Retrospective cohort study comparing activated partial thromboplastin time versus anti- XXXX activity nomograms for therapeutic unfractionated heparin monitoring in pediatrics.

@entity1 @entity1031 @entity6236
BACKGROUND: Unfractionated heparin (UFH) is widely used to treat @entity1031 , but monitoring in @entity1 is challenging. Both activated partial thromboplastin time (aPTT) and anti- @entity6236 activity (anti-Xa) are utilized, but a comparison of dosing nomograms has not been reported in pediatrics. OBJECTIVE: To compare the performance of aPTT and anti-Xa for UFH monitoring in pediatric @entity1 . DESIGN/METHODS: A retrospective cohort study was conducted in @entity1  <=  21  years old treated with UFH at Johns Hopkins Hospital from January 2009 to May 2011. For monitoring, an aPTT nomogram was used for the initial 15  months, and an anti-Xa nomogram was used for the subsequent 12  months. Clinical characteristics, laboratory data and outcomes were analyzed. RESULTS: Thirty-four @entity1 were monitored with aPTT and 26 patients with anti-Xa. There was no significant difference in median time to therapeutic range (11.6  h aPTT, 95%CI  =  6.0-17.0; 9.9  h anti-Xa, 95%CI  =  7.3-20.7) or per cent of @entity1 achieving therapeutic measurements at 24 (79% aPTT, 95%CI  =  62-91; 73% anti-Xa, 95%CI  =  52-88) and 48  h (88% aPTT, 95%CI  =  73-97; 96% anti-Xa, 95%CI  =  80-100). However, anti-Xa measurements were more frequently therapeutic than aPTT (74% [95%CI  =  69-78] vs. 54% [95%CI  =  50-59]). Variance between anti-Xa and aPTT measurements was high (R(2)   =  0.236). No significant difference was seen in bleeding incidence (9% aPTT, 95%CI  =  2-24; 15% anti-Xa, 95%CI  =  4-35). CONCLUSION: The time to achieve therapeutic measures and bleeding outcomes were not significantly different between anti-Xa and aPTT nomograms. However, a small study size limits the power to detect clinically relevant differences. The results warrant larger prospective studies of UFH monitoring in @entity1 with @entity1031 .
