Spider envenoming
OVERVIEW
- in Australia the only two spiders of real importance = Funnel-web and the Red-Back
- only these two can cause death or severe systemic illness
FUNNEL-WEB SPIDER
- Sydney Funnel-web the most poisonous (160 km radius)
- no death post the introduction of anti-venom
- bites don’t always produce envenomation -> but if envenomed it can be rapidly fatal
- venom = polypeptide which stimulates release of Ach at NMJ and catecholamines in CNS
CLINICAL FEATURES
- nausea/vomiting, profuse sweating, salivation, abdominal pain
- muscle fasciculation at bite site -> distal muscle groups
- hypertension, tachycardia, hypersalivation, bronchorrhoea
- coma, respiratory failure, pulmonary oedema, hypotension
MANAGEMENT
- pressure-immobilisation dressing
- anti-venom
- supportive of vital organ function
RED-BACK SPIDER
- distributed everywhere in Australia
- no deaths since 1956
CLINICAL FEATURES
- pin prick bit -> inflamed, severe pain -> radiates up limb
- profuse sweating, headache, nausea, vomiting, abdominal pain, fever, hypertension
- paraesthesia, rashes
- can develop progressive muscle paralysis
MANAGEMENT
- first aid not proven
- ice for symptomatic relief
- simple analgesia
- anti-venom IM or IV
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
- Tox conundrum 003 – Bitten by a Redback Spider
- Tox conundrum 003 – Is this a RedBack I see before me?
- Redback Spider Envenoming
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
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