Intravenous Lidocaine and Time to Regression of the Sensory Block After Spinal Anesthesia With Isobaric Bupivacaine in Patients Undergoing Surgery to Treat Skin and Soft Tissue Tumors of the Lower Limbs

The use of intravenous lidocaine in continuous infusion in the perioperative period is associated with a reduction in postoperative pain scores, opioid use, incidence of nausea and vomiting, among other favorable outcomes. However, this therapeutic intervention has not yet been adequately evaluated by clinical trials when associated with regional anesthesia. The aim of this study is to evaluate whether the use of intravenous lidocaine in continuous infusion during spinal anesthesia with isobaric bupivacaine alters the time to regression of sensory block in patients undergoing surgical procedures for the treatment of bone and connective tissue tumor surgeries. This will be a triple-blind randomized trial. The sample size estimated was 66 patients. The study will include all patients who meet the pre-established inclusion and exclusion criteria, choose to participate, and agree with the Informed Consent Form. The main anesthetic technique will be spinal anesthesia with 13 mg of isobaric bupivacaine. Patients will be allocated in two groups in a blindly after randomization: Group S (lidocaine 0.75mg.kg-1 in bolus followed by infusion of saline solution) and Group L (lidocaine 1.5 mg.kg-1 followed by continuous infusion of lidocaine solution at 2 mg.kg-1.h-1). The primary outcome will be the time to T12 regression of the sensory block. Will also be evaluated: time to regression of the motor block, most rostral dermatome achieved by the sensory block, time to two-segment regression oh the sensory block, propofol dose in the operating room, postoperative pain score at rest, pain at movement score, quality of recovery, use of opioids in the postoperative period, nausea or vomiting, dizziness, shivering, arrhythmias, hypotension, urinary retention, and length of stay. The records will be assigned to the RedCap database. The data will be extracted without identification of the allocation groups for the R software and the groups will be revealed to the researcher after the end of the statistical analysis to write the summary of the results. The results will be submitted to scientific journals afterward.