Snakebite enquiries to the NPIS 2004-2010

Objective: To describe trends regarding snakebite enquiries to the UK National Poisons Information Service (NPIS) from January 2004 to August 2010 and the indications concerning the use of Adder anti-venom with respect to the NPIS treatment guidelines. Methods: The UK NPIS Database was interrogated for enquiries from January 2004 to August 2010. Search terms used were “snake” and “snakebite”. Information from the national dataset was available from Cardiff and Edinburgh units from 2004 onwards, Birmingham from June 2005 and Newcastle from September 2006. Data concerning snakebites in animals were removed. The data were analysed using descriptive statistics. Results: 510 cases were identified, of which 69% were male and 31% female. Average age of patients was 32 years (±2 years 95% confidence interval). The snake was identified as follows: European adder in 52% of cases, a non-native species in 26%, unknown in 18% and another UK snake in 4%. 82% of enquiries occurred between the months of April to September with frequency peaking during August (19%). 42% of cases reported envenomation. Clinical features were as follows: 94% oedema, 28% cardiovascular signs, 23% gastrointestinal features and 7% had anaphylaxis. Eighty-five patients were assessed as requiring anti-venom but only 84 received treatment with anti-venom. One patient refused treatment due to concerns of a possible allergy to the anti-venom. The most frequent indications for anti-venom were oedema involving two joints (64%), cardiovascular compromise (29%) and anaphylaxis (7%). No adverse reactions to the anti-venom were reported and resolution of clinical features was reported in all treated cases. Advice to use an antidote was followed in 98.8% of cases. Conclusion: Snakebites account for one to two NPIS enquiries per week. Adder bites account for over half of these cases. A quarter of enquiries were due to non-UK snakes kept in captivity within the UK. Envenomation was said to have occurred in just under half of all cases. Oedema was the most significant feature, although systemic features also occurred in over half of cases. The anti-venom appears to be safe and effective. Advice given by the NPIS appears to closely reflect national practice guidelines.