Hypertension, Autonomic Storm, Increased Counter Regulatory Hormones and Suppressed Insulin in Acute Myocarditis in Scorpion Envenoming Syndrome

Abstract

Death due to scorpion envenoming syndrome is a common event in many of the tropical and non-tropical counties. Initial transient hypertension is commonly observed in scorpion sting victims. Scorpion envenoming causes autonomic storm resulting in initial transient hypertension followed by hypotension, cold clammy skin, hypothermia, cardiovascular disturbances, acute myocarditis, sarcolemmal defects, pulmonary oedema, acute pancreatitis, disseminated intravascular coagulation (DIC), Adult respiratory distress syndrome (ARDS), and many other clinical manifestations. All these manifestations could be due to sudden increase in catecholamines, angiotensin II, glucagon, Cortisol and either due to suppressed insulin secretion or insulin resistance and death. The sudden increase of metabolic A in counter-regulatory hormones along with either suppressed insulin secretion/or insulin resistance results in glycogenolysis in liver, cardiac and skeletal muscles causing hyperglycemia and a sudden increase in free fatty acid levels. Free Fatty Acids increase the susceptibility of the ventricles to the disorganized electrical behavior, inhibit cardiac sarcolemmal Na+-K+ ATPase activity, increase the tendency to intravascular thrombus, increase myocardial oxygen consumption, interfere with tropomyosin-troponin activation of Actin-Myosin coupling, show detergent effects on cell membranes and they could alter the stabilization of lysosomal membranes and probably become toxic to the myocardium. Based on our animal experiments in which insulin administration reversed the metabolic and ECG changes induced by scorpion envenoming and treating the poisonous scorpion sting victims with insulin, we consider that insulin has a primary metabolic role in preventing, counter-acting and reversing all the deleterious effects of FFA by inhibiting the catecholamine induced by lipolysis, and increasing intra-cellular K+, facilitating glucose transport to the myocardium and glucose metabolism through different pathways. Administration of insulin-glucose infusion to scorpion sting victims appears to be the physiological basis for the control of the metabolic response when that has become a determinant to survival. Treatment using continuous infusion of regular crystalline insulin should be given at the rate of 0.3 U/g glucose and glucose at the rate of 0.1 g/kg body weight/hour, for 48 - 72 hours, with supplementation of potassium as needed and maintenance of fluid, electrolytes and acid-base balance.