Anaphylaxis during induction of general anesthesia: subsequent evaluation and management.

Twenty-seven patients were referred for evaluation of anaphylaxis after induction of general anesthesia (GA) in which thiobarbiturates, muscle relaxants, or antibiotics were administered intravenously. Skin testing by the prick and intracutaneous methods was performed with dilutions of the thiobarbiturates and muscle relaxants; beta-lactam reagents were used in patients who had also received these drugs. No skin test reactivity was noted in 16 normal subjects. Skin tests were positive in 13 patients (thiobarbiturates in five, muscle relaxants in six, and antibiotics in two patients). Two patients were dermatographic and yielded indeterminate skin test results. Eleven of the 27 patients subsequently had GA; all patients received a premedication regimen of prednisone and diphenhydramine. Of three patients with negative skin tests, one experienced an arrhythmia, but no other signs attributable to anaphylaxis were noted. One patient with dermatographism had GA without a reaction. Positive skin tests implicated an agent that was avoided in seven patients; one of these patients experienced delayed urticaria/angioedema after the completion of GA. Thus, no patients developed anaphylaxis during subsequent GA for which agents producing positive skin tests were avoided, and a premedication regimen was used.