Adding Ketamine to Levobupivacaine in Paravertebral Block in Thoracotomy

Skin infiltration will be done using 3 ml lidocaine 2% and a 22-gauage block needle will be advanced using the in-plane approach craniocaudally. Once the costotransverse ligament is reached, negative aspiration of blood and air will be confirmed. Under ultrasound visualization, 19 mL of 0.5% levobupivacaine with 1ml ketamine (50mg)

Skin infiltration will be done using 3 ml lidocaine 2% and a 22-gauage block needle will be advanced using the in-plane approach craniocaudally. Once the costotransverse ligament is reached, negative aspiration of blood and air will be confirmed. Under ultrasound visualization, 19 mL of 0.5% levobupivacaine with (50mg) or normal saline