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

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

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.

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

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

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

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

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

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?

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

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.

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

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

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

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.

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.

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?

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?

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.

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