Randomized Controlled Trial Comparing the Effect of a Paravertebral Block on Pain Post Percutaneous Nephrolithotomy

Percutaneous nephrolithotomy/nephrolithotripsy (PCNL) is an effective treatment that offers maximal physical removal of large kidney stones. However, despite the minimally invasive nature of the procedure, postoperative pain still remains a significant concern. General anaesthetic (solution given to put the patient to sleep) for the procedure is routinely given, along with a local anaesthetic injection at the operative site (injection of anaesthetic solution to the incision area to reduce the pain after the procedure) and pain pills to reduce the pain even further after surgery. Paravertebral nerve blockade (PVB) is a technique for inserting anesthetic solution into an area near the vertebrae (bony segments that form the spinal column of humans or backbone), and is an effective method for reducing pain in the post operative period from a variety of surgeries.

The investigators expect that the PVB can decrease side effects from opioids (pain medication) and other analgesics used post-operatively. Opioid side effects include nausea, vomiting, urinary retention, constipation, and drowsiness. Other side effects associated with anaesthetic use include peptic ulcer disease and acute renal failure. The investigators also expect that PVB will result in decreased post-operative pain.