Extracorporeal membrane oxygenation in carbamate (methomyl) intoxication: systematic review of the literature and case presentation

Background and Objective: Since methomyl shows a highly significant toxicity, the clinical outcome of acute methomyl pesticide intoxication is extremely critical. Methomyl is a kind of carbamate poisons. Similar to intoxications with other carbamate insecticides, methomyl intoxication inhibits the activity of acetylcholinesterase, which is contained within synaptic junctions between neurons. Most of the methomyl intoxication cases present with symptoms of cholinergic excess, which provokes respiratory failure, cardiovascular failure, and/or cardiorespiratory failure. Methomyl poisoning in humans has not yet been fully evaluated and most studies have reported sporadic cases or series of intoxication. Methomyl poisoning remains a continuing challenge, because this difficult-to-treat clinical condition is frequently associated with significantly high mortality and morbidity. We evaluated the usefulness of extracorporeal membrane oxygenation in the treatment of methomyl intoxication. Methods: A systematic literature review was conducted using the PRISMA guidelines without language restriction. We searched for scientific publications via PubMed, Embase, Cochrane central register of controlled trial, Google Scholar, the KoreaMed, and the Research Information Sharing Service database. The goal of this study was to report on incidence, associated complications, and morbidity/mortality of methomyl poisoning, and to draw special attention to its management with extracorporeal membrane oxygenation. Results: Only 1 case of a child treated with extracorporeal membrane oxygenation for carbamate or organophosphate intoxication was identified in the literature. After carbamate or organophosphate intoxication, the patient suffered from severe complications including neurological deficits, renal insufficiency, and severe respiratory failure. This child was treated with continuous hemofiltration and extracorporeal membrane oxygenation, but expired after 38 days of extracorporeal membrane oxygenation. In case of our patient, he recovered from the methomyl intoxication after 7 days of VA-ECMO. Conclusions: With only a few exceptions, acute methomyl poisoning is potentially life-threatening and has high incidences of morbidity and mortality. Therefore, physicians should keep in mind the possibility of extracorporeal membrane oxygenation for the quick support of intoxication. Extracorporeal membrane oxygenation support might be an alternative to overcome the cholinergic excess, such as respiratory failure, cardiovascular failure, and/or cardiorespiratory failure, especially in the case of severe acute methomyl intoxication.