatively.
Results: 11 patients suffered an anastomotic leak or benign stricture. Because
of balloon failure or re-operation within 48 hours of surgery data was
not available for 1 patient from each of the complication and no complication
groups. Mean (s.d.) CO2 gap and pHi over the first 48 post-operative
hours were 1.7 kPa (0.8) and 7.26 (0.06) in the no complication group and
3.5 kPa (2.0) and 7.18 (0.11) in the complication group respectively. The
difference in CO2 gap between the 2 groups was more significant than in
pHi (p<0.005 and p<0.05). and the CO2 gap was a better predictor of outcome
than the pHi, with areas under their respective ROC curves of 0.847
and 0.684. A mean CO2 gap of 2.5kPa or above had a sensitivity of 80% , a
specificity of 82% and a likelihood ratio of 4.0 for predicting anastomotic
complications.
Conclusions: Gastric tube CO2 gap and pHi are easily measured using recirculating
gas tonometry. Mean CO2 gap was higher and pHi lower over the
first 48 hours following surgery in those patients in whom an anastomotic
complication subsequently developed than in those in whom it did not. The
CO2 gap proved to be a better predictor of complications than the pHi. These
findings suggest that the CO2 gap may useful as a therapeutic goal if used in
conjunction with measures to improve gastric tube CO2 gap post-operatively
and that this might reduce the incidence of anastomotic failure.
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