Snake Bites

Notes: Dimpho Mokoloko (use at own discretion)

Source: Journal article as below published 2022/2023

Info to be obtained from mother and ems

- How?
- Where
- How long?
- Description/identification snake
- Previous snakebite or antivenom given? (prone to allergic reactions)
- o/e:
o fang marks
§ double row of teeth w/o fang marks
• less venomous
§ two distinct fang marks
• venomous
§ single row teeth marks, opposite side of fang marks
• caused by teeth in lower jaw
• venomous
Signs and Symptoms
- progressive weakness
o paralysis
o ptosis
o paraethesia
o pupillary dilation
o sweating, salivation, slurred speech, swallowing difficulties
o ataxia
o broken neck syndrome (decreased tone in muscles of neck causing
slumping forward)
- painful progressive swelling
o swelling
o blisters
o skin discoloration
o frank necrosis
- resp distress
 - shock
Management
1. IV access
a. Bloods (FBC, UEC, clotting screen, CMP)
b. Bloods: CK à cytotoxic bites
c. Bloods: whole blood clotting time àbeside
2. Prep resus equipment
a. Airway
b. Ventilation
c. Shock
d. Anaphylaxis
3. Give simple analgesia
a. Opiates can complicate and worsen neurotoxic picture
b. Non-steoidal agents worsen bleeding risk/renal failure w cytotoxic pr
mixed syndrome bites
4. ATT 0.5ml IMI
5. DO NOT elevate limb excessively
a. Increases spread of venom
b. Limbs to be kept at level of heart
6. No a/b initially, may be needed if tissue necrosis occurs after 72 h
7. NO steroids/antihistamines as prophylaxis but you can use in rx for
anaphylaxis
8. Neurotoxic envomation
a. Early intubation + mechanical ventilation recommended
b. Can be up to 7 days ventilation
Observation is key
- Preferably in ICU setting
- Recommended monitoring
o SpO2, continuous ETCO2
o q30 min RR, HR, BP, LOC
o q30 peak flow measurements if neurotoxic
o q60min urine output
o q60min longitudinal and circumferential measurements of swollen limb
Syndromic Management
- painful progressive swelling syndrome
o sx: blistering, discoloration, subcut hemmorhage, necrosis
o complications:
§ pseudocompartment syndrome
§ nerve + vessels entrapment
§ DVP
§ Hypotension + shock
o Skip lesions:
§ Spitting cobra bites à Mozambique
§ Areas of necrosis w sparing of regions in between (?irregular
lymphatic spread or multiple bites
o Species:
§ Puff adder
§ Gaboon adder
§ Some dwarf adder species
§ Spitting cobras
§ Stiletto snakes
§ Night adders
 - progressive weakness syndrome
o causes: neurotoxic snakes
o can lead:
§ complete paralysis
§ resp failure
§ cardiac arrest
o symptoms
§ muscle spams, fasciculations
§ drooling, salivation
§ lacrimation, diaphroreis
§ dilated pupils
§ dypnea, resp failure, death
o species
§ black mamba
§ green mamaba
§ non-spitting cobra
§ berg adder
§ desert mountain adder
- bleeding syndrome
o hx:
§ snake needed to be “pulled off”
o VICC (venom induced consumption coagulopathy)
o Sx:
§ Early usually absent
§ Bleeding at bite site
§ Bruising, prolong 20min whole blood clotting time
§ Bleeding from everywhere e.g. drip sites, mucous membranes,
epistaxis
§ Late: haematuria, haemoptysis, melena, cerebral haemorrhage,
hypotension, hypovolemic shock (12-36 hours)
§
o Species
§ Boom slang
§ Vine snakes
- mixed (progressive swelling + weakness syndrome)
o usually weakness less severe
o species:
§ rinkhals
§ snouted cobra
§ berg adder
§ forest adder
Indications for anti-venom
Types of antivenom in south Africa
1. Polyvalent antivenom
a. Covers 10 snakes
b. 1,2,3,4
i. 1. Rinkahls
ii. Adders: puff, gaboon
iii. Mambas: black, green, jamesons
iv. Cobras: cape, snouted, Mozambique spitting, forest
2. Monovalent antivenom
a. Boomslang
Preparation for antivenom admin:
- As prev mentioned: ICU admin
- Monitors ready,
- resus equipment ready
- Drug ready
o Anaphylaxis
§ 0.5ml 1:1000 solution of adrenalin adults
§ 0.3ml 1:1000 solution of adrenalin paeds
§ Avoid premed in pt w hx ihd, stroke, ht, tachyarrhythmias
o Pre-meds
§ Corticosteroids/antihistamines NOOOOO
§ No prophylactic role
Administration
- Unsure: 10 vials of PAV or 1 vial MAV
- Give vials in increments 2 vials over 10min every 2 hours as necessitated by
continued signs and symptoms
- Painful progressive swelling syndrome
o 6-8 vials
- Progressive weakness syndrome
o 8-12 vials
- Gaboon adder
o 20 vials PAV
- Bleeding syndrome
o 1 vial of MAV
- How is it mixed?
o Dilute vials in 200ml saline
o IVI over 30-60 min at 200-400ml/hr
o MAV
§ Can be given as bolus
§ Infusion diluted in 50ml saline, ivi, over 15 min