Blood Cultures: the Importance of Meeting Pre-Analytical Requirements in Reducing Contamination, Optimizing Sensitivity of Detection, and Clinical Relevance

The primary goal of the clinical microbiology laboratory is to provide reliable, timely, and clinically relevant diagnostic test results. Blood cultures are one of the most important specimens managed by the clinical microbiology laboratory and are the primary and most sensitive method for diagnosing blood stream infections (bacteremia, fungemia, and sepsis), in addition to influencing appropriate antimicrobial therapy. Of the three phases of laboratory testing, pre-analytical, analytical, and post-analytical, the former is the most challenging for the clinical microbiology laboratory to control. The primary pre-analytical factors that significantly influence the sensitivity, interpretation, and clinical relevance of blood cultures are (i) skin antisepsis, (ii) blood volume, (iii) number of blood culture specimens collected, (iv) timing of blood culture collection, and (v) delays in incubation time. This overview focuses on these pre-analytical factors and the potential impact on blood culture results, which are essential for promoting safe, timely, effective, and efficient care for patients with serious infections, in addition to affecting health care expenses.