A Retrospective Study of Adult and Pediatric D‐Dimer Tests to Identify Opportunities for Improved Utilization

FIGURE 1. D‐dimer levels for adult and pediatric patients and the reasons for their D‐dimer assessments. The upper panel illustrates the very similar distributions of D‐dimer levels for consecutive adult and pediatric cases, and all adult cases for the 9‐month period evaluated (repeats included). The lower panel pie charts illustrate the reasons for D‐dimer tests among consecutive pediatric and adult patients. Among patients assessed during chimeric antigen receptor (CAR) T‐cell therapy, all were adults, evaluated before and during CAR T‐cell therapy, whereas one pediatric patient who previously received CAR T‐cell therapy had D‐dimer evaluated as part of coagulopathy investigations. DIC, disseminated intravascular coagulation; VTE, venous thromboembolism.

FIGURE 2. Distribution of D‐dimer levels above the cutoff among consecutive pediatric and adult patients who had D‐dimer assessed for different reasons. First D‐dimer results during the period of evaluation are shown. Results shown were above age‐specific cutoffs for children and above the validated cut‐off of ≥ 500 μg/L for adults. There was a wide range of abnormal findings, and overlap in D‐dimer levels, for the groups evaluated, with whiskers indicating the minimum and maximum values and boxes indicating the interquartile range and median values. CAR, chimeric antigen receptor; DIC, disseminated intravascular coagulation; VTE, venous thromboembolism.

FIGURE 3. Reasons for D‐dimer tests among consecutive patients who had five or more D‐dimer tests over a period of care. The percentages tested for different reasons are shown. CAR, chimeric antigen receptor; DIC, disseminated intravascular coagulation; ECMO, extracorporeal membrane oxygenation; VTE, venous thromboembolism.

FIGURE 4. Temporal changes in D‐dimer levels among patients who had five or more D‐dimer levels to evaluate for DIC secondary to malignancy, infection or other causes, or to monitor CAR T‐cell therapy. Panels show daily changes. Patients who were deceased at discharge are shown with red or black lines and symbols. Patients undergoing CAR T‐cell therapy were routinely monitored for 5 days pre‐infusion and for 3 weeks post‐infusion.