Shivinder Singh1, Haneesh Thakur2. 1. Department of Anaesthesiology, Critical Care and Pain Medicine, Command Hospital Western Command, Chandimandir, Panchkula, Haryana, India. Electronic address: sshivinder@hotmail.com. 2. Department of Anaesthesiology, Critical Care and Pain Medicine, Command Hospital Western Command, Chandimandir, Panchkula, Haryana, India.