Moderate glucose supply reduces hemolysis during systemic inflammation

Systemic inflammation alters energy metabolism. A sufficient glucose level, however, is most important for erythrocytes, since erythrocytes rely on glucose as sole source of energy. Damage to erythrocytes leads to hemolysis. Both disorders of glucose metabolism and hemolysis are associated with an increased risk of death. The objective of the study was to investigate the impact of intravenous glucose on hemolysis during systemic inflammation.

Systemic inflammation was accomplished in male Wistar rats by continuous lipopolysaccharide (LPS) infusion (1 mg LPS/kg and h, 300 min). Sham control group rats received Ringer's solution. Glucose was supplied moderately (70 mg glucose/kg and h) or excessively (210 mg glucose/kg and h) during systemic inflammation. Vital parameters (eg, systemic blood pressure) as well as blood and plasma parameters (eg, concentrations of glucose, lactate and cell-free hemoglobin, and activity of lactate dehydrogenase) were measured hourly. Clot formation was analyzed by thromboelastometry.

Continuous infusion of LPS led to a so-called post-aggression syndrome with disturbed electrolyte homeostasis (hypocalcemia, hyperkalemia, and hypernatremia), changes in hemodynamics (tachycardia and hypertension), and a catabolic metabolism (early hyperglycemia, late hypoglycemia, and lactate formation). It induced severe tissue injury (significant increases in plasma concentrations of transaminases and lactate dehydrogenase), alterations in blood coagulation (disturbed clot formation), and massive hemolysis. Both moderate and excessive glucose supply reduced LPS-induced increase in systemic blood pressure. Excessive but not moderate glucose supply increased blood glucose level and enhanced tissue injury. Glucose supply did not reduce LPS-induced alterations in coagulation, but significantly reduced hemolysis induced by LPS.

Intravenous glucose infusion can diminish LPS-related changes in hemodynamics, glucose metabolism, and, more interestingly, LPS-induced hemolysis. Since cell-free hemoglobin is known to be a predictor for patient's survival, a reduction of hemolysis by 35% only by the addition of a small amount of glucose is another step to minimize mortality during systemic inflammation.