Clinical Flowchart

Autopharmacological effects

Bitis sp. Echis sp.
Minutes (to hours)

Bitis atropos Echis sp.	Bitis arietans Bitis gabonica Bitis rhinoceros
Nausea, vomiting, abdominal pain, diarrhoea (urticaria, angio-oedema) (bronchospasm) arterial hypotension
	Hours

	Non-cardiogenic pulmonary oedema Cerebral oedema	Generalised oedema

		Hypovolaemia/hypovolaemic shock

Cardiovascular failure

Local effects

Bitis arietans Bitis gabonica Bitis rhinoceros Echis sp. Causus sp. Hemachatus haemachatus¹Naja mossambica¹Naja nigricollis¹Other African spitting cobras¹
Minutes (to hours)

Local pain and swelling

Painful swelling of the regional lymph nodes

Bitis arietans Bitis gabonica Bitis rhinoceros Naja mossambica ¹ Naja nigricollis¹ Other African spitting cobras¹		Bitis arietans Bitis gabonica Bitis rhinoceros Naja mossambica)¹Naja nigricollis¹Other African spitting cobras¹
Days		Hours

		Extensive swelling

		Hypovolaemia

Necrosis Loss of function of extremities Loss of extremities

1	EYE lesions: Spitting cobras (N. ashei, N katiensis, N. mossambica, N. nigricincta, N. nigricollis, N. nubiae)

Haematological effects

(Atheris sp.) Bitis arietans Bitis gabonica Bitis rhinoceros Echis sp.¹ Dispholidus typus Thelothornis sp. (Naja nigricollis)
< 1 hour to hours

Gingival bleeding

Bleeding from wounds remote from the site of the bite

Haematemesis, bleeding per rectum, haematuria

Systemic bleeding		Intracranial bleeding (focal neurological deficits, meningismus, coma)

Hypovolaemia/haemorrhagic shock

Cardiovascular failure	Renal failure	CNS failure

1	Additionally, thrombotic microangiopathy is observed in Echis sp. envenoming.

Neurological effects

(Aspidelaps scutatus)
Bitis atropos
Dendroaspis sp.¹(Hemachatus haemachatus)
Naja haje
Naja melanoleuca
Naja nivea
Other African neurotoxic cobras

Minutes to hours

Cranial nerve deficits (ptosis, ophthalmoplegia, dysphagia, dysarthria)

Paralysis of the skeletal musculature including the respiratory musculature

Respiratory failure

1	Autonomic dysfunction (nausea, vomiting, sweating)

Muscular effects

Not observed.

Cardiac effects

Bitis arietans, Bitis gabonica, Bitis rhinoceros: hypotension, bradycardia: among other factors direct myocardial effect of the venom? (Warrell et al. 1975). Bitis arietans: “Myocardial damage and cardiac arrhythmias may contribute to hypotension, a cause of early deaths.” (Amr et al. 2020).

Renal effects

Bitis arietans¹
Cerastes cerastes¹

Hours to days

Flank pain, renal bed sensitive to percussion

Urinary output <400 ml/24 h

Renal failure

According to the available data, acute renal failure following a snakebite in Central and Southern Africa generally appears to be a secondary effect (arterial hypotension, shock, DIC).
For Bitis arietans and Cerastes cerastes venom a primary nephrogenic effect is discussed (Warrell et al. 1975, Schneemann et al. 2004).