Author: Ciaran Eugene McKenna / Editor: John P Sloan / Reviewer: Jolene Rosario / Codes: EnvC8, PhC4, SLO3Published: 05/10/2020

A 36-year-old female, with a previous history of asthma, was brought to the emergency department (ED) at 1840hrs on a Saturday afternoon. She had been enjoying a walk through scenic woodlands in North West England (approximately 20km from a large zoo with a reptile enclosure). A snake was seen on the pathway and the patient stooped to take a photograph with her mobile phone. She subsequently was bitten on her right hand. She attended a local community hospital, but rapidly deteriorated. The paramedics found the patient to be pale, sweaty, wheezy, dizzy and light-headed with a BP of 82/46. She then had a syncopal episode. She was treated for anaphylaxis with IM adrenaline 0.5mg, nebulised B-agonists, IV steroids and a 500ml bolus of 0.9%

Sodium Chloride (NaCl) IV. She vomited several times during transfer.

On arrival to the ED she had mild lip swelling, but no overt airway compromise, respiratory distress or stridor. Respiratory rate was 20/min with slight wheeze, SpO2 98% on room air. Pulse 110/min BP 110/64. Two puncture wounds to the dorsal aspect of her right hand were noted, and the hand itself was slightly swollen.

A further 1000mls of 0.9% NaCl was given as a bolus along with IV chlorpheniramine 10mg. Despite this, her blood pressure dropped to 74/42. Another dose of 0.5mg IM adrenaline was given along with a further 1000mls of IV 0.9% NaCl. Her BP improved to 106/48 but needed 4000mls of crystalloid in total, along with another dose of IM adrenaline to maintain a systolic BP >90mmHg. Her tetanus status was unclear, so a tetanus booster was administered.

An initial ABG revealed a metabolic acidosis

  • pH 7.29
  • pCO2 4.5 kPa
  • pO2 10.3 kPa
  • HCO3 17.6 mmol/L
  • Base Excess -10.3 mmol/L
  • SpO2 96%
  • FiO2 21%

ECG demonstrated sinus rhythm with widespread flattening of T-waves, but no acute ST changes or conduction abnormalities.

The mobile phone picture was shown to a staff nurse in the ED, whose husband was a research scientist at a local university’s Tropical Medicine Venom Department. The reptile was identified as a European Viper (Vipera berus) more commonly known as an Adder in the UK.

Following consultation with the National Posions and Information Service, antivenom administration was advised. None was immediately available in the local ED and it had to be sourced regionally.

Fortunately, the staff nurse’s husband had access to Antivenom in his research facility and this was delivered to the ED, prior to arrival of the NHS regional supply, and administered to the patient.

The patient was admitted on a monitored bed under the care of the acute physicians with plastic surgery review. Her bites did not require surgical intervention other than elevation and analgesia, and antibiotics.