Venipuncture versus central venous access: a comparison of methotrexate levels in pediatric leukemia patients

Patients receiving methotrexate (MTX) therapy for treatment of acute lymphocytic leukemia (ALL) consistently have venipuncture MTX levels drawn twice during each hospitalization. The purpose of this study was to compare MTX levels drawn from central venous catheters (CVCs) with those drawn by venipuncture. A convenience sample of 14 pediatric patients was used, with a total of 33 peak levels and 33 trough level sample pairs collected. Venipuncture and CVC levels were compared by using the paired t-test and analyzing the peak and trough data pairs separately. Results confirmed there was no difference in MTX level results (peak, p = .502; trough, p = .114). However, the CVC trough levels would have changed clinical management for 5 of the 33 patients. Therefore, it is recommended that all MTX levels be drawn from the CVC but that trough MTX levels that would alter clinical management be verified by a venipuncture sample. This method will safely minimize the number of venipunctures for children with ALL.