Feasibility and preliminary efficacy of the Balance Program to reduce pain-related disability in pediatric sickle cell disease

BACKGROUND

Sickle cell disease (SCD) pain is associated with functional impairment, and treatment is often limited to pharmacological approaches with unwanted side effects. Although behavioral interventions exist for non-SCD pain populations, interventions designed to address pain-related impairment in SCD are lacking.

METHODS

Twenty youth (9-17 years) with SCD completed a four-week telemedicine pain intervention (NCT04388241). Participants and caregivers completed baseline and post-intervention PROMIS pain measures and the Treatment Evaluation Inventory-Short Form (TEI-SF). Descriptive analyses assessed feasibility and acceptability. Reliable Change Index analyses assessed for significant post-intervention changes in pain functioning. Paired t test analyses compared baseline and post-intervention opioid prescription fills.

RESULTS

All participants completed at least one treatment session. Eighteen (90%) youth completed all sessions. Youth (100%) and caregivers (94%) rated the intervention as moderately or highly acceptable on the TEI-SF. Forty-seven percent of caregivers and 44% of youth reported reliably significant improvements in pain interference after the intervention (median T-score differences: 24.8 and 23.5, respectively). Sixty-five percent of caregivers (T-score improvement difference: 19.3) and 31% of youth (T-score improvement difference: 32) reported improvements in pain behaviors. There was no significant difference in opioid prescription fills pre- and post-intervention (P > 0.05).

CONCLUSIONS

The Balance Program is feasible, highly acceptable, and can be delivered remotely to reduce barriers to care. Approximately half of youth and caregivers reported significant declines in pain interference following the intervention, with substantial improvements in functioning for treatment responders. Behavioral pain interventions are important adjunctive treatments to uniquely address functional impairment associated with acute and chronic pain in SCD.

Optimising the screening for haemoglobinopathies in pregnancy planning

Haemoglobinopathies are among the most common inherited disorders around the world. In the United States the diagnosis of haemoglobinopathy or a carrier state is made by universal newborn screening. However, many individuals of childbearing age do not know they are a haemoglobinopathy carrier. Screening for common haemoglobinopathies is generally offered as a part of pregnancy planning so that prospective parents can be counselled regarding the risk of having a child with a haemoglobinopathy. Multiple tests exist to screen patients for presence of haemoglobinopathy carrier or disease state; however, it is crucial to order and interpret the results correctly to appropriately counsel couples. In this case series, we describe clinical scenarios where prospective parents were surprised to unexpectedly have a child with sickle cell disease, a haemoglobinopathy that causes severe clinical complications. Through these cases we demonstrate that deficiencies in testing can occur at different levels which may lead to incorrect estimation of the risk of having a child affected by a haemoglobinopathy. Consultation with a haematologist, laboratory medicine specialist, or genetic counsellor should be considered to select the appropriate test and interpret its results.

The evolution of the COVID-19 pandemic in paediatric patients with sickle cell disease: From Alpha to Omicron

We compare the impact of SARS-CoV-2 variants on healthcare utilization and clinical presentation in paediatric patients with sickle cell disease (SCD). One hundred and ninety-one unique patients with SCD and positive SARS-CoV-2 polymerase chain reactions were identified between March 2020 and January 2022. Hospitalizations, which accounted for 42% (N = 81) of cases, were highest during the Delta dominant era (48%) and lowest during Omicron (36%) (p = 0.285). The most common SCD-related complication was vaso-occlusive pain (37%, N = 71), which accounted for 51% of all hospital admissions (N = 41), and acute chest was highest in the Alpha variant era (N = 15). Overall, COVID-19 remained mild in clinical severity within most paediatric SCD patients.

Neurocognitive and emotional factors predict pain-related healthcare utilization in children with sickle cell disease

BACKGROUND

Youth with sickle cell disease (SCD) experience increased rates of neurocognitive and emotional difficulties. Cross-sectional studies suggest neurocognitive and emotional functioning are associated with health outcomes in SCD. We investigated whether neurocognitive and emotional factors predicted future pain-related healthcare utilization in children with SCD.

PROCEDURE

Total 112 youth with SCD between ages 7 and 16 years reported sociodemographics and completed measures of neurocognitive functioning and emotional well-being. The number of emergency department (ED) visits and hospitalizations for pain 1 and 3 years after enrollment were determined by chart review.

RESULTS

The mean age of participants was 10.61 years (standard deviation = 2.91), with most being female (n = 65; 58%). Eighty-three (74%) participants had either HbSS or HbSβ⁰ thalassemia. Regression analyses showed that attention significantly predicted ED visits and hospitalizations for pain at 1 and 3 years after enrollment (all p-values ≤ .017), such that poorer attention was associated with higher healthcare utilization. Lower emotional quality of life also predicted more ED visits for pain at 3 years (b = -.009, p = .013) and hospitalizations for pain at 3 years (b = -.008, p = .020).

CONCLUSIONS

Neurocognitive and emotional factors are associated with subsequent healthcare use in youth with SCD. Poor attentional control might limit implementation of strategies to distract from pain or could make disease self-management behaviors more challenging. Results also highlight the potential impact of stress on pain onset, perception, and management. Clinicians should consider neurocognitive and emotional factors when developing strategies to optimize pain-related outcomes in SCD.

Telemedicine in sickle cell disease: Patient, parent, and provider perspectives

INTRODUCTION

Patients with sickle cell disease (SCD) need frequent health maintenance visits and may face barriers accessing care. Telemedicine, during COVID pandemic, has provided a unique model of care to improve access; however, potential barriers and satisfaction with its use in SCD have not been fully evaluated.

OBJECTIVE

To determine caregiver, patient, and healthcare provider (HCP) perspectives and satisfaction with telemedicine in healthcare delivery.

METHODS

We surveyed patients with SCD, caregivers, and HCP, who participated in at least one telemedicine visit from March 2020 to June 2021, using the Telemedicine Usability Questionnaire (TUQ). We also accessed and compared the Press Ganey surveys completed by families who completed a telemedicine or in-person visit. Data were summarized using descriptive statistics. The internal reliability of TUQ was assessed using Cronbach's coefficient alpha. Press Ganey data comparing satisfaction with telemedicine versus in-person visits were analyzed by Mann-Whiney U test.

RESULTS

Fifty-two patients/caregivers and 10 HCP completed the survey. Patients/caregivers rated satisfaction "excellent" in the five areas (Usefulness, Ease of use, Effectiveness, Reliability and Satisfaction). HCP rated Usefulness, Ease of use, Effectiveness, Satisfaction as "good," and Reliability as "excellent." Press Ganey scores for satisfaction with care for telemedicine and in-person visits were not statistically different (p > .05).

DISCUSSION

We found high satisfaction for caregivers and patients as well as HCP in the delivery of clinical services via telemedicine for SCD. We suggest that telemedicine is a viable option for this population and may help overcome the barriers SCD families often face accessing care.

Reduction in vaso-occlusive events following stem cell transplantation in patients with sickle cell disease

Hematopoietic stem cell transplantation (HSCT) is potentially curative for patients with sickle cell disease (SCD). Patients with stable donor engraftment after allogeneic HSCT generally do not experience SCD-related complications; however, there are no published data specifically reporting the change in vaso-occlusive events (VOE) after HSCT. Data regarding the number of VOEs requiring medical attention in the 2 years before allogeneic HSCT were compared with the number of VOEs in the 2 years (0-12 months and 12-24 months) after allogeneic HSCT in patients with SCD. One-hundred sixty-three patients with SCD underwent allogeneic HSCT between 2005 and 2019. The average age at the time of HSCT was 21 years (range, 7 months - 64 years). Most patients underwent nonmyeloablative conditioning (75% [N = 123]) and had a matched sibling donor (72% [N = 118]). The mean number of VOEs was reduced from 5.6 (range, 0-52) in the 2 years before HSCT to 0.9 (range, 0-12) in the 2 years after HSCT (P < .001). Among the post-HSCT events, VOE was more frequent during the first 12 months (0.8 [range, 0-12]) than at 12 to 24 months after HSCT (0.1 [range, 0-8) (P < .001)). In patients who had graft rejection (12%, N = 20), VOEs were reduced from 6.6 (range, 0-24) before HSCT to 1.1 (range, 0-6) and 0.8 (range, 0-8) at 0 to 12 months and 12 to 24 months after HSCT, respectively (P < .001). VOEs requiring medical care were significantly reduced after allogeneic HSCT for patients with SCD. These data will inform the development of novel autologous HSCT gene therapy approaches.

Clinical outcomes of children and adolescents with sickle cell disease and COVID-19 infection: A year in review at a metropolitan tertiary pediatric hospital

Background

COVID-19 was declared a global pandemic in March 2020. Early reports were primarily in adults, and sickle cell disease (SCD) was classified as a risk factor for severe COVID-19 disease. However, there are a limited number of primarily multi-center studies reporting on the clinical course of pediatric patients with SCD and COVID-19.

Methods

We conducted an observational study of all patients with SCD diagnosed with COVID-19 at our institution between March 31, 2020, and February 12, 2021. Demographic and clinical characteristics of this group were collected by retrospective chart review.

Results

A total of 55 patients were studied, including 38 children and 17 adolescents. Demographics, acute COVID-19 clinical presentation, respiratory support, laboratory findings, healthcare utilization, and SCD modifying therapies were comparable between the children and adolescents. Seventy-three percent (N = 40) of all patients required emergency department care or hospitalization. While 47% (N = 26) were hospitalized, only 5% (N = 3) of all patients required intensive care unit admission. Patients frequently had concurrent vaso-occlusive pain crisis (VOC) (N = 17, 43%) and acute chest syndrome (ACS) (N = 14, 35%). Those with ACS or an oxygen requirement had significantly higher white blood cell count, lower nadir hemoglobin, and higher D-dimers, supporting a pro-inflammatory and coagulopathic picture. Non-hospitalized patients were more likely to be on hydroxyurea than hospitalized patients (79 vs. 50%, p = 0.023).

Conclusion

Children and adolescent patients with SCD and acute COVID-19 often present with ACS and VOC pain requiring hospital-level care. Hydroxyurea treatment appears to be protective. We observed no mortality despite variable morbidity.

Spirometric Changes After Initiation of Hydroxyurea in Children With Sickle Cell Anemia

Individuals with sickle cell disease (SCD) develop a decline in lung function over time. Hydroxyurea (HU) is the most common disease-modifying therapy used in SCD. We hypothesized that children with SCD treated with HU will have a slower decline in pulmonary function. We performed a retrospective chart review of children with HbSS and HbS-beta zero thalassemia referred to pulmonology for respiratory symptoms. We compared the spirometry results at 2 time points between children on HU (HU group) and not on HU (control group). For the HU group, these endpoints were evaluated before and after being on HU. The mean time interval between 2 spirometry studies was not significantly different between the groups (2.6±1.5 y for HU group vs. 3.0±1.8 y for the control group; P =0.33). The mean age of patients in the HU group was 9.8±3.8 years (55% male) and 10.7±4.9 years (50% male) in the control group. The spirometry data was compared within and between the groups using t test. There was a significant increase in forced vital capacity in HU group during follow-up, while children in the control group showed a decline (7.2±17.1 vs. -3.4±18.2; P <0.01). Our study suggests that HU therapy may help preserve lung function over time in children with SCD.

Acupuncture as an Adjunctive Treatment for Pain in Hospitalized Children With Sickle Cell Disease

CONTEXT

Acute episodes of pain associated with sickle cell disease (SCD) account for over 100,000 hospitalizations and expenses of nearly one billion dollars annually in the U.S. New treatment approaches are needed as the current opioid based therapy is often inadequate in controlling pain, resulting in prolonged inpatient stays, and high rates of readmission.

OBJECTIVES

To evaluate acceptability of acupuncture as an adjunctive therapy and explore the impact of acupuncture on pain related outcomes in a population of youth with SCD hospitalized for management of acute pain.

METHODS

This IRB approved single center study recruited youth with SCD (9-20 years) who were hospitalized for management of acute pain into either the acupuncture group or controls. Both groups also received standard pain management therapies.

RESULTS

Participants in the acupuncture (n = 19) and control (n = 10) group were comparable in clinical characteristics. Acupuncture had an acceptability rate of over 66% and was tolerated well without any side effects. Acupuncture was associated with reduction in pain scores (6.84-5.51; P < 0.0001). Acupuncture group demonstrated a trend toward lower length of stay and readmission rates, but these were not statistically significant. Opioid use was not different between the groups. Treatment Evaluation Inventory survey showed high rates of satisfaction with acupuncture.

CONCLUSION

Acupuncture was broadly accepted and well-tolerated in our study population. Acupuncture treatment was associated with a statistically significant and clinically meaningful reduction in pain scores immediately following the treatments, and a trend towards a reduction in length of stay and readmission for pain.

Low Rates of Cerebral Infarction after Hematopoietic Stem Cell Transplantation in Patients with Sickle Cell Disease at High Risk for Stroke

Hematopoietic stem cell transplantation (HSCT) can be curative for sickle cell disease (SCD). SCD patients with cerebrovascular disease are often referred for HSCT. The objective of this study was to describe neurologic outcomes after HSCT in patients with pre-existing SCD and cerebrovascular comorbidity. Patients with SCD treated with HSCT at a single center between 1996 and 2019 were identified. Patients with cerebral ischemia and/or vasculopathy before undergoing HSCT were included. Patients with graft failure were excluded. The cohort was divided into 3 groups: symptomatic stroke, vasculopathy without symptomatic stroke, and isolated silent cerebral infarction (SCI). Magnetic resonance imaging/angiography and neurologic assessments pre- and post-HSCT were analyzed to assess outcomes. In a cohort of 44 patients, there were 25 with symptomatic infarction, 10 with vasculopathy, and 9 with isolated SCI. Post-HSCT ischemic injury (2 symptomatic strokes, 2 SCIs) was identified in 4 patients, all with previous symptomatic infarction. Within this group (n = 25), the post-HSCT incidence of subsequent symptomatic infarction was 1.6 events/100 patient-years, and SCIs occurred at a rate of 2.2 events/100 patient-years. No patient had progression of vasculopathy post-HSCT. Our data show a low incidence of new ischemic injury after successful HSCT for SCD. Patients with a history of both symptomatic stroke and vasculopathy are at greatest risk for post-HSCT ischemic injury.

Bridging the Gap Among Clinical Practice Guidelines for Pain Management in Cancer and Sickle Cell Disease

Opioids are a critical component of pain relief strategies for the management of patients with cancer and sickle cell disease. The escalation of opioid addiction and overdose in the United States has led to increased scrutiny of opioid prescribing practices. Multiple reports have revealed that regulatory and coverage policies, intended to curb inappropriate opioid use, have created significant barriers for many patients. The Centers for Disease Control and Prevention, National Comprehensive Cancer Network, and American Society of Clinical Oncology each publish clinical practice guidelines for the management of chronic pain. A recent JAMA Oncology article highlighted perceived variability in recommendations among these guidelines. In response, leadership from guideline organizations, government representatives, and authors of the original article met to discuss challenges and solutions. The meeting featured remarks by the Commissioner of Food and Drugs, presentations on each clinical practice guideline, an overview of the pain management needs of patients with sickle cell disease, an overview of perceived differences among guidelines, and a discussion of differences and commonalities among the guidelines. The meeting revealed that although each guideline varies in the intended patient population, target audience, and methodology, there is no disagreement among recommendations when applied to the appropriate patient and clinical situation. It was determined that clarification and education are needed regarding the intent, patient population, and scope of each clinical practice guideline, rather than harmonization of guideline recommendations. Clinical practice guidelines can serve as a resource for policymakers and payers to inform policy and coverage determinations.

Integrative holistic approaches for children, adolescents, and young adults with sickle cell disease: A single center experience

CONTEXT

Painful vaso-occlusive crises (VOCs) associated with sickle cell disease (SCD) are the most common cause of morbidity, hospitalizations, and poor quality of life. Additional symptoms such as sleep disturbances, fatigue, and stress are also common. Non-traditional approaches are often used by families, but concerns remain that patients may forgo standard of care effective therapies in favor of dangerous unproven alternatives.

OBJECTIVES

To describe a single center experience related to a multidisciplinary integrative medicine clinic within the division of hematology dedicated to children and young adults with SCD.

METHODS

The Sickle Cell Integrative Clinic at Children's National Hospital services patients with SCD. The main goal of this clinic is to provide access to non-pharmacologic interventions, and to manage patients' symptoms in a holistic manner along with standard of care management of SCD. This IRB approved study evaluated experiences of both patients and parents who attended this clinic.

RESULTS

Thirty-seven unique patients attended this clinic over 2 years and 31 participated in the study. After attending the SCD integrative clinic, the majority of patients reported integrative therapies to be an acceptable way of treating pain and believed these to be effective. Overall, the vast majority (88 %) of patients reported having a positive experience with the therapies offered in the clinic. None of the patients experienced any adverse events related to integrative therapies provided in the clinic.

CONCLUSION

Our experience suggests that encouraging conversations and offering safe and potentially effective integrative therapies alongside conventional SCD therapies under medical guidance allows patients to have an open discussion about their beliefs and treatment goals, improves patient satisfaction and can improve outcomes.

The CYB5R3c .350C>G and G6PD A alleles modify severity of anemia in malaria and sickle cell disease

Genetic modifiers of anemia in Plasmodium falciparum infection and sickle cell disease (SCD) are not fully known. Both conditions are associated with oxidative stress, hemolysis and anemia. The CYB5R3 gene encodes cytochrome b5 reductase 3, which converts methemoglobin to hemoglobin through oxidation of NADH. CYB5R3c.350C > G encoding CYB5R3T117S , the most frequent recognized African-specific polymorphism, does not have known functional significance, but its high allele frequency (23% in African Americans) suggests a selection advantage. Glucose-6-phosphate dehydrogenase (G6PD) is essential for protection from oxidants; its African-polymorphic X-linked A+ and A- alleles, and other variants with reduced activity, coincide with endemic malaria distribution, suggesting protection from lethal infection. We examined the association of CYB5R3c.350C > G with severe anemia (hemoglobin <5 g/dL) in the context of G6PD A+ and A- status among 165 Zambian children with malaria. CYB5R3c.350C > G offered protection against severe malarial anemia in children without G6PD deficiency (G6PD wild type or A+/A- heterozygotes) (odds ratio 0.29, P = .022) but not in G6PD A+ or A- hemizygotes/homozygotes. We also examined the relationship of CYB5R3c.350C > G with hemoglobin concentration among 267 children and 321 adults and adolescents with SCD in the US and UK and found higher hemoglobin in SCD patients without G6PD deficiency (β = 0.29, P = .022 children; β = 0.33, P = .004 adults). Functional studies in SCD erythrocytes revealed mildly lower activity of native CYB5R3T117S compared to wildtype CYB5R3 and higher NADH/NAD+ ratios. In conclusion, CYB5R3c.350C > G appears to ameliorate anemia severity in malaria and SCD patients without G6PD deficiency, possibly accounting for CYB5R3c.350C > G selection and its high prevalence.

Tricuspid regurgitation velocity and other biomarkers of mortality in children, adolescents and young adults with sickle cell disease in the United States: The PUSH study

In the US, mortality in sickle cell disease (SCD) increases after age 18-20 years. Biomarkers of mortality risk can identify patients who need intensive follow-up and early or novel interventions. We prospectively enrolled 510 SCD patients aged 3-20 years into an observational study in 2006-2010 and followed 497 patients for a median of 88 months (range 1-105). We hypothesized that elevated pulmonary artery systolic pressure as reflected in tricuspid regurgitation velocity (TRV) would be associated with mortality. Estimated survival to 18 years was 99% and to 25 years, 94%. Causes of death were known in seven of 10 patients: stroke in four (hemorrhagic two, infarctive one, unspecified one), multiorgan failure one, parvovirus B19 infection one, sudden death one. Baseline TRV ≥2.7 m/second (>2 SD above the mean in age-matched and gender-matched non-SCD controls) was observed in 20.0% of patients who died vs 4.6% of those who survived (P = .012 by the log rank test for equality of survival). The baseline variable most strongly associated with an elevated TRV was a high hemolytic rate. Additional biomarkers associated with mortality were ferritin ≥2000 μg/L (observed in 60% of patients who died vs 7.8% of survivors, P < .001), forced expiratory volume in 1 minute to forced vital capacity ratio (FEV1/FVC) <0.80 (71.4% of patients who died vs 18.8% of survivors, P < .001), and neutrophil count ≥10x10⁹ /L (30.0% of patients who died vs 7.9% of survivors, P = .018). In SCD children, adolescents and young adults, steady-state elevations of TRV, ferritin and neutrophils and a low FEV1/FVC ratio may be biomarkers associated with increased risk of death.

The vaso-occlusive pain crisis in sickle cell disease: Definition, pathophysiology, and management

Early diagnosis, treatment, and prevention of a vaso-occlusive crisis (VOC) are critical to the management of patients with sickle cell disease. It is essential to differentiate between VOC-associated pain and chronic pain, hyperalgesia, neuropathy, and neuropathic pain. The pathophysiology of VOCs includes polymerization of abnormal sickle hemoglobin, inflammation, and adhesion. Hydroxyurea, L-glutamine, crizanlizumab, and voxelotor have been approved by the US Food and Drug Administration for reducing the frequency of VOCs; the European Medicines Agency has approved only hydroxyurea. Other novel treatments are in late-stage clinical development in both the United States and the European Union. The development of agents for prevention and treatment of VOCs should be driven by our understanding of its pathophysiology.

Characteristics and outcomes of osteomyelitis in children with sickle cell disease: A 10-year single-center experience

BACKGROUND

Patients with sickle cell disease (SCD) are at increased risk for osteomyelitis (OM). Diagnosis of OM in SCD is challenging as the clinical presentation is similar to a vasoocclusive crisis (VOC) with no diagnostic gold standard. We report characteristics and outcomes of OM in SCD patients treated at our center over 10-year period.

DESIGN/METHOD

We conducted a retrospective analysis of patients with SCD who were treated for OM at our center over a 10-year period (2006-2016). Cases were identified utilizing radiology data mining software. Radiology reports and medical charts of potential OM cases were reviewed.

RESULTS

Twenty-eight children with SCD were treated for OM at our institution. Patients treated for OM were largely similar to patients treated for a VOC. However, patients treated for OM had significantly higher C-reactive protein (10 mg/dL vs 5.58 mg/dL, P = 0.03) and erythrocyte sedimentation rate (60 mm/h vs 47 mm/h, P = 0.02). Magnetic resonance imaging (MRI) findings were consistent with OM in 18 (64%) patients and indeterminate in the remaining. Based on clinical, laboratory, and radiological findings, the diagnosis of OM was considered confirmed in 3 patients, probable in 6 patients, and presumed in 19 patients. Nontyphoidal Salmonella was isolated from cultures in 9 (32%) patients, while no organism was identified in 19 (67%) patients. All patients were treated with antibiotics. Six patients (21%) required surgical interventions.

CONCLUSIONS

OM continues to pose diagnostic challenges. Most patients are treated for OM without definitive confirmation. Nontyphoidal Salmonella was the only organism identified in our cohort.

Bridging the Gap Among Clinical Practice Guidelines for Pain Management in Cancer and Sickle Cell Disease

Opioids are a critical component of pain relief strategies for the management of patients with cancer and sickle cell disease. The escalation of opioid addiction and overdose in the United States has led to increased scrutiny of opioid prescribing practices. Multiple reports have revealed that regulatory and coverage policies, intended to curb inappropriate opioid use, have created significant barriers for many patients. The Centers for Disease Control and Prevention, National Comprehensive Cancer Network, and ASCO each publish clinical practice guidelines for the management of chronic pain. A recent JAMA Oncology article highlighted perceived variability in recommendations among these guidelines. In response, leadership from guideline organizations, government representatives, and authors of the original article met to discuss challenges and solutions. The meeting featured remarks by the Commissioner of Food and Drugs, presentations on each clinical practice guideline, an overview of the pain management needs of patients with sickle cell disease, an overview of perceived differences among guidelines, and a discussion of differences and commonalities among the guidelines. The meeting revealed that although each guideline varies in the intended patient population, target audience, and methodology, there is no disagreement among recommendations when applied to the appropriate patient and clinical situation. It was determined that clarification and education are needed regarding the intent, patient population, and scope of each clinical practice guideline, rather than harmonization of guideline recommendations. Clinical practice guidelines can serve as a resource for policymakers and payers to inform policy and coverage determinations.

Review/overview of pain in sickle cell disease

Sickle cell disease (SCD) is a highly complex inherited disorder of hemoglobin structure. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of the disease. Its manifestations could be acute, chronic, nociceptive, neuropathic that could occur singly or in various combinations. Pain continues to be the major factor of SCD phenotypic complications and the most common cause of admissions to the Emergency Department and/or the hospital. Although progress has been made in understanding the pathophysiology of SCD as well as in developing curative therapies such as hematopoietic stem cell transplantation and gene therapy, effective pain management continues to lag behind. Palliative therapies continue to be the major approach to the management of SCD and its complications. The advent of hydroxyurea made partial success in preventing the frequency of vaso-occlusive crises and l-glutamine awaits post-trial confirmation of benefits. The search for additional pharmacotherapeutic agents that could be used singly or in combination with hydroxyurea and/or l-glutamine awaits their dawn hopefully in the near future. The purpose of this review is to describe the various manifestations of SCD, their pathophysiology and their current management. Recent impressive advances in understanding the pathophysiology of pain promise the determination of agents that could replace or minimize the use of opioids.

End points for sickle cell disease clinical trials: patient-reported outcomes, pain, and the brain

To address the global burden of sickle cell disease (SCD) and the need for novel therapies, the American Society of Hematology partnered with the US Food and Drug Administration to engage the work of 7 panels of clinicians, investigators, and patients to develop consensus recommendations for clinical trial end points. The panels conducted their work through literature reviews, assessment of available evidence, and expert judgment focusing on end points related to: patient-reported outcomes (PROs), pain (non-PROs), the brain, end-organ considerations, biomarkers, measurement of cure, and low-resource settings. This article presents the findings and recommendations of the PROs, pain, and brain panels, as well as relevant findings and recommendations from the biomarkers panel. The panels identify end points, where there were supporting data, to use in clinical trials of SCD. In addition, the panels discuss where further research is needed to support the development and validation of additional clinical trial end points.

Sickle cell disease subjects and mouse models have elevated nitrite and cGMP levels in blood compartments

The hypothesis of decreased nitric oxide (NO) bioavailability in sickle cell disease (SCD) proposes that multiple factors leading to decreased NO production and increased consumption contributes to vaso-occlusion, pulmonary hypertension, and pain. The anion nitrite is central to NO physiology as it is an end product of NO metabolism and serves as a reservoir for NO formation. However, there is little data on nitrite levels in SCD patients and its relationship to pain phenotype. We measured nitrite in SCD subjects and examined its relationship to SCD pain. In SCD subjects, median whole blood, red blood cell and plasma nitrite levels were higher than in controls, and were not associated with pain burden. Similarly, Townes and BERK homozygous SCD mice had elevated blood nitrite. Additionally, in red blood cells and plasma from SCD subjects and in blood and kidney from Townes homozygous mice, levels of cyclic guanosine monophosphate (cGMP) were higher compared to controls. In vitro, hemoglobin concentration, rather than sickle hemoglobin, was responsible for nitrite metabolism rate. In vivo, inhibition of NO synthases and xanthine oxidoreductase decreased nitrite levels in homozygotes but not in control mice. Long-term nitrite treatment in SCD mice further elevated blood nitrite and cGMP, worsened anemia, decreased platelets, and did not change pain response. These data suggest that SCD in humans and animals is associated with increased nitrite/NO availability, which is unrelated to pain phenotype. These findings might explain why multiple clinical trials aimed at increasing NO availability in SCD patients failed to improve pain outcomes.

Identification of red blood cell antibodies in maternal breast milk implicated in prolonged hemolytic disease of the fetus and newborn

BACKGROUND

Alloantibodies against more than 50 non-ABO blood group antigens have been implicated in hemolytic disease of the fetus and newborn (HDFN) and are expected to wane within weeks after delivery. Persistent anemia leads to the hypothesis of continued exposure to red blood cell (RBC) alloantibodies via breast milk, which has been shown in a murine model and suggested in rare case reports.

CASE REPORT

We report three cases of prolonged HDFN in two neonates with anti-D HDFN and one with anti-Jk^a HDFN. Patient 1 demonstrated 4+ anti-D serologic testing beyond 2 months; therefore, antibody testing was performed on maternal breast milk.

METHODS

Maternal serum samples were tested for the presence of unexpected antibodies using standard Ortho gel card and 37 °C 60 minutes with anti-human globulin (AHG) tube saline methods. Antibody titrations were performed using the standard 37 °C 60 minutes to AHG tube saline method. Fresh breast milk samples were tested using the standard 37 °C 60 minutes to AHG tube saline method for both unexpected antibodies and titration study. Fresh breast milk from an O-positive, antibody-negative donor was used as control for any reactivity that may have been due to milk solids or proteins alone.

RESULTS

Using a known methodology applied in a novel way to test breast milk for RBC alloantibodies, antibodies against fetal RBCs were identified in the maternal breast milk of three patients.

CONCLUSION

Maternal RBC alloantibodies are present in breast milk and may be clinically significant in patients with prolonged recovery from HDFN.

AAAPT Diagnostic Criteria for Acute Sickle Cell Disease Pain

Acute pain episodes are the most common complication in patients with sickle cell disease (SCD). Classically attributed to vaso-occlusion, recent insights suggest that chronic pain may also contribute to the pathogenesis of acute pain episodes, which adds complexity to their diagnosis and management. A taxonomy, or classification system, for acute pain in patients with SCD would aid research efforts and enhance clinical care. To meet this need, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the U.S. Food and Drug Administration, the American Pain Society, and the American Academy of Pain Medicine formed the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society-American Academy of Pain Medicine Pain Taxonomy initiative. One of the goals of this initiative was to develop taxonomies for acute pain disorders, including SCD. To accomplish this, a working group of experts in SCD and pain was convened. Based on available literature and expert opinion, the working group used a 5-dimenional structure (diagnostic criteria, common features, modulating factors, impact/functional consequences, and putative mechanisms) to develop an acute pain taxonomy that is specific to SCD. As part of this, a set of 4 diagnostic criteria, with 2 modifiers to account for the influence of chronic pain, are proposed to define the types of acute pain observed in patients with SCD. PERSPECTIVE: This article presents a taxonomy for acute pain in patients with SCD. This taxonomy could help to standardize definitions of acute pain in clinical studies of patients with SCD.

Targeted Hydroxyurea Education after an Emergency Department Visit Increases Hydroxyurea Use in Children with Sickle Cell Anemia

OBJECTIVE

To evaluate the impact of an initiative to increase hydroxyurea use among children with sickle cell anemia (SCA) who presented to the emergency department (ED).

STUDY DESIGN

This observational cohort study included children with SCA not taking hydroxyurea who presented to the ED with pain or acute chest syndrome and then attended a Quick-Start Hydroxyurea Initiation Project (Q-SHIP) session. A Q-SHIP session includes a hematologist-led discussion on hydroxyurea, a video of patients talking about hydroxyurea, and a direct offer to start hydroxyurea.

RESULTS

Over 64 weeks, 112 eligible patients presented to the ED and 59% (n = 66) participated in a Q-SHIP session a median of 6 days (IQR 2, 20 days) after ED or hospital discharge; 55% of participants (n = 36) started hydroxyurea. After a median follow-up of 49 weeks, 83% (n = 30) of these participants continued hydroxyurea. Laboratory markers of hydroxyurea adherence were significantly increased from baseline: median mean corpuscular volume +8.6 fL (IQR 5.0, 17.7, P < .0001) and median hemoglobin F +5.7% (IQR 2.5, 9.8, P = .0001). Comparing Q-SHIP participants to nonparticipants, 12 weeks after ED visit, participants were more likely to have started hydroxyurea than nonparticipants (53% vs 20%, P = .0004) and to be taking hydroxyurea at last follow-up (50% vs 20%, P = .001). Two years after the implementation of Q-SHIP the overall proportion of eligible patients on hydroxyurea presenting to our ED increased from 56% to 80%, P = .0069.

CONCLUSIONS

Participation in a clinic to specifically address starting hydroxyurea after a SCA complication increases hydroxyurea use.

Comprehensive Infant Clinic for Sickle Cell Disease: Outcomes and Parental Perspective

INTRODUCTION

Comprehensive care for children with sickle cell disease (SCD) includes penicillin prophylaxis, pneumococcal immunization, hydroxyurea therapy, and transcranial Doppler screening for stroke prevention. Along with caregiver education, these strategies have been shown to be effective in reducing early morbidity and mortality in this population. The subspecialty Infant Sickle Cell Clinic was initiated to improve access, education, patient outcomes, and family satisfaction.

METHOD

Telephone surveys were conducted with parents to assess satisfaction with the Infant Sickle Cell Clinic, compliance with guidelines, and comfort level with managing their child's SCD.

RESULTS

This quality improvement project reported high levels of parent satisfaction and improved outcomes with the proposed approach but also presents areas for improvement.

DISCUSSION

Our report presents a unique model of providing care to families with infants newly diagnosed with SCD. The group format serves as a useful model to allow families an interactive educational session with guest speakers.

Diverse manifestations of acute sickle cell hepatopathy in pediatric patients with sickle cell disease: A case series

The hepatic complications of sickle cell disease (SCD) are associated with increased morbidity and mortality in adults; children usually survive but may suffer significant sequelae. Few diagnostic tools differentiate the various hepatic manifestations of SCD. Why patients exhibit one hepatic pathology versus another is unclear. We report four pediatric patients with hemoglobin SS disease with diverse manifestations of acute hepatic involvement including acute sickle hepatic crisis, hepatic sequestration, sickle cell intrahepatic cholestasis, and a non-SCD cause of hepatopathy in a patient with viral hepatitis. These complications require a systematic approach to extensive evaluation and coordinated multidisciplinary care.

Views of parents of children with sickle cell disease on pre-implantation genetic diagnosis

Pre-implantation genetic diagnosis (PGD) is an option for parents who have a child with sickle cell disease (SCD) to have another child without SCD. We conducted a survey of 19 parents with at least one child with SCD to investigate views on PGD. Before education, 44% of parents were aware of PGD. All parents rated PGD education as important. All parents considering another child also reported interest in using PGD if insurance covered its costs. Parents who have a child with SCD appear to be interested in PGD and educational tools informing this group about PGD should be developed.

Pain-measurement tools in sickle cell disease: where are we now?

Pain is a complex multidimensional experience and the most common morbidity in patients with sickle cell disease (SCD). Tools to assess pain can be of use not only to guide pain treatment but also to provide insight into underlying pain neurobiology. Mechanisms of pain in SCD are multifactorial and are not completely elucidated. Although vaso-occlusion of microcirculation by sickled red cells is believed to be the underlying mechanism of acute vaso-occlusive pain, mechanisms for chronic pain and the transition from acute to chronic pain are under investigation. A number of modalities can be used in clinical practice and/or research to capture various dimensions of pain. Selection of a pain-assessment tool should be directed by the purpose of the assessment. Pain-assessment tools, many of which are currently in the early stages of validation, are discussed here. Development and validation of these multimodal tools is crucial for developing improved understanding of SCD pain and its management.

Determining the longitudinal validity and meaningful differences in HRQL of the PedsQL™ Sickle Cell Disease Module

Background

Detecting change in health status over time and ascertaining meaningful changes are critical elements when using health-related quality of life (HRQL) instruments to measure patient-centered outcomes. The PedsQL™ Sickle Cell Disease module, a disease specific HRQL instrument, has previously been shown to be valid and reliable. Our objectives were to determine the longitudinal validity of the PedsQL™ Sickle Cell Disease module and the change in HRQL that is meaningful to patients.

Methods

An ancillary study was conducted utilizing a multi-center prospective trial design. Children ages 4–21 years with sickle cell disease admitted to the hospital for an acute painful vaso-oclusive crisis were eligible. Children completed HRQL assessments at three time points (in the Emergency Department, one week post-discharge, and at return to baseline (One to three months post-discharge). The primary outcome was change in HRQL score. Both distribution (effect size, standard error of measurement (SEM)) and anchor (global change assessment) based methods were used to determine the longitudinal validity and meaningful change in HRQL. Changes in HRQL meaningful to patients were identified by anchoring the change scores to the patient’s perception of global improvement in pain.

Results

Moderate effect sizes (0.20–0.80) were determined for all domains except the Communication I and Cognitive Fatigue domains. The value of 1 SEM varied from 3.8–14.6 across all domains. Over 50% of patients improved by at least 1 SEM in Total HRQL score. A HRQL change score of 7–10 in the pain domains represented minimal perceived improvement in HRQL and a HRQL change score of 18 or greater represented moderate to large improvement.

Conclusions

The PedsQL™ Sickle Cell Disease Module is responsive to changes in HRQL in patients experiencing acute painful vaso-occlusive crises. The study data establish longitudinal validity and meaningful change parameters for the PedsQL™ Sickle Cell Disease Module.

Trial Registration

ClinicalTrials.gov (study identifier: NCT01197417). Date of registration: 08/30/2010

Electronic supplementary material

The online version of this article (doi:10.1186/s12955-017-0700-2) contains supplementary material, which is available to authorized users.

Provider Perspective on Integrative Medicine for Pediatric Sickle Cell Disease-related Pain

OBJECTIVE

Integrative medicine (IM) approaches are sometimes used to manage sickle cell disease (SCD)-related pain. The purpose of this research is to (1) understand provider perspective towards the use of IM for pain in children with SCD at a large urban children's hospital and (2) provide recommendations on how to better promote IM for children and adolescents with SCD.

METHODS

After approval from the institutional review board, a qualitative case study approach was used with criterion-type purposeful sampling to select providers from the division of hematology to adequately inform the study. Semistructured interviews were completed using audiotape to facilitate transcription. NVivo 10 analytic software (QSR International Pty Ltd, Doncaster, Victoria, Australia) was used to organize data into themes to answer the study questions.

RESULTS

Ten provider interviews were completed. Attitudes were generally positive, and most providers felt that IM is generally helpful. All providers reported that they do not optimally use integrative therapies for children with SCD. The barriers uncovered focused on lack of process for integration of IM, specifically that IM resources seem transient and based on short-term funding. Provider attitude towards CAM is generally positive, but provider comfort level is highly variable. No providers are completely comfortable with their knowledge base about IM, and increased knowledge is desired.

CONCLUSIONS

Creation of protocols and processes to incorporate IM into management plans for patients with SCD could help to promote its use. Education of providers about utility and efficacy of IM for SCD-related pain and about existing resources would aid in promotion of IM for children with SCD.

Frequency of Hospitalizations for Pain and Association With Altered Brain Network Connectivity in Sickle Cell Disease

Sickle cell disease (SCD) is a hemoglobinopathy that affects more than 100,000 individuals in the United States. The disease is characterized by the presence of sickle hemoglobin and recurrent episodes of pain. Some individuals with SCD experience frequent hospitalizations and a high burden of pain. The role of central mechanisms in SCD pain has not been explored. Twenty-five adolescents and young adults with SCD underwent functional magnetic resonance imaging. Participants were stratified into groups with high pain or low pain based on the number of hospitalizations for pain in the preceding 12 months. Resting state functional connectivity was analyzed using seed-based and dual regression independent component analysis. Intrinsic brain connectivity was compared between the high pain and low pain groups, and association with fetal hemoglobin, a known modifier of SCD, was explored. Patients in the high pain group displayed an excess of pronociceptive connectivity such as between anterior cingulate and default mode network structures, such as the precuneus, whereas patients in the low pain group showed more connectivity to antinociceptive structures such as the perigenual and subgenual cingulate. Although a similar proportion of patients in both groups reported that they were on hydroxyurea, the fetal hemoglobin levels were significantly higher in the low pain group and were associated with greater connectivity to antinociceptive structures. These findings support the role of central mechanisms in SCD pain. Intrinsic brain connectivity should be explored as a complementary and objective outcome measure in SCD pain research.

PERSPECTIVE

Altered connectivity patterns associated with high pain experience in patients with sickle cell disease suggest a possible role of central mechanisms in sickle cell pain. Resting state brain connectivity studies should be explored as an effective methodology to investigate pain in SCD.

Dexmedetomidine as an Adjuvant to Analgesic Strategy During Vaso-Occlusive Episodes in Adolescents with Sickle-Cell Disease

Patients with sickle-cell disease (SCD) can experience recurrent vaso-occlusive episodes (VOEs), which are associated with severe pain. While opioids are the mainstay of analgesic therapy, in some patients with SCD, increasing opioid use is associated with continued and increasing pain. Dexmedetomidine, an α2 -adrenoreceptor agonist with sedative and analgesic properties, has been increasingly used in the perioperative and intensive care settings and has been shown to reduce opioid requirement and to facilitate opioid weaning. Therefore, there might be a role for dexmedetomidine in pain management during VOEs in patients with SCD. Here, we present the hospital course of 3 patients who during the course of VOEs had severe pain unresponsive to opioids and ketamine and were treated with dexmedetomidine. Dexmedetomidine infusions that lasted for 3 to 6 days were associated with marked reduction in daily oral morphine-equivalent intake and decreases in pain scores (numeric rating scale). There were no hemodynamic changes that required treatment with vasoactive or anticholinergic agents. These preliminary findings of possible beneficial effects of dexmedetomidine in decreasing opioid requirements support the hypothesis that dexmedetomidine may have a role as a possible analgesic adjuvant to mitigate VOE-associated pain in patients with SCD.

Sleep disturbance, depression and pain in adults with sickle cell disease

BACKGROUND

Sleep disturbance and depression are commonly encountered in primary care. In sickle cell disease, depression is associated with pain, poor treatment compliance, and lower quality of life. The prevalence of sleep disturbance and its effect upon quality of life in adults with sickle cell disease is unknown. The goal of this study was to determine the prevalence of sleep disturbance and if it is associated with pain and depression in sickle cell disease.

METHODS

Three hundred twenty eight adults with sickle cell disease enrolled on the Bethesda Sickle Cell Cohort Study were assessed using the Pittsburgh Sleep Quality Index and Beck Depression Inventory II screening measures as a cross-sectional survey. Scores greater than 5 (Pittsburgh Sleep Quality Index) and 16 (Beck Depression Inventory II) defined sleep disturbance and depression, respectively. Clinical and laboratory parameters were also assessed.

RESULTS

The mean Pittsburgh Sleep Quality Index score was 8.4 (SD ± 4.2) indicating a 71.2% prevalence of sleep disturbance. The mean Beck Depression Inventory II score was 8.0 (SD ± 8.9). Sixty five (20.6%) participants had a score indicating depression, and half of these (10.0%) had thoughts of suicide. Both Pittsburgh Sleep Quality Index and Beck Depression Inventory II scores were significantly correlated (p < .001). The number of days with mild/moderate pain (p = .001) and a history of headaches (p = .005) were independently associated with depression by multivariate regression analysis. Patients with sleep disturbance were older (p = .002), had higher body mass index (p = .011), had more days of pain (p = .003) and more frequent severe acute painful events (emergency room visits and hospitalizations) during the previous 12 months (p < .001).

CONCLUSIONS

More than 70 percent of adults with sickle cell disease had sleep disturbance, while 21 percent showed evidence of clinical depression. Sleep disturbance and depression were correlated, and were most common among those with more frequent pain. Providers caring for adults with sickle cell disease and frequent pain should consider screening for these common co-morbidities. Additional study is needed to confirm these findings and to determine if treatments for pain, depression or sleep disturbances will improve quality of life measures in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00011648.

A GCH1 haplotype confers sex-specific susceptibility to pain crises and altered endothelial function in adults with sickle cell anemia

GTP cyclohydrolase (GCH1) is rate limiting for tetrahydrobiopterin (BH4) synthesis, where BH4 is a cofactor for nitric oxide (NO) synthases and aromatic hydroxylases. GCH1 polymorphisms are implicated in the pathophysiology of pain, but have not been investigated in African populations. We examined GCH1 and pain in sickle cell anemia where GCH1 rs8007267 was a risk factor for pain crises in discovery (n = 228; odds ratio [OR] 2.26; P = 0.009) and replication (n = 513; OR 2.23; P = 0.004) cohorts. In vitro, cells from sickle cell anemia subjects homozygous for the risk allele produced higher BH4. In vivo physiological studies of traits likely to be modulated by GCH1 showed rs8007267 is associated with altered endothelial dependent blood flow in females with SCA (8.42% of variation; P = 0.002). The GCH1 pain association is attributable to an African haplotype with where its sickle cell anemia pain association is limited to females (OR 2.69; 95% CI 1.21-5.94; P = 0.01) and has the opposite directional association described in Europeans independent of global admixture. The presence of a GCH1 haplotype with high BH4 in populations of African ancestry could explain the association of rs8007267 with sickle cell anemia pain crises. The vascular effects of GCH1 and BH4 may also have broader implications for cardiovascular disease in populations of African ancestry.

Alpha-thalassaemia and response to hydroxyurea in sickle cell anaemia

BACKGROUND

Hydroxyurea (HU) reduces vaso-occlusive crises (VOC) and other complications of sickle cell anaemia (SCA). Alpha-thalassaemia is a known modifier of SCA. Studies on the efficacy of HU in SCA patients with α-thalassaemia have yielded varying results.

OBJECTIVE

To determine the effect of α-thalassaemia in response to HU therapy in the Multicenter Study of Hydroxyurea (MSH) cohort.

METHODS

We compared the laboratory parameters and VOC incidence in the MSH cohort stratified by the presence or the absence of α-thalassaemia.

RESULTS

Hydroxyurea showed significant (P = 0.001 for all baseline vs. follow-up comparisons) treatment effect on red cell indices irrespective of α-globin gene deletion. The magnitude of the HU-related changes was similar for mean corpuscular volume (MCV) (no α-thalassaemia 13 fl and α-thalassaemia 13 fl) and mean corpuscular haemoglobin (MCH) (no α-thalassaemia 4 pg and α-thalassaemia 4 pg) in both groups. Foetal haemoglobin (HbF) and F-cells also increased significantly with HU treatment in both groups. Total haemoglobin increased after HU treatment in both groups, but the increase was smaller and not statistically significant in patients with α-thalassaemia. In contrast, HU-related reduction in VOCs was more pronounced in patients with α-thalassaemia (VOC incidence rate ratio HU/placebo: 0.63 for α-thalassaemia and 0.54 for no α-thalassaemia (P for interaction 0.003).

CONCLUSION

Hydroxyurea decreases VOCs in SCA patients with and without α-thalassaemia, and the degree of VOC reduction was more pronounced in the patients with alpha-thalassaemia. Despite the lower baseline values, changes in standard laboratory parameters such as MCV and HbF percent remain useful in monitoring HU therapy in the presence of α-thalassaemia.

Severe painful vaso-occlusive crises and mortality in a contemporary adult sickle cell anemia cohort study

Background

Frequent painful vaso-occlusive crises (VOCs) were associated with mortality in the Cooperative Study of Sickle Cell Disease (CSSCD) over twenty years ago. Modern therapies for sickle cell anemia (SCA) like hydroxyurea are believed to have improved overall patient survival. The current study sought to determine the relevance of the association between more frequent VOCs and death and its relative impact upon overall mortality compared to other known risk factors in a contemporary adult SCA cohort.

Methods

Two hundred sixty four SCA adults were assigned into two groups based on patient reported outcomes for emergency department (ED) visits or hospitalizations for painful VOC treatment during the 12 months prior to evaluation.

Results

Higher baseline hematocrit (p = 0.0008), ferritin (p = 0.005), and HDL cholesterol (p = 0.01) were independently associated with 1 or more painful VOCs requiring an ED visit or hospitalization for acute pain. During a median follow-up of 5 years, mortality was higher in the ED visit/hospitalization group (relative risk [RR] 2.68, 95% CI 1.1-6.5, p = 0.03). Higher tricuspid regurgitatant jet velocity (TRV) (RR 2.41, 95% CI 1.5-3.9, p < 0.0001), elevated ferritin (RR 4.00, 95% CI 1.8-9.0, p = 0.001) and lower glomerular filtration rate (RR=2.73, 95% CI 1.6-4.6, p < 0.0001) were also independent risk factors for mortality.

Conclusions

Severe painful VOCs remain a marker for SCA disease severity and premature mortality in a modern cohort along with other known risk factors for death including high TRV, high ferritin and lower renal function. The number of patient reported pain crises requiring healthcare utilization is an easily obtained outcome that could help to identify high risk patients for disease modifying therapies.

Trial Registration

ClinicalTrials.gov NCT00011648 http://clinicaltrials.gov/

Low-dose ketamine as a potential adjuvant therapy for painful vaso-occlusive crises in sickle cell disease

The hallmark of sickle cell disease (SCD) is the acute painful vaso-occlusive crisis (VOC). Among SCD patients, vaso-occlusive pain episodes vary in frequency and severity. Some patients rarely have painful crises, while others are admitted to the hospital multiple times in a year for parenteral analgesics. Opioids are the mainstay of therapy for SCD-related pain. However, a subset of patients report continued pain despite escalating doses of opioids. Tolerance and opioid-induced hyperalgesia (OIH) have been considered as possible explanations for this phenomenon. The activation of the N-methyl-d-aspartate (NMDA) receptor has been implicated in both tolerance and OIH. As a NMDA receptor agonist, ketamine has been shown to modulate opioid tolerance and OIH in animal models and clinical settings. Low-dose ketamine, by virtue of its NMDA receptor agonist activity, could be a useful adjuvant to opioid therapy in patients with refractory SCD-related pain. Based on limited studies of adjuvant ketamine use for pain management, low-dose ketamine continuous infusion appears safe. Further clinical investigations are warranted to fully support the use of low-dose ketamine infusion in patients with SCD-related pain.

Clinical correlates of acute pulmonary events in children and adolescents with sickle cell disease

OBJECTIVES

We aimed to identify risk factors for acute pulmonary events in children and adolescents in the Pulmonary Hypertension and the Hypoxic Response in SCD (PUSH) study.

METHODS

Patients with hemoglobin SS (n = 376) and other sickle cell genotypes (n = 127) aged 3-20 yrs were studied at four centers in a cross-sectional manner. A subgroup (n = 293) was followed for a median of 21 months (range 9-35).

RESULTS

A patient-reported history of one or more acute pulmonary events, either acute chest syndrome (ACS) or pneumonia, was obtained in 195 hemoglobin SS patients (52%) and 51 patients with other genotypes (40%). By logistic regression, history of acute pulmonary events was independently associated with patient-reported history of asthma (P < 0.0001), older age (P = 0.001), >3 severe pain episodes in the preceding 12 months (P = 0.002), higher tricuspid regurgitation velocity (TRV) (P = 0.028), and higher white blood cell (WBC) count (P = 0.043) among hemoglobin SS patients. History of acute pulmonary events was associated with >3 severe pain episodes (P = 0.009) among patients with other genotypes. During follow-up, 43 patients (15%) had at least one new ACS episode including 11 without a baseline history of acute pulmonary events. History of acute pulmonary events (odds ratio 5.0; P < 0.0001) and younger age (odds ratio 0.9; P = 0.007) were independently associated with developing a new episode during follow-up.

CONCLUSIONS

Asthma history, frequent pain, and higher values for TRV and WBC count were independently associated with history of acute pulmonary events in hemoglobin SS patients and frequent pain was associated in those with other genotypes. Measures to reduce pain episodes and control asthma may help to decrease the incidence of acute pulmonary events in SCD.

Beyond the definitions of the phenotypic complications of sickle cell disease: an update on management

The sickle hemoglobin is an abnormal hemoglobin due to point mutation (GAG → GTG) in exon 1 of the β globin gene resulting in the substitution of glutamic acid by valine at position 6 of the β globin polypeptide chain. Although the molecular lesion is a single-point mutation, the sickle gene is pleiotropic in nature causing multiple phenotypic expressions that constitute the various complications of sickle cell disease in general and sickle cell anemia in particular. The disease itself is chronic in nature but many of its complications are acute such as the recurrent acute painful crises (its hallmark), acute chest syndrome, and priapism. These complications vary considerably among patients, in the same patient with time, among countries and with age and sex. To date, there is no well-established consensus among providers on the management of the complications of sickle cell disease due in part to lack of evidence and in part to differences in the experience of providers. It is the aim of this paper to review available current approaches to manage the major complications of sickle cell disease. We hope that this will establish another preliminary forum among providers that may eventually lead the way to better outcomes.

Markers of severe vaso-occlusive painful episode frequency in children and adolescents with sickle cell anemia

OBJECTIVE

To identify factors associated with frequent severe vaso-occlusive pain crises in a contemporary pediatric cohort of patients with sickle cell anemia (SCA) enrolled in a prospective study of pulmonary hypertension and the hypoxic response in sickle cell disease.

STUDY DESIGN

Clinical and laboratory characteristics of children with SCA who had ≥3 severe pain crises requiring health care in the preceding year were compared with those of subjects with <3 such episodes.

RESULTS

Seventy-five children (20%) reported ≥3 severe pain episodes in the preceding year, and 232 (61%) had none. Frequent pain episodes were associated with older age (OR, 1.2; 95% CI, 1.1-1.3; P < .0001), α-thalassemia trait (OR 3.5; 1.6-6.7; P = .002), higher median hemoglobin (OR 1.7; 95% CI: 1.2-2.4; P < .003), and lower lactate dehydrogenase concentration (OR 1.82; 95% CI: 1.07-3.11; P = .027). Children with high pain frequency also had an increased iron burden (serum ferritin, 480 vs 198 μg/L; P = .006) and higher median tricuspid regurgitation jet velocity (2.41 vs 2.31 m/s; P = .001). Neither hydroxyurea use nor fetal hemoglobin levels were significantly different according to severe pain history.

CONCLUSIONS

In our cohort of children with SCA, increasing age was associated with higher frequency of severe pain episodes as were α-thalassemia, iron overload, higher hemoglobin and lower lactate dehydrogenase concentration, and higher tricuspid regurgitation velocity.