Sympathetic nervous system activation, antivenin administration and cardiovascular manifestations of scorpion envenomation.

We performed two-dimensional echocardiograms and determined plasma norepinephrine levels on admission and at 24h after hospitalization, in 16 children with scorpion envenomation. All patients came from areas where scorpions have been identified as Tityus zulianus and received antivenin at the site of the accident or upon admission. Based on the presence or absence of cardiovascular manifestations, patients were divided into two groups. GROUP A: 10 patients had cardiovascular manifestations of pulmonary edema. Four patients had mild pulmonary edema (Left ventricular ejection fraction: 0.43+/-0.19) and six had moderate to severe pulmonary edema (Ejection fraction: 0.31+/-0.09. p=NS, M+/-SD). Plasma norepinephrine was elevated on admission (1279+/-824) and decreased at 24h in seven of eight patients (474+/-140 pg/ml, p<0.03). GROUP B: Six patients had no cardiovascular manifestations. These patients had normal chest X-rays and normal echocardiograms. Plasma norepinephrine was not elevated (188+/-180 pg/ml). Time interval from the accident to antivenin administration was significantly longer in Group A compared to Group B (4.5+/-3.3 vs 1.2+/-0.4h, p<0.03) and correlated directly with the absolute change in plasma norepinephrine (r=0.76, p<001). Consequently, we strongly recommend very early administration of antivenin in the medical management of scorpion envenomation by T. zulianus.