Effects of vasoactive drugs on gastric intramucosal pH.

Abstract

To review current knowledge about the effects of vasoactive agents on gastric intramucosal pH (pHi). All studies involving pHi and vasoactive agents were retrieved from a computerized MEDLINE search from 1980 to 1997. We also reviewed the reference lists of all available review articles and primary studies to identify references not found in the computerized searches. Clinical and experimental studies using dopamine, dopexamine, dobutamine, norepinephrine, epinephrine, nitric oxide, N-acetylcysteine, prostaglandins, or pentoxifylline were considered if splanchnic perfusion and/or pHi measurements were utilized. From the selected studies, information was obtained regarding patient population, dosing regimen, duration of study, and effects on splanchnic blood flow (SBF), splanchnic oxygenation, and pHi. Although dopaminergic effects increase SBF, dopamine does not generally increase pHi. Data on the effects of dopexamine on pHi are scarce and inconsistent. Dobutamine can significantly increase SBF and usually increases pHi. In septic patients, norepinephrine seems to increase pHi. Epinephrine may have detrimental effects on gastric perfusion. Prostacyclin seems to increase pHi but data are limited. Insufficient evidence exists to support the beneficial effects of nitric oxide donors or blockers, pentoxifylline, or N-acetylcysteine on pHi. Overall, the effects of vasoactive agents on pHi are unpredictable. Among the catecholamines, dopamine is the least likely, and dobutamine the most likely, to increase pHi.