Examining the push-pull method of blood sampling from central venous access devices

The placement of a central venous access device (CVAD) has revolutionized supportive care for pediatric cancer patients. The CVAD is used to administer chemotherapy/biotherapy, blood products, total parenteral nutrition, antibiotics, and many other supportive medications. CVADs also provide the ability to obtain blood samples without the trauma associated with venipuncture. Frequent blood sampling is often needed to monitor the side effects and response of the cancer treatment. Unfortunately, the most common method requires discarding blood (0.5-10 mL, depending on the institution's protocol) with each lab draws, for various reasons. For pediatric oncology patients, this can result in a large volume of blood being discarded and subsequently increase the need for blood transfusions. Repeated exposure to allogeneic (donor) blood products can put this patient population at additional risk for alloimmunization and febrile reactions. The purpose of this study is to test the limits of agreement between laboratory values (chemistry panel 18 and complete blood count) obtained using the push-pull and standard methods of blood sampling from CVADs in pediatric oncology patients.