Rationale:

• Most individuals exposed to a nerve agent will have a combination of nicotinic and muscarinic signs after a sufficient dose or signs of complicating hypoxia.
• Patients exposed to organophosphates have developed an intermediate syndrome 2 to 3 days after cholinergic findings subside, resulting in neuromuscular weakness sometimes requiring respiratory support; this can occur, theoretically, after nerve agent exposure.

Evidence:

• In a case series reporting the numbers of patients affected by sarin exposure during the 1995 Tokyo subway incident, 984 were moderately affected, 37 severely affected, and there were 8 initial fatalities that increased to 12 (23).
• Case series describe the presenting symptoms and treatment of patients affected during the 1995 Tokyo subway sarin incident (24; 25; 26; 27).
• An observational trial studied 25 patients exposed to organophosphates and the development of intermediate syndrome (28).
• A review article details the effects of intermediate syndrome (29).

Comments:

• None.