Early diagnosis of anaphylactic reactions to neuromuscular blocking drugs

Neuromuscular blocking drugs (NMB) are involved in most of the anaphylactic reactions occurring during anaesthesia. Patients are evaluated usually 6 weeks after the reaction, by skin testing. In order to obtain an earlier diagnosis, we have measured plasma concentrations of histamine, tryptase and NMB-specific IgE antibodies in 14 patients after an anaphylactoid reaction. We have compared the results with those of skin tests and specific IgE obtained 8 weeks later. Good agreement was observed in all subjects between the results of skin tests and the values for histamine and tryptase, provided that both markers were measured simultaneously. Furthermore, there was no significant difference between the concentrations of NMB-specific IgE antibodies observed at the time of the reaction and 8 weeks later. Thus anaphylaxis to neuromuscular blocking drugs can be demonstrated at the time of the reaction by measuring plasma concentrations of histamine, tryptase and specific IgE. In the event of the patient's death, such measurements may be useful in identifying the likely cause.