According to evidence based research, using smaller blood tubes (from 8.5mL to pediatric sized 3.5 mL)decreases the amount of blood collected, does not appear to affect laboratory test results, and reduces the amount of blood drawn overall [http://www.medscape.com/viewarticle/718472].  This could not only lead to the amount of blood transfusions required, but may also lead to cost savings through materials used.