Inhaled methoxyflurane (Penthrox) is a potential agent for early administration of analgesia by 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. We intend to conduct a clinical evaluation trial comparing the use of inhaled Penthrox with IM Tramadol for early pain relief.