Effectiveness of Combining Erector Spinea Block With Non Opioid Infusions as Opioid Free Anesthesia in Spine Surgeries.

opioid free anesthesia consists of combination of pharmacological and non pharmacological modalities that target different pathways of pain mechanism. combining myofascial plane blocks with infusion of adjuvants such as lidocaine or dexmedetomidine can offer equivalent intraoperative hemodynamic stability compared to that of opioid with better pain control postoperatively. this study will investigate the efficacy of combined erector spina block with lidocaine and dexmedetomidine infusion as opioid sparing anesthesia in spine surgeries