Suspected snakebite: one year prospective study of emergency department presentations.
OBJECTIVE
Snakebite is an uncommon, but potentially life-threatening condition. The more common clinical scenario is suspected snake-bite. Our aim was to characterise the epidemiology, diagnosis and management of patients with suspected snakebites.


METHODS
Prospective cohort study of patients presenting with suspected snakebites to a tertiary referral hospital serving a large rural region in tropical northern Australia where a standard admission protocol for suspected snakebites is used.


RESULTS
Of 70 suspected snakebite cases, there were 45 definite bites: three severe envenomings (two western brown snakes [Pseudonaja nuchalis] and one mulga snake [Pseudechis australis]); seven mild/moderate envenomings by other snakes, two non-envenomings by identified P. nuchalis, five bites by identified non-venomous snakes and 28 definite bites without envenoming. The remaining 25 cases were either suspected bites (8), unlikely bites (15) and two people hit by snakes. Definite snake-bites occurred throughout the year, peaking in May and December. There were three severe envenomings (mainly coagulopathy), requiring antivenom treatment, but no deaths or major complications. Most patients had appropriate investigations. Of 47 venom detection kit swabs collected, 34 were not tested, venom was not detected in nine and was positive in the three envenomings with one false-positive tiger snake. Whole blood clotting time was highly sensitive for procoagulant coagulopathy and envenoming in this study. Median length of time from the bite to discharge was 20 h (interquartile range: 12-27).


CONCLUSIONS
The study shows that although suspected snakebite was common, severe envenoming occurred in less than 5% of cases. The study supports the proposition that a structured approach and admission policy of suspected snakebites leads to the appropriate management of severe envenoming, with no cases discharged early and no cases of non-envenoming treated with antivenom.
Isbister
Geoffrey K
GK
Discipline of Clinical Pharmacology, University of Newcastle and Newcastle Mater Misericordiae Hospital, Newcastle, New South Wales, Australia. gsbite@bigpond.com
Currie
Bart J
BJ
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000997:Antivenins / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D004638:Emergency Treatment / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015876:Northern Territory / Q000453:epidemiology; D010343:Patient Admission / Q000706:statistics & numerical data; D010808:Physical Examination; D011159:Population Surveillance; D011446:Prospective Studies; D012621:Seasons; D017678:Sex Distribution; D012909:Snake Bites / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D016482:Urinalysis; D014914:Whole Blood Coagulation Time
D000997:Antivenins