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Introduction/Background Combined Spinal Epidural (CSE) is often used as the primary anesthetic for Total Knee Arthroplasties (TKA) (4). Intrathecal morphine (ITM) is associated with pruritus, post-operative nausea and vomiting (PONV), and respiratory depression (3). Our institutional preference for TKA includes an opioid free CSE with Adductor Canal (AC) block. The objective of this study is to ascertain if CSE with AC block is beneficial as compared to CSE with ITM for TKA. We hypothesized improved side-effect profile and non-inferior pain control post-operatively. 17 th Annual GME Resident and Fellow Research Day June 4, 2020 2

Methods We reviewed 20 patients that received a CSE and AC block for TKA in 2018 and compared them to patients that had received CSE with ITM. The primary outcomes were side effect profile such as pruritus, respiratory depression, and PONV. Secondary outcomes were pain management requirements such as morphine equivalents (ME) and time until first narcotic. AC Block was performed under ultrasound via in-plane technique at the mid-thigh using 10 m. L of 0. 5% Ropivacaine. The majority of the patients received Celecoxib, Tylenol, Decadron, Scopolamine Patch, and Gabapentin pre-operatively. The comparison study patients all received a peri-articular injection of a combination of 0. 5% ropivacaine, 30 mg toradol, 0. 5 mg epinephrine, and 0. 08 mg clonidine in normal saline. An Unpaired T Test was used to compare the means of our control population (n= 1022 patients) versus our sample group (n=20 patients) to look for statistical significance, as the size of patient population in each group was different. 17 th Annual GME Resident and Fellow Research Day June 4, 2020 3

Results Sample group: 4 (20%), 6 (30%), and 1 (5%) experienced respiratory depression (P=0. 07955), PONV (P=0. 034129), and pruritis (P<0. 0001) respectively as shown in Table 2. All patients required narcotics in the first 24 hrs, the average time until first narcotic in (minutes) was 251. 8, the average ME was 56. 25. The control patient population data was pulled from a retrospective study done at our institution that included total knee and total hip arthroplasties (2). The incidence of respiratory depression in the control group was (3%), PONV was (54%), and pruritis (46%). (96%) required narcotics in the first 24 hrs, the average ME was 32. 3. 17 th Annual GME Resident and Fellow Research Day June 4, 2020 4

Discussion and Conclusion There was a decreased incidence in pruritus and PONV, with no statistical difference in post-operative respiratory depression in the sample group. Patient’s within the sample group had utilized a higher total ME compared to the control. This may be related to the nerve block wearing off, while ITM has a longer half-life and thus providing longer analgesia (1). There were some limitations to our study. The control population included total knee and hip arthroplasties while our population only included TKA. Patient information was obtained via chart review of nursing and medical personnel documentation of data retrospectively. We do not have the information beyond twenty-four hours for ME for our control population. Lastly, our sample population size is small with twenty patients included. We believe that utilizing CSEs with AC blocks instead of CSEs with ITM for TKA results in non-inferior pain control post-operatively, as well as decreased incidence of PONV and pruritus. There was similar incidence of respiratory depression which may be related to patient comorbidities. Overall, this may provide an alternative analgesic pathway for TKA. 17 th Annual GME Resident and Fellow Research Day June 4, 2020 5

References 1. Cummings A, Fitzgerald BM. Intrathecal Morphine. [Updated 2019 Oct 12]. In: Stat. Pearls [Internet]. Treasure Island (FL): Stat. Pearls Publishing; 2019 Jan-. Available from: https: //www. ncbi. nlm. nih. gov/books/NBK 499880/ 2. Hess SR, Lahaye LA, Waligora AC, Sima AP, Jiranek WA, Golladay GJ. (2018) Safety and side-effect profile of intrathecal morphine in a diverse patient population undergoing total knee and hip arthroplasty. European Journal of Orthopaedic Surgery & Traumatology. 29(1): 125 -129. doi: 10. 1007/s 00590 -018 -2293 -9. 3. Jacobson L, Chabal C, Brody M (1988) A dose-response study of intrathecal morphine: efficacy, duration, optimal dose, and side effects. Anesth Analg 67: 1082– 1088 4. Johnson RL, Kopp SL, Burkle CM, et al. Neuraxial vs General Anaesthesia for Total Hip and Total Knee Arthroplasty. Survey of Anesthesiology. 2016; 60(5): 200 -202. doi: 10. 1097/01. sa. 0000489977. 40736. 53. 5. Koh IJ, Choi YJ, Kim MS, Koh HJ, Kang MS, In Y. Femoral Nerve Block versus Adductor Canal Block for Analgesia after Total Knee Arthroplasty. Knee Surg Relat Res. 2017; 29(2): 87– 95. doi: 10. 5792/ksrr. 16. 039 6. Rasouli MR, Viscusi ER. Adductor Canal Block for Knee Surgeries: An Emerging Analgesic Technique. Arch Bone Jt Surg. 2017; 5(3): 131– 132. 7. Vora MU, Nicholas TA, Kassel CA, Grant SA. Adductor canal block for knee surgical procedures: review article. Journal of Clinical Anesthesia. 2016; 35: 295 -303. doi: 10. 1016/j. jclinane. 2016. 08. 021. 17 th Annual GME Resident and Fellow Research Day June 4, 2020 6