Correlation between Timing of ASV Administration and Complications in Snake Bites: An Analytical study

INTRODUCTION: Snake bites contribute to health problem in India and continue to be a major medical concern. India alone contributes to 81,000 envenomations and 11,000 deaths annually. It appears that every 10 seconds one individual is envenomed and one among four dies due to snake bite. Snake bite is an occupational disease of farmers (rice), plantation workers (rubber, coffee), herdsmen, hunters, snake handlers, fishermen and fish farmers. In Tamil Nadu the total number of snake bite cases admitted (and expired) in the secondary care hospitals alone during 2005 - 2006 and 2006 -2007 were 19321(85) and 20677(75) respectively. The total number of ASV vials used in these hospitals during the respective periods was 94481 and 96800. Over all analysis revealed that the snakebites and ASV usage in West, North, East, Central, South zone of Tamil Nadu were 13, 17, 20, 24 and 26% respectively. Snakebites are observed all over the country with a rural / urban ratio of 9:1. They are more common during monsoon and post monsoon seasons. Snakebites are seen often among agricultural workers and among those going to the forest. The male / female ratio among the victims is approximately 3:2. Majority are young and their age is between 25 to 44 years. Most of the bites (90 to 95%) are noticed on the extremities (limbs). AIMS AND OBJECTIVES: The present study was undertaken to study the relationship between the time of anti-snake venom (ASV) administration due to late arrival of patient at hospital and subsequent development of complications. MATERIAL AND METHODS: Study design: Analytical study. Place: Department of Medicine, Govt. Rajaji Hospital, Madurai. Period: 6 months (July- December 2008). Collaborating departments: Department of Biochemistry, Madurai Medical College, Madurai. and Department of Nephrology, Madurai Medical College, Madurai. Sample size: 164. Selection of the study subjects: 164 patients admitted with snake bite in the medical wards, Govt. Rajaji Hospital from July to December 2008 formed the study group. Inclusion criteria: 1. Local signs of envenomation: • Swelling and local pain with or without erythema. • Tender enlargement of local lymph nodes. • Local inflammation. • Local necrosis and / or blistering / bullae. 2. Haematological signs of envenomation • Haemostatic abnormalities: spontaneous systemic bleeding, coagulopathy (20WBCT) or thrombocytopenia. • Cardiovascular abnormalities: hypotension, shock, cardiac arrhythmia and abnormal ECG. • Acute renal failure: oliguria/anuria and rising blood creatinine and Urea. • Haemoglobinuria/myoglobinuria: dark brown urine, urine dipsticks, other evidence of intravascular haemolysis or generalised rhabdomyolysis. 3. Neurological signs of envenomation • Ptosis, diplopia, dysphagia and dysphonia. • Muscle paralysis/weakness. • Respiratory distress. • Confusion. Exclusion criteria: 1. Persons who did not show any signs of envenomation. 2. Patients who had received ASV prior to presenting to our institution. RESULTS: 164 patients were studied. The following results were obtained. In our study, among the total 164 patients 15.2% of patients (25) were below 20 years of age, 23.8% of patients (39) belonged to 21-30 years of age, 23.8% of patients (39) belonged to 31-40 years of age, 20.7% of patients (34) belonged to 41-50 years of age and 16.5% of patients (27) were in the age group of above 50 years. Most of the patients were in the age group of 21-50 years. The total 164 patients 63.4% of patients (104) were males and 36.6% of the patients (60) were females. Males were more commonly bitten by snakes. Among the 164 patients of our study, as in the table-5.3, 75.6% of the snake bites (124) occurred in their working fields and 24.4% of the snake bites (40) occurred in their houses. More number of snake bites occurred in the fields. CONCLUSION: The incidence of complications is directly proportional to the duration of venom in the blood prior to neutralization by ASV due to late arrival of patient at hospital. The early institution of ASV is beneficial in preventing complications however severe is the systemic envenomation