Hospital contacts after bite by the European adder (Vipera berus)

INTRODUCTION: Bites by the European adder, Vipera berus, may cause significant morbidity in bite victims, but this can be reduced through adequate treatment. Since the previous Danish study, a new treatment and a severity grading has been taken into use. The aims of this study were to review clinical cases after a bite from V. berus in The North Denmark Region and to evaluate the treatment given.

METHODS: In the regional health-care database, we retrospectively identified all patients discharged with the International Classification of Diseases, 10th version (ICD-10) code "T 63.0 snake venom" in the 2007-2013 period. We reviewed patient records for patient demographics, clinical information and information about treatment.

RESULTS: During the study period, 76 patients were discharged from a hospital after being bitten by V. berus in The North Denmark Region. Envenomation grade 2 or 3 was seen in 61% of victims, and 21% of these were treated with antivenom. T-wave inversion was seen in 9% of the 54 patients in whom an electrocardiography had been performed. The median duration of admittance was 24 hours (mean 48 hours), and risk factors for a prolonged stay at the hospital were grade 2 or 3 envenomation, leukocytosis and moderate/massive oedema at the time of admittance.

CONCLUSION: Patients were admitted for a longer time than reported from a previous Danish study on adder bites, and many patients were possibly undertreated with regard to use of antivenom according to recommendations in recent guidelines. No adverse effects were noted due to administration of antivenom. T-wave inversion was observed more frequently than previously described.

FUNDING: not relevant.

TRIAL REGISTRATION: The study was recorded with The North Denmark Region in accordance with a directive from the Danish Data Protection Agency.