Lessons Learned From Fatal and Near-Fatal Perioperative IgE-Mediated Anaphylaxis.

BACKGROUND: Perioperative anaphylaxis (POA), an acute circulatory failure usually IgE-mediated, remains a significant cause of anesthesia-related deaths. Because early recognition of this life-threatening condition is critical, we previously investigated the association of clinical characteristics with IgE-mediated allergy and showed that early cutaneous vasoconstriction was pathognomonic of IgE-mediated anaphylaxis. OBJECTIVE: To evaluate whether early cutaneous vasoconstriction phenotype is associated with an increased risk of fatal/near-fatal POA and analyze the mechanisms leading to poor outcomes. METHODS: This is a prespecified analysis of a retrospective observational cohort study conducted at 2 academic medical centers. Included in the study were adults diagnosed with IgE-mediated anaphylaxis (grades III and IV according to the modified Ring and Messmer scale) in the main analysis and those with a fatal or near-fatal outcome. IgE-mediated anaphylaxis successfully treated with mechanical circulatory support was defined as near-fatal. RESULTS: Of 72 included patients with IgE-mediated anaphylaxis (grade III: 65 [90.3%] and grade IV: 7 [9.7%]), 45 (62.5%) and 27 (37.5%) were, respectively, categorized in the miscellaneous (early or late cutaneous vasodilation or lack of cutaneous signs) and early cutaneous vasoconstriction groups. Six fatal or near-fatal cases (grade III: 4 and grade IV: 2) were exclusively reported in the early cutaneous vasoconstriction group. Early cutaneous vasoconstriction phenotype was associated with fatal/near-fatal outcomes. Fatal/near-fatal outcomes occurred in 22.2% of patients with cutaneous vasoconstriction (n = 6 of 27) while in none of those from the miscellaneous group (n = 0 of 45) (absolute risk difference: 22.2% [95% confidence interval: 8.2-40.8]). Fatal and near-fatal cases accounted for 18.5% (n = 5 of 27) and 3.7% (n = 1 of 27) of cases, respectively. Early cutaneous vasoconstriction was always associated with bradycardia (median [interquartile range]: 46 [38-57] beats/min) in the 6 fatal/near-fatal cases. A symptomatic treatment, disregarding the pathophysiological mechanisms of POA, might have contributed to poor outcomes. CONCLUSIONS: POA exhibiting early cutaneous vasoconstriction was associated with an increased risk of fatal/near-fatal outcomes. Early cutaneous vasoconstriction and bradycardia likely reflect greater initial severity, owing to profound hypovolemia. This highlights the importance of recognizing this lesser-known phenotype. Further research is warranted.