RRSIDEAD • Investigations

Investigations Overview

As with any basic and advanced life support it is important to have a systematic approach to managing toxicological emergency presentations. Pioneers in the field developed RRSIDEAD as a mnemonic to remember the key steps in Tox patient assessment and management.

I is for Investigations

RRSIDEAD Tox Tutes: Investigations

Listen to the Tox Tutes below to work out which three investigations we most commonly do. Discover what is the difference between screening and specific tests and what tests would you consider in the unconscious patient.

Tox Tute AUDIO
Tox Tute VIDEO

Q1. What 3 investigations are used for screening?

Reveal the Answer
  • Blood Sugar Level (BSL; Blood Glucose level BGL)
  • ECG (EKG)
  • Serum Paracetamol level

Q2. What specific drug levels may assist you in your risk assessment or management in certain patient scenarios? (clue: there are 16)

Reveal the Answer

Carbamazepine, Digoxin, Ethanol, Iron, Isoniazid, Lithium, Methotrexate, Paracetamol, Phenobarbitone, Phenytoin, Potassium, Salicylate, Theophylline and Valproic acid.

Methanol and Ethylene glycol can be measured but will rarely be back in a clinically useful time.

Q3. What drugs should you screen for in the unconscious patient in whom you do not know what they have taken as knowing their presence will change your management from regular supportive care?

Reveal the Answer
  • Carbamazepine – may require Multi-dose activated charcoal or haemodialysis
  • Isoniazid – may require pyridoxine
  • Opioids – not doing levels but if they look like an opiate toxidrome then giving naloxone may improve the patient’s GCS to the point they no longer require intubation.
  • Organophosphates – Cholinersterase levels maybe possible in some hospitals but you will treat on clinical grounds if the patient is cholinergic with atropine +/- pralidoxime.
  • Phenobarbitone – may need multi-dose activated charcoal or haemodialysis
  • Salicylate – urinary alkalisation and haemodialysis (in severe poisoning)
  • Sulfonylureas – again levels may not be possible but if requiring large amounts of dextrose and there is clinical suspicion of sulfonylurea use, giving octreotide will be beneficial.
  • Toxic Alcohols – either specific levels of looking for a high anion gap metabolic acidosis (HAGMA). Treatment options are ethanol as temporary treatment and haemodialysis. Foempazole is quoted as the antidote but is not available in NZ or Australia.
  • Valproic acid – may require haemodialysis
  • Ashbourne JF, Olson KR, Khayam-Bashi H. Value of rapid screening for acetaminophen in all patients with intentional drug overdose. Annals of Emergency Medicine 1989; 18(10):1035-1038
  • Sporer KA, Khayam-Bashi H. Acetominophen and salicylate serum levels in patients with suicidal ingestion or altered mental status. American Journal of Emergency Medicine 1996; 14(5):443-446
  • FAST HUGS in BED Please
LITFL Further Reading
Further Reading
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Toxicology Library


Emergency Physician and Clinical Toxicologist who thinks that life exists outside Emergency Departments and that there is a wide and wonderful world outside the web.

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