Skin reactions to intradermal neuromuscular blocking agent injections - A randomized multicenter trial in healthy volunteers

Background: Numerous reports confirm the performance Of intradermal tests for the diagnosis of anaphylaxis during anesthesia; however, there is controversy over their diagnostic value regarding the newer neuromuscular blocking agents (NMBAS). Methods: one hundred eleven healthy volunteers were randomly assigned to receive intradermal injections of two NMBAs, at five increasing concentrations. A concentration was considered as a reactive concentration when it led to a positive reaction in more than 5% of the subjects. These concentrations were compared with the maximal concentration recommended for the diagnosis of sensitization to NMBAs. Results: The maximal nonreactive concentrations were 10(-3) M for suxamethonium; 10(-4) M for pancuronium, vecuronium, rocuronium, and cisatracurium; and 10(-5) M for atracurium and mivacurium. Except for mivacurium, these nonreactive concentrations were close to the maximal concentrations used for the diagnosis of sensitization against NMBAs. For mivacurium, the nonreactive concentrations were higher than the maximal concentration currently recommended in clinical practice. Conclusion: The aminosteroidal NMBAs pancuronium, vecuronium, and rocuronium and the benzyhsoquinoline cisatracurium have a similar potency to induce a nonspecific skin reactivity. if the criteria for positivity and the maximal concentrations of the commercially available compounds recommended by French practice guidelines are used, the risk of false-positive results is limited, and only minor modifications of these recommendations could be suggested. A slight reduction in the maximal concentration used for rocuronium from 1:100 to 1:200 and an increase from 1:1,000 to 1:200 for mivacurium can be proposed.