EFFECT OF ULTRASOUND-GUIDED ERECTOR SPINAE PLANE BLOCK ON POSTOPERATIVE PAIN IN PATIENTS UNDERGOING OPEN NEPHRECTOMY AND PYELOPLASTY: A SINGLE-CENTER OBSERVATIONAL STUDY. Grn Int J Apl Med Sci [Internet]. 2026 Apr. 28 [cited 2026 May 23];4(2):65-70. Available from: https://gijams.in/index.php/gijams/article/view/104