Overdose and Poisoning

Question 1

How do you manage a suspected OD or poisoning?

Answer 1

Resuscitation - ABCDE

Identify the substance, get advice from toxbase, give specific tx if appropriate

Reduce absorption - skin decontamination, activated charcoal (rarely effective), gastric lavage (very rare), whole bowel irrigation (children and washing powder)

Improve elimination - urinary alkinisation, haemodialysis, haemoperfusion

Question 2

What do you need to bear in mind if
- P is involved in an industrial or farming accident?
- has come from a fire?

Answer 2

• Farm - think organophosphates - very lethal with specific antidotes. Are absorbed by the skin so PPE first!
• Fire - think cyanide - give immediate antidote

Question 3

What information do you need to get from the Hx?

Answer 3

Question 4

Answer 4

Anticholinergics - inc everything but bowel and sweating

Cholinergic - dec pupils and inc bowels and sweating

Hallucinogenic - everything inc except temp and sweating

Sympathomimetic - everything increased

Sedative - everything decreased

Serotonin syndrome - everything increased

Question 5

What drug class are the following all from?

Antihistamines
TCAs (amitryptyline)
Antiparkinsonian agents
Antimuscarinics
Antipsychotics - Chlorpromazine, Clozapine
Atropine

Answer 5

Anticholinergics

Question 6

What drug class are the following all from?

Organophosphates
Carbamate insecticides
Nerve agents
Nicotine
Pilocarpine

Answer 6

Cholinergic drugs

Question 7

What drug class are the following all from?

Phencyclidinene (rural sheep farm)
LSD
MDMA (ecstasy)

Answer 7

Hallucinogenics

Question 8

What drug class are the following all from?

Opioids
Morphine
Methadone
Oxycodone

Answer 8

Sedative-hyponotics

Question 9

What drug class are the following all from?

MAO-B Inhibitors (Rasagiline)
SSRIs - Citalopram, Fluoxetine, Sertraline
TCAs - Amitryptaline

Answer 9

Serotonin syndrome causing drugs

Question 10

What type of ECG should you do in OD/P Ps?

Answer 10

Telemetry - continuous ECG monitors to see if the heart is affected due to ion channel disruption

Question 11

What investigations should you for in an OD/P P?

Answer 11

Telemetry
ABG - pH and Anion gap
Bloods - FBC, U&Es, Lactate, LFTs, Coat studies AND check levels for specific drugs
Urine screen - drugs of abuse
CXR or CT if need to exclude pul oedema, trauma, head injury or drug smuggling

Question 12

What is the anion gap?

Answer 12

Difference between Na and Cl + HCO3.

Question 13

What is a normal anion gap?

Answer 13

Between 10-16

Question 14

What can cause a wide anion gap?

Answer 14

MUDPILES CAT

Question 15

What can a wide anion gap indicate?

Answer 15

Acidosis

Question 16

Answer 16

Question 17

How does paracetamol cause toxicity?

Answer 17

It reacts with proteins and nucleic acids - leading to cell death. Causes hepatotoxicity.

Question 18

Why is time important with paracetamol OD?

Answer 18

If you can identify a specific time that P has taken the OD - need to wait until 4 hours after this - take the serum paracetamol level and compare to the chart. If higher than the treatment line then need to give NAC - bolus dose initially and then staged doses after this.