Vernon D. Smith

Evaluation of National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network criteria for the diagnosis of anaphylaxis in emergency department patients

BACKGROUND Diagnostic criteria were proposed at the Second Symposium on the Definition and Management of Anaphylaxis convened by the National Institute of Allergy and Infectious Diseases/Food Allergy and Anaphylaxis Network (NIAID/FAAN). Validation is needed before these criteria can be widely adapted into clinical practice. OBJECTIVE Our aim was to retrospectively assess the diagnostic accuracy of the NIAID/FAAN criteria for the diagnosis of anaphylaxis in emergency department (ED) patients. METHODS A retrospective cohort study of ED patients presenting from April to October 2008 was conducted. Patients given a diagnosis of an allergic reaction or anaphylaxis and a subset of patients with related diagnoses were included. Electronic medical records were reviewed and data were abstracted to determine whether the NIAID/FAAN criteria were met. Records were also independently reviewed in a blinded fashion by 2 experienced attending allergists. Final diagnosis by allergists was considered the reference standard. RESULTS Of 214 patients, 86 (40.2%) met the NIAID/FAAN criteria for anaphylaxis. Allergists gave 61 (28.5%) patients diagnoses of anaphylaxis, 59 (96.7%) of whom satisfied the NIAID/FAAN criteria. The interrater agreement between allergists was substantial (κ = 0.77). The test characteristics of the NIAID/FAAN criteria were as follows: sensitivity, 96.7% (95% CI, 88.8% to 99.1%); specificity, 82.4% (95% CI, 75.5% to 87.6%); positive predictive value, 68.6% (95% CI, 58.2% to 77.4%); negative predictive value, 98.4% (95% CI, 94.5% to 99.6%); positive likelihood ratio, 5.48; and negative likelihood ratio, 0.04. CONCLUSIONS These results suggest that the NIAID/FAAN criteria are highly sensitive but less specific and are likely to be useful in the ED for the diagnosis of anaphylaxis.

Anaphylaxis in emergency department patients 50 or 65 years or older

BACKGROUND Anaphylaxis is a potentially life-threatening allergic reaction commonly managed in the emergency department (ED). Data describing patients 50 or 65 years or older with anaphylaxis are limited. OBJECTIVE To describe the presentation and management of patients with anaphylaxis who were 50 or 65 years or older and to compare these findings with those of younger patients. METHODS A consecutive cohort study of patients presenting to an ED with approximately 80,000 visits per year was conducted. Patients who met diagnostic criteria for anaphylaxis from April 2008 to June 2010 were included. Data were collected on suspected causes, signs and symptoms, management, ED disposition, and follow-up. RESULTS The study included 220 patients. Food was the most common suspected cause of anaphylaxis for patients younger than 50 (42.2%) or 65 years (38.5%) but was much less common in patients 50 (14.8%, P < .001) or 65 years or older (14.3%, P = .01). Cardiovascular symptoms were more likely to occur in older patients (≥50 years old, 55.6% vs 30.1%, P < .001; ≥65 years old, 64.3% vs 32.3%, P = .002). Patients 50 or 65 years or older were less likely to be dismissed home directly from the ED (≥50 years old, 35.2% vs 56.6%, P = .006; ≥65 years old, 32.1% vs 54.2%, P = .03) and were less likely to be prescribed self-injectable epinephrine (≥50 years old, 40.7% vs 63.3%, P = .004; ≥65 years old, 32.1% vs 61.5%, P = .003). CONCLUSIONS In ED patients presenting with anaphylaxis, age of 50 or 65 years or older is associated with a decreased likelihood of food-induced anaphylaxis, increased likelihood of experiencing cardiovascular symptoms, decreased dismissal to home directly from the ED, and decreased prescriptions for self-injectable epinephrine.

Emergency Department Rotational Patient Assignment

STUDY OBJECTIVE We compare emergency department (ED) operational metrics obtained in the first year of a rotational patient assignment system (in which patients are assigned to physicians automatically according to an algorithm) with those obtained in the last year of a traditional physician self-assignment system (in which physicians assigned themselves to patients at physician discretion). METHODS This was a pre-post retrospective study of patients at a single ED with no financial incentives for physician productivity. Metrics of interest were length of stay; arrival-to-provider time; rates of left before being seen, left subsequent to being seen, early returns (within 72 hours), and early returns with admission; and complaint ratio. RESULTS We analyzed 23,514 visits in the last year of physician self-assignment and 24,112 visits in the first year of rotational patient assignment. Rotational patient assignment was associated with the following improvements (percentage change): median length of stay 232 to 207 minutes (11%), median arrival to provider time 39 to 22 minutes (44%), left before being seen 0.73% to 0.36% (51%), and complaint ratio 9.0/1,000 to 5.4/1,000 (40%). There were no changes in left subsequent to being seen, early returns, or early returns with admission. CONCLUSION In a single facility, the transition from physician self-assignment to rotational patient assignment was associated with improvement in a broad array of ED operational metrics. Rotational patient assignment may be a useful strategy in ED front-end process redesign.