Clinical Significance of Immediate Determination of Plasma Cholinesterase Level in Patients Presenting with Organophosphate Ingestion at the Time of Hospitalization

ABSTRACT

PURPOSE: Plasma cholinesterase is a sensitive measure determining the severity of organophosphate intoxication. The author evaluated the usefulness of the plasma cholinesterase level as a prognostic indicator of the severity of organophosphate intoxication. METHODS: From June 1999 to May 2001, 55 patients presented with organophosphate insecticide intoxication to the Emergency Medical Center of the Chonnam National University Hospital, and these were enrolled in this study. The plasma cholinesterase activities of these 55 patients were determined at the time of presentation. The relationships between the plasma cholinesterase level and the clinical variables of organophosphate toxicity, quantity of ingested poison, elapsed time to gastric lavage, and the APACHE score at the time of hospitalization were analyzed. RESULTS: The plasma cholinesterase activity significantly decreased in association with the degree of toxicity of the poison (p<0.001), elapsed time to gastric lavage (p<0.001), and the quantity of organophosphate ingested (p=0.013). In the 55 patients, lower plasma values of cholinesterase were observed in patients with longer durations of mechanical ventilation (r=-0.717, p<0.001) and in patients who developed pneumonia during treatment (r=-0.538, p<0.001). Also, decreased cholinesterase activity correlated with a higher APACHE score (r=-0.672, p<0.001). CONCLUSION: These results suggest that immediate determination of the plasma cholinesterase level at the time of hospitalization may be useful as a prognostic indicator in patients with organophosphate intoxication.