Blood cultures with one venipuncture instead of two: a prospective clinical comparative single-center study including patients in the ICU, haematology, and infectious diseases departments

Abstract

Objectives

Blood culture is a key method for diagnosing bloodstream infections. In this prospective study, we aimed to investigate whether blood cultures collected with the one-puncture method results in fewer contaminants, i.e. microorganisms from the skin or the environment, and the same detection of relevant pathogens compared to the two-puncture method. Further, we aimed to investigate if the time to blood culture positivity could be useful in evaluating contaminants.

Methods

Patients planned for blood cultures were asked to participate in the study. From each recruited patient, six blood culture bottles were drawn, bottles 1–4 from the first venipuncture and bottles 5–6 from the second venipuncture. Within each patient, bottles 1–4 were compared to bottles 1, 2, 5, and 6 for contaminants and relevant pathogens. A sub-analysis was conducted on patients admitted to the ICU and those in the haematology department. We also assessed time-to-positivity for coagulase-negative staphylococci.

Results

In the final analysis, 337 episodes from 312 patients were included. Relevant pathogens were identified in 62/337 (18.4%) episodes in both methods. Contaminants were detected in 12 (3.6%) and 19 episodes (5.6%) using the one-puncture and two-puncture method (p = .039), respectively. Corresponding results were observed in the sub-analysis. Notably, relevant coagulase-negative staphylococci demonstrated a shorter time-to-positivity compared to contaminant coagulase-negative staphylococci.

Conclusion

Blood cultures obtained using the one-puncture method resulted in significantly fewer contaminants and detected relevant pathogens equally to the two-puncture method. Time-to-positivity may be a useful additive indicator for predicting coagulase-negative staphylococci contamination in blood cultures.

Keywords:

• Blood stream infection
• bacteraemia
• blood culture(s)
• one-puncture method
• time-to-positivity
• single sampling strategy

Acknowledgement

We are grateful for the outstanding contribution of the personnel at the emergency department, ICU, infectious diseases department, haematological department, and Department of Microbiology at Östersund Hospital.

Disclosure statement

No potential conflict of interest was reported by the author(s).