Blood volume collected for cultures in infants with suspected neonatal sepsis.

OBJECTIVES

To evaluate blood culture sample volumes, identify factors linked to insufficient samples, and compare volumes among neonates treated for culture-negative-sepsis, sepsis-rule-outs, and bloodstream infections (BSI).

METHODS

Observational cohort of blood cultures collected during NICU stay. Association of age, weight, gender, source, and collection time with lower-than-recommended volumes was determined by logistic regression. Blood culture inocula of patients with culture-negative-sepsis, sepsis rule-out, and BSI were compared using ANOVA.

RESULTS

742 blood cultures were obtained from 292 neonates. Median inoculum was 1 mL (IQR:0.6-1.4), and 259 bottles (35%) had inocula <0.9 mL. Night shift sample collection was associated with lower-than-recommended volumes (p = 0.006). No difference in sample volumes was observed between culture-negative-sepsis, sepsis-rule-outs, and BSI (p = 0.5).

CONCLUSIONS

Median NICU blood culture volumes align with recommendations. Night shift collections correlate with lower volumes. Sample volumes don't differ in patients with culture-negative-sepsis, BSI, and sepsis-rule-out, and should not be a justification for longer duration of antibiotics.