Deliberate Self-Harm

Question 1

How does amphetamine ingestion present?

Answer 1

Euphoria
Agitation
Sweating
Dilated pupils
Palpitations
Tachycardia
Hypertension

Question 2

How does an amphetamine overdose present?

Answer 2

Sympathetic overdrive

Hyperpyrexia
Dehydration
Muscle rigidity
Convulsions (due to hyponatraemia from polydipsia) 
Rhabdomyolysis
Arrhythmias 
Coma
DIC

Question 3

How do you manage an amphetamine overdose?

Answer 3

Refer to TOXBASE
Activated charcoal if <1hr after ingestion

Supportive treatment:

• Cooling measures, if rectal temp > 39 consider dantrolene
• Correct electrolyte imbalance
• Sodium bicarbonate
• Diazepam for convulsions
• Metoprolol for narrow complex tachycardias
• Nifedipine for hypertension

Question 4

How does an opiate overdose present?

Answer 4

Parasympathetic overdrive

Pinpoint pupils
Respiratory depression
Decreased GCS - potential coma
Hypotension

Question 5

What would an ABG show in amphetamine overdose?

Answer 5

Metabolic acidosis

Question 6

What would an ABG show in opiate overdose?

Answer 6

Respiratory acidosis

Question 7

What is the treatment for opiate overdose?

Answer 7

IV naloxone 0.4-2mg - repeat every 2 min until breathing adequate

Naloxone’s half life is shorter than morphine so may need to be given often

Question 8

How is paracetamol normally metabolised?

Answer 8

Metabolism occurs in the liver

By glucuronidation, 95% paracetamol is metabolised to harmless metabolites (glucoronide and sulphate)

5% of paracetamol is metabolised by the CYP450 system to NAPQ1 (harmful metabolite)
NAPQ1 is then metabolised by glutathione to harmless metabolites

Question 9

How does paracetamol overdose affect its metabolism?

Answer 9

In overdose, the pathways are saturated and there is insufficient glutathione to metabolise all the NAPQ1 so there is a build up of NAPQ1

Question 10

What dose of paracetamol is potentially fatal?

Answer 10

150mg/kg
12g = 24 tablets
If malnourished, 75mg/kg can be fatal

Question 11

How does paracetamol overdose present?

Answer 11

<24 hours: nausea and vomiting (or asymptomatic)

24-72 hours

• Nausea + vomiting
• RUQ pain

> 72 hours = symptoms of liver failure

• Jaundice
• Confusion
• Coagulopathy - bleeding, bruising
• Hypoglycaemia
• AKI

Question 12

How do you decide whether to treat a paracetamol overdose?

Answer 12

Do blood paracetamol level at 4 hours post dose
Plot graph of plasma concentration of paracetamol vs time since dose
Treat if the point is above the line

If symptoms of overdose prior to 4 hours, start treatment ASAP
If time of ingestion is unknown or staggered, treat anyway

Question 13

What defines a staggered dose of paracetamol?

Answer 13

Doses taken over 1+ hours

Question 14

What is important to find out in the psychiatric assessment of somebody who has taken a paracetamol overdose?

Answer 14

Intentions at time

• Was it a suicide attempt and was it planned?
• Any precautions against being found?
• Did they seek help after?
• Was there a final act e.g. suicide note?

Present intentions

• Do you feel suicidal?
• Do you wish it had worked?

What problems led to the act

Is there a psychiatric disorder?

What are your resources?
- Friends, family, work, personality

Question 15

What factors increase the likelihood of suicide risk?

Answer 15

Male
>50 years old 
Unemployed
Socially isolated
Previous suicide attempts
Presence of psychiatric disorder
Original intention was to die
Present intention is to die

Question 16

What is the criteria for liver transplant?

Answer 16

Either:
- pH < 7.3 24 hours after overdose
Or
- PT > 100 secs
- Creatinine > 300
- Grade 3 or 4 encephalopathy

Question 17

What LFTs would be deranged in paracetamol overdose?

Answer 17

ALT > 1000 indicates hepatotoxicity
AST increased
INR increased

Question 18

How is paracetamol overdose treated if it’s before 4 hours since the overdose?

Answer 18

0-1hr: activated charcoal

0-4hr: wait for 4hr to measure paracetamol levels BUT if symptoms start N-acetylcysteine ASAP

Question 19

How is N-acetylcysteine administered in paracetamol overdose?

Answer 19

IV infusion in 5% glucose, 3 consecutive doses over 21 hours

1. 150mg/kg in 200ml glucose over 1 hour
2. 50mg/kg in 500ml over 4 hour
3. 100mg/kg in 1 L over 16 hour

Question 20

What is a common side effect of N-acetylcysteine? How do you treat it?

Answer 20

Rash

Treat with chlorphenamine

Question 21

When should you continue treating with N-acetylcysteine until?

Answer 21

Until clotting is normal - INR <1.3 and ALT less than 2 times the upper limit of normal

Question 22

How does tricyclic antidepressant overdose present?

Answer 22

Can’t see, pee, shit, spit

• Dry skin and mouth
• Dilated unreactive pupils
• Urinary retention
• Jerky limb movements, ataxia
• Drowsiness, coma
• Tachycardia
• Hypertonia and hyperreflexia

Question 23

What might tricyclic depressant overdose be mistaken for?

Answer 23

Ventricular tachycardia - Broad QRS complexes seen on ECG

Question 24

What is seen on ABG of TCA overdose?

Answer 24

Metabolic acidosis

Question 25

What is the treatment for TCA overdose?

Answer 25

IV sodium bicarbonate to treat acidosis and arrhythmias