EFFECTS OF IV GLUCOSE-INFUSION VERSUS GLU COSE-XYLITOL (11) INFUSION ON CARBOHYDRATE AND LIPID-METABOLISM AFTER TRAUMA AND DURING SEPSIS

Objective: To detect the effects of glucose-xylitol infusion versus gl ucose infusion alone on carbohydrate and lipid metabolism in postopera tive stress and during sepsis. Design: Prospective randomized study (s tudy I after cardiac surgery) and intraindividual cross-over control s tudy (study II in septic patients), respectively. Setting: Intensive c are unit of a university hospital. Patients: 18 patients after aortoco ronary bypass (ACVB) and 5 patients with sepsis. Interventions: In stu dy I during the first 24 postoperative hours one group (K I, n = 6) re ceived glucose only (2 mg/kg BW/min), a second group (K II, n = 6) a m ixture of glucose and xylitol (1:1; 2 mg/kg BW/min) and a third group (K III, n = 6) a glucose-containing electrolyte solution (0.8 mg/kg BW /min). Glucose, lactate, insulin and free fatty acid concentrations we re measured pre- and postoperatively in 6-hour intervals over 36 h. In study II patients were firstly given 4 mg glucose/kg BW/min over 6 h, then infusion was changed to a 1:1 glucose-xylitol mixture (4 mg/kg B W/min) for another 6 h. Hepatic glucose production, palmitate oxidatio n rates and lactate concentrations were determined at the end of both infusion regimes. Results: Glucose and insulin concentrations were sig nificantly lower in K II and K III than in K I. The highest lactate va lues were observed 6 h postoperatively in K I. Concentrations of all f atty acids were lower in K I than in K II and K III during the infusio n periods. In study II the glucose production and lactate values were significantly reduced during xylitol infusion, whereas palmitate oxida tion rates were significantly increased when the infusion regimen chan ged from glucose to glucose-xylitol mixture. Conclusions: These data i ndicate that energetically ineffective high glucose concentrations wer e avoided and lactate production was diminished by infusion of glucose -xylitol in study I. In addition, xylitol achieved a higher endogenous release and oxidative utilisation of free fatty acids representing im portant fuel substrates after trauma and during sepsis.