Does continuous mucosal partial carbon dioxide pressure measurement predict leakage of intrathoracic esophagogastrostomy?

Background Gastroplasty after esophagectomy is associated with relevant morbidity due to anastomotic leakage of the esophagogastrostomy. The aim of this study was to find out whether continuous partial carbon dioxide pressure (pCO2) measurement of the gastric mucosa is an adequate method of monitoring the gastric tube during the postoperative course and of detecting patients with an anastomotic leakage. Methods Forty-seven patients with esophageal cancer underwent esophagectomy and gastric tube formation with intrathoracic esophagogastrostomy. Postoperatively, mucosal pCO2 of the gastric tube (pCO2i) was measured using continuous tonometry (TONOCAP, Datex Ohmeda). pCO2i was related to the arterial pCO2 (ΔpCO2 = pCO2i − pCO2a). Results A total of 4,338 ΔpCO2 measurements were recorded. On average, the pCO2i of each patient was monitored over a period of 92 hours. In 5 patients an anastomotic leakage of the esophagogastrostomy developed. The mean ΔpCO2 of this group was 31.7 mm Hg (±19.3 SD) and significantly higher (p< 0.0001) than that of patients without anastomotic leakage (20.7 mm Hg ± 12.8 SD). With a ΔpCO2 cut-off point of 56 mm Hg measured for 5 hours, the sensitivity was 0.8, the specifity 0.9, and the positive predictive value 0.5. In patients with anastomotic leakage, the peak ΔpCO2 preceded clinical symptoms. False positive ΔpCO2 measurements (n = 4) were mainly due to severe pneumonia with long-term ventilation. Conclusions Mucosal pCO2 measurement of the gastric tube can be used as an early indicator of a complicated postoperative course predicting anastomotic leakage of the esophagogastrostomy.