Emergency Flowchart

Signs and symptoms¹	Supportive emergency medical treatment	Identification of the culprit	Antivenom

	Possible culprit²


Nausea, vomiting, abdominal pain, diarrhoea, urticaria, angio-oedema, bronchospasm, arterial hypotension (autopharmacological effects of the venom, including anaphylaxis)	Treatment of anaphylactic/anaphylactoid reactions	Identification strategies 1. Morphological identification key (if snake is available for identification) 2. Narrowing down the cause with the aid of indirect criteria (if the snake is unavailable or could not be unequivocally identified) Which snake species are present in the country where the snake bite took place? Under what circumstances did the snake bite occur, and how did the snake behave? Syndromic approach: How does the clinical picture of snakebite envenoming develop? Comparative observations of the various species responsible in the region. Follow also links to species- and family-specific 'clinical entries' in the column `possible culprit' of this flowchart.	WHO Snakebite Information and Data Platform Check for nationally / regionally available antivenoms (assure safety and effectiveness) Antivenom indications and antivenom therapy: go to 'clinical management' Check for updates in case of an accident

	Bothrops asper Crotalus sp.

Generalised oedema → hypovolaemia → hypovolaemic shock (autopharmacological effects of the venom: increased capillary permeability)	Treatment of hypovolaemia/hypovolaemic shock

	Crotalus sp. Crotalus scutulatus (Mexico)?

Extensive local swelling possibly involving the trunk → hypovolaemia → hypovolaemic shock (local effects of the venom: regionally increased capillary permeability)	Treatment of hypovolaemia/hypovolaemic shock

	Bothrops asper Crotalus sp. Lachesis sp.

Systemic bleeding → hypovolaemia → haemorrhagic shock (haemostatic effects of the venom) Intracranial bleeding → focal neurological deficits, coma, meningismus (haemostatic effects of the venom)	Treatment of blood loss Treatment of intracanial bleeding

	Bothrops asper (Crotalus sp.) Lachesis sp.

Cranial nerve deficits, paralysis of the skeletal musculature including the respiratory musculature → respiratory insufficiency, respiratory failure (neurological effects of the venom)	Treatment of respiratory insufficiency/respiratory failure: acetylcholinesterase inhibitors, endotracheal intubation and artificial respiration

	Micrurus sp.

Sweating, repeated bilious vomiting, severe abdominal colic, profuse diarrhoea, hypotension, sinus bradycardia, and shock (autonomic syndrome)	Treatment of hypotension/shock, bradycardia, vomiting.

	Lachesis sp.³

Acute renal failure (usually secondary, rarely primary renal effects of the venom)	Treatment of acute renal failure



This section contains genera and species for which clinical data is either sparse or entirely missing. In this case, the link will lead you to the biological file. Under 'Risk', you will find what is known about the potential harm to humans which are well described for adjacent regions but not for the region you are currently looking at. The link will take you to the biological file and from there to the clinical file. When using the clinical information, however, you must consider that it is not from your region and therefore may not be applicable to your situation.	Follow ABCDE approach

	Colubridae Micruroides euryxanthus Agkistrodon sp. Atropoides picadoi Bothriechis sp. Cerrophidion sp. Metlapilcoatlus sp. Mixcoatlus sp. Ophryacus sp. Porthidium sp. Sistrurus sp.

1	See also the Clinical flowchart as a guide to the dynamics of envenoming.
2	Taxonomic name without parentheses/(in parentheses)/((in double parentheses)): these signs and symptoms are regularly/(rarely)/((questionably)) observed following bites by these species.
3	Lachesis sp. “Bushmaster (Lachesis sp.) envenoming causes a distinctive autonomic syndrome of sweating, repeated bilious vomiting, severe abdominal colic, profuse diarrhoea, hypotension, sinus bradycardia, and shock that can develop as early as 15 min after the bite.” (Warrell and Williams 2023; cit. Bolaños et al. 1982, Jorge et al. 1997).