Ultrasound Guided Continuous Erector Spinae Plane Block Versus Patient Controlled Analgesia in Patients Undergoing Nephrectomy for Renal Malignancies: A Randomized Controlled Study

Acute postoperative pain proper management is important not only for patient satisfaction but also for patient outcome. In addition to its early effects, poorly controlled acute postoperative pain may predispose patients to chronic post-surgical pain.

Open nephrectomy is still conducted, although the use of laparoscopic or robotic surgery has increased recently. A flank approach with an eleventh rib partial resection, which is the main method for open nephrectomy at our institution, could make for better dissection of the renal pelvis and the pedicles, and provide the best circumstances for nephrectomy; however, it induces more persistent pain compared with other approaches.

Several modalities have been implemented for acute postoperative pain control. Intravenous (IV) opioids is one of the earliest and most widely used method, it is insufficient only for managing postoperative pain in some patients with severe pain. In addition, opioids have many side effects like respiratory depression, nausea, vomiting and constipation hence it is important to decrease opioids use and the transition to other modalities such as regional blocks, nerve blocks, NSAIDs and multimodalities.ESPB is a relatively simple technique with easily identified sonographic landmarks. Additionally, the ESPB has the potential to provide both somatic and visceral sensory blockade.

The erector spinae muscle (ESM) is a complex formed by the spinalis, longissimus thoracis, and iliocostalis muscles that run vertically in the back. The ESP block is performed by depositing the local anesthetic (LA) in the fascial plane, deeper than the ESM at the tip of the transverse process of the vertebra. Hence, LA is distributed in the cranio-caudal fascial plane.Additionally, it diffuses anteriorly to the paravertebral and epidural spaces, and laterally to the intercostal space at several levels.

There are different case studies about the use of erector spinae block in nephrectomy but there is no randomized controlled study about it until now so it will be one of the earliest studies that investigate the effect of ESPB to relief acute postoperative pain in patients undergoing open nephrectomy.