A Study of Clinical, Biochemical and Electrocardiographic aspects of Yellow Oleander Poisoning

Yellow oleander poisoning is a common method of suicide in South India and Srilanka with thousands of cases occurring in Srilanka each year at present. This study was undertaken to find out the incidence of yellow oleander poisoning in our hospital, to study the clinical aspects, to find out correlation between clinical and biochemical parameters with electrocardiographic changes and to find out possible risk factors for cardiotoxicity and outcome. After institutional ethical clearance, with an informed consent and with inclusion and exclusion criteria 106 cases of yellow oleander poisoning were included in the study and were evaluated on clinical, biochemical and electrocardiographic aspects. The data were entered in Microsoft Excel spread sheet and analysed statistically in SPSS software The incidence of yellow oleander poisoning in general medicine wards of our hospital was 11.8 per 1000 admissions. 53.8% of the cases were females. The mean age of poisoning was 27+ 10 years. The intention was suicidal in majority. The most common symptoms were vomiting, numbness of tongue and lips, giddiness and diarrhea. The most common abnormal ECG findings were sinus bradycardia, ST – T changes similar to that described for digoxin effect / toxicity, sino-atrial block, first – degree AV block and third – degree AV block. Depending on the ECG changes, patients were decided into no, some and severe cardiotoxicity groups and relationship between various factors and cardiotoxicity analysed. The mean number of seeds / fruits ingested in patients who had cardiotoxicity was higher than in patients who had no cardiotoxicity. Majority had taken the poison crushed and in empty stomach which resulted in greater cardiotoxicity. Delay in inducing emesis or giving gastric lavage was associated with greater cardiotoxicity. The occurrence of cardiotoxicity was higher in patients who had vomiting, diarrhea or altered mental status. The mean serum potassium values at presentation were higher in patients who had cardiotoxicity. Hyperkalemia was noted in only two cases. The mean duration of hospital stay was 5 + 1.5 days and was higher in patients who had cardiotoxicity. The case fatality rate was 1.88%. Yellow oleander poisoning was found to be a common method of suicide among young adults and adolescents in this part of the country and was slightly more common in females. It accounted for 13.1% of cases among the total number of poisoning cases during the study period. Most of the patients were from rural areas belonging to upper lower and lower socio – economic class. The most common symptoms were vomiting, numbness of tongue and lips, giddiness sand diarrhea. The most common electrocardiographic abnormalities were sinus bradycardia, ST – T changes similar to digoxin effect ./ toxicity, first-degree AV block, third-degree AV block and sino-atrial block. Hyperkalemia was found to be uncommon when compared to previous Srilankan studies. The occurrence of cardiotoxicity was greater in patients who had taken the poison crushed and in empty stomach, who had taken more quantity of poison, in whom there was a delay in inducing emesis or giving gastric lavage, who had vomiting, diarrhea or altered mental status and who had higher serum potassium levels at admission. The more severe the cardiotoxicity more was the duration of hospital stay. The case fatality rate was low when compared to previous studies. Although this study could identify the risk factors for cardiotoxicity, the risk factors associated with poor outcome could not be well established as the deaths were very few. Hence further studies are required to identify risk factors associated with poor outcome in this poisoning. Further studies are also required to assess the role of glucocorticoids in improving outcome. The benefit reported with multiple doses of activated charcoal and anti-digoxin Fab fragments also need to be confirmed by further studies