Multiple Blood Cultures Improve Antimicrobial Decision-Making for Children

Taking 2 blood cultures before administering antibiotics for children admitted to the hospital with suspected sepsis or serious bacterial infection increased pathogen isolation and improved antimicrobial decision-making, a recent study found.

The number of blood cultures and method of volume determination for children varies widely, with multiple blood cultures being uncommon in pediatrics. Implementing multiple blood cultures may decrease unnecessary antibiotic use and health care costs, the study noted.

The study, published in Open Forum Infectious Diseases, compared blood culture yield, isolate classification and antimicrobial modifications before and after interventions were implemented at Children’s Hospital Colorado to recommend 2 blood cultures and simplify blood culture collection volume decisions prior to administration of antibiotics for suspected serious bacterial infections in children.

“The biggest takeaway is the 2 blood cultures taken prior to beginning antibiotics in children who are being admitted to the hospital increases the recovery of causative organisms and allows for better treatment decisions,” James Todd, MD, of the University of Colorado School of Medicine and Children’s Hospital Colorado, told Contagion^®.

The study included 3948 children admitted to inpatient units at Children’s Hospital Colorado between 2008-2009 and 2011-2013. All participants had blood cultures collected in the hospital’s emergency department before admission and antibacterial treatment.

The cohort study included patients admitted before and after the hospital began recommending 2 blood cultures prior to administering antibiotics with electronic medical record decision support in 2010. The hospital also implemented nursing protocols that simplified blood culture collection volume to an age-based recommendation of 1 ml minimum with the addition of 1 ml per year of age up to a maximum of 10 ml.

Before those interventions, the number of blood cultures was determined by the ordering physician and culture volumes were based on weight-based guidelines.

In 2013, an average of 1.96 cultures per patient were taken prior to antibiotics being administered, up from 1.2 cultures per patient in 2008, with 88% of patients in the later group having 2 or more blood cultures compared with 12% before the interventions. Compliance with blood culture volume recording increased from 20.8% to 83.7%, and collection of recommended age-based blood volumes increased from 15.2% to 74.3%.

The study found that 33.9% of patients had a clinical bacterial infection, 23.2% had a nonbacterial infection, and 42.9% had no clinical infection identified. The rate of positive cultures increased from 5.9% to 11.1% and the rate with at least 1 possible pathogen increased from 3.7% to 7.3%. The distribution between antimicrobial decision-making categories shifted (P < .001), with more cases with modified antimicrobials after blood culture results and fewer receiving inappropriate antibiotics after the interventions.

“The important message for clinicians is that taking appropriate blood and focal infection cultures prior to starting antibiotics empowers subsequent treatment decisions—either to modify or to discontinue antibiotics,” Todd told Contagion^®.

The study’s limitations included the concept of ruling out sepsis or serious bacterial infection solely with blood cultures, that blood culture volumes were based on nurse self-reporting rather than collection bottle mass, and assessment of the appropriateness of antimicrobial therapy was based on electronic data rather than chart review.

Despite these and other limitations, the study determined that multiple blood cultures with appropriate volume can improve the diagnosis and treatment of children with serious bacterial infection.

“Clinical care guidelines and microbiology laboratories should encourage getting 2 independent blood cultures prior to initiating antimicrobial therapy in hospitalized children to enhance appropriate antimicrobial stewardship,” Todd told Contagion^®.

Antimicrobial stewardship programs to improve treatment of infections, protect patients from harm of needless antibiotics, and combat the emergence of antibiotic-resistant pathogens have been a focus of health officials and hospitals.

A recent study found that most physicians around the globe do not follow World Health Organization guidelines for treating neonatal and pediatric sepsis, underscoring the diverse opinions about how to treat these cases.

Treating hospitalized children and infants with bacterial infections requires different considerations than for adults. A recent review article pointed out that hospital pharmacists can play an important role in improving care, particularly in facilities where pediatric patients are not regularly treated.