[Portal and peripheral blood insulin concentrations and arterial ketone body ratio before and after glucose infusion during gastrectomy].

The effect of glucose infusion on portal and peripheral blood immunoreactive insulin (IRI) concentrations and arterial ketone body ratio (AKBR) during gastrectomy were evaluated on twenty patients divided into two groups. Portal and peripheral blood IRI concentrations, AKBR, total ketone body concentration (TKB: acetoacetate + beta-hydroxybutyrate), and blood glucose were determined before and 30, 60, and 120 minutes after 25g glucose infusion in 30 minutes in ten patients (group 1) and 50 g glucose infusion in 30 minutes in ten patients (group 2). In both groups, the rate of increase in the portal blood IRI concentration was markedly higher than that in the peripheral blood IRI concentration after glucose infusion and AKBR increased and TKB decreased with the increase of the portal blood IRI concentration. These findings suggest that the peripheral blood IRI concentration does not reflect the pancreatic insulin secretion after glucose infusion during surgery and that portal insulin plays an important role for elevating and maintaining AKBR at higher levels. On the other hand, in both groups, the blood glucose had its peak just after completion of glucose infusion and then decreased gradually. After glucose infusion, however, the blood glucose in group 2 increased markedly and was significantly higher than that in group 1. It is suggested that, during surgery, glucose infusion rate of 50 g in 30 minutes may be too rapid.