Hypoxaemia in Toxicology
AGENTS
- CO
- cyanide
- methaemoglobinaemia
- any agent that causes a decreased LOC -> airway compromise!
CLINICAL FEATURES
- SOB
- air hunger
- lactic acidosis
- tachycardia
- hypertension -> hypotension
- seizures
- coma
INVESTIGATIONS
- oxymetry
- CN level
- metHb level
SPECIFIC MANAGEMENT AND TRIGGERS FOR INTERVENTION
- 100% O2
Cyanide
- treat a CN level of > 0.5mg/L
- sodium nitrate: produces methaemoglobin which cyanide has a high affinity for (savenger)
- sodium thiocyanate: transfer a sulphur group to cyanide -> thiocyanate which is excreted by the kidneys
- hydroxycobalamin: detoxifies cyanide by binding to it
- dicobal edentate: 300mg IV followed by 50mL of 50% dextrose (in severe disease)
Carbon monoxide
- hyperbaric O2
Methaemoglobinaemia
- cease precipitants
- methylene blue (1-2mg/kg over 5 minutes)
- ascorbic acid (if methylene blue contra-indicated – G6PD deficiency)
- exchange transfusion
- hyperbaric oxygen
References and Links
CCC Toxicology Series
General
Approach to acute poisoning, ECGs in Tox, Evidenced-based Tox, Toxicology literature summaries, Does anti-venom work?
Toxins / Overdose
Amphetamines, Barbituates, Benzylpiperazine, Beta Blockers, Calcium Channel Blocker, Carbamazepine, Carbon Monoxide, Ciguatera, Citrate, Clenbuterol, Cocaine, Corrosive ingestion, Cyanide, Digoxin, Ethanol, Ethylene Glycol, Iron, Isoniazid, Lithium, Local anaesthetic, Methanol, Monoamine oxidase inhibitor (MAOI), Mushrooms (non-hallucinogenic), Opioids, Organophosphate, Paracetamol, Paraquat, Plants, Polonium, Salicylate, Scombroid, Sodium channel blockers, Sodium valproate, Theophylline, Toxic alcohols, Tricyclic antidepressants (TCA)
Envenomation
Marine, Snakebite, Spider, Tick paralysis
Syndromes
Alcohol withdrawal, Anticholinergic syndrome, Cholinergic syndrome, Drug withdrawals in ICU, Hyperthermia associated toxidromes, Malignant hyperthermia (MH), Neuroleptic malignant syndrome (NMS), Opioid withdrawal, Propofol Infusion Syndrome (PrIS) Sedative toxidrome, Serotonin syndrome, Sympatholytic toxidrome, Sympathomimetic toxidrome
Decontamination
Activated Charcoal, Gastric lavage, GI Decontamination
Enhanced Elimination
Enhanced elimination, Hyperbaric therapy for CO
Antidotes
Antidote summary, Digibind, Glucagon, Flumazenil, HIET – High dose euglycaemic therapy, Intralipid, Methylene Blue, N-Acetylcysteine (NAC), Naloxone
Miscellaneous
Cocaine chest pain, Digoxin and stone heart theory, Hyperbaric oxygen, Hypoxaemia in tox, Liver failure in tox, Liver transplant for paracetamol, Methaemoglobinaemia, Urine drug screen
Critical Care
Compendium
