Fourteen mongrel dogs were anaesthetized and mechanically ventilated with oxygen. After oleic acid was administered intravenously, amrinone 1 mg/kg was intravenously administered to one group followed by a continuous infusion of 10 micrograms/kg/min for one hour (amrinone group, n = 7). Isovolumetric saline was administered to the control group (n = 7). Amrinone slightly lowered PaO2 but significantly increased oxygen delivery and improved gastric intramucosal pH (pHi) during the first 30 minutes (7.33 +/- 0.13) compared with the control group (7.21 +/- 0.06, P < 0.05). The pHi remained higher in the amrinone group (7.30 +/- 0.15) than in the control group (7.16 +/- 0.06, P < 0.05) after the drug was withdrawn. Extravascular lung water was significantly augmented after oleic acid injection and sustained in all animals for the remainder of the study.