Dexamethasone vs. Placebo: Blood sugar changes in diabetic patients undergoing foot and ankle surgeries after popliteal nerve block - a randomized double-blinded comparative study

Background: Regional anesthesia plays a crucial role in perioperative care and with the addition of adjuvants like dexamethasone to local anesthetics in peripheral nerve blocks has been shown to enhance the duration and quality of analgesia. However, the effect of dexamethasone on blood glucose, especially in diabetics, is not fully understood. This study was conducted to study the impact of perineural dexamethasone on plasma blood sugar after ultrasound-guided popliteal sciatic and adductor saphenous nerve block in diabetic patients undergoing foot and ankle surgeries. Methods: Seventy diabetic patients posted for elective diabetic foot surgeries were randomly allocated into two groups (35 each) to receive 0.25% bupivacaine with 8mg of dexamethasone (Group D) or 0.25% bupivacaine with placebo (Group P). Capillary blood sugar levels were noted via finger prick before administering the block (at baseline) and after performing the block at 1, 2, 3, 4, 5, 6, 12, 18, and 24 h. The duration of sensory and motor blockade was assessed. Results: Results showed an increase in blood sugar levels in the diabetic group compared to the placebo group, which was statistically significant at the 6th hour, i.e., 139.61±32.0 vs 124.13±18.60 (P value < 0.05), and at the 12th hour, i.e., 139.11±32.67 vs 122.20±20.30 (P value < 0.005), respectively. The difference in blood sugar between the two groups at other times was not significant. Conclusion: Thus, in our study, we found that perineural dexamethasone, when compared to placebo, raises blood sugar, though statistically but not clinically significant.