This clinical trial is focused on evaluating the effectiveness of a pain management technique called the erector spinae plane block in patients undergoing lumbar spinal surgery, specifically lumbar arthrodesis. Lumbar arthrodesis is a type of back surgery where two or more vertebrae in the lower back are fused together to reduce pain and improve stability. The study aims to assess whether this technique can reduce the need for pain medications, such as morphine, after surgery.

Participants in the study will receive either the erector spinae plane block or a placebo during their surgery. The block is a type of anesthesia that numbs the nerves in the back to help manage pain. The study will compare the amount of morphine needed by patients who receive the block to those who do not, over the first 24 hours after surgery. The trial will also monitor other factors such as blood pressure, heart rate, and any complications related to the block, as well as the overall quality of recovery.

In addition to morphine, other medications used in the study include etoricoxib, paracetamol, tramadol hydrochloride, methylprednisolone, propofol, lidocaine hydrochloride monohydrate, sevoflurane, sufentanil, rocuronium bromide, and levobupivacaine hydrochloride. These medications are commonly used for pain relief, anesthesia, and muscle relaxation during and after surgery. The study will help determine the best approach to managing pain and improving recovery for patients undergoing lumbar spinal surgery.