EXPERIENCE WITH HEMOPERFUSION FOR ORGANOPHOSPHATE POISONING

Objective: To evaluate the usefulness of extracorporeal clearance techniques in the treatment of organophosphate poisoning, particularly hemoperfusion. Design: Retrospective study. Setting. An ICU of a general hospital. Patients: Ten patients with organophosphate poisoning initially received classic treatment with gastric lavage and washing of the whole skin surface, as well as the administration of cathartics, activated charcoal, atropine, and obidoxime or pralidoxime. All patients underwent one to three hemoperfusions. Measurements and Main Results: Plasma insecticide concentrations and cholinesterase activity were determined daily. Two to three biopsies of fat tissue were carried out at 1- to 2-wk intervals. The amount of the insecticide removed during hemoperfusions was also determined. Five patients presented with a prolonged nicotinic syndrome. Two of these patients showed sequelae of delayed neurotoxicity. Another two of the five patients died and the remaining patient recovered without sequelae. In none of the patients could >0.1% of the total absorbed poison be removed by hemoperfusion. No changes in symptoms were observed after these procedures. Fat tissue concentrations of the insecticide were 20 to 50 times higher than the concentrations in plasma. Atropine decreased the intestinal transit time, and 10 days after poisoning, a powerful cathartic treatment indicated the persistence of gut content, which probably caused prolonged absorption of the toxin. Conclusions: Extracorporeal cleansing mechanisms did not remove any clinically important amount of insecticide from our patients due to the high lipid solubility of these agents and no changes in symptoms were observed after these methods. The use of atropine decreases bowel peristalsis. Early use of powerful cathartics could avoid protracted absorption of the poison stored in the gut, although the potential benefits of this therapy require confirmation by the performance of prospective, controlled investigations.