Myocardial injury induced by scorpion sting envenoming and evidence of oxidative stress in Egyptian children

In the present study, 45 children in Upper Egypt (less than 16 years old) were admitted to the Pediatric Intensive Care Unit for scorpion envenomation (SE). They were compared with 30 apparently healthy children of matching age and sex as controls. Out of the studied victims, 35 children (78%) showed signs of severe envenomation, while 10 victims (22%) showed signs of mild envenomation. The case fatality was 33%. The serum levels of cardiac markers, cardiac troponin T (cTnT) and I (cTnI), as well as the enzymatic activities of creatine kinase-MB (CPK-MB) and lactate dehydrogenase (LDH) were determined for both victims and controls. In addition, the serum levels of oxidative stress markers, nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH) and zinc (Zn) were measured. Electrocardiography and echocardiography were done. All the envenomed victims showed significantly higher mean values of cTnT, cTnI, CPK-MB and LDH than control group. These cardiac markers were elevated in severe cases and in non survivors in comparison with mild cases and survivors respectively. Furthermore, the serum levels of NO and MDA were significantly higher while the serum levels of SOD, GSH and Zn were significantly lower in all envenomed victims than the controls (p < 0.05 for all). There were no significant differences in the serum levels of oxidative stress markers among severe and mild cases or between survivors and non survivors victims. There were no significant correlations between the serum levels of cardiac markers and the oxidative stress markers in envenomed victims. In conclusions, oxidative stress occurs in scorpion envenomed children, but does not determine prognosis. Cardiac markers, but not the oxidative stress, remain the most important determining factor for the severity and the outcome of SE.