A Children's Hospital Experience with Warfarin Therapy

1Vanderbilt University, Nashville, TN
2Mayo Clinic, Rochester MN
3Mayo Clinic, Rochester, MN
4Mayo Clinic, Rochester, MN

Meeting: Hospital Medicine 2010, April 8-11, Washington, D.C.

Abstract number: 83


Despite the widely recognized risks of anticoagulant therapy, most pediatric patients are started on oral warfarin in the absence of standardized clinical protocols. Given the differing intensity of anticoagulation recommended for clinical and surgical indications, it is imperative that all providers be aware of the targeted level of anticoagulation, specifically the international normalized ratio (INR). The goal range INR (GRINR) would ideally be found in the medical record, readily retrievable to all involved in a pediatric patient's care. Research has noted the lack of adequate documentation of numerous items of clinical significance related to warfarin dosing, but not specifically the GRINR.


We sought to examine our recent practices on warfarin therapy in the children's hospital setting. This initiative served as the first step in development of a framework for standardized warfarin dosing by pediatric clinicians and pharmacists.


Retrospective medical records review included physician and nursing notes, medication administration records, hospital summaries, and pharmacy records of consecutive pediatric patients (age 17 and under) hospitalized at Mayo Children's Hospital between January 1, 2007, and December 31, 2008. Evidence of research authorization was confirmed before inclusion. One hundred and thirty‐five patients representing 176 in patient courses of warfarin were elucidated from the specified period of observation. Thirty‐three patients' courses (18.75%) were found to have no documentation of GRINR during their hospitalizatran, whereas 81 patients' courses (46.02%) were found to have the GRINR documented solely on the discharge summary. One hundred and thirty‐six courses (77.27%) of warfarin therapy were initiated after obtaining a baseline INR value (within 48 hours prior to first dose). One hundred and twenty‐one warfarin‐naive patients (no warfarin use within 7 days) were initiated on therapy with a goal INR documented at some point during hospitaiization. The average starting warfarin dose was 0.078 mg/kg (range 0.014–0.377 mg/kg, SD 0.047 mg/kg) among all weight distributions. The mean length of warfarin therapy until goal was achieved was 535 days (range 1–58 days, SD 7.57 days) Fifty‐seven patients (47.11%) reached the GRINR, of which only 38 (31.4%) were sustained at the GRINR at the time of discharge.


Patients given warfarin during hospitalization were found to lack appropriate documentation of the GRINR. Highly variable dosing and monitoring regimens resulted in inconsistent outcomes for pediatric warfarin therapy as measured by the INR. Our data strongly suggest a need for the development of a standardized pediatric warfarin dosing protocol based on the GRINR that would be universally documented and retrievable in the medical record in children's hospitals.

Author Disclosure:

J. LaBrin, none; B. Lee, none; K. Graner, none; C. Brands, none.

To cite this abstract:

LaBrin J, Lee B, Graner K, Brands C. A Children's Hospital Experience with Warfarin Therapy. Abstract published at Hospital Medicine 2010, April 8-11, Washington, D.C. Abstract 83. Journal of Hospital Medicine. 2010; 5 (suppl 1). https://www.shmabstracts.com/abstract/a-childrens-hospital-experience-with-warfarin-therapy/. Accessed April 9, 2020.

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