1 Department of Anesthesiology, Pain Medicine, and Critical Care, R. G. Kar Medical College, Kolkata, West Bengal, India.
2 Department of Anesthesiology, North Bengal Medical College & Hospital, Sushrutanagar, Darjeeling, West Bengal, India.
3 Department of Anesthesiology, Institute of Post Graduate Medical Education and Research/S.S.K.M. Hospital, Kolkata, West Bengal, 700020, India. drmcmandal@gmail.com.
4 Intensive Care Unit, Hospital Morales, Meseguer, Murcia, Spain.