Effects of Initial Specimen Diversion on Blood Culture Contamination Rates in the Emergency Department

BACKGROUND: Blood cultures are laboratory tests used in diagnosing sepsis and creating a care plan for patients involving antibiotics and possible admission. Contaminated blood cultures lead to false positives which result in inappropriate antibiotic administration, hospital admissions, and additional costs to the patient and the hospital. Current research shows that initial specimen diversion can be used to decrease contamination rates.

LOCAL PROBLEM: The selected Middle Tennessee ED draws 1,000+ blood cultures monthly. Blood culture contamination rates were documented at 5.3% on October 2023 before initial specimen diversion was initiated. This project aimed to decrease blood culture contamination rates at the project site to below the national benchmark of 3% by May 31, 2024.

METHODS: This project used the Evidence-Based Practice Improvement Model as a basis for the methods and interventions. Base line data was collected from the hospital for the same months as the previous year and the four months leading up to implementation. Upon initiation, the contamination rate was reviewed every two to four weeks, and a plan, do, study, act cycle will be conducted.

INTERVENTION: The implementation portion of this project spanned from February 2024 to May of 2024 starting with a two week in-person education period for emergency department staff on blood culture collection using initial specimen diversion.

RESULTS: Blood culture contamination rates were 5.3% in October 2023 prior to initial specimen diversion and project implementation for staff education. After implementation, this rate decreased to 3.7% by May of 2024. While this final rate did not meet the project aim of the national benchmark of 3.0%, this decrease was clinically significant.

DISCUSSION: Initial in-person education on initial specimen diversion and frequent re-education of staff decreased blood culture contamination rates. This intervention required no additional charge to the hospital and is sustainable with ongoing staff education on initial specimen diversion to reduce blood culture contamination.