A new paradigm to understand severe outcomes in anaphylaxis

Published: July 21, 2020

National and international guidelines highlight the need to avoid changes in posture during anaphylaxis, as this can trigger cardiorespiratory arrest and death. However, the impact of allergic reactions on the cardiovascular system in non-fatal reactions remains poorly understood.

In a study recently published in The Journal of Allergy and Clinical Immunology (JACI), Ruiz-Garcia and colleagues present detailed cardiovascular data from 57 peanut-allergic adults undergoing acute reactions to peanut under medical supervision, of whom 38% had anaphylaxis. The study was funded by the UK Medical Research Council with additional support from the UK Food Standards Agency, European Commission and National Institute for Health Research.

Allergic reactions were associated with significant fall in stroke volume (the amount of blood pumped out of the heart, per beat) which was reproducible and occurred irrespective of reaction severity. There was evidence of compensation, in that the heart rate increased which would then maintain overall cardiac output. The administration of intravenous fluids reversed the fall in stroke volume and was associated with faster resolution of abdominal symptoms.

These data provide a sound evidence-base for optimizing venous return during significant allergic reactions to food. In addition, the findings suggest a new paradigm for understanding severity in anaphylaxis, where poor outcomes occur due to a failure in compensatory mechanisms.

The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

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