1. Toxicology for Medical Students
Dr Kent Robinson
Emergency Staff Specialist
Liverpool and Campbelltown Hospital's

2. OBJECTIVES Understand basic approach to the poisoned patient.
Recognose the major toxidromes.
Apply your knowledge to clinical cases.

3. Approach to Poisoned Patient
Supportive care is the mainstay of therapy.
Decontamination of the patient is now rarely indicated.
In specific situations, antidotes may used in the management of the poisoned patient.

5. Case 1 21 year old female - found down at home
Drug paraphenalia found next to patient
Pinpoint pupils, GCS 3, cyanotic

6. Case 1 Naloxone 2 mg x 2 dose intravenous - no response
O2 therapy, IPPV
How would you manage this patient?

7. Case 1 Assess and manage ABC's Disability - check BSL
Reading "low on glucometer"
Treated with dextrose 25 g iv, GCS to 15/15

8. Teaching Point
In any patient with altered mental status, always check a BSL

9. Case 2 41 year old male brought in from police cells
Patient states he has taken overdose of diazepam
Ataxic and drowsy
Vital signs T 39, P 140 (ST), BP 90/60
Pupils fixed and dilated
Dry, warm skin, urinary retention

10. Case 2 Is this presentation consistent with the stated overdose?
What toxidrome is the patient exhibiting?
What drugs are likely to cause this problem?
How would you manage the patient?

11. Anticholinergic Toxidrome
Antihistamines
Antipsychotics
Anticonvulsants
Antidepressants
Antispasmodics
Antimuscarincs
Plants - Datura, Mushrooms

12. Case 2 - Management Assess and manage ABC's Sedation - benzodiazepines
One to one nursing care
Intravenous fluids for tachycardia and hypotension
Insertion of IDC
Consider physostigmine if pure anticholinergic overdose.

13. Teaching Point
In patients who present with a drug overdose, always assume that they may have taken drugs other than what they have volunteered.

14. Teaching Point
Patients who present with any overdose - make every attempt to get collateral information.

15. Case 3 18 year old female Paracetamol overdose (50 x 500 mg tablets)
Observations; T 37, P 90, BP 120/60, GCS 15
Management?

16. Case 3 Assess and manage ABC's Toxic dose considered to be 150 mg/kg.
Baseline bloods (FBC, EUC, LFT, Coag's, Paracetamol level)
Repeat paracetamol at 4 hours
Start NAC infusion.

19. Teaching Point NAC is the "antidote" for paracetmol toxicity
In the setting of potentially hepatotoxic ingestion, start NAC early.
Decision for ongoing therapy should be based on the 4 hour paracetamol level.

20. Case 4 45 year old male Chronic alcohol dependence
Alcohol intoxication, presents aggressive and agitated.
Vital Signs; T 37, P 100, BP 110/60, RR 16, GCS 14/15
Management?

21. Case 4 Assess and manage ABC's (Intravenous fluids for HR and BP)
Check BSL
Give dextrose 25 g and thiamine 300 mg
If no response, will need chemical restraint - what agent will you choose to sedate, and why?

22. Teaching Point
Alcohol and benzodiazepines are sedative- hypnotic agents.
Giving a BDZ to an agitated alcoholic will make the problem worse - use an antipsychotic.
Always think of the possibility of intracranial pathology in an agitated alcoholic - low threshold for CT Brain.

23. Summary Management of poisoned patient is largely supportive
Decontamination is rarely indicated (seek senior advice)
In specific situations, an antidote may be of benefit.