1. Department of Anaesthesia, Jaffna Teaching Hospital , Jaffna 40000 , Sri Lanka
2. Department of Surgery , Faculty of Medicine, , Post Box 57, Jaffna , Sri Lanka
3. University of Jaffna , Faculty of Medicine, , Post Box 57, Jaffna , Sri Lanka
4. Department of Anaesthesia, Jaffna Teaching Hospital , Jaffna 40000 , Srilanka