Second Dose of Scorpion Antivenom in Children with Indian Red Scorpion (Mesobuthus tamulus) Sting Envenomation (original) (raw)

S corpion sting envenomation is a commonly encountered emergency and preventable cause of morbidity and mortality [1,2]. Symptoms range from local pain to myocardial dysfunction and respiratory failure in Mesobuthus tamulus sting envenomation, an important Indian species [3,4]. In the management of scorpion sting envenomation, the efficacy of Scorpion antivenom (SAV) has been shown in many studies [2,5,6]. The current dose of SAV used in children is primarily based on studies in the adult population [2,5]. Even after the use of 30 mL of SAV, few children may deteriorate [5,7]. Antivenom, when injected intravenously, binds to the venom and facilitates its excretion [8-10]. Subsequently, a concentration gradient of venom between the vascular compartment and the peripheral tissue compartment facilitates the redistribution of venom from peripheral tissues to the vascular compartment from where the antivenom moderates further excretion of venom [8-10]. The dose of SAV required seems to be related to the severity of envenomation, but has not been well researched. The purpose of this study was to describe the effect of the second dose of SAV in children with non-resolving envenomation. METHODS This prospective study was undertaken in the Pediatric Critical Care Unit in a tertiary hospital in Puducherry between April 2015 and July 2016. Approval was obtained from the Institute Ethics Committee. All children ≤12 years presenting with definite scorpion sting (red scorpion was seen by bystanders/ brought the killed scorpion or identified it on pictures) or unknown bite with features of grade 2 and above scorpion sting envenomation were included [2,5]. Grading of clinical features was done as follows: Grade-1: local pain and reaction at the sting site, without systemic involvement; Grade-2: Signs and symptoms of autonomic storm characterized by parasympathetic or sympathetic overactivity; Grade-3: Evidence of myocardial dysfunction diagnosed when any one of the following were observed. (a) Heart failure or cardiomegaly-Clinically or by echo without previous heart disease (b) Required an inotrope (≥ 5µg/kg/min of dobutamine or dopamine)/ hypotension with cold peripheries (cold shock); Grade-4: Hypotension with warm peripheries (warm shock) /Multiorgan dysfunction involving more than two-organ. All children showing envenomation-Grade 2 and above were administered the first dose of three vials (30 mg) of SAV, i.e., a single 30 mL dose of monovalent M. tamulus antivenom (Haffkine Biopharma, Mumbai) in