Impact of Hydroxyurea On Peri-Operative Management and Outcomes in Children with Sickle Cell Anemia.

Surgical procedures in children with sickle cell anemia (SCA) can be complicated by vasoocclusive events (VOE) such as acute chest syndrome (ACS) and pain. Peri-operative management requires a multidisciplinary approach to provide appropriate pre-operative intravenous hydration and intra- and post-operative monitoring. Transfusion therapy has been controversial. Our institution previously described a low incidence of complications in children who received serial transfusions over 3-4 weeks prior to surgery. Subsequently, an increasing number of children have been prescribed hydroxyurea (HU) to prevent SCA complications. In general, children on HU at our institution only receive a single top-off transfusion the day prior to surgery if their hemoglobin is less than 10 g/dL. We hypothesized that children in the HU group would have a lower number of serial transfusion compared to the non-HU group and that there would be no difference in complications or days to discharge between the two groups. We conducted a single-institution retrospective cohort study of children with SCA, who were age less than 18 years and underwent at least one surgical procedure at Duke University Medical Center between January 1, 2003 and April 30, 2008. Data were abstracted from electronic and written medical records. Descriptive statistics were used to characterize the cohort. Wilcoxon test was used to compare continuous variables and Pearson test was used to compare categorical variables between the non-HU and HU groups. Fifty-three subjects were included (Table 1). The non-HU group was significantly younger than the HU group, but children in the non-HU group were significantly more likely to be transfused pre-operatively, primarily with serial transfusions or erythrocytopheresis, compared to the HU group. One subject in the non-HU group developed a pre-operative delayed hyperhemolytic transfusion reaction. Post-operative complications are detailed in Table 1; the overall rate was low. Two subjects in the HU group developed acute chest syndrome despite pre-operative transfusion; one episode was likely related to underlying asthma and poor response to hydroxyurea; the second was likely related to pain and hypoventilation after laparoscopic splenectomy and tonsillectomy/adenoidectomy. Overall, there were no significant differences in complications and no significant difference in days to discharge between the two groups. In summary, children with SCA on HU may safely undergo surgery without significantly reducing their percent HbS. Nonetheless, attention should still be made towards multidisciplinary effort to reduce intra- and post-operative complications, and clinicians should consider response to HU, pulmonary status and type of surgery when planning peri-operative management in children with SCA on HU.

Off Label Use: hydroxyurea in young children.