GASTRIC TONOMETRY - EFFECT OF SUCRALFATE ON CALCULATED INTRAMURAL PH

Tonometric measurement of gastric intramural pH (pHi) is a noninvasive method to assess adequacy of splanchnic perfusion. Calculation of pHi may be influenced by various factors. This prospective study was desi gned to determine if stress ulcer prophylaxis with sucralfate interfer es with pHi measurement. Twenty-five adult patients admitted to the in tensive care unit (ICU) after open heart surgery were studied. Nasogas tric tonometers were placed. Patients received sucralfate 1 g via the nasogastric tube 8 hours after termination of surgery, thereafter ever y 6 hrs. Gastric luminal pH and intramural pH were determined immediat ely prior and 1 hour after the first sucralfate administration. Gastri c intramural pH was calculated from the arterial HCO3- concentration a nd the tonometrically determined intraluminal PCO2 Value using the Hen derson-Hasselbalch equation. Intraluminal PCO2(ss) was measured to be 6.86 +/- 0.75 kPa prior to sucralfate administration as compared to 6. 96 +/- 0.68 kPa 1 hour after 1 g sucralfate (P=0.92). Intramural pH, a s calculated by tonometry, was 7.31 +/- 0.05 vs 7.31 +/- 0.05, and was thus not influenced by sucralfate administration (P=0.97). Mean gastr ic intraluminal juice pH: was 4.2 +/- 1.3 compared to 4.2 +/- 1.2 (P=0 .59). These data suggest that sucralfate does not interfere with tonom etrically determined intraluminal PCO2 measurement and calculation of gastric intramural pH.