Abstract Number: PB0788
Meeting: ISTH 2021 Congress
Background: Hospitalized children are at increased risk of healthcare acquired venous thromboembolism (HA-VTE). Studies have shown that prophylactic enoxaparin may prevent HA-VTE in hospitalized older children, but not in hospitalized infants <1 year old. Other factors may be associated with HA-VTE despite prophylactic enoxaparin.
Aims: To characterize the biochemical and clinical outcomes of hospitalized children who received prophylactic enoxaparin.
Methods: We conducted a single-center, retrospective study of hospitalized children <18 years old who received prophylactic enoxaparin against HA-VTE. Children received age-based enoxaparin dose, which was adjusted to achieve anti-Xa level of 0.2-0.5 IU/mL. Primary biochemical and clinical outcomes were achievement of goal anti-Xa range and development of HA-VTE, respectively. Secondary clinical outcome was development of clinically relevant bleed.
Results: We analyzed 194 children composed of 13 (7%) infants and 181 (93%) older children. Anti-Xa levels were drawn in 9 (69.2%) infants and 107 (59.1%) older children (p=0.47). Goal anti-Xa range was achieved in 6 (66.7%) infants and 88 (82.2%) older children (p=0.37). Median number of anti-Xa levels prior to goal was 2 (interquartile range, IQR: 2, 3) in infants and 1 (IQR: 1, 2) in older children (p=0.01). HA-VTE developed in 2 (15.4%) infants and 9 (5.0%) older children (p=0.16). Personal history of VTE was associated with HA-VTE (odds ratio, OR: 11.98; 95% confidence interval, CI: 2.30, 62.32). Infant status (OR: 6.25; 95% CI: 0.99, 39.53) and prophylactic enoxaparin started within 3 days after hospital admission (OR: 0.25; 95% CI: 0.06, 1.07) were marginally associated with HA-VTE. Bleeds developed in none (0%) of the infants and in 4 (2.2%) older children.
Figure 1. 
Distribution of Anti-Xa Levels after the Initial Enoxaparin Dose (A) and the Number of Measurements Prior to Achievement of Goal Range (B) among Hospitalized Children who received Prophylactic EnoxaparinTable 2.
| Variable |
Unadjusted Odds Ratio | 95% Confidence Interval | Adjusted Odds Ratio | 95% Confidence Interval |
| Infant | 3.47 | 0.67, 18.07 | 6.25 | 0.99, 39.53 |
| Obesity | 0.91 | 0.19, 4.38 | ||
| Personal history of VTE | 7.25 | 1.64, 32.06 | 11.98 | 2.30, 62.32 |
| Congenital Heart Disease | 2.49 | 0.49, 12.58 | ||
| Cancer | 3.06 | 0.75, 12.47 | ||
| Surgery | 1.3 | 0.38, 4.4 | ||
| Trauma | 0.4 | 0.08, 1.92 | ||
| Admission to the Intensive Care Unit | 3.5 | 0.73, 16.63 | ||
| Sequential compression device | 1.26 | 0.37, 4.27 | ||
| Central venous catheter | 5.92 | 1.25, 28.19 | ||
| Patient on other anticoagulant | 1.47 | 0.30, 7.23 | ||
| Early prophylaxis | 0.27 | 0.07, 1.04 | 0.25 | 0.06, 1.07 |
| Starting dose | 9.37 | 0.92, 95.27 | ||
| Hemoglobin | 1.13 | 0.89, 1.44 | ||
| Platelet | 1 | 0.99, 1 | ||
| Anti-Xa Measured | 0.54 | 0.16, 1.84 |
Factors Associated with Healthcare-Acquired Venous Thromboembolism (VTE) among Hospitalized Children who received Prophylactic Enoxaparin
Conclusions: HA-VTE developed in hospitalized children despite prophylactic enoxaparin. HA-VTE among infants seemed related to delay in achieving goal anti-Xa range. Early administration of therapeutic enoxaparin may prevent HA-VTE in infants and in those with personal history of VTE.
To cite this abstract in AMA style:
Bennett E, Delgado Corcoran C, Heyrend C, Wilcox R, Pannucci C, Faustino V. Outcomes of Prophylactic Enoxaparin against Venous Thromboembolism in Hospitalized Children [abstract]. Res Pract Thromb Haemost. 2021; 5 (Suppl 2). https://abstracts.isth.org/abstract/outcomes-of-prophylactic-enoxaparin-against-venous-thromboembolism-in-hospitalized-children/. Accessed September 29, 2023.« Back to ISTH 2021 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/outcomes-of-prophylactic-enoxaparin-against-venous-thromboembolism-in-hospitalized-children/