Establishment of Natural History of Scorpion Envenomation

The study objective was to document the clinical syndrome of scorpion envenomation in the absence of antivenom treatment in pediatric patients. This was done to establish historical control data on the time from sting to the time of resolution of signs of envenomation. These historical control data are intended to be used for comparison with Alacramyn treated patients in two prospective studies being conducted in Mexico and the U.S.for which a control population could not otherwise be established.

The total duration of clinically important systemic signs of envenomation was determined based upon overall investigator assessment of the last signs of any respiratory compromise, any pathological agitation or other indicator of continuing illness (e.g., continuing need for sedative administration).

To facilitate comparison of these historical data with prospective open label trials, periodic assessments of the overall presence or absence of clinically important signs was performed. Periodic assessments were also performed for each individual component indicator of respiratory compromise and of pathological agitation, when available.

A research nurse reviewed hospital discharge diagnoses for all pediatric charts coded for "scorpion sting". For these cases demographic, diagnostic, and therapeutic data were entered on the case report form (CRF) as well as data necessary to assess compliance with study inclusion and exclusion criteria.

A physician subinvestigator reviewed the research nurse's findings for the key outcome indicators, which consisted of clinically important systemic signs of scorpion envenomation and adjunctive sedation treatment (dose and timing of dose) when medical judgment was required.

Inclusion criteria

• Males and females 6 months to 18 years of age
• Presenting for emergency treatment with clinically important systemic signs of scorpion sting envenomation

Exclusion criteria

• Use of any antivenom within the last month or concomitantly
• Signs and symptoms confined to local sting site
• Concurrent medical condition involving a baseline neurologic status mimicking envenomation (chorea, tardive dyskinesia, uncontrolled epilepsy)
• Incomplete or unavailable medical record