Comparison of Analgesic Efficacy of Intrathecal Morphine and Ultrasound-Guided Bilateral Erector Spinae Plane Block in Patients Undergoing Open Heart Surgery with Midline Sternotomy: An Open Label Randomized Control Trial. - Karuppiah, Visalatchi; Kumar, Rakesh; Mohammed, Sadik; Chouan, Anita; Kamal, Manoj; Chhabra, Swati; Sharma, Alok (Annals of Cardiac Anaesthesia, 2026)