List I - Act Core Conditions Flashcards
1
Q
What are the signs and symptoms of paracetamol overdose?
A
- Often symptomatic - people suspected of taking a paracetamol overdose should be urgently taken to hospital
- Nausea and vomiting usually settle within 24 hours - if these continue with the development of hepatic necrosis this may lead to encephalopathy, hypoglycaemia, haemorrhage, cerebral oedema and death
- People may present with coma or reduced level of consciousness if they have taken paracetamol with a drug that does this such as paracetamol and opioid presentation or with alcohol
2
Q
Which resource is used for any overdose?
A
- TOXBASE
3
Q
What is the hospital management of paracetamol overdose?
A
- If patients present within 1 hour - activated charcoal
- Acetylcysteine should be given immediately if:
- Staggered overdose or there is any doubt over the time of ingestion of paracetamol, regardless of the plasma paracetamol concentration or
- Plasma paracetamol concentration is on or above a single treatment line joining points of 100 mg/L at 4 hours and 15 mg/L at 15 hours, regardless of risk factors of hepatotoxicity
- Infusion - acetylcysteine is now infused over 1 hour to reduce the number of adverse effects.
- Acetylcysteine commonly causes an anaphylactoid reaction (non-IgE mediated mast cell release)
- Anaphylactoid reactions to IV acetylcysteine are generally treated by stopping the infusion, then restarting at a slower rate
4
Q
What is considered a staggered overdose of paracetamol?
A
- If all the tablets were not taken within 1 hour
5
Q
Which criteria are used to determine if a patient requires liver transplantation following paracetamol liver failure?
A
- King’s College Criteria
- Arterial pH < 7.3, 24 hours after ingestion
Or all of the following:
- Prothrombin time > 100 seconds
- Creatinine > 300 mmol/L
- Grade III or IV encephalopathy
6
Q
What levels of paracetamol is considered potentially fatal?
A
- 150mg/kg
or - 12g (x 24 500mg tablets)
- 1/2 if malnourished
7
Q
What are the risk factors for (paracetamol) overdose?
A
- Deliberate self harm
- Young
- Female
- Overdose
- Impulsive character
- Psychiatric disorder (rarely)
- Suicidal intention
- Old (>40 years)
- Male
- Violent method
- Planned
- Psychiatric disorder (90%)
8
Q
How common is paracetamol overdose in the UK?
A
- Most common form of OD in UK
- 70,000 non-fatal attempts every year
- 9% need therapy
9
Q
What is the normal metabolism of paracetamol?
A
Normal metabolism
- Paracetamol is normally absorbed in the duodenum/small intestine
- Hepatic metabolism by CYP450 forms the toxic metabolite NAPQUI - this is detoxified by conjugation to glutathione and is then renally excreted
10
Q
What is the process of paracetamol toxicity in overdose?
A
Overdose
- Glutathione stores become depleted
- NAPQUI enters the hepatic/renal cell nuclei leading to cell death (this is increased with enzyme inducers such as anticonvulsants, rifampicin, St John’s Wort, alcohol, malnutrition, anorexia, HIV)
- Ingestion of 12g or 150mg/kg of paracetamol (half this if there is concurrent liver disease/alcoholism)
- Treatment threshold 75mg / kg
- In severe liver damage there is increase in nitrogenous products (NH3) which cross BBB
- Cleared by astrocytes involving conversion of glutamate to glutamine
- Increase in glutamine causes osmotic imbalance allowing fluid into cells causing cerebral oedema and encephalopathy
11
Q
What is the approach to assessment of the history of a person who has overdosed?
A
- Before
- What time OD
- Trigger/build up of stressors
- Was is planned, how detailed, how long
- Other methods
- During
- Drug (type, where, dose, number of tablets, time frame, staggered +/- alcohol
- Was the intention to die
- How did you reach medical care
- Final acts
- Leave a note
- Did you intend to be found
- After
- How do you see the OD now
- Regretful
- Reaction of loved ones
- Anything changed
- Will you repeat
12
Q
What is the approach to the assessment of suicidal thoughts in a person who has OD?
A
- Have you considered ending it all
- Do you see a future
Risk factors
- Young/Old
- F/M
- OD/Violent method/mixed
- +/- psychiatric illness
- Previous attempts
- Relationships
- Recent events - deaths, redundancy
- Physically ill
- Unemployed
- Alcohol dependent
Past medical history
- Previous attempts or methods
- Psychiatric history
- Chronic illness
- HIV status
DH
- Allergies
- Regular medicines
- OTC (St John’s Wort)
- Tetanus status
- Alcohol
- Substance abuse
SH
- Who do they live with
- Who is at home
- Relationships
- Employment status
13
Q
What is SAD PERSONS in the context of assessment of a patient who has OD’ed?
A
- Produces a risk score and this can indicate if the patient can be discharged or requires further assessment
- Sex M (1)
- Age <19/>45 (1)
- Depressed/hopeless (2)
- Previous suicide attempts/psychiatric care (1)
- Excess alcohol/drugs (1)
- Rational thinking loss: psychosis/organic illness (2)
- Separated/widowed/divorced (1)
- Organised serious attempt at suicide (2)
- No social support (1)
- States future intent - repeat/ambivalent (2)
Score
- <6 possible for discharge
- 6-8 likely requires psych review
- > 8 likely admission and urgent psych assessment
14
Q
What are the initial signs and symptoms of paracetamol OD?
A
<24 hours
- Asymptomatic
- Abdominal/RUQ pain
- N/V - if V >12h worry
- Increased RR
> 24 hours
- Hepatic pain
- Tender
- Low glucose
> 48 hours
* Jaundice
> 72 hours
* Hepatic encephalopathy
Later
- ARF - loin pain, haematuria, proteinuria, oliguria, lactic acidosis
- Hepatic failure, bleeding, DIC
15
Q
How is OD paracetamol managed?
A
- ABC assessment (if GCS <8 ICU/anaesthetist
- Brief Hx about OD
- Staggered start NAC straight away
- Otherwise take paracetamol levels at 4 hours
- Check on treatment graph - if on or above line treat with NAC
- Give IV NAC loading dose 150mg/kg IV (now over 1 hour to reduce the number of reactions)
- Then 50mg/kg IV over 4 hours in 500 ml
- Then 100 mg/kg IV in 1L over 16 hrs
