ALBERT

Description: Abstract 2660 Background: Sickle cell disease causes considerable morbidity and mortality. Three guidelines exist for the management of vaso-occlusive pain, although studies have shown that these guidelines are not well followed and that there is considerable variation in care. Investigations of clinical pathways for pediatric sickle cell pain have not been published to our knowledge, but research in other pediatric conditions has shown that the implementation of clinical pathways can improve medical care. We initiated an investigation of the effects of a pain management pathway for sickle cell vaso-occlusive crisis in the emergency department (ED) with the hypothesis that the introduction of a clinical pathway would improve the efficiency and efficacy of acute pain management. Methods: We conducted a prospective, cohort study from February 2009 to March 2010 in an urban, tertiary care ED. We collected data from patients aged 3–18 years old with sickle cell disease who presented to the ED with vaso-occlusive crisis (VOC) pain. Baseline data was collected for five months prior to the introduction of the clinical pathway, followed by a four-week time interval in which the ED physicians and nurses were in-serviced on the pathway, followed by six months in which data was collected with the clinical pathway in place. Our pathway, which is in checklist format with instructions for triage, monitoring, medication administration, and timing of assessments and interventions, was developed by representatives from the divisions of Pediatric Hematology, Pediatric Emergency Medicine, and Pediatric Pain Medicine, Symptom Management and Palliative Care and based upon current standard-of-care guidelines. Results: Over the eleven month study period, 68 patients were enrolled. Random chart audits revealed a 75% capture rate. Significant improvement was demonstrated in time interval to first analgesic from 74 minutes to 42 minutes (p value 0.02), time interval to first opioid from 94 minutes to 46 minutes (p value 〈 0.01), and time interval to subsequent assessment of pain score from 110 minutes to 72 minutes (p value 0.02). The percentage of patients who received ketorolac also increased from 57% to 82% (p value 0.03). Change in pain scores was not significantly different, nor was admission rate. Conclusions: Implementation of a pain management pathway for sickle cell VOC led to an improvement in the time interval to administration of first analgesic and time interval to pain re-assessment, bringing these aspects of patient management closer to accepted guidelines. Whether improvement can be made in admission rates, change in pain ratings, and patient satisfaction will require further study. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 2641 Abstract: Only few genes appear to strongly regulate HbF levels in adults with sickle cell disease (SCD). We aim to: (1) Extend these observations to children with SCD, who likely have better preserved marrow capacity; (2) Assess whether these same genes and other previously identified candidates (Ma et al., 2007) associate with HbF response to HU. Methods: We performed a retrospective analysis from 6 sites (see author affiliations) of children age 5–21 with HbSS or HbS-B thalassemia, untreated with HU or treated for 〉 6 months at comparable indications and dosing, using %HbF at steady state (baseline) and on HU at or near maximal tolerated dose (MTD), defined as 〉20mg/kg/day. Subject adherence to HU was assessed by report to their hematology clinician. Siblings were excluded to ensure genetic independence. Candidate 36 SNPs from 2 groups of genes were genotyped: 1) those from reported GWAS: 15 SNPs in BCL11A, 3 in HBS1L-MYB intron, 5' site in B globin, plus sar1; and 2) 15 candidate SNPs exhibiting the largest effect size on HbF with HU treatment (Ma, 2007). SNP genotyping (minor allele frequency (MAF) ranging from 0.10 to 0.50) was performed on the Sequenom MassArray iPLEX platform. (SNP sequences are available.) Duplicate samples assured genotype concordance. Genotype frequency distribution at each SNP was tested for deviations from Hardy-Weinberg equilibrium. MAFs were comparable across our 6 sites, to allele frequencies in HapMap for CEU populations, and CSSCD (Lettre et al., 2008), confirming validity of pooling SNP genotype data from the sites. Using HbF as a continuous trait, genetic associations were assessed from a total of 80 children, 29 of whom are on HU, between each of the 36 SNPs and: a) baseline %HbF; b) %HbF on HU treatment; c) delta %HbF (HU treatment - baseline). For each model, linear regression analysis was used to test quantitative trait and disease trait SNP associations assuming an additive effect for each copy of the minor allele on the phenotype. Resultant p-values were assessed for significance using Bonferroni adjustment for multiple testing. Results: Of the 80 children, comparing the 51 not on HU to those 29 on HU, no significance differences were seen in the distribution and average of baseline %HbF (9.2 vs. 8.9, p=0.820). SNP analyses are summarized in Table 1. 8 SNPs were nominally significantly associated with baseline %HbF. Direction of SNP association differed among these SNPs; some MAF may be reversed in this population compared to those previously reported. For %HbF on HU, the B globin SNP was significantly associated. The delta %HbF on HU is significantly associated with the B globin SNP and nominally so with BCLA11 and SAR1A gene. Our preliminary data begin to extend findings of specific genetic variants regulating HbF to children with SCD. Early data suggest that HbF in response to HU may share some of the mechanisms governing baseline HbF in SCD, not surprising given the commonality of enhanced erythropoiesis. Subject recruitment and analyses are on-going. Disclosure: Off Label Use: Hydroxyurea has not been FDA approved for use in children with sickle cell disease, a topic of the submitted abstract.