Objective To assess the efficacy and safety of low dose adrenaline injected subcutaneously to prevent acute adverse reactions to polyspecific antivenom serum in patients admitted to hospital after snake bite. Design Prospective, double blind, randomised, placebo controlled trial. Setting District general hospital in Sri Lanka. Subjects 105 patients with signs of envenomation after snake bite, randomised to receive either adrenaline (cases) or placebo (controls) immediately before infusion of antivenom serum. Interventions Adrenaline 0.25 ml (1:1000). Main outcome measures Development of acute adverse reactions to serum and side effects attributable to adrenaline. Results 56 patients (cases) received adrenaline and 49 (controls) received placebo as pretreatment. Six (11%) adrenaline patients and 21 (43%) control patients developed acute adverse reactions to antivenom serum (P = 0.0002). Significant reductions in acute adverse reactions to serum were also seen in the adrenaline patients for each category of mild, moderate, and severe reactions. There were no significant adverse effects attributable to adrenaline. Conclusions Use of 0.25 ml of 1:1000 adrenaline given subcutaneously immediately before administration of antivenom serum to patients with envenomation after snake bite reduces the incidence of acute adverse reactions to serum.

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Cardiac toxicity after self-poisoning from ingestion of yellow oleander seeds is common in Sri Lanka. We studied all patients with yellow oleander poisoning (YOP) admitted to a secondary care hospital in north central Sri Lanka from May to August 1999, with the objective of determining the outcome of management using currently available treatment. Patients with bradyarrhythmias were treated with intravenous boluses of atropine and intravenous infusions of isoprenaline. Temporary cardiac pacing was done for those not responding to drug therapy. During the study period 168 patients with YOP were admitted to the hospital (male:female=55:113). There were six deaths (2.4%), four had third-degree heart block and two died of undetermined causes. They died soon after delayed admission to the hospital before any definitive treatment could be instituted. Of the remaining 162 patients, 90 (55.6%) patients required treatment, and 80 were treated with only atropine and/or isoprenaline while 10 required cardiac pacing in addition. Twenty-five (14.8%) patients had arrhythmias that were considered life threatening (second-degree heart block type II, third-degree heart block and nodal bradycardia). All patients who were treated made a complete recovery. Only a small proportion of patients (17%) admitted with YOP developed life-threatening cardiac arrhythmias. Treatment with atropine and isoprenaline was safe and adequate in most cases.

The outcome of snakebite is related to the biting species but it is often difficult to identify the biting snake, particularly in community settings. We have developed a clinical scoring system suitable for use in epidemiological surveys, with the main aim of identifying the presumed biting species in those with systemic envenoming who require treatment. The score took into account ten features relating to bites of the five medically important snakes in Sri Lanka, and an algorithm was developed applying different weightings for each feature for different species. A systematically developed artificial data set was used to fine tune the score and to develop criteria for definitive identification. The score was prospectively validated using 134 species-confirmed snakebites. It correctly differentiated the bites caused by the three snakes that commonly cause major clinical problems (Russell's viper (RV), kraits and cobra) from other snakes (hump-nosed viper (HNV) and saw-scaled viper (SSV)) with 80% sensitivity and 100% specificity. For individual species, sensitivity and specificity were, respectively: cobra 76%, 99%; kraits 85%, 99%; and RV 70%, 99%. As anticipated, the score was insensitive in the identification of bites due to HNV and SSV.