Prophylactic Enoxaparin Against Catheter-Associated Thrombosis in Postoperative Cardiac Children: An Interrupted Time Series Analysis.

Abstract

The effectiveness of pharmacologic prophylaxis against catheter-associated thrombosis in children is unclear. We evaluated the compliance and outcomes associated with a prophylactic enoxaparin protocol in postoperative cardiac children. The protocol was implemented as a quality improvement initiative and then analyzed using interrupted time series method. Data collected from November 2014 to December 2018 were divided into preprotocol (period 1), protocol implementation (period 2), and protocol revision (period 3). A 12-bed academic pediatric cardiac ICU. Children less than or equal to 18 years old with congenital heart disease admitted postoperatively with central venous catheter in situ for greater than or equal to 1 day. Before 2016, prophylactic enoxaparin was administered according to physician preference. In January 2016, an enoxaparin protocol was implemented with a goal anti-Xa range of 0.25-0.49 international units/mL. Protocol was revised in February 2017 to increase the starting dose by 25% for infants less than 1 year old. We analyzed 780 hospitalizations from 636 children. Median percentage of catheter-days on prophylactic enoxaparin was 33% (interquartile range [IQR], 23-47%), 42% (IQR, 30-51%), and 38% (IQR, 35-52%) in periods 1-3, respectively. Percentage of catheter-days on enoxaparin showed immediate increase of 90% (95% CI, 17-210%) between periods 1 and 2 and sustained increase of 2% (95% CI, 0.3-4%) between periods 2 and 3. Median rates of thrombosis per 1,000 catheter-days were 5.8 (IQR, 0-9.3), 3.8 (IQR, 0-12), and 0 (IQR, 0-5.3) in periods 1-3, respectively. Rate of thrombosis showed immediate decrease of 67% (95% CI, 12-87%) between periods 1 and 2 and sustained decrease of 11% (95% CI, 2-18%) between periods 1 and 3. The temporal association between increase in percentage of catheter-days on enoxaparin and decrease in rate of thrombosis suggests the effectiveness of prophylactic enoxaparin.