Toxicology

Question 1

Whats the ingested dose for toxicity for salicylate?

Answer 1

Greater than 125 mg/kg body weight: likely toxicity is mild.

Greater than 250 mg/kg body weight: likely toxicity is moderate.

Greater than 500 mg/kg body weight: likely toxicity is severe, possibly fatal.

Question 2

What are the serum levels for salicylate toxicity?

Answer 2

< 450 mg/l = mild toxicity

450 - 700 mg/l = moderate toxicity

> 700 mg/l = severe toxicity

Question 3

How would you manage salicylate poisoning? Give 6 management steps in the ED.

Answer 3

1. Consider oral activated charcoal (50 g for an adult, 1 g/kg for a child) if ingested more than 125 mg/kg body weight salicylate less than one hour previously.
2. Gastric lavage if the patient has ingested more than 500 mg/kg body weight
3. Aggressive rehydration.
4. Urinary alkalinisation - 225 mL of 8.4% over 60 minutes or 1.5 L of 1.26% over two hours
5. Treat hypokalaemia
6. Haemodialysis

Question 4

What are the indication for Haemodialysis in Salicylate poisoning?

Answer 4

1. Plasma concentrations > 700 mg/L (5.1mmol/L)
2. Acute kidney injury
3. Congestive cardiac failure
4. Non-cardiogenic pulmonary oedema
5. Coma
6. Convulsions
7. CNS effects not resolved by correction of acidosis
8. Persistently high salicylate concentrations unresponsive to urinary alkalinisation
9. Severe metabolic acidosis (pH below 7.2)

Question 5

Give 4 physical signs of CO poisoning?

Answer 5

1. Ataxia
2. Cognitive deficit
3. Cherry red macula
4. Cherry skin (Pre-terminal sign)

Question 6

What are the indications for hyperbaric therapy in patients with CO poisoning?

Answer 6

1. COHB > 20%
2. Pregnancy
3. Neuro - LOC
4. Neuro - Neurological abnormality
5. Neuro - Psychiatric abnormality
6. Cardiac - ECG abnormalities (Ischaemia/Arrythmias).

Question 7

What are the indication for RSI in TCA OD?

Answer 7

1. Airway compromise
2. GCS < 8/15
3. Inadequate respiration (Bradypnea/hypoxia/hypercapnea)
4. Unmanageable agitation

Question 8

Give three treatment options for calcium channel blocker overdose?

Answer 8

1. Calcium glutinate 10% 20 - 60 mls
2. High dose insulin - euglycaemic therapy (HIET)
3. Intralipid

Question 9

Which substances are not absorbed by activated charcoal?

Answer 9

• • PHAILS **
    1. Pesticides
    2. hydrocarbons
    3. Alkalis , acids
    4. Iron
    5. Lithium
    6. Solvents