GI & Hepatology: Paracetamol Overdose Flashcards
Outline the pathophysiology of a Paracetamol overdose.
150mg/kg or 12g in an adult may be fatal
What are the signs and symptoms of a paracetamol overdose?
Initially none
Drowsiness
Coma
Seizures
Vomiting
RUQ pain
Later = jaundice, encephalopathy, AKI
How would you investigate a Paracetamol overdose?
Bloods = glucose, U+Es, LFTs, INR, ABG, FBC, HCO3
Blood paracetamol levels at 4h post ingestion
How would you manage a Paracetamol overdose?
Activated charcoal 1g/kg (max 50g) = limiting GI absorption
N-acetylcysteine = provides cystine to replenish the body stores of the antioxidant glutathione = glutathione reacts with the toxic NAPQI metabolite so that it does not damage cells and can be safely excreted
<10-12h since over dose , not vomiting, [plasma paracetamol] above treatment line = N-acetylcysteine
> 8-24h and suspicion of large over dose (>7.5g) = N-acetylcysteine
Next day = INR, U+Es, LFTs
If INR rising continue N-acetylcysteine until <1.4
If continued deterioration = discuss with liver team
What are the complications of a paracetamol overdose?
Liver failure
Encephalopathy
What clinical guideline / tool would you use to determine specific treatment for the paracetamol overdose, if indicated?
Plasma concentration of paracetamol vs time graph
How would you conduct a Mental State Examination?
Behaviour = eye contact, facial expression, body language, level of arousal, ability to follow requests, rapport
Speech = rate, quantity, tone, volume
Mood and affect = observed emotion, overall demeanour
Thought = speed, flow, coherence, delusions, obsessions, overvalued ideas, suicide, homicidal thoughts
Perception
Insight and judgement
What would be the criteria for safely discharging a paracetamol overdose patient?
If the paracetamol level was obtained 4-16 hours post ingestion and the level is under the treatment line and patient symptom free then NAC is ceased (if already started earlier) and discharge to psychiatric review.
