The practice of blood volume submitted for culture in a neonatal intensive care unit

Neonatal sepsis is the leading cause of mortality and morbidity in neonatal intensive care units. The volume of blood taken for culture remains one of the most important factors in isolating microorganisms.

To evaluate the impact of the intervention on the blood volume submitted for culture and to identify factors influencing the volume as determined by the phlebotomist.

Blood culture volume was determined by weighing the culture bottle before and immediately after blood inoculation. A 3-month preintervention audit revealed that in 126/130 samples (96.9%), the volume of blood submitted was suboptimal. Multiple intervention measures were instituted, and volume was monitored over the next 9 months.

637 blood culture samples were included in the study, 130 were in preintervention and 507 were in postintervention epochs. Following the intervention, suboptimal volume samples reduced from 96.9% (126/130 samples) to 25% (126/507 samples), p<0.0001 and the median (IQR) sample volume improved from 0.36 (0.23) ml to 0.9 (0.27) ml, p<0.0001. Poor blood flow was identified as the most common reason for an inadequate sample.

The study underscores the role of educational intervention in improving the blood culture volume in newborn infants. Poor backflow from the cannula is an important cause of inadequate volume collection.