Utilization of the Total Error Allowance Rule to Determine the Clinical Acceptability of Complete Blood Counts in the...

Peripherally inserted central catheters (PICCs) are widely used in oncology patients for drug infusion and nutritional support; however, their usefulness for blood sample collection has not been clarified. This study aimed to evaluate the clinical acceptability of complete blood count (CBC) measurements in blood samples drawn from PICC lines in oncology patients. Blood samples were drawn twice successively from the PICC lines (PICC0 and PICC1 samples, respectively), and a peripheral blood collected from the contralateral limb was used as reference sample. Significant differences and sources of bias in the CBC measurements in two PICC samples were analyzed. Clinical acceptability was determined based on the total error allowance (TEa) rules. Except for hemoglobin and erythrocyte, no significant differences were observed in the other parameters between PICC1 and reference samples (all P > 0.05), including leukocyte, hematocrit, platelet, erythrocyte parameters and leukocyte differential counts. Deviations of erythrocyte and hemoglobin in PICC1 samples was only attributed to random error, whereas proportional bias were also observed in PICC0 samples. According to the given TEa, erythrocyte, leukocyte, hemoglobin, and platelet of the PICC1 samples met the 1/2 TEa criteria and had favorable clinical acceptability. However, the hematocrit and the three erythrocyte parameters failed to meet the 1/2 TEa criteria. Adherence to the TEa criteria may provide higher clinical acceptability for CBC results. Satisfactory results in oncology patients may be involve discarding the first 2 mL of blood samples during sample collection using PICC lines.