EFFECTS OF VASOACTIVE DRUGS ON GASTRIC INTRAMUCOSAL PH

Objective: To review current knowledge about the effects of vasoactive agents on gastric intramucosal pH (pHi). Data Sources: All studies in volving pHi and vasoactive agents were retrieved from a computerized M EDLINE search from 1980 to 1997. We also reviewed the reference lists of all available review articles and primary studies to identify refer ences not found in the computerized searches. Study Selection: Clinica l and experimental studies using dopamine, dopexamine, dobutamine, nor epinephrine, epinephrine, nitric oxide, N-acetylcysteine, prostaglandi ns, or pentoxifylline were considered if splanchnic perfusion and/or p Hi measurements were utilized. Data Extraction: From the selected stud ies, information was obtained regarding patient population, dosing reg imen, duration of study, and effects on splanchnic blood flow (SBF), s planchnic oxygenation, and pHi. Data Synthesis: Although dopaminergic effects increase SBF, dopamine does not generally increase pHi. Data o n the effects of dopexamine on pHi are scarce and inconsistent. Dobuta mine can significantly increase SBF and usually increases pHi. In sept ic patients, norepinephrine seems to increase pHi. Epinephrine may hav e detrimental effects on gastric perfusion. Prostacyclin seems to incr ease pHi but data are limited. Insufficient evidence exists to support the beneficial effects of nitric oxide donors or blockers, pentoxifyl line, or N-acetylcysteine on pHi. Conclusions: Overall, the effects of vasoactive agents on pHi are unpredictable. Among the catecholamines, dopamine is the least likely, and dobutamine the most likely, to incr ease pHi.