Lowering of plasma glucose concentration in septic cancer-bearing patients: metabolic significance.
Academic Article
Overview
abstract
Previous work has indicated that 40-50% of glucose intake is oxidized in normal humans with protein-sparing effect. In contrast, the catabolic stressed patient is hyperglycaemic with decreased glucose oxidation and protein wasting. This study evaluated whether the plasma glucose concentration alone would be a reliable indicator of efficient glucose utilization and protein sparing in the critically ill septic cancer patients receiving glucose infusions. Glucose turnover, glucose concentration, nitrogen excretion, oxygen consumption, and glucose oxidation were measured in 8 septic cancer-bearing patients during a glucose infusion of 4.0 mg/kg/min followed by the infusion of insulin with the same glucose load. During glucose infusion without insulin the glucose concentration was 11.8 +/- 1.4 mmol/l, glucose oxidation 10 +/- 5% of glucose tissue uptake, and nitrogen excretion 9.0 +/- 1.3 mg/kg/h. During the euglycaemic clamp the glucose concentration was 3.8 +/- 0.2 mmol/l, glucose oxidation increased to 45 +/- 6% of glucose tissue uptake (p < 0.001), and nitrogen excretion dropped to 6.8 +/- 1.2 mg/kg/h (p < 0.001). The glucose concentration was greater than 10 mmol/l in 4 patients and between 6.9 and 9.3 mmol/l in 4 patients after glucose infusion alone. Despite this difference in initial glucose concentration, normalization of plasma glucose to less than 5 mmol/l with insulin resulted in the same decrease in nitrogen excretion and improvement in glucose oxidation. We conclude that, independent of the initial glucose concentration, maintenance of euglycaemia with insulin appears to be a good indicator of efficient glucose utilization and protein sparing in septic cancer-bearing patients receiving glucose as the primary mode of nutritional support.
