A comparative study on effect of 4% gelatin and dextran-40 on blood glucose levels during surgery under subarachnoid block – A randomised, prospective study

Background: Stress response to surgery induces hyperglycaemia to limited extent. An additive hyperglycaemic response, secondary to the metabolism of intravenous fluids, can thus prove detrimental to the well-being of the patient, if ignored. Methods: We compared the effects of 4% gelatin and dextran-40 on blood glucose levels during surgery under subarachnoid block and their potential to induce hyperglycaemia. Sixty American Society of Anesthesiologists grade I and II patients were randomised into two groups, 30 patients in each. Group 1 patients were preloaded with 4% Gelatin (10 mL/kg) and Group 2 patients were preloaded with dextran-40 in normal saline (10 mL/kg), over a period of 30 min. Just prior to preloading, base line capillary blood glucose (CBG) level was noted this is followed by subsequent readings at 20 min interval until 100 min from base line reading. All patients received normal saline (0.9%) as a maintenance fluid. Under strict aseptic precautions, subarachnoid block using 15 mg of hyperbaric bupivacaine at L3-L4 or L4-L5 level was given after preloading. Results: The CBG levels in both the groups at 20, 40, 60, 80 and 100 min from base line were within physiological limits. In group 2, the maximum CBG level was found at 60 min from onset of preloading (P = 0.017), when compared with corresponding CBG level in Group 1. Preloading the patients prior to subarachnoid block with 4% gelatin or dextran 40 do not raise CBG levels significantly above the physiological limits.