Evidence-based Toxicology
OVERVIEW
- much of what we do in toxicology is because we think it works, not because we know it works
- clinical toxicology has traditionally been based on animal studies, case reports and case series based on clinical observation rather than clinical trials
- as such the overall evidence base is weak
- an increasing number of new synthetic street drugs are being used recreationally with little prior scientific study
BARRIERS TO HIGH QUALITY EVIDENCE
- very few newly synthesised chemicals undergo RCTs to determine their effects on humans
- there are few validated animal models for toxicology research
- ethical considerations prevent volunteers from being subjected to known toxic agents as part of a clinical trial
- mortality is of little use in clinical toxicology as the cas fatality rate in the West is only 0.5% – most patients who make it to hospital survive
- intoxicated and/or suicidal patients usually lack the capacity for informed consent
- poison center registries have many limitations:
— limited to acute toxicity
— dependent on individuals to report cases
— severely under-report overdose fatalities
SOURCES OF EVIDENCE
RCT
- RCTs remain the gold standard
- infeasible for many problems in clinical toxicology
Observational studies and data registries
- routine prospective clinical data collection in a database is the optimal way of conducting observational studies in clinical toxicology
Case reports and case series
- limited as they are subject to uncontrolled biases and tend to emphasize the bizarre
- useful for recognition and description of new toxic agents and manifestations
- useful for recognition of adverse events and rare manifestations
- useful for education
Other sources
- understanding of novel recreational agents can be obtained from lay websites such as Erowid
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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