Journal of Neuroanaesthesiology and Critical Care [Thieme Medical and Scientific Publishers Private Ltd. 20th Annual Conference of Indian Society of Neuroanaesthesiology and Critical Care (ISNACC) - Gurugram, Haryana, India (2019.02.15-2019.02.17)] 20th Annual Conference of Indian Society of Neuroanaesthesiology and Critical Care (ISNACC) - A002 Correlation between Analgesia Nociception Index and Surgical Plethysmographic Index in Supratentorial Tumor Surgery under General Anesthesia