The preoperative detection of risk of anaphylaxis during anaesthesia.

In 144 patients who were referred to an anaesthetic allergy clinic because of perceived risk of anaphylaxis during anaesthesia, the only 'at risk' group that could be identified was patients with a history of unexplained severe adverse reaction during previous anaesthesia. Twenty-two of 45 patients with such a history had positive skin tests to an anaesthetic drug. Twenty-one positive tests were to neuromuscular blocking drugs and one to an opiate. In 18 of these patients the medical records were available and an adverse event had been recorded consistent with anaphylaxis. On the contrary, investigation of patients without a previous adverse reaction did not appear to be of value. These findings suggest that those patients with a history of a severe undiagnosed adverse event during previous anaesthesia should be investigated with preoperative skin-testing before undergoing further elective surgery.