Effect of surgical stress on the erythrocyte insulin receptor

Labetalol attenuates the negative effects of deliberate hypotension induced by isoflurane

The effect of labetalol on deliberate hypotension was studied in 24 adult patients undergoing middle-ear surgery. Hypotension was induced in Group I (12 patients) with isoflurane 3.0 vol% in inspiratory gas, and in Group II (12 patients) with labetalol 0.5 mg.kg-1 i.v., in addition to isoflurane. The induction time of hypotension was 4.9 +/- 1.0 (s.e.mean) min in Group I, and 1.8 +/- 0.2 min in Group II (P less than 0.01). The mean isoflurane concentration in inspiratory gas for the maintenance of hypotension was 1.4 +/- 0.2 vol% in Group I, and 0.7 +/- 0.1 vol% in Group II (P less than 0.01). There were no differences in urine flow rates (UF) between the groups during any phase, though UF decreased in Group I from the prehypotensive value 0.58 +/- 0.12 ml.min-1 to 0.07 +/- 0.02 ml.min-1 during hypotension (P less than 0.01) and increased to 1.28 +/- 0.17 ml.min-1 after anaesthesia (P less than 0.05). UF in Group II were 0.56 +/- 0.17, 0.25 +/- 0.10 and 0.56 +/- 0.06 ml.min-1, respectively. Creatinine clearances per 1.73 m2 body surface area (CCreat) in Group I were 78 +/- 14 ml.min-1, and in Group II 78 +/- 11 ml.min-1 before hypotension. During hypotension, CCreat were lower in Group I (8 +/- 1 ml.min-1) than in Group II (33 +/- 8 ml.min-1) (P less than 0.01). After anaesthesia, there was no difference in CCreat between the groups (Group I: 110 +/- 17 ml.min-1 and Group II: 120 +/- 17 ml.min-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic effects of branched chain amino acids in patients with severe pancreatitis

Twenty-four patients with acute severe pancreatitis were randomised to receive total parenteral nutrition for 7 days with one of two isocaloric (35 kcal/kg/day) and isonitrogenous (0.16 g/kg/day) programmes containing either a low (15.5% w/w (control group)) or a high (57%) content of branched chain amino acids (BCAA (BCAA group)). During treatment, the nitrogen balance was similar in both groups. The concentrations of serum protein, albumin, prealbumin and retinol-binding protein did not differ between the groups. The plasma concentrations of BCAA measured 2 h after discontinuation of amino acid infusions rose in the BCAA group. In urine, only the concentrations of valine increased as compared with those of control patients. Serum glucose levels were higher in the BCAA group than in the control group, although the BCAA group received slightly more insulin than the control group in order to keep the blood glucose concentration below 10 mmol/l. The results suggest that BCAA-enriched solutions may stimulate gluconeogenesis without affecting catabolism.