Seeing Red: Blood Sample Hemolysis Is Associated with Prolonged Emergency Department Throughput

Abstract

Introduction: Hemolyzed emergency department (ED) blood specimens impose substantial burdens on various aspects of delivering care. The ED has the highest incidence of hemolysis among hospital departments. This study assessed the association and potential impact of hemolyzed blood samples on patient throughput time using ED length of stay (LOS) as the primary outcome measure.

Methods: This study was a secondary analysis of data collected during a performance improvement project aimed at reducing the incidence of hemolysis in ED blood specimens. The electronic medical record was queried for potassium orders and results and for key patient throughput time points. Throughput times were stratified according to hemolysis, ED disposition (admitted vs discharged), and Emergency Services Index (ESI) triage categorization. Two-tailed t tests were used to compare throughput times for patients with and without hemolysis.

Results: Potassium values were reported for 11 228 patient visits. The mean ED LOS was 287 minutes for patients with nonhemolyzed samples and 349 minutes for patients who had hemolyzed samples, a mean delay of 62 minutes. The mean throughput time for discharged patients was 92 minutes shorter in the group without hemolysis (337 vs 429 minutes). The mean throughput time for admitted patients was 28 minutes shorter in the group without hemolysis (264 vs 292 minutes). The increased LOS for patients with a hemolyzed blood sample was independent of the most commonly encountered ESI levels.

Conclusion: Hemolysis of blood samples obtained in the ED is associated with prolonged patient throughput via delays in patient disposition, independent of various markers of acuity, such as the patients' ultimate disposition or triage categorization.

Keywords: Emergency Medicine; hemolysis; poor sample; pre-analytical; rework; throughput; waste.