Incidence and risk factors for near-fatal and fatal outcomes after perioperative and periprocedural anaphylaxis in the USA, 2005–2014

Background: The incidence of fatal and near-fatal outcomes after perioperative anaphylaxis is unknown in the USA. Previously identified risk factors of neuromuscular-blocker-induced fatal perioperative anaphylaxis include male sex, obesity, and use of beta blockers. We examined the incidence of fatal and near-fatal outcomes after perioperative anaphylaxis in the USA and the underlying risk factors using a large national database. Methods: Using the Nationwide Inpatient Sample from 2005 to 2014, we identified cases of fatal and near-fatal perioperative anaphylaxis, defined as perioperative anaphylaxis cases complicated by respiratory or cardiac arrest, using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Results: Amongst 5223 perioperative anaphylaxis cases, the proportion of near-fatal or fatal cases attributable to perioperative anaphylaxis was 7.0% (95% confidence interval [CI]: 6.2–7.7), with near-fatal perioperative anaphylaxis cases accounting for 5.0% (95% CI: 4.4–5.6%) and fatal cases accounting for 2.0% (95% CI: 1.5–2.5%) of cases overall. Thus, the incidence of fatal or near-fatal perioperative anaphylaxis is 1.26 in 100 000 procedures. Risk factors for fatal or near-fatal perioperative anaphylaxis include age (≥65 yr); undergoing a cardiac procedure; and comorbid conditions of weight loss, non-metastatic solid tumours, metastatic cancer, paralysis, coagulopathy, renal failure, congestive heart failure, fluid and electrolyte disorder, and neurological disorders. Individuals with near-fatal or fatal perioperative anaphylaxis reactions had increased lengths of stay and hospital costs compared with controls. Conclusions: The incidence of fatal or near-fatal perioperative anaphylaxis in the USA was 1.26 in 100 000 procedures. Risk factors for fatal or near-fatal outcomes include older age, cardiac procedures, and specific comorbidities.