Objective: The aim of this study is the evolution of the intramucosal pH (pHi) during the quirurgic and the immediate postoperative process in pediatric patients, operated in abdominal surgery longer than 90 minutes.
Material and methods: A prospective study including 25 patients was done. In all of them intraabdominal surgery was performed. The mean age was 5.6 +/- 3 years, range from 9 months to 13 years. The operative time was 207 +/- 76 minutes. The pHi was measured by means of a sigmoid tonometer introduced in the stomach. A tonometry was done hourly during the operative procedure, and every 8 hours during the postoperative period.
Results: 157 determinations of pHi were made with an average of 6.28 per patient. During the operative period the pHi decreased from 7.36 +/- 0.11 (30') to 7.22 +/- 0.11 (210'). During the postoperative, the pHi increased to 7.36 +/- 0.05, 24 hours later (p < 0.005).
Conclusions: During the surgery there was a significant reduction of the pHi, which recovered 16 hours after in the postoperative.