Opioid overdose and its reversal

Opioid poisoning and its related harm are increasing worldwide. In recent years, opioid related mortality has surpassed motor vehicle accidents to become the major cause of fatal injury in Australia. Despite this there is limited granular clinical data describing opioid poisoning and its management within the Australian context. The aims of this piece of work were to better characterise opioid poisoning related presentations to Australian hospitals and to optimise the management of opioid toxicity in the Emergency Department regarding both its nursing management and antidotal reversal. This thesis includes five primary publications and six associated publications. These works characterise the changing epidemiology of opioid poisoning over the last 30 years from heroin to prescription opioids and demonstrate the harm of opioids as a co-ingestant in poisoning using the example of pregabalin. Furthermore, it demonstrates the effectiveness of implementing a nursing care pathway to improve the management of opioid poisoning within the Emergency Department. Finally, it establishes the safety and effectiveness of 1600 mcg intramuscular naloxone and its superior effectiveness over titrated intravenous boluses in reversing opioid related respiratory depression in the Emergency Department. This work is already being translated into practice. The Queensland Ambulance Service has changed their naloxone treatment protocols to only use 1600 mcg intramuscular naloxone following this research. Furthermore, Emergency Departments across the country have started to use the opioid care pathway for patients with opioid poisoning. It is also likely that the Australian Therapeutic Guidelines will include 1600 mcg intramuscular naloxone as a first line treatment for opioid poisoning in its upcoming revision in response to this research.