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Family: Viperidae
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Subfamily: Viperinae
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Genus: Echis
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Species: omanensis
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Common Names
Oman Saw-scaled Viper
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Region
Middle East
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Countries
Oman, United Arab Emirates
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Taxonomy and Biology
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Adult Length: 0.40 m
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General Shape
Small in length, medium bodied snake with a moderately short to short length tapering tail. Can grow to a maximum of about 0.70 metres. Dorsal scale count 28 - 35 - 21.
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Habitat
Desert areas mainly in dry rocky hillside and mountain terrain with widely scattered vegetation up to 2500 metres.
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Habits
Nocturnal and terrestrial snake.
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Prey
Feeds mainly on lizards and rodents.
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Venom
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General: Venom Neurotoxins
Not present
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General: Venom Myotoxins
Not present
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General: Venom Procoagulants
Mixture of procoagulants
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General: Venom Anticoagulants
Possibly present
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General: Venom Haemorrhagins
Zinc metalloproteinase
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General: Venom Nephrotoxins
Possibly present
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General: Venom Cardiotoxins
Probably not present
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General: Venom Necrotoxins
Possibly present
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General: Venom Other
Unknown
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Clinical Effects
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General: Dangerousness
Severe envenoming possible, potentially lethal
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General: Rate of Envenoming: >80%
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General: Untreated Lethality Rate: 1-10%
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General: Local Effects
Marked local effects; pain, severe swelling, bruising, blistering, necrosis
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General: Local Necrosis
Common, moderate to severe
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General: General Systemic Effects
Variable non-specific effects which may include headache, nausea, vomiting, abdominal pain, diarrhoea, dizziness, collapse or convulsions
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General: Neurotoxic Paralysis
Does not occur, based on current clinical evidence
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General: Myotoxicity
Does not occur, based on current clinical evidence
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General: Coagulopathy & Haemorrhages
Common, moderate to severe coagulopathy + haemorrhagins causing extensive bleeding
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General: Renal Damage
Recognised complication, usually secondary to coagulopathy
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General: Cardiotoxicity
Unlikely to occur
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General: Other
Shock secondary to fluid shifts due to local tissue injury is likely in severe cases
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First Aid
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Description: First aid for bites by Viperid snakes likely to cause significant local injury at the bite site (see listing in Comments section).
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Details
1. After ensuring the patient and onlookers have moved out of range of further strikes by the snake, the bitten person should be reassured and persuaded to lie down and remain still. Many will be terrified, fearing sudden death and, in this mood, they may behave irrationally or even hysterically. The basis for reassurance is the fact that many venomous bites do not result in envenoming, the relatively slow progression to severe envenoming (hours following elapid bites, days following viper bites) and the effectiveness of modern medical treatment. 2. The bite wound should not be tampered with in any way. Wiping it once with a damp cloth to remove surface venom is unlikely to do much harm (or good) but the wound must not be massaged. 3. All rings or other jewellery on the bitten limb, especially on fingers, should be removed, as they may act as tourniquets if oedema develops. 4. The bitten limb should be immobilised as effectively as possible using an extemporised splint or sling; if available, crepe bandaging of the splinted limb is an effective form of immobilisation. 5. If there is any impairment of vital functions, such as problems with respiration, airway, circulation, heart function, these must be supported as a priority. In particular, for bites causing flaccid paralysis, including respiratory paralysis, both airway and respiration may be impaired, requiring urgent and prolonged treatment, which may include the mouth to mask (mouth to mouth) technique of expired air transfer. Seek urgent medical attention. 6. Do not use Tourniquets, cut, suck or scarify the wound or apply chemicals or electric shock. 7. Avoid peroral intake, absolutely no alcohol. No sedatives outside hospital. If there will be considerable delay before reaching medical aid, measured in several hours to days, then give clear fluids by mouth to prevent dehydration. 8. If the offending snake has been killed it should be brought with the patient for identification (only relevant in areas where there are more than one naturally occurring venomous snake species), but be careful to avoid touching the head, as even a dead snake can envenom. No attempt should be made to pursue the snake into the undergrowth as this will risk further bites. 9. The snakebite victim should be transported as quickly and as passively as possible to the nearest place where they can be seen by a medically-trained person (health station, dispensary, clinic or hospital). The bitten limb must not be exercised as muscular contraction will promote systemic absorption of venom. If no motor vehicle or boat is available, the patient can be carried on a stretcher or hurdle, on the pillion or crossbar of a bicycle or on someone's back. 10. Most traditional, and many of the more recently fashionable, first aid measures are useless and potentially dangerous. These include local cauterization, incision, excision, amputation, suction by mouth, vacuum pump or syringe, combined incision and suction ("venom-ex" apparatus), injection or instillation of compounds such as potassium permanganate, phenol (carbolic soap) and trypsin, application of electric shocks or ice (cryotherapy), use of traditional herbal, folk and other remedies including the ingestion of emetic plant products and parts of the snake, multiple incisions, tattooing and so on.
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Treatment
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Treatment Summary
Echis bites cause moderate to severe, potentially lethal envenoming, requiring urgent assessment & treatment, including IV fluids, IV antivenom and good wound care.
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Key Diagnostic Features
Local pain, swelling, blistering, necrosis + coagulopathy, bleeding, renal failure
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General Approach to Management
All cases should be treated as urgent & potentially lethal. Rapid assessment & commencement of treatment including appropriate antivenom (if indicated & available) is mandatory. Admit all cases.
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Antivenom Therapy
Antivenom is the key treatment for systemic envenoming. Multiple doses may be required.
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1. Antivenom Code: SAfSAI04
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Antivenom Name: SAIMR Echis Antivenom
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Manufacturer: South African Vaccine Producers (Pty) Ltd
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Phone: +27 11 386-6000; +27 11 386-6078
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Address: Postal address PO Box 28999 Sandringham 2131 Gauteng Province
Physical address 1 Modderfontein Road Sandringham, Johannesburg
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Country: South Africa
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2. Antivenom Code: SAsFRC02
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Antivenom Name: Anti Echis coloratus
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Manufacturer: Felsenstein Medical Research Center
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Phone: ++972-3-937-7507
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Address: Rabin Medical Center, Beilinson Campus Petah Tikva 49100
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Country: Israel
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3. Antivenom Code: SAfAVC02
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Antivenom Name: Polyvalent Snake Antivenom
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Manufacturer: National Antivenom and Vaccine Production Centre
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Phone: ++966-1-252-0088 ext 45626, 45637.
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Address: P.O. Box 22490 Riyadh 11426
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Country: Saudi Arabia
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