부산대학교 도서관

Organophosphate compound (OPC) poisoning with suicidal intent is common in Indian ICUs. The effect of OPCs is to produce a persistent depolarization of the neuromuscular junction leading to muscle weakness. After initial recovery from cholinergic crisis, some patients have resurgence of respiratory muscle paralysis requiring continued ventilatory support. This is termed intermediate syndrome (IMS). This could be due to a change in the type of neuromuscular block to a non depolarisation block characterized by a fade on tetanic stimulation. However peripheral nerve stimulation using train-of-four ratio (TOF) and/tetanus have failed to consistently show such a change. We elected to study whether electro physiological monitoring using repetitive nerve stimulation might show a decremental response during IMS. 9 out of 45 patients required ventilation for more than 6 days and showed overt signs of intermediate syndrome - proximal muscle weakness, twitching and respiratory weakness. Only 2 patients out of the 9 had a decremental response on RNS at 3Hz indicating a post-junctional dysfunction at the motor endplate, Both patients had consumed a very large quantity of OPC and were deeply comatose for >4 days and required ventilation for >12 days. All other patients with IMS showed no changes on RNS. The exact type of poison consumed varied with each individual patient. RNS is a poorly sensitive marker in diagnosing intermediate syndrome after OPC poisoning. We need to develop more sensitive markers to diagnose IMS [ABSTRACT FROM AUTHOR]