Active Monitoring and Feedback to Improve Blood Culture Fill Volumes and Positivity Across a Large Integrated Health System

Abstract

Background: The sensitivity of blood cultures increases with the volume of blood collected. However, hospitals face challenges in collecting adequate volume, and underfilled blood bottles are ubiquitous.

Methods: Blood bottle fill volumes were measured using an automated monitoring system across multiples sites (10 hospitals, 3 laboratories) within a large suburban/urban health system. Baseline fill volumes were measured for 4 months. A quality improvement program was then implemented over 36 months. Strategies to improve fill volumes included education, standardized data collection, novel and unblinded information cascades, targeted communication, and bottle markings for blood collectors.

Results: A total of 516 201 blood cultures were evaluated over 40 months. In the preimplementation period (January-April 2015), no hospitals collected the recommended 8-10 mL/bottle, and the average system fill volume was 2.3 mL. In the final postimplementation period (January-April 2018), 7 of 10 hospitals achieved ≥8 mL per bottle and the system average increased to 8.6 mL (P < .0001). The positivity rate increased 20%, from 7.39% to 8.85% (P < .001), whereas the contamination rate did not change and remained low. Compared to the preimplementation period, the odds of positive cultures containing potential pathogens increased to 1.18 (95% confidence interval, 1.05-1.32; P = .003).

Conclusions: Here we show that underfilled blood cultures are extremely common but that operational and educational strategies can result in sustained improvements across a complex network of hospitals and laboratories. This leads to increased detection of pathogens, which can have tremendous impact on the management of bloodstream infections and sepsis.

Keywords: blood culture; fill volume; positivity; quality improvement; sensitivity.