The incidence of thrombocytopenia after cardiopulmonary bypass in children with Down syndrome

OBJECTIVES
We investigated the incidence of thrombocytopenia in pediatric patients with Down syndrome following cardiac surgery for congenital heart disease.

STUDY DESIGN
We retrospectively evaluated 162 patients (81 girls, 81 boys; mean age 26.1±39.5 months) who underwent total surgical correction for congenital heart disease. The patients were divided into two groups with respect to the presence (n=118) or absence (n=44, controls) of Down syndrome. Platelet counts were performed preoperatively and on days 1 to 7 after surgery and thrombocytopenia was defined as a platelet count of less than 100,000/mm3.

RESULTS
The incidence of thrombocytopenia was significantly higher in patients with Down syndrome compared to controls (61.9% vs. 34.1%, p=0.002). Severe thrombocytopenia was observed in 22% and 4.6% of cases with and without Down syndrome, respectively. Postoperative platelet counts showed sharp decreases in both groups, bottoming out on day 3 and with more significant decreases in patients with Down syndrome; they started to rise on day 4, but remained lower than baseline levels on day 7. The only significant differences between the two groups in preoperative and postoperative variables were higher incidences of reintubation (26.3% vs. 9.1%, p=0.003) and complications during intensive care (50.9% vs. 27.3%, p=0.007) in cases with Down syndrome. Comparison of patients with and without thrombocytopenia independent of Down syndrome yielded significant differences for thrombocytopenic patients with respect to age, operation age, the presence of cyanosis, type of surgery and operation time, aortic clamp and bypass times, lengths of intensive care and hospital stay, intubation and chest tube drainage times, and the incidence of postoperative complications (p<0.05).

CONCLUSION
Despite higher incidence of thrombocytopenia, the presence of Down syndrome was not associated with significant differences other than increased reintubation requirement and higher complication rate during intensive care.