GLUCOSE DYNAMICS DURING CONTINUOUS HEMODIAFILTRATION AND TOTAL PARENTERAL-NUTRITION

Objective: To determine glucose balance during dextrose-free continuou s hemodiafiltration with or without dextrose-containing ultrafiltrate replacement fluid and full nutritional support. Design: Prospective, n onrandomized, observational study. Setting. A 24-bed multiple trauma c ritical care unit in a level-I trauma center. Patients: Seventeen mult iple trauma patients with multiple organ dysfunction syndrome requirin g hemodialysis for acute renal failure. Interventions: Continuous hemo diafiltration effluent volume and glucose concentration were measured. Study days were classified according to whether dextrose was used in the ultrafiltrate replacement therapy. Use of dextrose in replacement therapy was determined clinically. Parenteral nutrition was not altere d for potential glucose absorption from continuous hemodiafiltration. Ultrafiltrate replacement consisted of 5% dextrose in saline on 21 stu dy days (D5YES) and dextrose-free solutions on 54 study days (D5NO). R esults: The D5YES group received 316 +/- 145 g glucose/day from the ul trafiltrate replacement fluid, in addition to glucose in total parente ral nutrition (total glucose intake = 942 +/- 229 g/day in D5YES, 682 +/- 154 g/day in D5NO) (p < 0.05). Glucose loss in continuous hemodiaf iltration effluent was 82 +/- 61 g/day in D5YES and 57 +/- 22 g/day in D5NO (P < 0.05), for a net glucose uptake of 8.1 +/- 2.1 mg/kg per mi n in D5YES and 5.4 +/- 1.5 mg/kg per min in D5NO (p < 0.05). Glucose l oss was predictable when dialysate and ultrafiltrate replacement fluid s were dextrose-free (R(2) = 0.77), but less so when dextrose was used as ultrafiltrate replacement (R(2) = 0.47). Conclusion: Dextrose-free dialysate promotes glucose loss during continuous hemodiafiltration, but the loss is small and predictable. Use of a dextrose-containing ul trafiltrate replacement fluid results in a significant increase in glu cose intake without a commensurate increase in glucose loss, and makes glucose loss in effluent less predictable.