Comparison of ultrasound guided erector spinae plane block and local infiltration of incision site for post operative analgesia in patients undergoing percutaneous nephrolithotomy - Randomized Controlled Trial.

Percutaneous Nephrolithotomy (PCNL) is a minimally invasive surgical technique used to remove renal stones which are either difficult to reach or large or numerous or too dense to be removed by any other method.

It offers less morbidity, shorter hospital stays and early recovery after surgery.

Pain after PCNL is caused by dilatation of the renal capsule and the parenchymal tract and from incision of the skin, subcutaneous tissue, muscle layer and the presence of nephrostomy tube.

Intense post operative pain also relates to postoperative complications including pulmonary dysfunction**.**

NSAIDS can cause severe side effects in these patients with pre existing kidney disease. Therefore they are not preferred.

Loco-regional pain management techniques available for postoperative analgesia provides good pain control.

Post operative analgesia can also be provided by opioids. However, opioids have certain side effects such as nausea, vomiting, itching, respiratory depression etc.

Other regional techniques such as subcutaneous infiltration, peri tubal infiltration, nephrostomy tract infiltration can be invasive.

Local anesthetic infiltration at the site of incision does not provide adequate analgesia thereby increasing the duration of hospital stay.

Erector spinae plane block(ESPB) is a novel technique that is being used nowadays for providing postoperative analgesia in patients undergoing Percutaneous Nephrolithotomy (PCNL) surgery.

It is a paraspinal fascial plane block in which the needle placement is between the erector spinae muscle and the thoracic transverse processes at the level of T10, and a local anesthetic is administered, blocking the dorsal and ventral rami of the thoracic and abdominal spinal nerves.

This blockage of the dorsal and ventral rami of the spinal nerves helps to achieve a multi-dermatomal sensory block of the anterior, posterior, and lateral thoracic and abdominal walls.

The main sources of acute pain after PCNL are visceral pain originating from the kidneys and ureters and somatic pain from the incision site. Renal pain is conducted through the T10–L1 spinal nerves, and ureter pain is conducted through T10–L2.

Moreover, cutaneous innervation of the incision site is predominantly supplied by T10–T11 (T8–T12) because the incision site and tract for PCNL is usually used in the tenth to eleventh intercostal space, or in the subcostal area.

There are limited studies to evidence the benefits of ESPB compared to local anesthetic with respect to postoperative analgesic effect for patients undergoing PCNL surgeries.

The aim of our study is to evaluate the efficacy of ESPB compared to local anesthetic for providing effective postoperative analgesia, requirement of rescue analgesics as well as to record any complications appearing within 24 hours of surgery.