1. Department of Anaesthesiology and Intensive Care, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, Cheras 56000, Kuala Lumpur, Malaysia
2. Department of Anaesthesiology and Intensive Care, Hospital Tuanku Jaafar, Seremban 70300, Malaysia
3. Department of Anaesthesia and Intensive Care, Hospital Kuala Lumpur, Jalan Pahang 50586, Kuala Lumpur, Malaysia