Haemolytic-Uraemic Syndrome Complicating Snake Bite

Anand Date, MD, Professor of Pathology, Christian Medical College Hospital, Vellore 632004, Tamil Nadu (India) Dear Sir, The triad of acute renal failure (ARF), thrombocyto-penia and haemolytic anaemia with fragmented erythrocytes (schistocytes) comprise the haemolytic-uraemic syndrome (HUS) [1]. In addition to its primary idiopathic childhood form, this syndrome can occur secondarily with viral and bacterial infections, oral contraceptive use and in pregnancy and in the puerperium [2]. Its occurrence after snake bite is not well known. During the period 1975–1983, 12 female and 12 male patients, with a mean age of 36 years (SD 14 years), were treated for ARF following snake bite at the Christian Medical College Hospital at Vellore in southern India. They had been referred for treatment from peripheral clinics 2–21 days after the onset of oliguria. Initially the patients had severe pain and swelling at the site of the bite and bleeding manifestations, most commonly haematu-ria with prolonged bleeding and clotting times. Oliguria or anuria developed within 24 h of the bite, and lasted for 4–47 days. The snake was identified by description as Vipera russelli in 7 cases. In the remainder, identification could not be made, although the symptomatology suggested that the Russell’s viper was involved in all cases and this is the only snake in this region whose bite is reported to cause ARF [3]. Results of laboratory investigations were as follows: Blood urea, mean 46.5, SD 25 mmol/l; plasma creati-nine, mean 967, SD 417 μmol/l; platelet count, mean 104, SD 92 × 10V1; packed cell volume, mean 0.27, SD 0.11; reticulocyte count, mean 5, SD 3%; total leukocyte count, mean 13.3, SD 4× 10V1; differential neutrophil count, mean 80, SD 8%. Schistocytes were present in the peripheral blood smears of 22 patients. Sixteen patients had HUS with anaemia, schistocytosis and thrombocyto-penia. Six patients had normal platelet counts when first examined 7 days or more after the bite, and there was no record of schistocytes in the peripheral blood smear in 2 cases. Absence of the complete triad could, in most cases, be attributed to incomplete or delayed investigation. Percutaneous renal biopsies performed in 15 patients showed cortical necrosis in 3 cases and acute tubular necrosis in the rest. Fibrin and platelet clusters were demonstrable in glomeruli and small calibre blood vessels in 5 of the 7 biopsies examined electron microscopically [4, 5]. Two patients were treated conservatively, 2 with hae-modialysis and the rest by peritoneal dialysis. One patient died of massive haematemesis soon after admission to hospital. Patients with cortical necrosis developed chronic renal failure, the others made a complete recovery.