Improvement of Umbilical Cord Blood Gas Analysis with Implementation of Clot Catchers

Umbilical cord blood gas testing is a key component of objective pre- and perinatal evaluation of fetal acid base status to determine presence of intrapartum asphyxia and risk of neonatal encephalopathy. Heparinized cord blood is more likely to form small clots than other blood sources, which can interfere with, or preclude, sample analysis. Cord blood samples are irreplaceable and cannot be recollected, thereby compromising clinical decision-making when analysis is not possible. We evaluated processes to prevent excessive rates of cord blood clotting and quantified their impact on successful testing of blood gas specimens.

Verified result and cancellation data were obtained retrospectively from the laboratory information system. Clot catchers were evaluated using noncord remnant specimens. Collection syringes were compared via collection from remnant cord sections.

Prior to implementation of any interventions, retrospective analysis indicated a cancellation rate of 18.6% for umbilical cord blood gas specimens (arterial and venous) and 0.7% for noncord blood arterial and venous samples. Clot catchers were validated for clinical use, with a bias of <±4% for all analytes. After clot catchers were implemented for all cord specimens, cancellation rate decreased approximately 5-fold in the first month and remained <5% a year after implementation. A limited comparison of two heparin syringe types revealed a small difference in the overall rate of specimen clotting.

Implementation of clot catchers was acceptable for analysis of cord blood samples, and when implemented resulted in a sustained 5-fold decrease in the rate of cord blood gas order cancellation.