Harkin Maura, Shaddix Brittany Powers, Neely Stephen B, Peek Leigh A, Stephens Katy, Barker Philip, McMullan Lauren, Gormley Andrew, Johnson Peter N
Department of Pharmacy: Clinical and Administrative Sciences, University of Oklahoma College of Pharmacy, Oklahoma City, OK.
Department of Pharmacy Services, Ascension: The Children's Hospital at Sacred Heart, Pensacola, FL.
Am J Health Syst Pharm. 2020 Jun 23;77(13):1018-1025. doi: 10.1093/ajhp/zxaa111.
Prophylactic warfarin with an International Normalized Ratio (INR) goal of 1.5 to 2.0 is one antithrombotic therapy utilized in children after cardiothoracic surgery (CTS); published sources suggest a dose of 0.1 mg/kg per day to achieve this goal. However, few studies have evaluated dosing in this population. The purpose of this study was to evaluate dosing and safety outcomes in children receiving warfarin after CTS.
A descriptive, retrospective review was conducted to evaluate warfarin dosing and INR outcomes in patients 18 years of age or younger who underwent CTS and received prophylactic warfarin with an INR goal of 1.5 to 2.0 from January 2014 through December 2018. The primary objective was to determine the median initial warfarin dose. Secondary objectives included identifying the percentage of documented INR values that were outside the therapeutic range, the percentage of patients with therapeutic INRs at discharge, and the 30-day readmission rate.
Twenty-six patients were included in the review. The median initial warfarin dosage was 0.07 mg/kg/d (interquartile range [IQR], 0.05-0.10 mg/kg/d). Of the total of 177 INR values collected during the entire study period, 67 (37.9%) were therapeutic, 64 (36.2%) were subtherapeutic, and 46 (26.0%) were supratherapeutic. Eighteen patients (69.2%) had at least 1 supratherapeutic INR at any point during the study period, most frequently on days 2 through 4 of therapy. At discharge, 11 patients (42.3%) had therapeutic INRs. Four patients (15.4%) were readmitted within 30 days, with bleeding documented in 2 patients during their readmission.
The majority of patients received an initial warfarin dose less than that specified in published recommendations but still had a supratherapeutic INR at least once during the study period. When initiating warfarin after CTS, a dosage of <0.1 mg/kg per day and frequent monitoring may be needed to achieve an INR goal of 1.5 to 2.0.
国际标准化比值（INR）目标为1.5至2.0的预防性华法林是心胸外科手术（CTS）后儿童使用的一种抗血栓治疗方法；已发表的资料表明，每日剂量为0.1mg/kg可达到这一目标。然而，很少有研究评估该人群的给药情况。本研究的目的是评估CTS后接受华法林治疗的儿童的给药情况和安全性结果。
进行了一项描述性回顾性研究，以评估2014年1月至2018年12月期间接受CTS并接受预防性华法林治疗、INR目标为1.5至2.0的18岁及以下患者的华法林给药情况和INR结果。主要目的是确定初始华法林剂量的中位数。次要目的包括确定记录的INR值超出治疗范围的百分比、出院时INR处于治疗范围的患者百分比以及30天再入院率。
26名患者纳入回顾。初始华法林剂量中位数为0.07mg/kg/d（四分位间距[IQR]，0.05 - 0.10mg/kg/d）。在整个研究期间收集的177个INR值中，67个（37.9%）处于治疗范围，64个（36.2%）低于治疗范围，46个（26.0%）高于治疗范围。18名患者（69.2%）在研究期间的任何时间至少有1次INR高于治疗范围，最常见于治疗的第2至4天。出院时，11名患者（42.3%）的INR处于治疗范围。4名患者（15.4%）在30天内再次入院，其中2名患者在再次入院期间有出血记录。
大多数患者接受的初始华法林剂量低于已发表建议中的规定剂量，但在研究期间仍至少有一次INR高于治疗范围。CTS后开始使用华法林时，可能需要每日剂量<0.1mg/kg并频繁监测，以实现INR目标为1.5至2.0。
