[Anaphylactoid reaction to vecuronium].

A 4 year-old male (weight 18 kg, height 100 cm) required an emergency operation for the open fracture of his left ankle. He had no history of atopy or allergics. Rapid intubation with vecuronium was planned. To shorten the onset time of vecuronium, the "priming principle" was utilized. Two minutes after the intravenous administration of vecuronium 0.25 mg as a "first dose", bronchospasm and skin rashes appeared. These symptoms resolved following the treatment with aminophylline and steroids. Immunological studies performed two weeks after the operation revealed positive intradermal test to vecuronium, low plasma IgE and elevated complement C3. These results suggest that the reaction was an anaphylactoid reaction caused by physico-chemical histamine release rather than IgE mediated type I allergic reaction. Though vecuronium have a low potential for histamine release, it is important to note that adverse reactions can occur even in patients who have no history of atopy or allergic disorders.