Current practice in Singapore Emergency Ambulance Service (EAS) includes the use of analgesia delivered via inhalation Enthanox (Nitrous Oxide). However there are difficulties administering Enthanox on-scene due to the added weight of carrying bulky cylinder tanks. It is common for a delay in administration of analgesia. Inhaled methoxyflurane (Penthrox) is a potential agent for early administration of analgesia by Singapore Civil Defense Force (SCDF) EAS. It is extensively used in the pre-hospital setting in Australia. However data on its use as an analgesic agent in general are limited and there are few published controlled trials of methoxyflurane in an analgesic role. Intramuscular (IM) tramadol is a common medication used in the hospital setting for analgesia. It is well proven, simple to deliver and is not a controlled drug.