Background and Aim: Organophosphates irreversibly inhibit the enzyme acetyl cholinesterase, leading to accumulation of acetylcholine at synapses and myoneural junctions. Present study was done with an aim to assess the severity of organophosphorus compound poisoning both clinically by using Peradeniya scoring, estimating seum cholinesterase levels and to correlate serum cholinesterase levels and Peradeniya OP poisoning scale to predict the need for ventilatory support.

Material and Methods: Present study was a prospective descriptive and intention to treat study conducted at Gujarat Adani Institute of Medical science, Bhuj, Kutch for the period of one year. There were 150 patients of OP compound poisoning admitted to the Department of Medicine during the study period from which 59 fulfilled the inclusion criteria. All patients who presented to emergency department with history of organophosphorus compound poisoning were taken as study subjects. In all study subjects, 3 ml of plain blood was collected on admission before administration of atropine and serum cholinesterase was estimated. Patients were classified as mild (20-50%), moderate (10- 20%) and severe (10%) poisoning based on PChe levels.

Results: Most of patients with moderate (41%) and severe poisoning (100%) according to POP scale expired. (p≤0.05) 84.9% of patients with PChe levels <50% required ventilatory support. Our study showed a highly significant correlation between PChe levels and the need for ventilatory support. Patients with PChe levels <50% had more mortality compared to patients with PChe levels >50%. (p≤0.05). 

Conclusion: pseudo cholinesterase levels were significantly depressed in patients who required ventilatory support and correlated with mortality. POP score of more than 5 correlated in predicting the need for ventilatory support and mortality.