Transfusion-associated anaphylaxis during anaesthesia and surgery--a retrospective study

Area of Science:

• Anesthesiology
• Immunology
• Hematology

Background:

• Transfusion-associated anaphylaxis (TAA) is a severe adverse reaction with a reported incidence of 1:9000-90,000 transfusions.
• The Danish Registration of Transfusion Risks (DART) reports a lower frequency (1:300,000), suggesting underreporting in Denmark.
• This study aimed to identify TAA cases, characterize their symptoms and tryptase levels, and investigate reporting to haemovigilance systems.

Purpose of the Study:

• To identify potential cases of transfusion-associated anaphylaxis (TAA) in patients investigated for allergic reactions during anesthesia and surgery.
• To characterize the clinical symptoms and serum tryptase levels of suspected TAA cases.
• To evaluate the reporting rates of TAA to Danish haemovigilance systems.

Main Methods:

• Reviewed 245 patients with suspected allergic reactions during anesthesia and surgery at the Danish Anaesthesia Allergy Centre (DAAC).
• Classified patients as DAAC positive (confirmed hypersensitivity) or DAAC negative (no confirmed hypersensitivity).
• Identified TAA cases using International Society of Blood Transfusion (ISBT) criteria and collected data on case history, transfusions, and investigations.

Main Results:

• Ten possible TAA cases were identified, all classified as DAAC negative.
• These TAA cases showed significantly higher frequencies of elevated serum tryptase, hypotension, and male sex compared to other DAAC negative patients.
• Only one TAA case was reported to the Blood Bank haemovigilance system; none were reported to DART.

Conclusions:

• Unreported cases of possible TAA were identified, exhibiting symptoms and elevated tryptase levels similar to confirmed hypersensitivity reactions.
• Application of ISBT criteria for adverse transfusion reactions suggests that TAA during anesthesia and surgery is likely underreported in Denmark.
• The findings highlight a potential gap in TAA detection and reporting within Danish haemovigilance systems.