Clinical course of Centruroides sculpturatus envenomations managed without antivenom

In 2004, most supplies of the antivenom used to treat serious cases of Centruroides sculpturatus sting in the southwestern USA was exhausted, and supportive care and interventions became the only option available. Ayrn O'Connor and Anne-Michelle Ruha have now published a study showing the clinical course of Bark scorpion envenomations managed without antivenom.

The results show that treatment without antivenom are effective without antivenom, but 24 % of 88 patients (mainly children between 2 and 9 years) experienced respiratory failure and needed intubation. No mortality occurred, but this study show that C. sculpturatus is a dangerous scorpion for young children (and not only infants and toddlers).

In August 2011, a new antivenom for Centruroides was approved by FDA after studies showing it being effective in the treatment for serious cases. Unfortunately, this treatment is very expensive, and may force doctors and/or patients to limit the use. O'Connor & Ruha therefor highlight the importance of supportive treatment of severe scorpions stings.

Abstract:
Bark scorpion envenomation is potentially life threatening in children and traditionally treated with antivenom (AV). We sought to describe the clinical course, management, complications and outcome of children with severe scorpion envenomation treated with supportive care during a period when AV was unavailable. A retrospective chart review was performed, all children presenting to a referral hospital between September 1, 2004 and July 31, 2006 with severe scorpion envenomation not receiving AV, were included. A standardized data abstraction form was used to record time of symptom onset, time to healthcare facility (HCF), clinical findings, treatment, complications, and length of stay. Eighty-eight patients were included with mean age of 3.7 years (0.33–12). Mean time to symptom onset was 20 min (0–130) and mean time to HCF was 79 min (10–240). Incidence of clinical manifestations include: neuromuscular agitation, 100 %; opsoclonus, 97 %; hypersalivation, 81 %; tachycardia, 82 %; hypertension, 49 %; vomiting, 38 %; fever, 28 %; respiratory distress, 33 %; and hypoxia, 18 %. Complications included rhabdomyolysis in 18 (20 %) and aspiration in 12 (13 %) patients. Intubation was required in 24 % of patients. The most frequently used agents to control symptoms were benzodiazepines (98 %) followed by opioids (69 %). Intravenous fluids were given to 84 %. Mean length of stay was 29 h (range, 6–73 h). There were no deaths. In addition to the classic findings of neuromuscular hyperactivity, opsoclonus, and hypersalivation, a high incidence of hyperadrenergic findings and respiratory compromise are noted in this series. A significant number of patients required mechanical ventilation. Benzodiazpines and opioids were the most common medications used to control symptoms.

Reference:
O'Connor A, Ruha AM. Clinical Course of Bark Scorpion Envenomation Managed Without Antivenom. Journal of Medical Toxicology. 2012. Epub 2012/05/09. [Subscription required for full text]