Continuous renal replacement therapy increased plasma cholinesterase activity in a case of acute organophosphate poisoning

Extracorporeal removal of organophosphate from blood has been proposed, but the efficacy of hemodialysis and hemoperfusion has not been established. We report a case of organophosphate poisoning in which continuous renal replacement therapy (CRRT) was applied with conventional indications and was found to increase plasma cholinesterase levels by hemodiafiltration. A 73-year-old male was found unconscious at home and was brought to the emergency department by ambulance. An empty bottle of Supracide insecticide, of which the active ingredient is methidathion, was found beside him. CRRT was initiated because he showed signs of oliguria and acidosis with an unstable hemodynamic condition. Although his condition improved temporarily after CRRT initiation, it subsequently deteriorated, and he died despite maximal supportive effort. His prefilter plasma cholinesterase levels remained at <200 U/L for 3 days, while his postfilter levels were 358 U/L 1 hour after CRRT initiation and they were 689 U/L 18 hours later. Our case suggests that CRRT might play a role in treating organophosphate poisoning by possibly eliminating organophosphate.