Intermediate Syndrome After Organophosphate Poisoning: Clinical Course and a Case of Delayed Neuromuscular Dysfunction

Intermediate Syndrome (IMS) is a delayed neuromuscular complication of organophosphate poisoning, typically occurring 24–96 hours post-exposure and often leading to respiratory failure. The author reports a 39-year-old male who ingested 40% chlorpyrifos and developed IMS on day 4 post-ingestion, presenting with proximal muscle weakness, neck flexor involvement, and respiratory compromise. Laboratory tests revealed markedly decreased serum cholinesterase, and electromyography confirmed postsynaptic receptor desensitization with early proximal involvement. Pralidoxime was initially administered but discontinued after 48 hours due to early receptor desensitization. The patient received supportive care, including mechanical ventilation for eight days, physiotherapy, and structured follow-up. He regained independent walking by day 10 and was discharged on day 11. By integrating clinical, laboratory, electrophysiological, and follow-up data, this case highlights IMS progression and recovery, emphasizing the critical role of supportive care in resource-limited settings and providing valuable insights into its management.