A comparative study on coagulation and hematologic laboratory techniques for blood sampling using the push-pull method from a CVC versus venipuncture.

OBJECTIVES

To demonstrate the equivalence and substitutability of two blood collection methods: the push-pull method from a CVC and direct venous puncture (DVP).

METHODS

A comparative, within-subject study was conducted between September 2021 and December 2021 at a hospital in NanTong city. The sample comprised critically ill patients aged 18 and older in critical care units such as general, emergent, cardiac, respiratory, and neurological units. A total of 154 paired blood samples were collected via a CVC and direct venous puncture. This study focused on the laboratory results of the coagulation and hematologic tests. The reproducibility and reliability of the results were calculated by the mean of the coefficient of variation (CV) and the intraclass correlation coefficient (ICC). Bland-Altman statistics were used to analyze the substitutability of the two blood collection methods.

RESULTS

The difference in the means between the two methods ranged from -1.61 to 0.09, and the coefficients of variation for both methods were similar. The ICCs of the two methods were all above 0.90, which indicated excellent reliability. In the Bland-Altman plots, all of the blood samples that obtained by the push-pull method were within clinically acceptable ranges compared to the samples obtained by direct venous puncture.

CONCLUSION

The push-pull method of collecting blood specimens from a CVC should be acceptable for coagulation and hematologic laboratory tests.