Journal: Acta Anaesthesiol Scand 52(2):175-181, 2008. 25 References
Reprint: Dept of Anesthesia and Intensive Care, Hôpital Maison Blanche, 45 rue Cognacq-Jay, F-51092 Reims, France (JM Malinovsky, MD) LE.03 JU0803/153 ©2008
Faculty Disclosure: Abstracted by L. Easley, who has nothing to disclose.
The clinical diagnosis of a hypersensitivity reaction during anesthesia can be difficult. The objective of this prospective study was to better evaluate the incidence of hypersensitivity reactions during anesthesia. The authors systematically investigated all suspected hypersensitivity or unexplained reactions in anesthetized patients by performing serial circulating histamine and tryptase concentration measurements, followed by systematic allergological investigations including skin testing.
During this 2-year prospective study nearly 70,000 surgical procedures were performed under anesthesia. A database was constructed including all patients who experienced a hypersensitivity reaction or an unexplained adverse reaction during anesthesia. Blood was systematically sampled to measure the concentrations of plasma histamine and serum tryptase within 1 hr after the reaction and 24 hr later, and skin tests were performed nearly 6 weeks later. Reactions were rated by the anesthesiologist as a ‘hypersensitivity reaction’ or as an ‘unexplained reaction.’ Blood was sampled for plasma histamine and serum tryptase concentration determination. Prick and intradermal tests were accompanied by control tests carried out with negative (saline) and positive controls (9% codeine phosphate) to determine whether or not the skin was liable to release histamine and react to it. Finally, hypersensitivity reaction was diagnosed on the basis of clinical history, mediator concentrations in blood, and skin tests. The treatments used and follow-up until allergologic investigation were recorded and analyzed. Thirty-nine patients were enrolled in the database over a 24-month period. In 22 patients, a clinical diagnosis of hypersensitivity reaction was proposed, and in 9 cases the adverse reaction was considered as unexplained by the attending physician. Among the 22 patients with a clinical hypersensitivity reaction, 15 were diagnosed as IgE-mediated hypersensitivity reactions on the basis of positive skin tests. Latex was the main causative agent, followed by neuromuscular blocking agents (NMBAs), gelatins and antibiotics. Despite similar symptoms, reactions with NMBAs required longer treatment than those with latex; 100% and 30% of the patients were admitted in ICU, respectively.
Systematic follow-up of unexplained reaction during anesthesia allowed the authors to detect more IgE-mediated hypersensitivity reactions than if they had investigated suspected hypersensitivity reactions alone. Based on these results, the estimated overall incidence of IgE-mediated hypersensitivity reactions was increased by 50%, from 1:4667 to 1:3180 anesthesias. As expected, increased tryptase value is a strong argument to support the diagnosis of IgE-mediated hypersensitivity reactions. These results demonstrate that neither a modification of the actual diagnostic threshold nor the determination of tryptase basal values the day following the adverse reaction will increase the diagnostic value in a clinically relevant manner. Although the authors found a higher incidence of hypersensitivity reactions than reported previously, they observed a similar ratio between IgE- and non-IgE-mediated reactions of 7:3. Hypersensitivity reactions during anesthesia were mostly related to latex (55%) and NMBAs (27%), followed by gelatins (14%), and antibiotics (5%).
These results support the liberal use of immediate biological investigation and skin test in case of hypersensitivity reactions but also in case of adverse events considered as unexplained by anesthesiologists. In addition, these results emphasize the need for a better preoperative screening of latex sensitization in anesthetized patients. |
