PROGNOSTIC VALUE OF SERUM-CHOLINESTERASE IN ORGANOPHOSPHATE POISONING

Objective: To determine whether serum cholinesterase level has a progn ostic value in human acute organophosphorus poisoning. Design: Cohort (prospective) prognosis study. Setting: Medical ICU at University Hosp ital. Patients: Thirty consecutive patients admitted to the ICU for ac ute organophosphate poisoning. Measurements: Serum cholinesterase leve l was measured in all patients at the time of hospital admission. Seve rity of intoxication was assessed by the total dose of atropine requir ed to relieve poisoning manifestations, the Simplified Acute Physiolog y Score, the need for assisted ventilation, and by a specific grading system previously validated that identified two groups of patients: gr oup 1 (low severity, n=18) and group 2 (high severity, n=12). Results: Serum cholinesterase level did not correlate with the total dose of a tropine or with the Simplified Acute Physiology Score. Mean serum chol inesterase level was not significantly different between group 1 and g roup 2 patients (448+/-409 U/L in group 1 compared with 611+/-575 U/L in group 2 (p=NS); it was also not significantly different between pat ients with and without mechanical ventilation support (567+/-571 vs 41 0+/-409, respectively). Conclusion: Serum cholinesterase levels have n o prognostic value in acute organophosphate poisoning. Thus, a grading system to identify high-risk patients based on this measurement is mo st likely unreliable.