Effectiveness of Subcutaneous Bupivacaine–Ketamine Wound Infiltration in Reducing Post-Cesarean Section Pain: A Randomized, Double-Blind, Controlled Trial - Nadra Septiadi Nadra; Riyadh Firdaus Riyadh; Besthadi Sukmono Besthadi; Rafidya Indah Septica Rafidya Indah (Frontiers on Healthcare Research, 2026)