HEMODYNAMIC PATTERNS IN PATIENTS WITH SCORPION ENVENOMATION

Objective-To study cardiovascular haemodynamics following scorpion env enomation. Setting-Intensive care unit of a university hospital. Patie nts-Eight patients with Indian red scorpion (Mesobuthus tamulus) sting s. Intervention-Captopril (6.25 to 12.5 mg orally) every 30 minutes un til pulmonary oedema resolved. Main outcome measures-Haemodynamic data obtained by pulmonary artery catheterisation. Results-Two haemodynami c patterns were seen. There was a predominant vascular effect in one p atient, with severe hypertension, tachycardia, increased systemic vasc ular resistance index (SVRI = 5893 dyn.s.cm(-5)), and normal cardiac i ndex (2.73 l/m(2)). A predominant myocardial effect with left ventricu lar dysfunction and normal right ventricular function was seen in the other seven patients, with tachycardia, pulmonary oedema, mild hypoten sion, reduced stroke volume (mean (SD), 25.9 (8.3) ml/m(2)), normal SV RI (1812 (831) dyn.s.cm(-5)), and increased pulmonary artery wedge pre ssure (PAWP = 25 (4.4) mm Hg). Following mild dehydration pulmonary oe dema subsided (PAWP = 14 (8.5) mm Hg) in three of these patients, but hypovolaemic shock developed (right atrial pressure (RAP)=1.3 (2.1) mm Hg); pulmonary oedema recurred with rehydration. One patient develope d fatal cardiogenic shock with raised PAWP (27 mm Hg) and RAP (11 mm H g), and vasodilatation (SVRI = 1129 dyn.s.cm(-5)). Stroke volume (30.5 (8.7) ml/m(2)) and cardiac output (4.3 (1.5) l/m(2)) improved with re solution of pulmonary oedema (PAWP = 14.4 (4.2) mm Hg) following after load reduction with captopril. Conclusions-Mild envenomation causes se vere vasoconstriction and hypertension. Severe envenomation produces p redominant left ventricular dysfunction with normal systemic vascular resistance manifesting as pulmonary oedema or severe hypotension depen ding on the fluid balance. Shock due to biventricular dysfunction and vasodilatation occurs terminally.