Dobutamine in the treatment of severe scorpion envenoming

Scorpion envenoming is a frequent and deadly event in Tunisia. It is caused mainly by Androctonus australis and Buthus occitanus. Pulmonary edema and shock following scorpion envenoming are related to adrenergic cardiomyopathy, and are the main symptoms leading to death. Our aim was to search for the effect of dobutamine on "scorpion myocardiopathy" and to define the optimal dose of dobutamine to start with. This study was conducted in the medical surgical ICU of Habib Bourguiba University Hospital in Sfax - Tunisia. We included 21 patients with pulmonary edema or hemodynamic shock following scorpion envenoming. All patients were monitored using Swan-Ganz catheter. After a first check of the hemodynamic parameters (baseline), all patients received dobutamine infusion at 5, 10, and 15 μg/kg/min. The median age of patients was 19 years (IQR: 14-26) and 12 patients (57.1%) were males. On ICU admission, 11 patients (52.4%) had shock, all patients (100%) had pulmonary edema, 20 patients (95.2%) had neurologic manifestations, and 16 patients (76.2%) had gastro-intestinal manifestations. During ICU stay, 18 patients (85.7%) received mechanical ventilation (MV). The median duration of MV was 3 days (IQR: 2-4). The median duration of dobutamine administration was 4 days (IQR: 3-5). Cardiac index at baseline was 2.7 L/min/m2 (IQR: 2.3-3.2). Under dobutamine at 5, 10 and 15 μg/kg/min, it was 3.6 (IQR: 3.2-3.9), 4.0 (IQR: 2.9-4.8), and 4.1 (IQR: 3.6-4.9) respectively. Arterio-venous oxygen difference at baseline was 6.0 ml/dl (IQR: 5.0-7.0). Under dobutamine at 5, 10 and 15 μg/kg/min, it was 6.1 (IQR: 4.7-6.4), 3.9 (IQR: 3.4-4.3), and 3.9 (IQR: 3.1-4.7) respectively. The length of stay in ICU was 4 days (IQR: 4-5) and 2 patients died during ICU stay (9.5%). Our study confirms that cardiac dysfunction following scorpion envenomation in Tunisia improved well and safely under dobutamine infusion. The optimal dose of dobutamine to start with was between 5 and 10 μg/kg/min.