Like ALS and APLS it is important to have an approach, a system for managing patients. Toxicology is no different and can have a myriad of presentations, pioneers in the field developed RRSIDEAD as a mnemonic to remember the following steps.
- Risk Assessment
- Supportive Care
- Enhanced Elimination
We believe the above is a robust and simple clinical approach to managing the heterogeneity of presentations. The first podcast in our series is a focus on the first step, resuscitation. There are a few examples of what might be a different treatment or course of action in the poisoned patient beyond your normal ABCDE approach.
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The show notes are presented in a very exciting ‘show and reveal‘ mini quiz.
- Alkalis, acids, glyphosate and paraquat
- Organophosphorous agents. Treat with atropine starting at 1.2mg (20microgram/kg in paeds). Further doses are given every 2-3 mins, doubling the dose each time until drying of the secretions is achieved. Handy Hint: HR is not a useful endpoint as maybe tachycardic from nicotinic effects.
- Ethylene glycol, methanol, salicylates and TCA.
- Even with the slickest of intubations there will be a period of reduced ventilation and temporal worsening of the metabolic acidosis therefore some advocate the use of sodium bicarbonate pre-intubation.
- Paraquat. Where possible avoid supplemental oxygen, if this occurs titrate supplemental oxygen to maintain sats at 90% or a PaO2 60 mmHg.
- One possible culprit is hydrofluoric acid. Extensive cutaneous exposure causes hypocalcaemia therefore by giving boluses of IV calcium e.g. 60-90ml of calcium gluconate every 2 mins alongside defibrillation may restore a perfusing rhythm.
- This patient will require a boluses of sodium bicarbonate alongside urgent intubation and hyperventilation. Multiple pharmaceutical and recreational drugs have fast sodium channel blocking properties and in overdose this precipitates widening of theQRS until VT occurs.
- Sodium bicarbonate gives a sodium load as well as creates an alkalotic state which helps reduce the binding of the drug to various sites including the myocardium. Seetoxtutes 4 for further explanation.Other agents can be used including lignocaine when there is a pH of >7.5.
- Also in extremis the use of lipid-emulsion therapy has been gaining support although most of the evidence is with local anaesthetic toxicity.
- Amiodarone is contraindicated as it also has sodium channel blocking effects alongside all the other Vaughan Williams type 1a antidysrhythmic drugs (quinidine, procainamide and disopyramide)
- Chloral hydrate, Hydrocarbons, Organochlorines and Theophylline
- IV benzodiazepines e.g. diazepam 5mg IV and titrate every 5 mins potentially with increasing doses to reach a HR close to 100-110. Usually this only results in minor sedation and does not require intubation as a result of your benzodiazepine use. BP will also decrease due to benzodiazepine receptors in the vascular system. If this fails the use of a short acting antihypertensive such as GTN would be appropriate (other agents include phentolamine and sodium nitroprusside).
- Calcium channel blockers and beta blockers
- Digoxin. In large overdose, usual resuscitation maybe futile without the antidote (digoxin-specific antibodies)
- Isoniazid and this requires pyridoxine 1g per gram of isoniazid ingested, up to 5g
Theophylline – urgent haemodialysis
Cyanide – hydroxocobalamin, thiosulfate or dicobalt edetate.
- A sulfonylurea – octreotide administration will reduce the requirement of dextrose supplementation as it suppresses the release of endogenous insulin from the pancreatic cells. In children give a bolus of 1 microgram/kg (max 50 micrograms) followed by an infusion of 1 microgram/kg/hr (max 25 micrograms initially but rate can be doubled if hypoglycaemia reoccurs)
- Albertson TE, Dawson AH, de Latorre F et al. TOX-ACLS: Toxicology-orientated advanced cardiac life support. Annals of Emergency Medicine 2001;37:S78-S90
- Australian Resuscitation Council. Adult advanced life support: Australian Resuscitation Council guidelines 2006: Guideline 11.6 Emergency Medicine Australasia 2006;18:337-356
- Gunja N, Graudins A. Management of cardiac arrest following poisoning. Emergency Medicine Australasia 2011;23:16-22
- Murray L, Little M, Pascu O, Hoggett K. Toxicology Handbook 3rd Edition. Elsevier 2015. ISBN 9780729542241