Erector Spinae Plane Block Versus Control for Pain Control Following Percutaneous Nephrolithotomy: A Randomized, Double-Blind, Placebo Controlled Study

This is a double-blind, randomized control trial involving 128 subjects undergoing an elective percutaneous nephrolithotomy. All subjects who meet all inclusion and exclusion criteria will be equally randomized on the day of the procedure by operating room pharmacy into either the ESP block or the control block. An interim analysis at the sample size required for a large effect size (n = 52, with n = 26 in each treatment arm) will be performed. In order to blind the anesthesiologist performing the block, the control arm will be equally randomized by the pharmacist at the time of distributing the pre-filled syringes for the ESP block procedure. Randomization will occur with the use of a random number generator with 1:1 ESP:Control allocation ratio.

Subjects will be followed at Pre-op and the 24-h, 48-h, 7 days and 30 days post operatively to assess the quality of recovery utilizing the Quality of Recovery-15 (QoR-15) questionnaire, VAS pain scale, and opioid consumption. Intraoperative MMEs, PACU MMEs, total MME's, FLACC scores at 30 minutes/1 hour VAS scores at 1 hour/2 hours/6 hours/24 hours, PACU LOS, hospital LOS, time to first flatus will be documented in patient chart, reviewed by study personnel and uploaded into a password protected database on the UTMCK server.

All aspects of the study and consent forms will be IRB approved prior to implementation. Potential candidates will be selected for consent based on chart review and surgery scheduling.

• The Surgeon will initially approach potential subjects and provide them with a copy of the consent form to take home and read prior to pre-anesthesia testing.
• At the subject's pre-anesthesia testing appointment, the research staff will explain the risks and benefits of the study, answer any questions, and obtain consent to participate.
• The Biostatistician will randomize the subjects with a random number generator. Once randomized, a blinded package labeled "ESP" or "Control" will be delivered to the regional anesthesia team containing the following:

ESP