Pediatric Sickle Cell Disease Population Research Articles

Peak Systolic Velocity Measurements with Transcranial Doppler Ultrasound Is a Predictor of Incident Stroke among the General Population in China.

Background and ObjectiveIt is necessary to develop an effective and low-cost screening tool for identifying Chinese people at high risk of stroke. Transcranial Doppler ultrasound (TCD) is a powerful predictor of stroke in the pediatric sickle cell disease population, as demonstrated in the STOP trial. Our study was conducted to determine the prediction value of peak systolic velocities as measured by TCD on subsequent stroke risk in a prospective cohort of the general population from Beijing, China.MethodsIn 2002, a prospective cohort study was conducted among 1392 residents from 11 villages of the Shijingshan district of Beijing, China. The cohort was scheduled for follow up with regard to incident stroke in 2005, 2007, and 2012 by a study team comprised of epidemiologists, nurses, and physicians. Univariate and multivariate Cox proportional hazard regression models were used to determine the factors associated with incident stroke.ResultsParticipants identified by TCD criteria as having intracranial stenosis had a 3.6-fold greater risk of incident stroke (hazard ratio (HR) 3.57, 95% confidence interval (CI) 1.86–6.83, P<0.01) than those without TCD evidence of intracranial stenosis. The association remained significant in multivariate analysis (HR 2.53, 95% CI 1.31–4.87) after adjusting for other risk factors or confounders. Older age, cigarette smoking, hypertension, and diabetes mellitus remained statistically significant as risk factors after controlling for other factors.ConclusionsThe study confirmed the screening value of TCD among the general population in urban China. Increasing the availability of TCD screening may help identify subjects as higher risk for stroke.

A Patient Event Diary Improves Self-Management In Pediatric Sickle Cell Disease Patients

IntroductionPromotion of chronic illness self-management is crucial to improve outcomes of children with sickle cell disease (SCD). Improvements in patient outcomes and quality of life as well as enhancement in health literacy and patient agency are also imperative. Through an event diary developed by the Bronx Lebanon Hospital Sickle Cell Program, our pediatric SCD patients are better able to track significant health events and health care appointments. This study seeks to validate the effectiveness of the patient event diary as a tool for improvement in self management, allowing for improvement in medication and clinic visit compliance, as well as in a reduction in number of emergency room visits. Additionally, the education section at the beginning of the diary has become an integral teaching tool and reference for patients and their families. It is our hypothesis that the event diary as an educational tool, a self management tool, and a tool for providers, will lead to better management of chronic illness and improved patient outcomes. MethodsWe utilized laboratory and demographic data from the Bronx Lebanon Hospital Center patient electronic medical record between July 2011 and July 2013. Our sample included a population of 50 sickle cell disease patients aged 0 to 21, median age being 7 years. Sickle cell disease types included SS (64%), SC (32%), Sβ+ thalassemia and Sβ0thalassemia (4%). We used a paired, two tailed t-test to assess patients' medication compliance on vitamin D (22 patients) and hydroxyurea (14 patients) through 25-hydroxyvitamin D (25-OHD) and MCV (mean corpuscular volume) levels, respectively. Increased MCV was used as a proxy to indicate improved medication compliance in patients on hydroxyurea. We compared patients on hydroxyurea and vitamin D six months before receiving the event diary and six months after.Additionally, we compared compliance with hematology clinic visits one year before and one year after receiving the event diary. We also compared the number emergency room visits during the year before and the year after patients received the event diary. Results25-OHD data from six months after receiving the event diary showed significantly improved compliance with vitamin D treatment (M = 47, SD = 20) as compared to six months before receiving the event diary (M = 26, SD = 15), t(20) = 2.1, p < 0.05. Additionally, there was a statistically significant improvement in MCV levels six months after receiving the event diary (M=101.6, SD=9.6), as opposed to six months before receiving it (M=97.7, SD=5.6), t(12)=2.2, p<0.05. When looking at patient hematology clinic appointment compliance, there was an improvement, however not statistically significant, in compliance with appointments between one year before (M=33.3%, SD=41.7%) and one year after patients received the event diary (M= 27.2%, SD=30.3%), t(17)=2.1, p=0.2. Emergency department visits did decrease, however not significantly, one year before receiving the event diary (M=1.8, SD=2.5) to one year after receiving the event diary (M= 1.3, SD=1.9), t(47)=2.0, p=0.17. ConclusionsThese data suggest the patient event diary has significantly improved patient self-management. We believe this effect is due to enhanced understanding of disease processes and increased confidence and skills in self-management of the disease. There is improved compliance with hydroxyurea and vitamin D, as well as a trend toward improvement in clinic visit compliance and decreased emergency room visits. The patient event diary is crucial to improved patient outcomes in the pediatric SCD population, and may be useful for other pediatric populations with chronic illness. It is a significant part of our current practice and our ability to teach and empower patients and their families to manage sickle cell disease while at home. Additionally, this tool allows for better management of patients by providers. The event diary helps to elucidate difficulties in patient self-management and gives better insight into complications patients are experiencing at home. In the future, we hope to see that with improved patient knowledge of sickle cell disease and self-management facilitated by use of the event diary, there will be significantly fewer emergency room visits, fewer hospital admissions, and most important, quality of life. Disclosures:Moulton:HRSA: Research Funding; New York State Grant: Research Funding.

Epidemiology of Bloodstream Infections in Children with Sickle Cell Disease

The incidence of invasive Streptococcus pneumoniae and Haemophilus influenzae type b infections in the sickle cell disease population has declined. In this report, we determine the predominant organisms responsible for bloodstream infections in a pediatric sickle cell disease population during the postheptavalent conjugate vaccine era. Central venous access device associated infections are a new burden to efforts aimed at preventing bloodstream infections in this population.

Early Detection of Renal Dysfunction in Pediatric Sickle Cell Patients

AbstractAbstract 1017▪▪This icon denotes a clinically relevant abstractIn sickle cell disease, patients are predisposed to renal dysfunction and eventual renal failure as they reach adulthood. Many advances have been made within the field of sickle cell anemia, yet to this day sickle cell nephropathy remains an important cause of mortality in adult patients. Previous studies have determined that proteinuria and hematuria are two useful markers of sickle cell nephropathy. Currently, the best marker for detecting early renal dysfunction is proteinuria on urine dipstick due to its ease of use and efficiency. Our goal in this study is to determine the age at which the first signs of renal dysfunction appear.Pediatric patients with sickle cell disease were selected for a retrospective chart review to determine age of onset for renal abnormalities. The sickle cell pediatric roster was used from the Children’s Hospital University of Illinois to study a total of 175 patients within the age range of 0–31 years. Urinalysis was captured at patient’s baseline when available and possible risk factors for glomerular dysfunction were studied. Factors such as urine protein and blood on dipstick were recorded and proteinuria was further quantified by using the urine protein to creatinine ratio. Blood on dipstick was further analyzed by red blood cells on microscopic urinalysis. Patients with positive urine for blood on dipstick with <5 RBCs on microscopic UA were marked as patients with hemoglobinuria. Other factors such as sickle cell hemoglobin type, LDH, reticulocyte count, HbF, and hydroxyurea treatment were also recorded to look for correlation with predictors of early renal dysfunction. The Fisher’s exact test was used to compute the (two-tailed) probability.Urinalysis results were available for 141 of the 175 pediatric patients from the sickle cell roster. From the 141 patients that were studied 65% of the patients had urinalysis done at baseline, the other 35% had UA when acutely ill. The mean overall age was 9.9 years and a total of 25 of the 141 (17.7%) patients were observed to have proteinuria on dipstick. In the proteinuria group, 64% of the UA were obtained at baseline and the other 36% were during a sick visit. The majority (66%) of these ‘sick' patients were febrile under the age of 7. Obtaining a UA during an acute illness could skew our results since pediatric patients who are acutely ill may have transient proteinuria but none at baseline. In our pediatric sickle cell population, about 14% had hemoglobinuria. Analysis of only baseline UA showed that no patients under the age of 5 at baseline had proteinuria and there is a strong correlation between age and proteinuria (R2 = 0.81, p<0.02). Similarly there is a correlation between age and hemoglobinuria (R2 = 0.57). Hemoglobinuria is occasionally observed in 11.4% of children <5 years of age, and at 12.9% in the teenage group. A significant increase in incidence of hemoglobinuria is noted in the young adults (40%). Of the 16 patients with hemoglobinuria only 8 had concurrent proteinuria. A larger sample size is needed to determine whether proteinuria and hemoglobinuria are independent versus correlated markers of early renal dysfunction. Preliminary analyses of baseline UA found no correlations between proteinuria and Hb level, LDH, reticulocytes, serum creatinine, or creatinine clearance.From this retrospective chart review in this pediatric sickle cell disease population, it can be deduced that proteinuria becomes a concern in sickle patients in the adolescent years while hemoglobinuria appears in late teen to young adult years. It can be concluded that the first clinical signs of renal dysfunction which lead to nephropathy in sickle patients are more frequently seen in adolescent to late teen years and this is likely the marks the beginning of the deterioration of kidney function. Further studies are needed for multivariate analysis of other markers (GFR, Cr, Cr Clearance) of nephropathy and to improve early detection of renal dysfunction by conducting longitudinal studies. Our goal is to improve our current practice by routine screening in sickle patients to preserve renal function and improve the morbidity and mortality related to sickle cell nephropathy in the aging patient. [Display omitted] [Display omitted] [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Examination of Risk and Resiliency in a Pediatric Sickle Cell Disease Population Using the Psychosocial Assessment Tool 2.0

To evaluate the Psychosocial Assessment Tool 2.0 (PAT) as an appropriate screening measure of risk for patient and family psychological distress in pediatric sickle cell disease (SCD). 219 caregivers completed the PAT during regular hematology clinic visits. Confirmatory factor analysis and tests of reliability were conducted. Multilevel modeling examined change and predictors of risk scores across four assessments. Confirmatory factor analysis factor loadings ranged from .03 to .81, and reliability coefficients ranged from .43 to .83. Risk for patient and sibling emotional problems, family problems, and parent stress reaction decreased over time. Increased patient age, chronic blood transfusion, lower caregiver education, caregivers being divorced, fewer adults and more children in the home, and greater financial difficulties were independent predictors of psychosocial risk. Results suggest that the PAT has utility in a pediatric sickle cell disease sample. Most caregivers reported low distress and high resiliency factors in this population.

Pneumococcal Bacteremia in a Vaccinated Pediatric Sickle Cell Disease Population

The incidence of pneumococcal disease in sickle cell disease declined significantly with penicillin prophylaxis as well as with the pneumococcal polysaccharide and heptavalent conjugate vaccines. In this report, we describe our experience with pneumococcal bacteremia in pediatric patients with sickle cell disease in the post-heptavalent pneumococcal conjugate vaccine era. Despite established prophylactic strategies, pneumococcal bacteremia continues to occur in patients with sickle cell disease.

Disparities In Pulmonary Complications of Sickle Cell Disease

AbstractAbstract 2645 RATIONALE:Pulmonary complications are of particular importance in patients with sickle cell disease (SCD) as they are commonly associated with high morbidity and mortality. Research suggests that children with both SCD and asthma have higher morbidity as measured by more frequent hospitalizations for vaso-occlusive crises and acute chest syndrome episodes, and as much as double the risk of mortality when compared to pediatric SCD patients without asthma. Therefore, the diagnosis of reactive airway disease in pediatric SCD patients is clearly a poor prognostic factor. However, it is currently not known whether there is any degree of modifiable risk associated with aggressive empirical treatment of asthma in the pediatric SCD population. Although SCD disproportionately affects people of African and Latino ancestry, there is no clear linkage of SCD with socioeconomic status. HYPOTHESIS:Low socioeconomic status, as determined by zip code distribution in the Washington Metropolitan Area, correlates with higher rates of acute pulmonary complications in pediatric SCD patients as it does in asthmatic children without SCD. Methods:A five-year retrospective chart review examined the records of 400 children randomly sampled from the 950 SCD patients seen at Children's National Medical Center in the past two years. Information extracted from the electronic medical record (Cerner PowerChart system) included hematological, pulmonary as well as demographic patient information. Patients with insufficient data because of young age or care at other hospitals were excluded. Median household incomes from 2008 were linked to zip codes in various regions of the Washington Metropolitan Area and results were then analyzed using non-parametric statistical methods. Asthma data was obtained from DC Burden of Asthma 2009 project. The Mann Whitney U test was used to test for differences in the properties between pediatric SCD patients with a diagnosis of reactive airway disease versus those without a diagnosis of reactive airway disease. Findings associated with a p-value of less than 0.05 were considered statistically significant. Results:Among the 400 pediatric SCD patients analyzed, there was a strong inverse relationship between socioeconomic status and the rate of acute chest syndrome episodes (mean number of episodes per patient per year). The rate of acute chest syndrome episodes was 0.20 for all of Washington DC (n=56), 0.15 for Prince George's County (n=147), 0.10 for Montgomery County (n=81), and 0.04 for Fairfax County (n=33), which had median household incomes of $58k, $72k, $94k, and $107k, respectively. Pediatric asthma diagnoses and need for pediatric asthma care showed similar distribution: Washington DC regions with the lowest income, such as Ward 8, had the highest rates of Emergency Department visits for asthma care. Acute chest syndrome episodes were also significantly more prevalent in children diagnosed with asthma, 18.75% of the total sample, as compared to those with no history of asthma (p < 0.05). Overall, pediatric SCD patients with reactive airway disease had a rate of 0.30 acute chest syndrome episodes per patient per year, while those without reactive airway disease had a rate of 0.16 episodes. The data suggest that the strongest association between asthma and sickle cell acute chest syndrome episodes for the Metropolitan Area is amongst residents of DC and Prince George's County; both of which were in the lowest range of median household incomes of the regions studied. Ward 8 had the highest disparity between the rates of acute chest syndrome episodes in patients with reactive airway disease (0.66) and those without reactive airway disease (0.16), a 4-fold difference; again, Ward 8 represents the lowest median household income in Washington DC ($26k). Discussion:Socioeconomic status as marked by geographical distribution appears to be a strong source of diversity in pulmonary complications of pediatric SCD patients in the Washington Metropolitan Area. Low-income areas have higher rates of asthma and also as much as 5-fold higher rates of sickle cell acute chest syndrome, compared to higher-income areas. Children with an asthma diagnosis had 2-fold higher rates of acute chest syndrome overall, but 4-fold higher in low income areas such as Ward 8. These data are subject to the limitations of a retrospective chart review, but the results set the stage for future prospective studies. Disclosures:No relevant conflicts of interest to declare.

Criterion and Convergent Validity for 4 Measures of Pain in a Pediatric Sickle Cell Disease Population

To evaluate the psychometric properties of 4 measures of acute pain in youth with sickle cell disease (SCD) during a medical procedure. Heart rate, child self-report, parent proxy-report, and observable pain behaviors were examined in 48 youth with SCD ages 2 to 17 years. Criterion validity for acute pain was assessed by responsiveness to a standardized painful stimulus (venipuncture) in a prospective pre-post design. Convergent validity was evaluated through the correlation across measures in reactivity to the stimulus. Child self-reported pain, parent proxy-report, and behavioral distress scores increased in response to venipuncture (concurrent and convergent validity). In contrast, heart rate did not reliably change in response to venipuncture. Extent of change in response to venipuncture showed moderate intercorrelation across child and parent pain ratings, and behavioral distress. Preprocedure pain ratings correlated with pain experienced during the procedure. An item analysis of observable pain behaviors suggested differences in the presentation of pain in SCD compared with previous pediatric research. Criterion and convergent validity were demonstrated for child-report, parent-report, and observable pain behaviors. These measures seem to tap into distinct, yet overlapping aspects of the pain experience. Assessment of acute procedural pain responses in SCD requires evaluation of preprocedural pain due to the frequent presence of low-level, baseline pain.

Pulmonary Hypertension in Pediatric Patients with Sickle Cell Disease; a Retrospective Study.

Background: While pulmonary hypertension (PHT) contributes significantly to the morbidity and mortality of adults with sickle cell disease (SCD), it has not been studied in pediatric SCD patients. We sought to evaluate the prevalence and significance of PHT in pediatric SCD population.Methods: From May 1999 to July 2004, 123 echocardiograms were performed in SCD patients. Utilizing the tricuspid valve regurgitant jet, right ventricular systolic pressure (RVSP) was estimated in 56 studies (47 patients, aged 0 to 18 years). PHT was defined as RVSP >30 mmHg.Mean steady-state as well as the most recent white blood count (WBC), hemoglobin (Hb) level, reticulocyte count, ferritin level, and number of red cell units transfused in the year prior to the study were noted. In addition, all chest X-ray readings were reviewed to determine the number and type of life-time pulmonary events (effusions, infiltrates, pneumonia, atelectasis or CHF) in each patient. Acute chest syndrome (ACS) was determined to be any effusion, infiltrate or pneumonia.Statistical analysis included Fisher's exact test and Spearman's correlation coefficients.Results: Eleven patients were acutely ill at the time of the echocardiogram and were excluded from the analysis. Of the remaining 36 patients, pulmonary hypertension was present in 24 (66%). There was a significant difference in RVSP between younger (0 to 9 years) and older (10 to 18 years) groups of patient (p<0.004). There was a positive correlation between the age and RVSP (r = 0.36; p = 0.031).A significant negative correlation was shown between RVSP and most recent Hb (r = −0.41; p = 0.012) as well as RVSP and the mean steady state platelet count (r = −0.35; p = 0.035). A positive correlation was found between RVSP and the number of ACS episodes (r = 0.37; p = 0.024), RVSP and mean steady state reticulocyte count (r = 0.51; p = 0.002) as well as the most recent reticulocyte count (r = 0.42; p = 0.012). There was however, no correlation found between RVSP and the number of episodes of CHF, collapse or atelectasis separately or grouped together. No correlation was found between RVSP and the number of units transfused or ferritin level.Conclusion: Pulmonary Hypertension is highly prevalent in the pediatric SCD population and its prevalence increases with age. It correlates with indicators of acute and chronic hemolysis as well as the number of ACS events. Our study did not demonstrate correlations between PHT and iron overload indices. Prospective clinical trials monitoring PHT in SCD pediatric patients are indicated.