Comparison Of Dexamethasone As An Adjuvant To Ropivacaine With Ropivacaine Alone In USG Guided Popliteal Sciatic Block For Post-Operative Analgesia In Below Knee Surgeries -A Randomized Controlled Trial.

Background- Popliteal Sciatic block is a peripheral nerve block of sciatic nerve at the level of Popliteal fossa. It results in anaesthesia of the lower limb below the knee, both motor and sensory anaesthesia, with the exception of the medial leg and foot, which is the territory of the Saphenous nerve, a branch of the femoral nerve. Different adjuvants have historically been utilized to extend the duration of analgesia in peripheral nerve blocks. Research examining the pain-relieving effects of dexamethasone combined with local anesthetics like bupivacaine has yielded encouraging findings. Nonetheless, there is limited research comparing the effectiveness of dexamethasone with ropivacaine. Aims- To compare the efficacy of Dexamethasone as an adjuvant to Ropivacaine and Ropivacaine alone in ultrasound guided popliteal sciatic block. Materials and methods- this RCT done in department of anaesthesiology at NKP Salve institute of medical sciences and research centre and Lata Mangeshkar Hospital, Nagpur, Maharashtra, during the period of November 2022 to May 2024 after the approval of the Institutional Ethics Committee. Ropivacaine with and without the inclusion of Dexamethasone as an adjuvant for use in Sonography directed PSNB (Popliteal Sciatic Nerve Block) during below knee operations. As per the sample size calculated, there were 25 patients included in each group, i.e., 50 patients were taken for the study. Data was added and analysed in statistical software STATA (Version 10.1, 2011). Results- The age of participant in Cluster RD and Cluster R was 42.56 ± 14.18 years and 44.08 ± 17.17 years respectively. Male were 80% and female were 20% in group RD. Male were 72% and female were 28% in group R. ASA grade I patients were 40% and ASA grade II were 60% in group RD. ASA grade I patients were 24% and ASA grade II were 76% in group R. Mean height, mean weight and mean BMI showed statistically non-significant results. Pulse rate, systolic blood pressure and diastolic blood pressure at 1 hr, 3 hr, 6 hr, 12 hr and 24 hr are likely to be same notably between two study Clusters (P-value>0.05 for all). Respiratory Rate, Spo2, showed statistically non-significant results at each time interval 1 hr, 3 hr, 6 hr, 12 hr and 24 hr. Mean pain score at 1 hr and 6 hr did not differ significantly between two study groups (P-value>0.05). Distribution of mean pain score at 3 hr, 12 hr and 24 hr is significantly higher in Group R compared to Group RD (P-value < 0.05). Mean time for first rescue analgesia is significantly higher in Group RD compared to Group RA (P-value<0.05). Allocation of median total rescue analgesia required in 24-hrs is notably higher in group R compared to group RD and to be considered significant (P value = 0.001). Incidence of post-op complications in terms of nausea and vomiting among the cases studied are likely to be same notably among both the research. Conclusion- Ultrasound guided popliteal sciatic nerve block is efficacious and found to be higher in providing postoperative analgesia for below knee Surgeries. Addition of Dexamethasone as an adjuvant to Ropivacaine reduces pain scores, prolonged the duration of first rescue analgesia and required less postoperative analgesia compared to Ropivacaine alone. Hence based on this study, addition of Dexamethasone to Ropivacaine is highly recommended for post-operative analgesia in ultrasound guided block for below knee surgeries.