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OBJECTIVES: The objective was to test the hypothesis that exclusive use of butterfly needles for phlebotomy, compared with sample collection via intravenous (IV) catheter, will reduce rates of sample hemolysis.

METHODS: This was an observational study of hemolysis rates before and after implementation of a “butterfly-only” phlebotomy protocol. Weekly hemolysis rates, generated by the central laboratory, were collected and the proportion of hemolyzed specimens before and after protocol implementation were compared.

RESULTS: Prior to institution of the butterfly-only protocol, 11.3% of specimens sent from the emergency department were reported as hemolyzed. During the postintervention period, only 4.3% of specimens were hemolyzed for a proportionate decrease of 62% and an absolute decrease of 7.0% (95% confidence interval = 6.6% to 7.3%).

CONCLUSIONS: Use of a butterfly-only phlebotomy protocol cuts hemolysis rates by more than half when compared with IV catheter phlebotomy.


Barnaby, D.P., Wollowitz, A., White, D., Pearlman, S., Davitt, M., Holihan, L., Bijur, P. and Gallagher, E.J. (2016) Generalizability and Effectiveness of Butterfly Phlebotomy in Reducing Hemolysis. Academic Emergency Medicine. January 14th. .

DOI: 10.1111/acem.12858.

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