Case report

A case of snake bite

Sangram Patil¹

Madhu Gowda²

1. Specialist registrar in Anaesthetics, Morriston Hospital Swansea, SA6 6PU, UK.

2. SHO in ITU, Morriston Hospital Swansea, SA6 6PU, UK.

Introduction

Snake bite though very rare in UK, is a very common life-threatening condition in many tropical countries. Snake bite causes 3-5 million victims/yr with nearly 50,000 deaths & staggering 4,00,000 amputations world-wide. About 40% bites by venomous snakes don’t produce signs of envenoming. As it is difficult to predict which bites produce symptoms or clinical outcome, all victims should be treated and observed under medical care immediately. Here we report a case of snake bite brought to our hospital for emergency treatment.

Case summary

A 54years lady with adder snake bite was brought to casualty by air ambulance.

She had bite mark to her right big toe. At the scene she squeezed the toe immediately. She had a vomiting episode and developed confusion subsequently.

On the way to hospital, in an ambulance, she developed typical anaphylactic reaction- she became hypotensive (BP 76/54 mmHg), agitated with pain in affected big toe and foot.

Paramedics gave her adrenaline 0.5 mg intramuscularly and pushed intravenous fluids (2 litres of crystalloid + colloids) to which she responded well.

On arrival in emergency department she was conscious, oriented (GCS 13) and was phonating well. She had a difficulty in swallowing, complained of pain right foot, abdomen and change in voice. She vomited immediately on arrival to casualty.

Her clinical examination revealed-

Tongue swollen

The affected site: cellulitic reaction, puncture wound, splint in-situ. Her cardiovascular and respiratory parameters were stable.

Treatment in A & E-

Humidified oxygen with face mask

Intravenous fluids

Piriton & Hydrocortisone

Augmentin to cover the snake bite site

Tetanus injection

Antivenom- as per protocol.

Morphine for pain relief.

She was continuously monitored. After couple of hours she improved clinically. She became completely alert (GCS: 15/15) and was haemdynamically stable

Tongue swelling reduced and her voice improved. Foot pain got better.

Observations at 24 hours were-

Leg swelling worsened

She developed right groin lymphadenopathy

The affected leg became oedematous and hot

Her coagulation was slightly deranged with prothrombin time 19, APTT 45 seconds.

Snake bite specialists in Liverpool were contacted for further treatment. The advised that there was no evidence for steroid and asked to watch for necrotic changes in foot.

At 48 hours-

Her swelling improved and she became symptomatically better. Her coagulation parameters returned to normal.

At 72 hours-

She was very comfortable and independent and was discharged home with advice to watch for swelling, redness or any unusual symptoms.

Discussion:

Amount of venom injected via the bite is highly variable. It depends on the length of time since the snake last ate and also its aggression. The clinical effects of snake bite will depend on the type of snake involved. In our case the lady knew the type of snake well. The relatives/friends may bring the snake with them to hospital.

Snake venom is complex mixture of proteins & small polypeptides with enzymatic activities. Snake venom can be neurotoxic, haematoxic or myotoxic, usually a combination of these.

Our patient had a combination of signs and symptoms. The usual clinical picture is as follows.

The signs & symptoms of envenomation:

Vomiting

Diarrhoea

Abdominal pain

Angioedema and shock

Confusion and/or drowsiness

Loss of consciousness

Unrecordable pulse and/or BP

Swelling and discoloration of the whole of the affected limb and trunk

Lymphadenopathy

Non-specific ECG changes, heart block, cardiac arrhythmias

Coagulopathy

Coma & Seizures

Pulmonary edema, adult respiratory distress syndrome (ARDS)

Acute pancreatitis & renal failure

The initial first aid received was accurate and in time. She also received advanced treatment for allergic manifestations on the way to hospital. This could have been resulted in milder course later on. The guidelines for management of snake bite are-

Reassure

Immobilise the bitten area (minimises venous spread)

Identify the snake

Firm bandage to occlude lymphatic drainage

Unhelpful things are–

Tourniquets – doesn’t prevent venom spread & often applied incorrectly

Incision @ bite site & attempt to suck out

Hospital Management-

Observation for 12 – 24 hrs

Symptomatic treatment for - pain & vomiting

Anti-tetanus

Timely administration of species specific antivenin

Rule of h/o allergy – intradermal sensitivity testing

Coagulopathy/thrombocytopenia/DIC: FFP, cryoprecipitate & platelets ay be indicated.

In our case clotting abnormalities were self-limiting and did not need any treatment.

She did not develop excessive swelling of her affected limb, rhabdomyolysis or compartment syndrome.

Because of cardiovascular instability during transfer and increasing swelling she received antivenin. The antivenin is indicated in following situations-

Cardiogenic Shock

Spontaneous systemic bleeding

Incoagulable blood

Neurotoxicity

Haematuria

Evidence of haemolysis/rhabdomyolysis

Rapidly progressive extensive swelling

Bites on digits by snakes with known necrotic venoms


Most commonly seen snake in UK is European Adder (Viperidae family). Antivenom for this snake is Antivenin Vipera tab (European Viper antivenom).

Prevention is better than cure. Awareness & avoidance of the habitat of snakes may help to reduce the incidence of snake bite.

References:

·Davidson’s principle & practice of Medicine – 20^th edition

·Sprivulis P, Jelinek G Toxicology - Snakebite. In: Cameron et al.(eds). Textbook of Adult Emergency Medicine 2nd Ed. Churchill Livingstone, Edinburgh pp. 881-884

·Stewart CJ; Snake bite in Australia: first aid and envenomation management.;Accid Emerg Nurs 2003 Apr;11(2):106-11.[abstract]

·Harborne DJ; Emergency treatment of adder bites: case reports and literature review.;Arch Emerg Med 1993 Sep;10(3):239-43.[abstract]

·TOXBASE. Poisons information site.

·Sutherland S, Tibballs J. First Aid for Bites and Stings. In Australian Animal Toxins 2nd Ed. OUP 2001. pp28-47

·Thomas PP, Jacob J. Randomized trial of antivenom in snake envenomation with prolonged clotting time. Brit Med J 1985;291:177-178.

·Warrel DA, Venoms, toxins and poisons of animals and plants. In: Wealtherall DJ, Ledingham JGG, Warrell DA (eds) Oxford Textbook of Medicine. 3nd ed. Vol 1, Oxford, Oxford University Press. 1996.