Clinical profile of Intermediate Syndrome following Organophosphate Poisoning

Organophosphate (OP) poisoning is a global issue, causing over 200,000 deaths annually especially in developing countries, such as Sri Lanka and India. Clinical presentation of a typical OP poisoning may follow three well-defined phases. The initial phase is an acute cholinergic crisis, after that Intermediate Syndrome (IMS) may develop within 24-96 hours, and lastly, Organophosphate-Induced Delayed Polyneuropathy (OPIDPN) may present after 2-3 weeks. The signs and symptoms of the IMS are weakness of the respiratory muscles, including the diaphragm, intercostal, accessory, neck, and proximal limbs muscles. The aim of this study was to highlight the clinical profile of the IMS following organophosphate poisoning. This descriptive, prospective, and cross-sectional study was conducted at the Teaching Hospital, Batticaloa, Sri Lanka, over a period of 6 months from March 1, 2017 to August 31, 2017. Of the total 65 enrolled patients, 60% (n=39) were male. All patients ingested OP pesticide for deliberate self-harm and all of them had some degrees of initial cholinergic crises. The prevalence of IMS in the studied patients was 5.88%. All 5 patients with IMS had neck, facial and proximal limbs muscle weakness from whom, two cases (40%) had extra-ocular muscle paralysis. There was no in-hospital fatality among IMS patients. IMS is a rare and life-threatening problem in OP intoxication. Early diagnosis and intensive care management can prevent further complications and mortality. Prevalence of IMS in this study was lower than previous reports with almost similar clinical features.