Liver Failure in Toxicology
AGENTS
- paracetamol
- iron
- idiosyncratic
- illicit and herbal
- alcohol
CLINICAL FEATURES
- asymptomatic
- nausea and vomiting
- RUQ pain
- jaundice
- coagulopathy
- hypoglycaemia
ENCEPHALOPATHY
- sleep disturbance
- asterixis
- hyper-reflexic
- can be hemiplegic
- precipitating factor: GIH, infection, hypokalaemia, sedatives, increased protein intake, progressive hepatic dysfunction, renal failure
- types: A = acute liver failure, B = presence of portocaval shunting, C = in context of cirrhosis
- grade I -> IV: mildly drowsible but rousable and coherent -> responding to pain/unconscious
INVESTIGATIONS
- level as indicated
-> paracetamol: Rumack-Matthews nomogram @ 4 hours or within 8 hours of OD
-> iron level: > 90 micromoles/L (children), > 145 micromoles/L (adults) within 4 hours of ingestion. - LFT’s
- coagulation
- glucose
- renal function
SPECIFIC MANAGEMENT AND TRIGGERS FOR INTERVENTION
- early discussion with liver transplant unit
- attempt not to reverse coagulopathy until discussion unless actively bleeding
- avoid renal and hepatotoxic agents
Paracetamol
- decrease absorption: activated charcoal if presented within 4 hours (controversial as if NAC given then this is a benign OD)
- vitamin K IV
- N-acetyl cystine in D5W (based on 4 hour level or empirically if > 8 hours since OD):
-> 150mg/kg LD
-> 50mg/kg over 4 hours
-> 100mg/kg over 16 hours
Iron
- gastric lavage with large bore tube (2gm of desferrioxamine in 1L warm water -> leave 10g in 50mL in stomach to chelate any remaining iron)
- IV or IM desferrioxamine (1gm loading dose -> 500mg Q4 hrly depending on severity – maximum = 6g in 24 hrs)
- desferrioxamine -> binds Fe2+ to form water soluble ferrioxamine that is renally excreted
- can use HCO3- (controversial)
- whole bowel irrigation with polyethylene glycol
- gastric lavage
- laparotomy or endoscopic tablet removal (if tablets seen on plain XR)
- exchange transfusion with plasmapheresis
- dialysis – limited efficacy
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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