Background: To avoid additional venipuncture, blood cultures (BC) are often drawn and set aside when placing an intravenous line (IV), wasting BC bottles. If BCs could be drawn through indwelling IVs without an increased rate of contamination, later blood draws for culture samples would provide a viable alternative.

Objective: Determine the contamination rates of BC drawn through the same IV at two different times. Describe the pathogens found in all cultures.

Design/Setting: Prospective patient series in an urban Pediatric Emergency Department

Participants: 1014 children with a mean age 4.1 y (range: 9d-22.1y; median: 2.1y) who required a BC and IV placement. Exclusion criteria included central lines, latex allergy, and IM or IV antibiotic administration in the 24 h preceding the blood draw.

Methods: All BCs were drawn using a sterile technique prior to the administration of antibiotics. The first BC was drawn when the IV was placed and the second BC was drawn from the same site at a later time. The amount of blood drawn for each culture and patient temperature at the time of the second blood draw were recorded.

Measurements: The primary outcome measure was the contamination rates of the two groups. Secondary outcomes included the ability to draw the second culture and the pathogen yield.

Main Results: Thus far, 1014 children have been enrolled. In 55(5.4%) the second culture could not be drawn off the IV. 959 remained for paired comparison. The average time between cultures was 98 minutes (range: 1-493 minutes). The mean amounts of blood cultured were 1.72 ml and 1.74 ml in the first & second samples, respectively (p=NS). 19/959 (1.98%) of the initial cultures and 29/959 (3.02%) of the second cultures grew a contaminant(p=NS). Contaminant organisms were oral or skin flora. 22/1918 (1.15%) cultures grew pathogens; 10 cultures represent 5 patients who had growth in both samples. Organisms cultured in paired samples included S. pneumoniae (8) and N. meningitidis (2). The remaining 12 pathogens were cultured from only 1 of 2 specimens drawn from the same patient. Of these 12 pathogens, 4 were found in the first BC and 8 were found in the second BC. Organisms grown in 1 of 2 cultures included S. pneumoniae (7), E. coli (2), Salmonella group B (1),H. influenzae (1), and N. meningitidis (1).

Conclusions:Blood cultures may be obtained from previously placed IV catheters without a statistically significant increase in the contamination rate. More pathogens may be identified when two cultures are drawn.