Meta-analysis of controlled studies on immunotherapy in severe scorpion envenomation
- Fekri Abroug1,
- Lamia Ouanes-Besbes1,
- Islem Ouanes1,
- Fahmi Dachraoui1,
- Mohamed Fkih Hassen2,
- Habib Haguiga3,
- Souheil Elatrous2,
- Christian Brun-Buisson4
- 1Intensive Care Unit, Centre Hospitalo, Universitaire Fatouma Bourguiba, University of Monastir, Tunisia
- 2Intensive Care Unit, Centre Hospitalo, Universitaire Tahar Sfar, Mahdia, University of Monastir, Tunisia
- 3ICU, Emergency Department, Hôpital Régional, Tozeur, Tunisia
- 4Intensive Care Unit, Université Paris Val de Marne, Assistance Publique-Hopitaux de Paris, CHU Henri Mondor, Créteil, France
- Correspondence to Fekri Abroug, Intensive Care Unit, Centre Hospitalo, Universitaire Fatouma Bourguiba, Monastir, CHU F. Bourguiba 5000, Tunisia;
- Accepted 4 April 2011
- Published Online First 11 May 2011
Background Despite conflicting evidence, specific serotherapy is recommended for scorpion envenomation.
Methods A meta-analysis of prospective or observational controlled studies, comparing intravenous scorpion antivenin (SAV) with control, was performed. Binary outcomes are reported as risk difference for clinical improvement and mortality rates. Analysis was performed both for the whole number of included studies and for two subgroups (set up according to the geographic origin of scorpions).
Results Nine studies (four randomised controlled trials (RCTs), five observational) enrolling 687 patients were identified. Six dealt with Old World scorpions and three originated from Arizona. Overall, the rate of clinical improvement was similar in SAV treated and untreated patients (risk difference=0.22, 95% CI −0.35 to 0.79; p=0.45 for effect). Subgroup analysis showed favourable effects of SAV in the Arizona scorpion envenomation (risk difference=0.53; 95% CI 0.16 to 0.91; p<0.001), and non-significant unfavourable effects in Old World scorpion envenomation (risk difference=−0.05; 95% CI −0.28 to 0.18; p=0.65; p=0.003 for z-value, indicating a true heterogeneity of treatment effects). In Old World scorpion envenomation, there was no statistical difference in the risk of death in SAV treated and untreated scorpion envenomated patients (risk difference=0.007, 95% CI −0.02 to 0.03; p=0.6 for effect). Overall, administration of scorpion antivenin was associated with a reduction by 13 h in the mean time of symptom resolution (95% CI −17 to −9; p<0.0001). Serious adverse events were reported at a rate of 1–2% while minor adverse events occurred in up to 40% of patients.
Conclusions SAV should not be administered in Old World scorpion envenomation until its efficacy is established by an appropriately designed RCT. In the Arizona scorpion sting, SAV hastens the recovery process.
- Scorpion envenomation
- cardiac care
- comparitive system research
- environmental medicine
- infectious diseases
- major incidents
- clinical care
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.