Thinking beyond sickling to better understand pain in sickle cell disease

The Risk of Kidney Injury in Patients With Sickle Cell Disease Treated With Ketorolac for Acute Pain

Ketorolac, a nonsteroidal anti-inflammatory drug, is used in combination with opioids to manage vaso-occlusive episodes (VOEs). The relationship between ketorolac use and kidney injury in pediatric patients with sickle cell disease (SCD) remains incompletely understood. We hypothesize that ketorolac is associated with acute kidney injury (AKI) in patients with SCD presenting with pain. All nonsurgical hospitalizations for VOEs treated with ketorolac between January 2014 and December 2022 were included. We used optimal matching methodology to identify control admissions (2:1 ratio) and used nonparametric tests to compare ketorolac administration between cases and controls. A total of 1319 encounters/253 patients were included in this study. AKI was noted in 1.1% of encounters and 5.5% of patients. Cases had significantly higher initial BUN than controls (9.0 vs. 6.0 mg/dL, P =0.012). In cases versus controls, there was significantly lower serum sodium (136.0 vs. 138.0 mmol/L, P =0.021). There was no association between ketorolac dose and development of AKI among children with SCD. Higher BUN and lower sodium in cases suggest that patients with AKI were more volume depleted on admission than controls. This highlights the need for strict assessment of fluid status upon admission for VOE.

Incidence and risk factors of pain crisis after hematopoietic cell transplantation for sickle cell disease

ABSTRACT

Vaso-occlusive episodes (VOC) or pain crises are the most common indications for hematopoietic cell transplantation (HCT) for sickle cell disease (SCD). Elimination of pain crisis after HCT is an important patient-centered outcome and may improve understanding of the natural history of pain syndromes in SCD. We examined deidentified records of 763 patients followed-up for a median of 36.7 months (range, 0.3-168.6 months), with 69.6% patient's age <18 years at HCT, 83.3% patient's Karnofsky-Lansky performance score (KPS) ≥90, overall survival 92.9%, event-free survival 72.4%, graft failure (GF) 22.4%, AGVHD 21.4%, CGVHD 27%, and pain crisis 8.65%. On unadjusted logistic regression, increased risk of pain crisis after HCT was observed in patient's aged >10 years at HCT (range, 11-17 years; OR, 9.43; 95% CI, 3.20-27.79; P < .0001), in age ≥18 years (OR, 16.62; 95% CI, 5.85-47.16; P < .0001), in those with history of pain crisis 2 years before HCT (OR, 13.16; 95% CI, 4.08-42.42; P < .0001), alternate donors (haploidentical [OR, 4.80; 95% CI, 2.48-9.31; P < .0001], unrelated matched [OR, 2.71; 95% CI, 1.23-5.97; P = .0132], and mismatched unrelated [OR, 3.19; 95% CI, 1.44-7.05; P = .0041], and those with GF (n = 41 [5.37%]; OR, 7.15; 95% CI, 4.20-12.18; P < .0001). Pain crisis was less frequent with KPS of ≥90 (OR, 0.31; 95% CI, 0.18-0.55; P < .0001). Multivariable logistic regression models confirmed age at HCT, KPS, graft type, donor type, history of VOC 2 years before HCT, and GF as independent predictors of pain crisis after HCT and generated predictive models and nomograms for pain crisis after HCT for SCD, which can support shared decision making.

Biopsychosocial Factors Associated With Pain and Pain-Related Outcomes in Adults and Children With Sickle Cell Disease: A Multivariable Analysis of the GRNDaD Multicenter Registry

Pain is the primary symptomatic manifestation of sickle cell disease (SCD), an inherited hemoglobinopathy. The characteristics that influence pain experiences and outcomes in SCD are not fully understood. The primary objective of this study was to use multivariable modeling to examine associations of biopsychosocial variables with a disease-specific measure of pain interference known as pain impact. We conducted a secondary analysis of data from the Global Research Network for Data and Discovery national SCD registry. A total of 657 children and adults with SCD were included in the analysis. This sample was 60% female with a median age of 34 (interquartile range 26-42 years) and a chronic pain prevalence of 64%. The model accounted for 58% of the variance in pain impact. Low social (P < .001) and emotional (P < .001) functioning, increasing age (P = .004), low income (P < .001), and high acute painful episodes (P = .007) were most strongly associated with high pain impact in our multivariable model. Additionally, multivariable modeling of pain severity and physical function in 2 comparable samples of registry participants revealed that increasing age and low social functioning were also strongly associated with higher pain severity and low physical functioning. Overall, the results suggest that social and emotional functioning are more strongly associated with pain impact in individuals with SCD than previously studied biological modifiers such as SCD genotype, hemoglobin, and percentage fetal hemoglobin. Future research using longitudinally collected data is needed to confirm these findings. PERSPECTIVE: This study reveals that psychosocial (ie, social and emotional functioning) and demographic (ie, age) variables may play an important role in predicting pain and pain-related outcomes in SCD. Our findings can inform future multicenter prospective longitudinal studies aimed at identifying modifiable psychosocial predictors of adverse pain outcomes in SCD.

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.

Chronic pain management in sickle cell disease: A systematic scoping review of controlled trials

Existing treatment for chronic pain in sickle cell disease (SCD) is opioid-dependent, which is ineffective and carries risks. We conducted a scoping literature review to assess the size and scope of available literature about controlled trials of therapies for SCD chronic pain and identify research gaps. The search strategy in PubMed and EMBASE utilized keywords for chronic pain and sickle cell and identified seven original articles that met inclusion criteria. Six of the studies recruited from clinics while one recruited from community sources. Cannabis and behavioral modification were associated with improvements in pain scores. However, existing evidence does not represent best practices for assessing chronic pain, and this along with small sample sizes prevents translation to clinical care. The limited evidence concerning treatment for SCD chronic pain highlights the need for larger trials of opioid alternatives and the utilization of chronic pain measures that capture nociplastic pain in SCD.

Ketamine use for management of vaso-occlusive pain in pediatric sickle cell disease

BACKGROUND

Typical sickle cell disease (SCD) vaso-occlusive pain episode (VOE) management includes opioids, which are often inadequate and can be associated with significant side effects. Ketamine, a dissociative anesthetic, is a potentially effective adjunct to VOE management.

OBJECTIVES

This study aimed to characterize ketamine use for VOE management in pediatric SCD.

METHOD

This retrospective case series summarizes a single-center experience regarding the use of ketamine for inpatient management of pediatric VOE in 156 admissions from 2014 to 2020.

RESULTS

Continuous low-dose ketamine infusion was most commonly prescribed to adolescents and young adults as an adjunct to opioids (median starting dose 2.0 μg/kg/min; median maximum dose 3.0 μg/kg/min). Ketamine was started a median of 13.7 hours after admission. Median ketamine infusion duration was 3 days. In most encounters, ketamine infusion was discontinued prior to opioid patient-controlled analgesia (PCA) discontinuation. The majority of encounters (79.3%) had a reduction in either PCA dose, continuous opioid infusion, or both while receiving ketamine. Low-dose ketamine infusion was associated with side effects noted in 21.8% (n = 34) of encounters. The most common side effects included dizziness (5.6%), hallucinations (5.1%), dissociation (2.6%), and sedation (1.9%). There were no reports of ketamine withdrawal. Most patients who received ketamine went on to receive it again during a subsequent admission.

CONCLUSION

Further study is needed to determine the optimal timing of ketamine initiation and dosing. The variability of ketamine administration highlights the need for standardized protocols for ketamine use in VOE management.

Patient Controlled Analgesia for Vaso-Occlusive Episodes in Children: A Retrospective Study

OBJECTIVE

To describe Patient-Controlled Analgesia (PCA) administration in pediatric patients admitted with sickle cell vaso-occlusive episode (VOE).

METHODS

This single-center retrospective study included all inpatient hematology admissions for VOE between 2014 and 2020. PCA-ratio was calculated as the ratio of bolus over continuous IV opioids dose, and time to PCA adjustment as time between first PCA order and a subsequent order that increased dosing or changed opioid medication.

RESULTS

A total of 866 encounters (172 unique patients) with PCA for VOE were included. The mean age was 15.4 years old (SD = 5.0). On average, after admission (hospital arrival), the first opioid dose was given at 1 hour, PCA started at 3.5 hours, and mean length of stay was 4.3 days (SD = 2.5). The mean initial PCA-ratio was 1.7 (SD = 0.6). There were no significant associations between age, gender, initial pain score, or admission hemoglobin and PCA-ratio (linear regression model P = 0.443). In 24.7% of encounters, the PCA was adjusted within 6 hours. After adjusting by age and gender, lower admission pain scores (OR = 1.15, P = 0.004), lower PCA-ratio (OR = 2.1, P = 0.003), longer time to PCA start (OR = 1.2, P = 0.001), and no adjuvant ketamine (OR = 2.4, P < 0.001) were associated with PCA unadjusted within 6 hours.

CONCLUSION

At our institution, patients with VOE received opioids and PCA within the first hours of admission. PCAs were started at a ratio of 1.5-1.8, considered normal continuous. While no specific PCA-ratio was clearly superior for pain control, lower ratios (high continuous infusion) were associated with not requiring PCA adjustments at 6 hours. Prospective studies are needed.

Personalized Nutrition as a Key Contributor to Improving Radiation Response in Breast Cancer

Understanding metabolic and immune regulation inherent to patient populations is key to improving the radiation response for our patients. To date, radiation therapy regimens are prescribed based on tumor type and stage. Patient populations who are noted to have a poor response to radiation such as those of African American descent, those who have obesity or metabolic syndrome, or senior adult oncology patients, should be considered for concurrent therapies with radiation that will improve response. Here, we explore these populations of breast cancer patients, who frequently display radiation resistance and increased mortality rates, and identify the molecular underpinnings that are, in part, responsible for the radiation response and that result in an immune-suppressive tumor microenvironment. The resulting immune phenotype is discussed to understand how antitumor immunity could be improved. Correcting nutrient deficiencies observed in these populations should be considered as a means to improve the therapeutic index of radiation therapy.

A systematic review of ketamine for the management of vaso-occlusive pain in sickle cell disease

Vaso-occlusive episodes (VOEs) are a common complication of sickle cell disease (SCD) and a significant cause of morbidity. Managing VOE pain can be difficult and complex. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been used to manage VOE pain. This systematic literature review synthesizes research published from 2010 to 2020 on the use of ketamine infusion to decrease VOE pain. The review demonstrates that ketamine, a safe and effective treatment for VOE pain, could be considered more widely. However, the significant variability among published clinical studies with regard to dosing, timing of initiation, duration of infusion, and timing of discontinuation highlights the need for standardized ketamine infusion protocols for the management of VOE pain. We conclude with a brief discussion of key components of a potential standardized protocol supported by the literature reviewed as well as areas for future investigation.

American Society of Hematology 2020 guidelines for sickle cell disease: management of acute and chronic pain

BACKGROUND

The management of acute and chronic pain for individuals living with sickle cell disease (SCD) is a clinical challenge. This reflects the paucity of clinical SCD pain research and limited understanding of the complex biological differences between acute and chronic pain. These issues collectively create barriers to effective, targeted interventions. Optimal pain management requires interdisciplinary care.

OBJECTIVE

These evidence-based guidelines developed by the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in pain management decisions for children and adults with SCD.

METHODS

ASH formed a multidisciplinary panel, including 2 patient representatives, that was thoroughly vetted to minimize bias from conflicts of interest. The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic reviews. Clinical questions and outcomes were prioritized according to importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel reached consensus on 18 recommendations specific to acute and chronic pain. The recommendations reflect a broad pain management approach, encompassing pharmacological and nonpharmacological interventions and analgesic delivery.

CONCLUSIONS

Because of low-certainty evidence and closely balanced benefits and harms, most recommendations are conditional. Patient preferences should drive clinical decisions. Policymaking, including that by payers, will require substantial debate and input from stakeholders. Randomized controlled trials and comparative-effectiveness studies are needed for chronic opioid therapy, nonopioid therapies, and nonpharmacological interventions.

Do chronic pain and comorbidities affect brain function in sickle cell patients? A systematic review of neuroimaging and treatment approaches

Sickle cell disease (SCD) is a medical condition in which chronic pain is common and negatively impacts psychosocial function and quality of life. Although the brain mechanisms underlying chronic pain are well studied in other painful conditions, the brain mechanisms underlying chronic pain and the associated psychosocial comorbidities are not well established in SCD. A growing literature demonstrates the effect of treatment of chronic pain, including pharmacological and nonpharmacological treatments, on brain function. The present systematic review aimed to (1) determine the effects of chronic pain and psychosocial comorbidities on brain function of patients with SCD; (2) summarize pharmacological and nonpharmacological approaches to treat these symptoms; and (3) identify areas for further investigation of potential beneficial effects of treatments on brain function. Titles were screened using predefined criteria, including SCD, and abstracts and full texts were reviewed by 2 independent reviewers. A total of 1167 SCD articles were identified, and 86 full articles were included covering 3 sections: chronic pain (4 studies), psychosocial comorbidities (11 studies), and pharmacological and nonpharmacological treatments (71 studies). Neuroimaging evidence demonstrates aberrant neural processing related to chronic pain and psychosocial comorbidities in SCD beyond ischemic stroke and cerebral hemorrhage. Although neuroimaging studies show an important role for psychological factors, pain management is nearly exclusively based on opioids. Behavior therapy seems useful to improve psychological symptoms as well as chronic pain and quality of life. Further investigation is required with larger cohorts, matched controls, and examination of treatment-related neural mechanisms.

Changes in Pain and Psychosocial Functioning and Transition to Chronic Pain in Pediatric Sickle Cell Disease: A Cohort Follow-up Study

OBJECTIVES

This study aimed to: (1) examine changes in pain, psychosocial functioning, and health care utilization among children and adolescents with sickle cell disease (SCD) over a 2-year period and (2) identify baseline biopsychosocial variables associated with the development and maintenance of chronic SCD pain at follow-up.

MATERIALS AND METHODS

Forty-two youth (8 to 18 y old) with SCD completed a battery of self-report measures at baseline and 2-year follow-up. Analgesic, Anesthetic, and Addiction Clinical Trial Translational Innovations Opportunities and Networks and American Pain Society Pain Taxonomy (AAPT) diagnostic criteria were used to categorize patients into pain frequency groups at both timepoints: chronic (pain on most [≥15] d/mo for the past 6 mo, per AAPT diagnostic criteria), episodic (pain on 1 to 14 d/mo), or asymptomatic (0 d/mo).

RESULTS

At baseline, 31% (n=13) had chronic pain, 50% (n=21) episodic pain, and 19% (n=8) were asymptomatic. At follow-up, 40.5% (n=17) had chronic pain, 52.4% (n=22) episodic pain, and 7.1% (n=3) were asymptomatic. Between baseline and 2-year follow-up, 12% (n=5) developed chronic SCD pain. Depressive symptoms and admissions for pain significantly increased over time for youth with chronic pain (Ps<0.05). An interaction effect revealed that baseline pain groups differed in their change in pain intensity over time (P<0.01). Baseline psychosocial factors (ie, higher functional disability, greater depressive symptoms, higher pain catastrophizing, and lower quality of life) were significantly associated with chronic pain at follow-up.

DISCUSSION

Biopsychosocial factors may be associated with the development and maintenance of chronic SCD pain and their relative contributions warrant further study.

A Healthcare Improvement Initiative to Increase Multidisciplinary Pain Management Referrals for Youth with Sickle Cell Disease

BACKGROUND

Chronic pain is a complex integration of biological, psychological, and social variables. Multidisciplinary pain management experts design interventions that treat the multidimensional experience. Children and adolescents with sickle cell disease (SCD) are at risk for chronic pain. Increased risk is associated with multiple characteristics including sickle cell genotype, age, gender, frequency of hospitalization, duration of hospitalization, and certain comorbid diagnoses. Referral to pain management professionals for this population is often delayed.

AIMS

To increase multidisciplinary pain management referrals for youth with SCD identified to be at risk for chronic pain.

DESIGN

Implementation research.

SETTING

One pediatric, academic medical facility serving as a regional sickle cell treatment center in the Midwest.

PARTICIPANTS

Children greater than 2 years of age and less than 21 years of age with laboratory confirmed SCD.

METHODS

Implementation of an evidence-based screening tool using the consolidated framework for implementation research (CFIR) to guide project planning, design, and evaluation. The CFIR model was paired with the Plan-Do-Study-Act (PDSA) quality improvement methodology to operationalize workflow and sustain project aims.

RESULTS AND CONCLUSIONS

Eighty-four percent of all eligible patients were screened during their routine sickle cell appointments resulting in a 110% increase in multidisciplinary pain management referrals. Future interventions and PDSA cycles are targeted at improving attendance at scheduled appointments, reducing hospitalizations, decreasing 30-day readmissions, and shortening length of stay.

Prevalence and predictors of chronic pain intensity and disability among adults with sickle cell disease

Among 170 adults with sickle cell disease, we evaluated chronic pain impact and disability prevalence, assessed age and gender differences, and identified psychosocial predictors of chronic pain intensity and disability. Most participants had a high level of disability. Chronic pain intensity and disability were significantly associated with pain catastrophizing and chronic pain self-efficacy, and worsened with age. Further research is needed to confirm study findings and develop interventions, including palliative care approaches that address catastrophizing and disability, particularly for young women and middle-aged adults with sickle cell disease. Moreover, consistent clinical assessment of chronic pain and psychosocial health should be implemented.

Preliminary evaluation of the clinical implementation of cognitive-behavioral therapy for chronic pain management in pediatric sickle cell disease

OBJECTIVES

Evaluate the implementation of cognitive-behavioral therapy (CBT) for chronic pain in a clinical setting by comparing youth with sickle cell disease (SCD) who initiated or did not initiate CBT.

DESIGN

Youth with SCD (ages 6-18; n = 101) referred for CBT for chronic pain were compared based on therapy attendance: Established Care; Early Termination; or Comparison (i.e., did not initiate CBT).

SETTING

Outpatient pediatric psychology and comprehensive SCD clinics in 3 locations at a southeastern children's hospital.

INTERVENTIONS

CBT delivery was standardized. Treatment plans were tailored to meet individualized needs.

MAIN OUTCOME MEASURES

Healthcare utilization included pain-related inpatient admissions, total inpatient days, and emergency department reliance (EDR) at 12-months pre-post CBT. Patient-reported outcomes (PROs) included typical pain intensity, functional disability, and coping efficacy pre-post treatment.

RESULTS

Adjusting for age, genotype, and hydroxyurea, early terminators of CBT had increased rates of admissions and hospital days over time relative to comparisons; those who established care had faster reduction in admissions and hospital days over time relative to comparisons. EDR decreased by 0.08 over time for Established Care and reduced by 0.01 for every 1 completed session. Patients who completed pre- and post-treatment PROs reported decreases in typical pain intensity, functional disability, and improved coping efficacy.

CONCLUSIONS

Establishing CBT care may support reductions in admissions for pain, length of stay, and EDR for youth with chronic SCD pain, which may be partially supported by patient-reported improvements in functioning, coping, and lower pain intensity following CBT. Enhancing clinical implementation of multidisciplinary treatments may optimize the health of these youth.

Interpersonal Violence Exposure and Chronic Pain in Adult Sickle Cell Patients

Almost half of sickle cell disease (SCD) patients develop chronic, debilitating physical pain with uncertain genesis for which they primarily receive opiate-based palliative treatment. Psychological trauma exposure, especially interpersonal victimization, has been linked to the perception of pain in several medical diseases, but has yet to be examined in SCD patients. This study examines self-reported chronicity of pain and use of prescribed opiates in 50 adult SCD patients with and without a history of interpersonal violence exposure. We conducted a retrospective chart review of 50 consecutive SCD patients seen for medical care in an adult subspecialty hematology clinic. Data collected included demographics, opiate use, pain chronicity, and measures of anxiety, depression, and interpersonal violence exposure. Sixty-eight percent of patients reported past interpersonal violence exposure. The mean number of types of interpersonal violence exposure, including physical, sexual, or emotional abuse, was 2.76 (SD = 1.63). SCD patients with a history of interpersonal violence exposure were almost five times more likely to report chronic pain and more than six times more likely to report use of opiate-based medications on a daily basis compared with SCD patients with no history of violence exposure. Depression and anxiety symptoms were associated with violence exposure, but did not account for the relationship between violence exposure and chronic pain or prescribed opiate use. Screening and assessment of exposure to interpersonal violence may be useful in addition to screening for mental health problems in the management of chronic pain with adults diagnosed with SCD. Such screening may contribute to addressing health care disparities given the preponderance of SCD patients who are of African American ethnoracial background.

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.

Relationship of Pain Quality Descriptors and Quantitative Sensory Testing: Sickle Cell Disease

BACKGROUND

Chronic pain in adults with sickle cell disease (SCD) may be the result of altered processing in the central nervous system, as indicated by quantitative sensory testing (QST). Sensory pain quality descriptors on the McGill Pain Questionnaire (MPQ) are indicators of typical or altered pain mechanisms but have not been validated with QST-derived classifications.

OBJECTIVES

The specific aim of this study was to identify the sensory pain quality descriptors that are associated with the QST-derived normal or sensitized classifications. We expected to find that sets of sensory pain quality descriptors would discriminate the classifications.

METHODS

A cross-sectional quantitative study of existing data from 186 adults of African ancestry with SCD. Variables included MPQ descriptors, patient demographic data, and QST-derived classifications.

RESULTS

The participants were classified as central sensitization (n = 33), mixed sensitization (n = 23), and normal sensation. Sensory pain quality descriptors that differed statistically between mixed sensitization and central sensation compared to normal sensitization included cold (p = .01) and spreading (p = .01). Aching (p = .01) and throbbing (p = .01) differed statistically between central sensitization compared with mixed sensitization and normal sensation. Beating (p = .01) differed statistically between mixed sensitization compared with central sensitization and normal sensation. No set of sensory pain quality descriptors differed statistically between QST classifications.

DISCUSSION

Our study is the first to examine the association between MPQ sensory pain quality descriptors and QST-derived classifications in adults with SCD. Our findings provide the basis for the development of a MPQ subscale with potential as a mechanism-based screening tool for neuropathic pain.

A QST-based Pain Phenotype in Adults With Sickle Cell Disease: Sensitivity and Specificity of Quality Descriptors

BACKGROUND

We sought to refine a screening measure for discriminating a sensitized or normal sensation pain phenotype among African American adults with sickle cell disease (SCD).

OBJECTIVE

To develop scoring schemes based on sensory pain quality descriptors; evaluate their performance on classifying patients with SCD who had sensitization or normal sensation, and compare with scores on the Self-report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and the Neuropathic Pain Symptom Inventory (NPSI).

METHODS

Participants completed PAINReportIt, quantitative sensory testing (QST), S-LANSS, and NPSI. Conventional binary logistic regression and least absolute shrinkage and selection operator (lasso) regression were used to obtain 2 sets of weights resulting in 2 scores: the PR-Logistic (PAINReportIt score weighted by conventional binary logistic regression coefficients) and PR-Lasso (PAINReportIt score weighted by lasso regression coefficients). Performance of the proposed scores and the existing scores were evaluated.

RESULTS

Lasso regression resulted in a parsimonious model with non-zero weights assigned to 2 neuropathic descriptors, cold and spreading. We found positive correlations between the PR-Lasso and other scores: S-LANSS (r = 0.22, P < 0.01), NPSI (r = 0.22, P < 0.01), and PR-Logistic (r = 0.35, P < 0.01). The NPSI and PR-Lasso performed similarly at different levels of required specificity and outperformed the S-LANSS and PR-Logistic at the various specificity points.

CONCLUSION

The PR-Lasso offers a way to discriminate a SCD pain phenotype.

Neurocognitive and psychological effects of persistent pain in pediatric sickle cell disease

BACKGROUND

Pain is a major complication of sickle cell disease (SCD), spanning vaso-occlusive crises and persistent pain. Although it is known that persistent pain is associated with considerable impairment in youth without SCD, little is known about the functional effects of persistent pain in SCD. The current study aimed to (a) characterize persistent pain in youth with SCD and (b) determine the extent to which youth with SCD and persistent pain differ in disease morbidity, functional impairment, and neurocognitive and psychological functioning.

PROCEDURE

Eighty-nine participants (ages 7-16) and caregivers completed questionnaires (BRIEF [Behavior Rating Inventory of Executive Function], Conners-3 [Conners-third edition], and PedsQL™-SCD Module, where PedsQL is Pediatric Quality of Life Inventory). Participants completed neurocognitive tests WISC-V [Wechsler Intelligence Scale for Children-fifth edition], WJ-III [Woodcock Johnson Tests of Achievement-third edition], and WIAT-III [Wechsler Individual Achievement Test-third edition]). Youth were classified as having persistent pain if they reported daily pain for 7 days. Chi-square and independent sample t-test analyses were used to assess group differences (those with vs without persistent pain).

RESULTS

Patients with persistent pain (n = 18) reported lower health-related quality of life (P = .000). Caregivers were more likely to rate youth with persistent pain as having lower planning/organization abilities (P = .011) and clinically elevated symptoms of defiance/aggression and oppositional defiance (Ps = .00; .01). Patients with persistent pain demonstrated poorer working memory (P = .023) and processing speed (P = .027), and fewer demonstrating reading fluency abilities in the average or above range (P = .026).

CONCLUSIONS

Youth with SCD and persistent pain are at risk for psychosocial and neurocognitive impairments, suggesting that persistent pain may be an important indicator of disease burden. Furthermore, disease management may be enhanced by assessing cognitive and psychosocial functioning and incorporating interdisciplinary treatments addressing impairment associated with persistent pain.

Sensitization of nociceptors and dorsal horn neurons contributes to pain in sickle cell disease

Sickle cell disease (SCD) describes a group of disorders associated with a point mutation in the beta chain of hemoglobin. The mutation leads to the creation of sickle hemoglobin (HbS) and causes distortion of erythrocytes through polymerization under low oxygen, resulting in characteristic sickle red blood cells. Vaso-occlusion episodes caused by accumulation of sRBCs results in ischemia-reperfusion injury, reduced oxygen supply to organs, oxidative stress, organ damage and severe pain that often requires hospitalization and opioid treatment. Further, many patients suffer from chronic pain, including hypersensitivity to heat and cold stimuli. Progress towards the development of novel strategies for both acute and chronic pain in patients with SCD has been impeded by a lack of understanding the mechanisms underlying pain in SCD. The purpose of this review is to highlight evidence for the contribution of peripheral and central sensitization that leads to widespread, chronic pain and hyperalgesia. Targeting the mechanisms that initiate and maintain sensitization in SCD might offer effective approaches to manage the severe and debilitating pain associated with this condition.

Pediatric pain screening identifies youth at risk of chronic pain in sickle cell disease

BACKGROUND

This study aimed to evaluate the preliminary validation and application of a pain screening tool to identify biopsychosocial risk factors for chronic pain in pediatric sickle cell disease (SCD) and classify youth with SCD into prognostic risk groups.

METHOD

Youth presenting to a pediatric SCD clinic completed the Pediatric Pain Screening Tool (PPST), a brief 9-item self-report questionnaire developed for rapid identification of risk in youth with pain complaints. Youth also completed a battery of standardized patient-reported outcomes, including pain characteristics, pain burden, functional disability, pain interference, depressive symptoms, pain catastrophizing, and fear of pain. Healthcare utilization was extracted from medical chart review.

RESULTS

Seventy-three 8- to 18-year-olds (94% Black, 57% female) with SCD participated. The PPST demonstrated discriminant validity that ranged from fair to excellent (area under the curves (AUC) = 0.74-0.93, P values < 0.001) for identifying significant pain frequency, disability, pain interference, and psychosocial distress. Receiver operating characteristic curve analyses indicated that previously established cutoff scores were appropriate for the SCD sample. Participants were classified into low-risk (28.8%), medium-risk (38.4%), and high-risk (32.9%) groups, with significant group differences across measures, F(18, 116) = 6.67, P < 0.001. The high-risk group reported significantly higher pain intensity, pain frequency, pain burden, functional disability, pain interference, and depressive symptoms relative to both low-risk and medium-risk groups (P values < 0.005).

CONCLUSIONS

The high-risk group demonstrated a pain and psychosocial profile consistent with chronic SCD pain. The PPST may be useful for efficiently identifying youth with chronic SCD pain or those at risk of poor outcomes.

Ketamine Infusion for Pain Control in Acute Pediatric Sickle Cell Painful Crises

OBJECTIVES

Sickle cell disease is the most common hemoglobin variant in the world and can present with recurrent vaso-occlusive painful crises. Pain control in these patients is often difficult and requires a multimodal approach. In patients with uncontrolled pain after traditional pain control methods, ketamine infusions have proven beneficial. Unfortunately, no source alone had described ketamine infusions for pediatric sickle cell patients. Our objective was to provide a thorough definitive reference for health care providers regarding the use of ketamine infusion for pain control in pediatric sickle cell painful crises.

METHODS

Literature review.

RESULTS

Low-dose ketamine infusions for pediatric patients with sickle cell disease painful crises resulted in improved pain scores and reduced opioid usage.

CONCLUSIONS

Ketamine infusions have shown promise in assisting physicians in appropriately treating pediatric sickle cell painful crises.

Advances in the Treatment of Sickle Cell Disease

Sickle cell disease (SCD) is a monogenic disorder that afflicts approximately 100,000 Americans and millions of people worldwide. It is characterized by hemolytic anemia, vaso-occlusive crises, relentless end-organ injury, and premature death. Currently, red blood cell transfusion and hydroxyurea are the major disease-modifying therapies available for SCD. Hematopoetic stem cell transplant is curative, but barriers to treatment are substantial and include a lack of suitable donors, immunologic transplant rejection, long-term adverse effects, prognostic uncertainty, and poor end-organ function, which is especially problematic for older patients. Gene therapy to correct the β^s point mutation is under investigation as another curative modality. Deeper insights into the pathophysiology of SCD have led to the development of novel agents that target cellular adhesion, inflammation, oxidant injury, platelets and/or coagulation, vascular tone, and hemoglobin polymerization. These agents are in preclinical and clinical trials. One such agent, L-glutamine, decreases red blood cell oxidant injury and is recently US Food and Drug Administration approved to prevent acute pain episodes of SCD in patients 5 years of age or older. The purpose of this review is to describe the currently established therapies, barriers to curative therapies, and novel therapeutic agents that can target sickle cell hemoglobin polymerization and/or its downstream sequelae. A PubMed search was conducted for articles published up to May 15, 2018, using the search terms sickle cell disease, novel treatments, hematopoietic stem cell transplantation, and gene therapy. Studies cited include case series, retrospective studies, prospective clinical trials, meta-analyses, online abstracts, and original reviews.

Executive Functioning Mediates the Relationship Between Pain Coping and Quality of Life in Youth With Sickle Cell Disease

Objective

Sickle cell disease (SCD) is a lifelong condition characterized by pain, which is associated with reduced health-related quality of life (HRQL). Data suggest that patients with SCD vary in how they cope and their neurocognitive abilities. This study aimed to characterize executive functioning and pain coping styles in children with SCD experiencing a range of pain frequency (i.e., chronic, episodic, and asymptomatic) and to examine whether executive functioning mediates the relationship between pain coping and HRQL.

Method

Participants included 100 children and adolescents with SCD between the ages of 8 and 18 years (M = 13.53, SD = 2.8) and their parents who were recruited during outpatient SCD clinic visits in a children's hospital. Children completed questionnaires related to pain experience and pain coping. Parents completed questionnaires about demographic information, their child's executive functioning, and HRQL.

Results

Pain intensity, executive dysfunction, and engagement in emotion-focused coping (i.e., internalizing/catastrophizing and externalizing) predicted poor HRQL. In addition, engagement in emotion-focused coping predicted executive dysfunction. Multivariate analysis of covariance revealed executive functioning did not differ based on pain frequency; however, executive functioning was a significant mediator that helped explain the relationships between distraction and emotion-focused coping techniques on HRQL.

Conclusion

Findings support that executive functioning is an important factor in understanding the relationship between pain coping and HRQL in youth with SCD. Future research is warranted to examine the potential impact of executive functioning on the utility of interventions targeting adaptive pain coping in youth with SCD.

A Qualitative Study of Chronic Pain and Self-Management in Adults with Sickle Cell Disease

Acute, intermittent vaso-occlusive pain is the hallmark of sickle cell disease (SCD) and is associated with substantial morbidity and impaired quality of life (QOL). The subgroup of adults with SCD who transition from recurrent, acute pain to chronic, persistent pain have even greater QOL impairment and higher rates of healthcare utilization. Self-management is central to SCD management; however, its role in chronic pain management is not established. This qualitative study was conducted to answer the following research questions: (1) What is the chronic pain experience of adults with SCD? (2) What self-management strategies do adults with SCD use for chronic pain? and (3) Do adults with SCD have any needs in the self-management of chronic pain? Eighteen Black adults with SCD completed a demographics questionnaire and an interview. The majority of the participants were 21-30 years of age (mean 33.5, SD 7.6), female (61.1%), employed at least part-time (61.1%), single/never married (72.2%), and had a SCD type of sickle cell anemia (55.5%). Interview analysis revealed three major themes: (1) the chronic pain experience; (2) strategies for managing chronic pain; and (3) challenges and needs in managing chronic pain. Study findings can be used to support chronic pain management among adults with SCD. Further research is needed to devise and implement effective strategies for the prevention and management of chronic SCD pain.

Magnesium in Breast Cancer: What Is Its Influence on the Progression of This Disease?

Breast cancer is a disease of high mortality, characterized by the progressive accumulation of mutations that contribute to the uncontrolled development of breast tissue cells. Literature shows that disturbances in mineral homeostasis, such as magnesium, may interfere with tumor progression. The objective of this study is to provide updated information about magnesium's role in the pathogenesis of breast cancer. A review of literature was carried out from a search for articles in the PubMed and CAPES Periodicals databases published between 1995 and 2016 with the cross-references of the descriptors "magnesium," "breast neoplasms," and "oxidative stress" and the corresponding words in Portuguese. We included studies on the metabolism and bioavailability of magnesium and studies related to breast cancer and excluded articles in which only the abstract was available, dissertations, theses, articles involving adjuvant and/or neoadjuvant therapies, and supplementation of minerals in breast cancer patients. Magnesium is a mineral that participates in the metabolism of various nutrients and nucleic acids. In the presence of breast cancer, neoplastic cells increase the expression of magnesium transport channels, which raises the intracellular concentration of the mineral, contributing to tumor growth through its function of increasing energy demand. The data obtained in this review illustrates the influence of magnesium on the progression of breast cancer. However, the existing data are scarce and inconsistent, which demonstrates a need for further studies on the subject with a goal to have better control of the disease.

Bivalent ligand MCC22 potently attenuates nociception in a murine model of sickle cell disease

Sickle cell disease (SCD) is a chronic inflammatory disorder accompanied by chronic pain. In addition to ongoing pain and hyperalgesia, vaso-occlusive crises-induced pain can be chronic or episodic. Because analgesics typically used to treat pain are not very effective in SCD, opioids, including morphine, are a primary treatment for managing pain in SCD but are associated with many serious side effects, including constipation, tolerance, addiction, and respiratory depression. Thus, there is a need for the development of novel treatments for pain in SCD. In this study, we used the Townes transgenic mouse model of SCD to investigate the antinociceptive efficacy of the bivalent ligand, MCC22, and compared its effectiveness with morphine. MCC22 consists of a mu-opioid receptor agonist and a chemokine receptor-5 (CCR5) antagonist that are linked through a 22-atom spacer. Our results show that intraperitoneal administration of MCC22 produced exceptionally potent dose-dependent antihyperalgesia as compared to morphine, dramatically decreased evoked responses of nociceptive dorsal horn neurons, and decreased expression of proinflammatory cytokines in the spinal cord. Moreover, tolerance did not develop to its analgesic effects after repeated administration. In view of the extraordinary potency of MCC22 without tolerance, MCC22 and similar compounds may vastly improve the management of pain associated with SCD.

Genetic modifiers of severity in sickle cell disease

Sickle cell disease (SCD) is one of the most common single disease disorders world-wide. It is remarkable for its clinical heterogeneity, even among individuals with identical genotypes. Some individuals experience morbidity and mortality in early childhood, while others have a relatively mild course, and normal or near normal life expectancy. Many clinical complications are associated with SCD; most notably frequent pain episodes, stroke, acute chest syndrome, avascular necrosis, nephropathy, retinopathy and pulmonary hypertension. While the effects of higher fetal hemoglobin (HbF) levels, UGTA1A polymorphisms, alpha-thalassemia and G6PD deficiency on SCD has been extensively studied, these variables do not explain all of the clinical heterogeneity of SCD. It is not known why some patients develop certain complications, and it is difficult to predict which complications a particular patient will experience. Much work has been done to identify genetic variants associated with these disease complications; many associations remain unvalidated. As the field continues to move beyond small sample collections and candidate gene approaches into whole genome sequencing and merging of samples from all over the world, we will identify more genetic variants associated with development of specific SCD related complications, and hopefully leverage this knowledge into targeted therapies.

Sensitization of C-fiber nociceptors in mice with sickle cell disease is decreased by local inhibition of anandamide hydrolysis

Chronic pain and hyperalgesia, as well as pain resulting from episodes of vaso-occlusion, are characteristic features of sickle cell disease (SCD) and are difficult to treat. Since there is growing evidence that increasing local levels of endocannabinoids can decrease hyperalgesia, we examined the effects of URB597, a fatty acid amide hydrolase (FAAH) inhibitor, which blocks the hydrolysis of the endogenous cannabinoid anandamide, on hyperalgesia and sensitization of cutaneous nociceptors in a humanized mouse model of SCD. Using homozygous HbSS-BERK sickle mice, we determined the effects of URB597 on mechanical hyperalgesia and on sensitization of C-fiber nociceptors in vivo. Intraplantar administration of URB597 (10 μg in 10 μL) decreased the frequency of withdrawal responses evoked by a von Frey monofilament (3.9 mN bending force) applied to the plantar hind paw. This was blocked by the CB1 receptor antagonist AM281 but not by the CB2 receptor antagonist AM630. Also, URB597 decreased hyperalgesia in HbSS-BERK/CB2R sickle mice, further confirming the role of CB1 receptors in the effects produced by URB597. Electrophysiological recordings were made from primary afferent fibers of the tibial nerve in anesthetized mice. The proportion of Aδ- and C-fiber nociceptors that exhibited spontaneous activity and responses of C-fibers to mechanical and thermal stimuli were greater in HbSS-BERK sickle mice as compared to control HbAA-BERK mice. Spontaneous activity and evoked responses of nociceptors were decreased by URB597 via CB1 receptors. It is suggested that enhanced endocannabinoid activity in the periphery may be beneficial in alleviating chronic pain associated with SCD.

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.

Daily Pain, Physical Activity, and Home Fluid Intake in Pediatric Sickle Cell Disease

Objectives

This study examined the temporal relationship between physical activity, fluid intake, and daily pain in children with sickle cell disease (SCD) with frequent pain.

Methods

A total of 30 African American children ( M age  =  13.9; 53% female; 76.3% type SS) who reported pain more than or equal to once every 2 weeks and their parents completed measures of pain and anxiety/depressive symptoms. Children then completed a daily pain diary and wore a physical activity Actiwatch for 14 days at home.

Results

Contrary to physiological theory-based hypotheses, lower physical activity was associated with greater pain during the same day and the next day. Less pain was associated with greater physical activity the next day. There was no relationship between self-reported home fluid intake and daily pain ( p 's  <  .05).

Conclusions

Results lend support for a complex bidirectional relationship between physical activity and daily pain in pediatric SCD, and identify physical activity as a target for future research.

Depressive symptoms and sickle cell pain: The moderating role of internalized stigma

Recent studies describe the clinical implications of sickle cell disease (SCD) stigma. However, little is known about its link to depressive symptoms or its relative influence on the association between depressive symptoms and SCD pain. We examined whether internalized stigma about SCD moderated the relation between depressive symptoms and pain among 69 adults attending a SCD clinic who reported pain episodes and healthcare use over the past three months. Unadjusted bivariate analyses showed a marginal association between depressive symptoms and SCD pain frequency (r = .21, p < .10). Further analyses adjusting for health care use indicated a moderating effect of internalized stigma (b = -.10, p < .05): a significant association between depressive symptoms and pain was observed among participants low in internalized stigma, but this relationship was attenuated at moderate and high stigma levels. These results denote counterintuitive consequences of internalized attitudes about SCD and suggest a need for further study of the psychosocial and clinical implications of SCD stigma.

Central sensitization associated with low fetal hemoglobin levels in adults with sickle cell anemia

BACKGROUND AND AIMS

Pain is the hallmark of sickle cell anemia (SCA), presenting as recurrent acute events or chronic pain. Central sensitization, or enhanced excitability of the central nervous system, alters pain processing and contributes to the maintenance of chronic pain. Individuals with SCA demonstrate enhanced sensitivity to painful stimuli however central mechanisms of pain have not been fully explored. We hypothesized that adults with SCA would show evidence of central sensitization as observed in other diseases of chronic pain.

METHODS

We conducted a prospective study of static and dynamic quantitative sensory tests in 30 adults with SCA and 30 matched controls.

RESULTS

Static thermal testing using cold stimuli showed lower pain thresholds (p=0.04) and tolerance (p=0.04) in sickle cell subjects, but not for heat. However, SCA subjects reported higher pain ratings with random heat pulses (p<0.0001) and change in scores with temporal summation at the heat pain threshold (p=0.002). Similarly, with the use of pressure pain stimuli, sickle cell subjects reported higher pain ratings (p=0.04), but not higher pressure pain tolerance/thresholds or allodynia to light tactile stimuli. Temporal summation pain score changes using 2 pinprick probes (256 and 512mN) were significantly greater (p=0.004 and p=0.008) with sickle cell, and delayed recovery was associated with lower fetal hemoglobin (p=0.002 and 0.003).

CONCLUSIONS

Exaggerated temporal summation responses provide evidence of central sensitization in SCA.

IMPLICATIONS

The association with fetal hemoglobin suggests this known SCA modifier may have a therapeutic role in modulating central sensitization.

Low-dose methotrexate in sickle-cell disease: a pilot study with rationale borrowed from rheumatoid arthritis

Background

Inflammation is a major feature of sickle cell disease (SCD). Low-dose methotrexate (MTX) has long been used in chronic inflammatory diseases. This pilot study examined the MTX effect on acute vaso-occlusive pain crises (VOC) in SCD patients.

Methods

Fourteen adults on hydroxyurea with severe and refractory VOC received one intramuscular injection of 10 mg of MTX per week for 12 weeks. A single weekly dose of 5 mg of leucovorin was administered orally 48 h after each MTX injection. The primary outcome was reduction in number/intensity of acute pain episodes. The secondary outcomes were improvement of quality of life (QOL) and reduction of the inflammatory status.

Results

MTX did not significantly change the median VOC frequency (12 before vs 10.5 during treatment, P = 0.6240) or the median McGill pain index (45 at week 0 vs 39.5 at week 12, P = 0.9311). However, there was a decrease of ≥50% in chronic pain resulting from avascular osteonecrosis (AVN) in 5 out of 7 patients with radiologic evidence of AVN, with the perception of longer pain-free periods. There was a 44.4% median gain in physical function in the SF-36 QOL questionnaire (P = 0.0198). MTX treatment up-regulated two C-X-C motif chemokines (CXCL), CXCL10 (P = 0.0463) and CXCL12 (P < 0.0001), without significant effect on 14 additional plasma inflammatory markers. Adverse events: One individual had fever of unknown origin. Respiratory tract infections were recorded in five patients. Among the latter, one also had dengue fever and another had a central venous line infection and died of pneumonia and septic shock. Three patients with previous history of hydroxyurea-induced hematological toxicity developed low blood platelet counts while receiving simultaneously MTX and hydroxyurea.

Conclusions

Although MTX did not reduce acute VOC frequency/intensity, it decreased chronic pain and led to QOL improvement.

Trial registrationhttp://www.who.int/ictrp/en/ and http://www.ensaiosclinicos.gov.br, RBR-2s9xvn, 19 December 2016, retrospectively registered

Electronic supplementary material

The online version of this article (doi:10.1186/s40164-017-0078-1) contains supplementary material, which is available to authorized users.

Sickle cell disease in adults: developing an appropriate care plan

BACKGROUND

Sickle cell disease (SCD) is primarily characterized by pain. This chronic pain with acute exacerbations is the most common reason for hospital visits, admissions, and readmissions, particularly in young adults (aged 18–39 years). People who present to the hospital for pain crises often report that nurses lack knowledge of SCD and, consequently, they do not provide appropriate, timely care.

OBJECTIVES

Because pain episodes often result in hospital admissions, this article highlights prominent issues that staff nurses need to know.

METHODS

Using a review of the literature and case studies, the authors provide recommendations to improve care of adults with SCD.

FINDINGS

No objective signs of a sickle cell pain crisis exist. Patients react to pain in different ways and use various coping mechanisms in response. Suspected opioid addiction should not affect the provision of nursing care. Pain must be treated appropriately to decrease the potential for prolonged admissions and/or readmissions. Patients are to be acknowledged as experts and collaborated with in developing an appropriate plan of care. Advocacy on behalf of the patient is important for better communication with providers. With this knowledge, nurses will be better equipped to provide the appropriate and timely care required to manage pain crises experienced by individuals living with SCD.

Disease-Related, Nondisease-Related, and Situational Catastrophizing in Sickle Cell Disease and Its Relationship With Pain

Catastrophizing is a potent psychological modulator of pain across several chronic pain populations; yet despite evidence that patients with sickle cell disease (SCD) catastrophize more than patients with other chronic pain conditions, previous research indicates that catastrophizing is not related to sickle cell pain after controlling for relevant covariates such as depression. Recent research suggests that pain-related catastrophizing should be assessed across pain contexts (eg, dispositional and situational). In this study, we measured disease-specific, general non-disease-related, and situational catastrophizing and assessed the relationship between these contextual dimensions of catastrophizing and laboratory and clinical pain among patients with SCD. Results revealed differential catastrophizing across pain contexts, with patients reporting greater catastrophizing about SCD-specific pain compared with non-SCD pain and laboratory pain. SCD-specific and non-SCD catastrophizing were associated with clinical pain outcomes, and situational catastrophizing with markers of central sensitization and laboratory pain. Further examination of the time course of laboratory responses revealed that increases in situational catastrophizing were associated with subsequent increases in laboratory pain sensitivity. Taken together, results show the relevance of catastrophizing in understanding pain in SCD, and suggest that context-specific anchors may be beneficial in predicting different aspects of the pain experience (eg, chronic pain, pain sensitization).

PERSPECTIVE

Patients with SCD report greater catastrophizing about sickle cell-specific pain relative to other pains. Disease-specific and non-disease-related pain catastrophizing were associated with clinical pain, and situational catastrophizing predictive of subsequent laboratory pain. Evaluation of context-specific catastrophizing may more accurately predict different aspects of the pain experience.

Sensitization of nociceptive spinal neurons contributes to pain in a transgenic model of sickle cell disease

Chronic pain is a major characteristic feature of sickle cell disease (SCD). The refractory nature of pain and the development of chronic pain syndromes in many patients with SCD suggest that central neural mechanisms contribute to pain in this disease. We used HbSS-BERK sickle mice, which show chronic features of pain similar to those observed in SCD, and determined whether sensitization of nociceptive neurons in the spinal cord contributes to pain and hyperalgesia in SCD. Electrophysiological recordings of action potential activity were obtained from single identified dorsal horn neurons of the spinal cord in anesthetized mice. Compared with control HbAA-BERK mice, nociceptive dorsal horn neurons in sickle mice exhibited enhanced excitability as evidenced by enlarged receptive fields, increased rate of spontaneous activity, lower mechanical thresholds, enhanced responses to mechanical stimuli, and prolonged afterdischarges following mechanical stimulation. These changes were accompanied by increased phosphorylation of mitogen-activated protein kinases (MAPKs) in the spinal cord that are known to contribute to neuronal hyperexcitability, including c-Jun N-terminal kinase (JNK), p44/p42 extracellular signaling-regulated kinase (ERK), and p38. These findings demonstrate that central sensitization contributes to pain in 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.

Perceptions of young adults with sickle cell disease concerning their disease experience

AIM

To describe the perceptions of young adults with sickle cell disease concerning their disease experience.

BACKGROUND

Sickle cell disease is a lifelong, genetic condition with both acute and chronic painful exacerbations. Little is known of the experiences of young adults with sickle cell disease.

DESIGN

This study used a qualitative, descriptive design with semi-structured, life review interviews.

METHODS

Between August 2010-September 2012, purposive sampling was used to recruit participants with a known sickle cell disease diagnosis who were ages 18-35 years, were being seen in an outpatient sickle cell clinic and were English speaking. Participants provided demographic information and responded to two interviews. A content analysis was then used to interpret participants' narratives of their experiences of living with sickle cell disease.

RESULTS/FINDINGS

A sample of 29 young adults with sickle cell disease consisted of 79·3% females, 35·6% employed full-time or part-time, 71·6% single/never married and 57·8% with sickle cell anaemia. Their mean age was 25·8 with 13·2 years of education. Four major interview themes were identified: (1) struggles to maintain or achieve good quality of life or life satisfactions; (2) strategies to maintain self-care; (3) interruptions to family, work and social roles; and (4) difficulties accessing needed health care.

CONCLUSION

Young adults face many challenges while living with sickle cell disease. With a better understanding of their disease experience and how it influences their quality of life, researchers can begin tailoring appropriate interventions to improve health outcomes in this vulnerable, minority population.

Small-molecule nociceptin receptor agonist ameliorates mast cell activation and pain in sickle mice

Treatment of pain with morphine and its congeners in sickle cell anemia is suboptimal, warranting the need for analgesics devoid of side effects, addiction and tolerance liability. Small-molecule nociceptin opioid receptor ligands show analgesic efficacy in acute and chronic pain models. We show that AT-200, a high affinity nociceptin opioid receptor agonist with low efficacy at the mu opioid receptor, ameliorated chronic and hypoxia/reoxygenation-induced mechanical, thermal and deep tissue/musculoskeletal hyperalgesia in HbSS-BERK sickle mice. The antinociceptive effect of AT-200 was antagonized by SB-612111, a nociceptin opioid receptor antagonist, but not naloxone, a non-selective mu opioid receptor antagonist. Daily 7-day treatment with AT-200 did not develop tolerance and showed a sustained anti-nociceptive effect, which improved over time and led to reduced plasma serum amyloid protein, neuropeptides, inflammatory cytokines and mast cell activation in the periphery. These data suggest that AT-200 ameliorates pain in sickle mice via the nociceptin opioid receptor by reducing inflammation and mast cell activation without causing tolerance. Thus, nociceptin opioid receptor agonists are promising drugs for treating pain in sickle cell anemia.

Breathing Exercises for Inpatients with Sickle Cell Disease

Sickle cell disease (SCD) is a painful condition wherein breathing often is compromised. This pilot study supports the premise that individuals with SCD are willing to learn breathing exercises. Medical-surgical nurses should encourage breathing exercises for managing pain and preventing complications.