Title: A study of Peradeniya organophosphorus poisoining scale (POP scale) in predicting the mortality in cases of acute organophosphorus poisoining
Authors: Dr Sourav Chattopadhyay, Dr Srikanth Shetty
DOI: https://dx.doi.org/10.18535/jmscr/v6i12.144
Abstract
Background & Objectives: India is a tropical country where agriculture forms the backbone of the nation. Majority of the population is engaged in agriculture and the most hazardous materials that the farmers are exposed to are the organophosphorus compounds which are used as pesticides. In addition to the accidental intoxication from use of these compounds as agricultural insecticides, these agents are frequently used for suicidal purposes because of their easy availability.
This study was done to assess the severity of symptoms of organophosphorus compound poisoning both clinically, by Peradeniya organophosphorus poisoning scoring system and by pseudocholine esterase estimations. Peradeniya scoring system could be a simple and effective system to determine the cases which would require ventilator support, early on in the course. This study will help us identify the factors, which help in the need for ventilator support in a patient with consumption of organophosphorus compound.
Methods: This randomized cross sectional study was carried out in Sri Adichunchanagiri institute of medical science and research centre, B.G.Nagara,Mandya district on 100 patients admitted in intensive care unit of the hospital.
Pseudocholine esterase estimations were done at presentation. Subsequent pseudocholine esterase estimations was done at 24 hours, 48 hours and 120 hours after time of poisoning.
Diagnosis was made on clinical history, physical examination & investigations, which include pseudocholine esterase levels.
Results: 92% of the cases were suicidal and 8% were accidental. The mortality was 4% in this study. Out of the 100 cases 68 were males and 32 were females. The male and female ratio was 2.125: 1. The maximum number of cases was seen in the age group of 18 to 30 years. Maximum number of cases were from agricultural background. In this study 52% of the cases consumed dimethoate. PChE activity in 10 control patients had values in range of 3714 – 11513 u/l, which is within the normal reference values. 79% of cases in the present study had PChE levels of less than 50% of the normal at the time of admission and out of which 94.8% required ventilatory support.
Pseudocholine esterase levels were significantly depressed in patients who required ventilatory support. Patients who survived showed rising values of mean pseudocholine esterase enzyme activity on successive days, while patients who expired had low pseudocholine esterase activity and did not show much increase in subsequent days.
This points out that better prognosis is directly proportional to higher rise in enzyme activity. Increased interval between consumption and hospitalization correlated with need for ventilatory support. Peradeniya scores of ≥6 correlated with an increased requirement of ventilatory support.
Interpretation & Conclusion: Pseudocholine esterase levels were significantly depressed in patients who required ventilatory support. Patients who survived showed rising values of mean pseudocholine esterase enzyme activity on successive days,while patients who expired had low pseudocholine esterase activity and did not show much increase in subsequent days. This points out that better prognosis is directly proportional to higher rise in enzyme activity.Signs of miosis, fasciculations, bradycardia, increased respiratory rate with cyanosis and impaired levels of consciousness all correlated with the need for ventilator support. Increased interval between consumption and hospitalization correlated with need for ventilatory support. Peradeniya scores of ≥6 correlated with an increased requirement of ventilatory support.
Keywords: Organophosphorus compound; Pseudocholine esterase.
