Enoxaparin Prophylaxis Not Associated With Reduced Need for Blood Transfusion in Children With Severe Ulcerative Colitis

Investigators assessed the safety and efficacy of enoxaparin as thromboprophylaxis in children hospitalized with severe ulcerative colitis.

Among children hospitalized with severe ulcerative colitis (UC), enoxaparin prophylaxis was not associated with a significant decrease in hemoglobin (Hb) or need for blood transfusion compared with those who did not receive enoxaparin, researchers reported in the Journal of Pediatric Gastroenterology and Nutrition.

The retrospective cohort study assessed the safety of enoxaparin thromboprophylaxis in children with UC aged <18 years who were admitted to a pediatric hospital in Canada from 2007 to 2016.

The Pediatric Ulcerative Colitis Activity Index (PUCAI) score was used to determine clinical disease activity — PUCAI <10, mild disease (PUCAI 10-34), moderate disease (PUCAI 35-64), and severe disease (PUCAI ≥65). Primary outcomes were the likelihood of subsequent packed red blood cell (pRBC) transfusions and variation in Hb levels during a 7-day period following admission.

A total of 218 patients diagnosed with UC were included; those who received enoxaparin (n=88; median age, 14.6 years; 42% boys) were compared against those who did not (n=130; median age, 13.3 years; 56.9% boys).

A statistically significant difference was observed in the decrease in Hb levels between the enoxaparin prophylaxis group and the nonenoxaparin-treated group (P =.003) the week following hospital admission, when all patients were included in analysis. Participants who had severe UC were also analyzed separately, and those treated with enoxaparin did not have a greater Hb decrease vs those not treated with enoxaparin (P =.60).

A total of 9 patients received enoxaparin before general care changes were implemented in 2011, 6 of whom had severe UC. When these patients were excluded, there was no longer a difference in Hb change between the 2 groups (P =.45).

No statistically significant difference was found (log-rank test, P =.80; Cox proportional hazard, P =.72) in the proportion of patients who received a pRBC transfusion in the week after admission between nonenoxaparin-treated patients (3.85%; 95% CI, 1.62%-8.99%) and enoxaparin-treated patients (4.55%; 95% CI, 1.73%-11.66%). In addition, no significant difference was observed (log-rank test, P =.88; Cox proportional hazard, P =.85) among patients with severe UC between the nonenoxaparin-treated group (4.08%; 95% CI, 1.04%-15.35%) and enoxaparin-treated group (4.69%; 95% CI, 1.54%-13.83%).

Potential study limitations include the retrospective, observational design from a single pediatric medical center, the small study population, and the lack of protocolization for UC care, including the need for transfusions.

“There was no significant difference in the risk of requiring pRBC transfusion between children with UC receiving enoxaparin as [venous thromboembolism] prophylaxis compared with those that did not receive enoxaparin,” stated the investigators. “Along with implementation, larger studies, prospective trials, comparison of other options for VTE prophylaxis, and whether there are benefits for extension of VTE prophylaxis following hospital discharge are all important questions needing study,” they concluded.


Story E, Bijelic V, Penney C, Benchimol EI, Halton J, Mack DR. Safety of venous thromboprophylaxis with low-molecular-weight heparin in children with ulcerative colitis. J Pediatr Gastroenterol Nutr. 2021;73(5):604-609. doi: 10.1097/MPG.0000000000003231