To Compare Dexamethasone And Dexmedetomidine As Adjuvants To Ropivacaine In Ultrasound Guided Saphenous Nerve Block For Postoperative Analgesia In Anterior Cruciate Ligament Reconstruction Surgery- A Randomized Controlled Trial.

Abstract

condylar approach or below the knee using the greater saphenous vein as a landmark.      Ultrasound guidance is ideally suited for saphenous nerve block as it reduces block performance time, improves success rate, shortens onset time, reduces vascular puncture, and achieves a reduction in the volume of local anesthetic required.

Aims- main aim of our study is To Compare Dexamethasone and Dexmedetomidine as adjuvants to Ropivacaine in Ultrasound Guided Saphenous Nerve Block for postoperative analgesia in Anterior Cruciate Ligament Reconstruction Surgery.

Methods and materials- this RCT done in department of anaesthesiology at NKP Salve Institute of medical sciences and Research Center and Lata Mangeshkar Hospital, Nagpur, Maharashtra, during the period of November 2022 to May 2024 after the approval of the Institutional Ethics Committee. A total of 76 patients that satisfied inclusion and exclusion criteria were included in the study (38 patients were randomized to Group A (Study group - Patients received 10 ml of 0.5% Ropivacaine and 8 mg of Dexamethasone) and the remaining 38 to Group B (Control group - Patients received 10 ml of 0.5% Ropivacaine and 1mcg/kg Dexmedetomidine). Sample size was determined considering difference in mean NRS scores in 2 groups as the main outcome measure for effect size. Patients posted for Anterior Cruciate Ligament Reconstruction Surgery were enrolled. Post-operative pain assessment was done by Numerical Rating scale (NRS) with score. Data was added and analyzed in statistical software STATA (Version 10.1, 2011). Descriptive statistics were used to summarize constitutive parameters with mean and standard deviation and qualitative parameters with mean and percentage. Inferential statistics improved test of significance and p values between the groups, differences in mean for 2 groups were compared with ANOVA and F-test. Bonferroni Multiple Comparison test was used to carry out all possible comparisons. Difference in proportions in 2 groups for qualitative parameters were compared by using Pearson’s Chi - Square test. P value < 0.05 was considered statistically significant for all comparisons.

Results- The mean ± SD of age of cases in Group A and Group B was 28.71 ± 8.06 years and 32.34 ±10.42 years respectively. The minimum – maximum age range in Group A and Group B was 15 – 50 years and 16 – 60 years respectively. Group A, 30 cases (78.9%) were male and 8 cases (21.1%) were female. Of 38 cases in Group B, 25 cases (65.8%) were male and 13 cases (34.2%) were female. Group A, 31 cases (81.6%) had grade I ASA and 7 cases (18.4%) had grade II ASA. Of 38 cases in Group B, 31 cases (81.6%) had grade I ASA and 7 cases (18.4%) had grade II ASA. The mean ± SD of BMI of cases in Group A and Group B was 21.56 ± 2.21 kg/m² and 21.66 ± 2.15 kg/m² respectively. The minimum – maximum BMI range in Group A and Group B was 18.4 – 27.5 kg/m² and 18.4 – 27.5 kg/m² respectively. Mean heat rate, mean systolic blood pressure, diastolic blood pressure and mean arterial pressure at 1 Hour, 3 Hours, 6 Hours, 12 Hours and 24 Hours among the cases studied did not differ significantly between two study groups. Distribution of mean Oxygen saturation (SpO2) and mean respiratory rate at 1 Hour, 3 Hours, 6 Hours, 12 Hours and 24 Hours among the cases studied did not differ significantly between two study groups. mean pain score at 1 Hour, 3 Hours and 6 Hours among the cases studied did not differ significantly between two study groups (P value >0.05 for all). Distribution of mean pain score at 12 Hours and 24 Hours among the cases studied is significantly higher in Group A compared to Group B (P- value<0.05 for all). The mean ± SD of time to first rescue analgesia, second rescue analgesia and total rescue analgesia in Group A and Group B did not differ significantly between two study groups (P-value>0.05). Group A, all had score 2. Of 38 cases in Group B, 35 cases (92.1%) had score 2 and 3 cases (7.9%) had score 3 so Ramsay sedation score among the cases studied did not differ significantly between two study groups (P-value>0.05).

Conclusion- Ultrasound guided Saphenous Nerve Block proves to be an effective and useful method for providing postoperative analgesia for anterior cruciate ligament reconstruction surgery. Addition of Dexamethasone as an adjuvant to Ropivacaine reduces pain scores, prolongs duration of first rescue analgesia and required postoperative analgesia similar to when Dexmedetomidine is added to Ropivacaine. Hence based on this study, addition of Dexamethasone to Ropivacaine is recommended for postoperative analgesia in ultrasound guided saphenous nerve block for anterior cruciate ligament reconstruction surgery.