1. Department of Surgery Sibu Hospital Sibu Malaysia
2. Department of Surgery, Faculty of Medicine University of Malaya Kuala Lumpur 50603 Malaysia
3. Department of Surgery Hospital Raja Permaisuri Bainun Ipoh Malaysia
4. Department of Anaesthesiology and Critical Care Hospital Raja Permaisuri Bainun Ipoh Malaysia
5. Department of Anaesthesiology University of Malaya Kuala Lumpur 50603 Malaysia