Establishment of Natural History of Scorpion Envenomation

Condition(s) targeted: Scorpion Sting Envenomation

Intervention: None, this is an observational study (Other)

Phase: N/A

Status: Completed

Sponsored by: Instituto Bioclon S.A. de C.V.

Official(s) and/or principal investigator(s):
Walter García, MD, Study Chair, Affiliation: Instituto Bioclon

This retrospective study was conducted to collect data from approximately 100 patients from 6 months to 18 years of age who were stung by a scorpion but were not treated with antivenom. The study consisted of a review of hospital records of patients who were admitted for intensive care management of scorpion envenomation, at the only two hospitals in North America known to admit children routinely for scorpion sting management without antivenom. The standard of care consisted of symptomatic and supportive care, including airway maintenance, fluid and electrolyte support and, if necessary, sedation.

Official title: Establishment of Natural History of Scorpion Envenomation in the Absence of Antivenom Treatment in Pediatric Patients

Study design: Case-Only, Retrospective

Primary outcome: Assessment of overall duration of clinically important signs of scorpion envenomation (Clinically important signs of envenomation were divided into those indicative of respiratory distress and those comprising pathological agitation)

Secondary outcome: To characterize treatment in the absence of antivenom (total dose, maximum rate per hour and duration of use of midazolam)

Detailed description: 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.

Minimum age: 6 Months. Maximum age: 18 Years. Gender(s): Both.

Criteria:

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

The University of Arizona Health Science Center & Tucson Medical Center, Tucson, Arizona 210202, United States

Starting date: August 2004
Ending date: July 2005
Last updated: June 11, 2008