AAPT Diagnostic Criteria for Chronic Sickle Cell Disease Pain

Implementation of Individualized Pain Care Plans Decreases Length of Stay and Hospital Admission Rates for High Utilizing Adults with Sickle Cell Disease

OBJECTIVE

Patients with sickle cell disease (SCD) face inconsistent effective analgesic management, leading to high inpatient healthcare utilization and significant financial burden for healthcare institutions. Current evidence does not provide guidance for inpatient management of acute pain in adults with sickle cell disease. We conducted a retrospective analysis of a longitudinal cohort quality improvement project to characterize the role of individualized care plans on improving patient care and reducing financial burden in high healthcare-utilizing patients with SCD-related pain.

METHODS

Individualized care plans were developed for patients with hospital admissions resulting from pain associated with sickle cell disease. A 2-year prospective longitudinal cohort quality improvement project was performed and retrospectively analyzed. Primary outcome measure was duration of hospitalization. Secondary outcome measures included: pain intensity; 7, 30, and 90-day readmission rates; cost per day; total admissions; total cost per year; analgesic regimen at index admission; and discharge disposition.

RESULTS

Duration of hospitalization, the primary outcome, significantly decreased by 1.23 days with no worsening of pain intensity scores. Seven-day readmission decreased by 34%. Use of intravenous hydromorphone significantly decreased by 25%. The potential cost saving was $1,398,827 as a result of this quality initiative.

CONCLUSIONS

Implementation of individualized care plans reduced both admission rate and financial burden of high utilizing patients. Importantly, pain outcomes were not diminished. Results suggest that individualized care plans are a promising strategy for managing acute pain crisis in adult sickle cell patients from both care-focused and utilization outcomes.

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.

Parental Psychosocial Distress in Pediatric Sickle Cell Disease and Chronic Pain

BACKGROUND

Pediatric sickle cell disease (SCD) management can result in considerable caregiver distress. Parents of youth with chronic SCD pain may face the additional challenge of managing children's chronic pain and chronic illness. This study examined associations between parent psychological distress and child functioning and the moderating role of chronic pain among youth with SCD.

METHODS

Youth presenting to pediatric outpatient comprehensive SCD clinics and their primary caregivers completed a battery of questionnaires. Parents reported on parenting stress, parent mental and physical health, and family functioning. Children completed measures of pain characteristics, depressive symptoms, catastrophic thinking, functional disability, and quality of life.

RESULTS

Patients (N = 73, Mage = 14.2 years, 57% female) and their caregivers (Mage = 41.1 years, 88% mothers, 88% Black) participated. Worse parent functioning was associated with worse child pain, functioning, quality of life, and depressive symptoms. Beyond the effects of SCD, chronic SCD pain magnified the negative associations between parenting stress frequency and child quality of life, parent physical health and child quality of life, and parent depressive symptoms and child depressive symptoms.

CONCLUSIONS

Chronic pain may exacerbate the relations between parent and child functioning beyond the effects of SCD alone. The management of both SCD and chronic pain may present additional challenges for parents that limit their psychosocial functioning. Family-focused interventions to support parents and youth with chronic SCD pain are warranted to optimize health outcomes.

AAAPT Diagnostic Criteria for Acute Neuropathic Pain

OBJECTIVE

Acute neuropathic pain is a significant diagnostic challenge, and it is closely related to our understanding of both acute pain and neuropathic pain. Diagnostic criteria for acute neuropathic pain should reflect our mechanistic understanding and provide a framework for research on and treatment of these complex pain conditions.

METHODS

The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the U.S. Food and Drug Administration (FDA), the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) collaborated to develop the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) for acute pain. A working group of experts in research and clinical management of neuropathic pain was convened. Group members used literature review and expert opinion to develop diagnostic criteria for acute neuropathic pain, as well as three specific examples of acute neuropathic pain conditions, using the five dimensions of the AAAPT classification of acute pain.

RESULTS

AAAPT diagnostic criteria for acute neuropathic pain are presented. Application of these criteria to three specific conditions (pain related to herpes zoster, chemotherapy, and limb amputation) illustrates the spectrum of acute neuropathic pain and highlights unique features of each condition.

CONCLUSIONS

The proposed AAAPT diagnostic criteria for acute neuropathic pain can be applied to various acute neuropathic pain conditions. Both the general and condition-specific criteria may guide future research, assessment, and management of acute neuropathic pain.

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.

Digital behavioural interventions for people with sickle cell disease

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To identify and assess the effects of digital behavioural interventions focused on behavioural change in people with SCD on: medication adherence or disease management (such as managing acute and chronic pain), or both, on health- and other-related outcomes;specific subgroups defined by age (i.e. children, adolescents and adults) and type of modality or delivery (e.g. cell phone, the Internet).

A pilot study of the acceptability, feasibility and safety of yoga for chronic pain in sickle cell disease

OBJECTIVES

To determine the acceptability, feasibility and safety of yoga for chronic pain in sickle cell disease.

DESIGN AND SETTING

In Part A of this two-part study, adolescents with SCD and chronic pain (Group 1) and their parent (Group 2) completed a survey designed to capture pain characteristics, attitudes and practices related to yoga, and potential acceptability of a yoga program. In Part B, the study assessed the feasibility and safety of an instructor-led group yoga program. The study was registered on clinicaltrials.gov (NCT03694548).

INTERVENTION

Eight instructor-led group yoga sessions.

MAIN OUTCOME MEASURES

Feasibility and safety outcomes were chosen a priori, as follows: 1) Proportion of adolescent patients with SCD and chronic pain approached that consent to participate in Part A, 2) Proportion of adolescent participants enrolled in Part A that consent to participate in Part B, 3) Proportion of participants enrolled in Part B that attend at least 6 of 8 yoga sessions, 4) Proportion of participants enrolled in Part B with an ED visit or a hospitalization for pain within 24 h of completion of each yoga session, 5) Proportion of participants in Part B who complete all study assessments before, and at the end of the yoga program, 6) Adherence to submission of pain diary.

RESULTS

The median age of 15 patient participants in Part A was 16 (IQR 14-17), and 14 parents was 43.5 (IQR 42-51). Most participants were female. Most participant responses indicated a positive opinion of yoga. Nine adolescents (60 %) from Part A participated in Part B of the study. The median age of 9 participants in Part B was 17 (IQR 15-18), and 5 of the 9 participants were female (53.3 %). Only one participant was able to attend 3 of the 8 yoga sessions offered, and did not experience any ED visits or hospitalizations following the yoga sessions. None of the other feasibility endpoints were met in this study.

CONCLUSIONS

Patients with SCD and chronic pain overall have a positive opinion of yoga, but there are challenges with recruitment and retention of participants in a clinical trial of yoga, and barriers to feasibility of an in-person group yoga intervention.

Descriptive analysis of sickle cell patients living in France: The PHEDRE cross-sectional study

Background

Sickle cell disease (SCD) induces chronic haemolytic anaemia and intermittent vaso-occlusion that results in tissue ischaemia causing acute, severe pain episodes that can lead to frequent hospitalizations. These consequences can have repercussions on family, social, school and/or professional life. Here, we present some of the results of the PHEDRE study (Pharmacodépendance Et DREpanocytose—drug dependence and sickle-cell disease), which is the largest study of patients with SCD in France. This paper intends to describe characteristics of the French SCD population. We also aimed to assess the impact of the disease on the lives of patients using objective and subjective variables.

Methods

The PHEDRE study was a national multicentric observational study. Adults, adolescents and children with a confirmed SCD diagnosis were included in the study by their referring doctor. Then, they were interviewed by phone about their socioeconomic status, about the impact of the disease on their lives and about their analgesic and psychoactive drug use.

Results

The study population consisted of 872 patients (28% were minors). Seventy-two percent of adults were active, and all minors were in school. Many patients presented criteria of severe SCD. Seventy-five percent were homozygous SS, 15% were double heterozygotes SC and 8% were heterozygotes Sβthal, 87% received specific treatment, 58% were hospitalized at least once for vaso-occlusive crisis in the past 12 months, and the number of analgesic drugs taken averaged 3.8. Seventy-five percent of patients reported academic or professional consequences related to their SCD, and 52% reported social consequences.

Conclusions

The impact of SCD on patients’ lives can be significant, nevertheless their social integration seems to be maintained. We highlighted respect of recommendations regarding analgesic treatments and only a few patients used tobacco, alcohol or cannabis.

Trial registration

Clinical Trials, NCT02580565; https://clinicaltrials.gov/ Registered 16 October 2015.

Management of Sickle Cell Disease Complications Beyond Acute Chest Syndrome

Sickle cell disease results in numerous complications that can lead to significant morbidity and mortality. Amongst them, acute chest syndrome is the leading cause of mortality. As a result, most providers are in tune with this complication and well versed with management. As sickle cell patients now live longer, they face a multitude of other complications that if left unattended, can lead to significant morbidity and mortality as well. It is critical to look beyond acute chest syndrome and adopt a more comprehensive approach to the management of the sickle cell patient.

Pain in Youth With Sickle Cell Disease: A Report From the Sickle Cell Clinical Research and Intervention Program

OBJECTIVES

Pain is prevalent among youth with sickle cell disease (SCD). However, previous research has been limited by small sample sizes and lacked examinations of developmental differences in pain, which are critical to minimizing the development of chronic pain as youth transition into adulthood. The primary aim of the current study was to compare pain and pain interference across 4 developmental groups in a large sample of youth with SCD. The secondary aim was to identify risk factors for greater pain and pain interference.

MATERIALS AND METHODS

Utilizing a cross-sectional study design, the expression and predictors of pain and pain interference were compared across 4 developmental stages: toddlers/preschoolers (2 to 4 y), school-aged children (5 to 7 y), preadolescents (8 to 12 y), and adolescents (13 to 18 y). Participants included 386 youth with SCD and their caregivers.

RESULTS

Caregiver-reported pain and pain interference and youth-reported pain interference increased across developmental groups and plateaued approaching adolescence (multivariate analyses of variance P=0.002 for pain and P<0.001 for pain interference). Elevated fatigue, anxiety, and perceived difficulties with pain management were the most robust predictors of higher youth- and caregiver-reported pain (βs ranging from 0.15 to 0.68; P<0.001) and pain interference (βs ranging from 0.18 to 0.64; P<0.001).

DISCUSSION

Disease and treatment-related variables were not associated with pain. Self-reported pain was elevated in older versus younger developmental groups and was largely linked to anxiety, fatigue, and perceptions of pain management, thus highlighting the modifiable nature of factors influencing pain among youth with SCD.

Nitric oxide and sickle cell disease-Is there a painful connection?

Sickle cell disease is the most common hemoglobinopathy and affects millions worldwide. The disease is associated with severe organ dysfunction, acute and chronic pain, and significantly decreased life expectancy. The large body of work demonstrating that hemolysis results in rapid consumption of the endogenous vasodilator nitric oxide, decreased nitric oxide production, and promotion of vaso-occlusion provides the basis for the hypothesis that nitric oxide bioavailability is reduced in sickle cell disease and that this deficit plays a role in sickle cell disease pain. Despite initial promising results, large clinical trials using strategies to increase nitric oxide bioavailability in sickle cell disease patients yielded no significant change in duration or frequency of acute pain crises. Further, recent investigations showed that sickle cell disease patients and mouse models have elevated baseline levels of blood nitrite, a reservoir for nitric oxide formation and a product of nitric oxide metabolism, regardless of pain phenotype. These conflicting results challenge the hypotheses that nitric oxide bioavailability is decreased and that it plays a significant role in the pathogenesis in sickle cell disease acute pain crises. Conversely, a large body of work demonstrates that nitric oxide, as a neurotransmitter, has a complex role in pain neurobiology, contributes to the development of central sensitization, and can mediate hyperalgesia in inflammatory and neuropathic pain. These results support an alternative hypothesis: one proposing that altered nitric oxide signaling may contribute to the development of neuropathic and/or inflammatory pain in sickle cell disease through its role as a neurotransmitter.

Optimizing the management of chronic pain in sickle cell disease

Chronic pain in sickle cell disease (SCD) refers to pain present on most days lasting over six months. It can start during childhood and the prevalence increases with age. By adulthood, over 55% of patients experience pain on over 50% of days; 29% reporting pain on 95% of days. The true prevalence of chronic pain in SCD is likely underappreciated as it is mostly managed at home. Patients with chronic pain and SCD frequently seek acute care for exacerbation of underlying chronic pain difficult to distinguish from their usual acute vaso-occlusive crises. When treating chronic pain in SCD, the challenge is distinguishing between non-SCD related etiologies versus chronic pain resulting from SCD pathophysiological processes. This distinction is important to delineate as it will drive appropriate management strategies. Chronic pain in SCD has profound consequences for the patient; is often associated with comorbid psychiatric illnesses (depression and anxiety), not dissimilar from other chronic pain syndromes. They may also experience challenges with sleep hygiene, various somatic symptoms, and chronic fatigue that impair quality of life. How best to treat chronic pain in SCD is not definitively established. Both acute and chronic pain in SCD is typically treated with opioids. Emerging data suggests that chronic opioid therapy (COT) is a suboptimal treatment strategy for chronic pain. This review will discuss the complexity of managing chronic pain in SCD; pain that may be dependent or independent of the underlying SCD diagnosis. We will also describe alternative treatment approaches to high-dose COT.

Neuropathic pain in sickle cell disease: measurement and management

The identification of chronic pain and neuropathic pain as common contributors to the overall pain experience of patients with sickle cell disease (SCD) has altered the way we should evaluate difficult-to-treat pain. The recognition of these 2 entities is not generally routine among various medical specialties and provider levels that treat SCD. Due to the relative recency with which neuropathic pain was first described in SCD, validated assessment tools and evidence-based treatments remain lacking. Although clinical assessment and judgment must continue to inform all decision making in this understudied area of SCD pain management, a number of validated neuropathic pain assessment tools exist that can make possible a standardized evaluation process. Similarly, investigation of available neuropathic pain treatments for the uniquely complex pain phenotypes of SCD has only just begun and is better established in pain conditions other than SCD. The aim of this review is to briefly summarize the proposed basic pathophysiology, assessment, and treatment of neuropathic pain in patients with SCD. Furthermore, the aim of this review is to encourage an expanded framework for the assessment and treatment of SCD pain that appreciates the hidden complexities of this common complication of SCD.

Chronic Pain Diagnosis Using Machine Learning, Questionnaires, and QST: A Sensitivity Experiment

In the last decade, machine learning has been widely used in different fields, especially because of its capacity to work with complex data. With the support of machine learning techniques, different studies have been using data-driven approaches to better understand some syndromes like mild cognitive impairment, Alzheimer’s disease, schizophrenia, and chronic pain. Chronic pain is a complex disease that can recurrently be misdiagnosed due to its comorbidities with other syndromes with which it shares symptoms. Within that context, several studies have been suggesting different machine learning algorithms to classify or predict chronic pain conditions. Those algorithms were fed with a diversity of data types, from self-report data based on questionnaires to the most advanced brain imaging techniques. In this study, we assessed the sensitivity of different algorithms and datasets classifying chronic pain syndromes. Together with this assessment, we highlighted important methodological steps that should be taken into account when an experiment using machine learning is conducted. The best results were obtained by ensemble-based algorithms and the dataset containing the greatest diversity of information, resulting in area under the receiver operating curve (AUC) values of around 0.85. In addition, the performance of the algorithms is strongly related to the hyper-parameters. Thus, a good strategy for hyper-parameter optimization should be used to extract the most from the algorithm. These findings support the notion that machine learning can be a powerful tool to better understand chronic pain conditions.

Development of a Severity Classification System for Sickle Cell Disease

Purpose

There is no well-accepted classification system of overall sickle cell disease (SCD) severity. We sought to develop a system that could be tested as a clinical outcome predictor.

Patients and Methods

Using validated methodology (RAND/UCLA modified Delphi panel), 10 multi-disciplinary expert clinicians collaboratively developed 180 simplified patient histories and rated each on multiple axes (estimated clinician follow-up frequency, risk of complications or death, quality of life, overall disease severity). Using ratings on overall disease severity, we developed a 3-level severity classification system ranging from Class I (least severe) to Class III (most severe).

Results

The system defines patients as Class I who are 8-40 years with no end organ damage, no chronic pain, and ≤4 unscheduled acute care visits due to vaso-occlusive crises (VOC) in the last year. Patients <8 or >40 years with no end organ damage, no chronic pain, and <2 unscheduled acute care visits are also considered Class I. Patients any age with ≥5 unscheduled acute care visits and/or with severe damage to bone, retina, heart, lung, kidney, or brain are classified as Class III (except patients ≥25 years with severe retinopathy, no chronic pain, and 0-1 unscheduled acute care visits, who are considered Class II). Patients not meeting these Class I or III definitions are classified as Class II.

Conclusion

This system consolidates patient characteristics into homogenous groups with respect to disease state to support clinical decision-making. The system is consistent with existing literature that increased unscheduled acute care visits and organ damage translate into clinically significant patient morbidity. Studies to further validate this system are planned.

Physical Therapy in Pediatric and Young Adult Patients With Sickle Cell Disease: Assessing Potential Benefits and Barriers

BACKGROUND

Despite advances in the treatment of sickle cell disease (SCD) in pediatric and young adult patients, pain remains a significant cause of disease-related morbidity. Physical therapy has been shown to be useful for the treatment of pain in young patients with chronic illnesses, however, limited data exists regarding potential benefits of physical therapy in patients with SCD.

MATERIALS AND METHODS

We conducted a web-based survey of health care providers and support staff in the New England area to identify potential benefits of and barriers to outpatient physical therapy in this patient population.

RESULTS

Nearly 92% of survey participants felt that physical therapy had the potential to be beneficial in pediatric and young adult patients with SCD. A majority of physicians reported having referred patients with SCD for physical therapy. Perceived potential benefits included improved functional mobility, improved chronic pain symptoms, decreased opiate use, improved mood symptoms, improved acute pain symptoms, and improved adherence with medications and clinic visits. Significant perceived barriers identified included lack of transportation, time constraints, patient lack of understanding, and difficulty with insurance coverage.

CONCLUSIONS

Health care providers have a positive view of the use of physical therapy in the management of this patient population. Significant barriers exist which need to be addressed.

AAAPT Diagnostic Criteria for Acute Low Back Pain with and Without Lower Extremity Pain

OBJECTIVE

Low back pain is one of the most common reasons for which people visit their doctor. Between 12% and 15% of the US population seek care for spine pain each year, with associated costs exceeding $200 billion. Up to 80% of adults will experience acute low back pain at some point in their lives. This staggering prevalence supports the need for increased research to support tailored clinical care of low back pain. This work proposes a multidimensional conceptual taxonomy.

METHODS

A multidisciplinary task force of the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) with clinical and research expertise performed a focused review and analysis, applying the AAAPT five-dimensional framework to acute low back pain.

RESULTS

Application of the AAAPT framework yielded the following: 1) Core Criteria: location, timing, and severity of acute low back pain were defined; 2) Common Features: character and expected trajectories were established in relevant subgroups, and common pain assessment tools were identified; 3) Modulating Factors: biological, psychological, and social factors that modulate interindividual variability were delineated; 4) Impact/Functional Consequences: domains of impact were outlined and defined; 5) Neurobiological Mechanisms: putative mechanisms were specified including nerve injury, inflammation, peripheral and central sensitization, and affective and social processing of acute low back pain.

CONCLUSIONS

The goal of applying the AAAPT taxonomy to acute low back pain is to improve its assessment through a defined evidence and consensus-driven structure. The criteria proposed will enable more rigorous meta-analyses and promote more generalizable studies of interindividual variation in acute low back pain and its potential underlying mechanisms.

Common Biological Modulators of Acute Pain: An Overview Within the AAAPT Project (ACTTION-APS-AAPM Acute Pain Taxonomy)

OBJECTIVE

The ACTTION-APS-AAPM Acute Pain Taxonomy (AAAPT) project relies on the identification of modulators to improve characterization and classification of acute pain conditions. In the frame of the AAAPT effort, this paper presents an overview of common biological modulators of acute pain.

METHODS

Nonsystematic overview.

RESULTS

Females may experience more acute pain than males, but the clinical significance may be modest. Increasing age is associated with decreasing analgesic requirement and decreasing pain intensity after surgery and with higher risk of acute low back pain. Racial and ethnic minorities have worse pain, function, and perceived well-being. Patients with preexisting chronic pain and opioid use are at higher risk of severe acute pain and high opioid consumption. The OPRM1 gene A118G polymorphism is associated with pain severity and opioid consumption, with modest quantitative impact. Most studies have found positive associations between pain sensitivity and intensity of acute clinical pain. However, the strength of the association is unclear. Surgical techniques, approaches, and complications influence postoperative pain.

CONCLUSIONS

Sex, age, race, ethnicity, preexisting chronic pain and opioid use, surgical approaches, genetic factors, and pain sensitivity are biological modulators of acute pain. Large studies with multisite replication will quantify accurately the association between modulators and acute pain and establish the value of modulators for characterization and classification of acute pain conditions, as well as their ability to identify patients at risk of uncontrolled pain. The development and validation of quick, bed-side pain sensitivity tests would allow their implementation as clinical screening tools. Acute nonsurgical pain requires more investigation.

Opioid Prescription Filling Trends Among Children with Sickle Cell Disease After the Release of State-Issued Guidelines on Pain Management

OBJECTIVE

To assess the impact of Ohio's 2012, 2013, and 2016 opioid prescribing guidelines on opioid and nonsteroidal anti-inflammatory drug (NSAID) prescription filling and health care utilization for pain among children with sickle cell disease (SCD).

DESIGN

Quasi-experimental retrospective cohort study.

SETTING

Ohio Medicaid claims data from August 2011 to August 2016.

SUBJECTS

Medicaid beneficiaries under age 19 years with SCD.

METHODS

Interrupted time series analyses comparing population-level rates of opioids and NSAID prescriptions filled, standardized amounts of opioids dispensed, and acute health care utilization for pain before and after release of each guideline.

RESULTS

In our cohort of 1,505 children with SCD, there was a temporary but significant decrease in the opioid filling rate (-2.96 prescriptions per 100 children, P = 0.01) and in the amount of opioids dispensed (-31.39 milligram morphine equivalents per filled prescription, P < 0.001) after the 2013 guideline but a temporary but significant increase in the opioid filling rate (7.44 prescriptions per 100 children, P < 0.001) and in the amount of opioids dispensed (72.73 mg morphine equivalents per filled prescription, P < 0.001) after the 2016 guideline. The NSAID filling rate did not significantly change after any of the guidelines. Acute health care utilization rates for pain after the 2016 guideline were similar to those before the 2013 guideline (rate ratio = 1.04, P = 0.63).

CONCLUSIONS

Our results suggest that Ohio's 2013 and 2016 guidelines were associated with significant but nonsustained changes in opioid prescription filling among children with SCD. Additional studies are needed to confirm that opioid guidelines have a sustained impact on excessive opioid prescribing, filling, and misuse.

Improving self-management in adolescents with sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is associated with significant medical challenges that often worsen in adolescence when caregivers are beginning to transfer responsibility for disease management. Behavioral activation (BA) is an important precedent to improvements in self-management and ultimately health outcomes; however, few interventions targeting BA have been developed for the SCD population. The goal of the present study was to evaluate a technology-enhanced self-management intervention for adolescents and young adults (AYA) with SCD targeting BA domains (ie, disease knowledge, self-efficacy, motivation, and self-management skills).

DESIGN/METHODS

Participants were randomized to one of two study arms. SCThrive participants (N = 26) completed six weekly group sessions, an in-person booster session, and used a companion app (iManage) to record symptoms, progress on goals, and connect with other group members. Each SCHealthEd participant (N = 27) received six weekly phone calls on SCD-related and general health education topics. All AYA completed questionnaires assessing BA at baseline and posttreatment.

RESULTS

Separate mixed ANOVA analyses to assess for the effects of group (SCThrive/SCHealthEd), time (baseline/posttreatment), and group × time interaction indicated that there was a clinically meaningful improvement (8-point change) in self-efficacy, with a medium effect size, P = .09, η2  = .06, and there was statistically significant improvement in one self-management skill (tracking health), P = .001, d = .71, among SCThrive participants.

CONCLUSIONS

The results support the potential for a self-management intervention to improve self-efficacy in AYA with SCD. Health care providers are encouraged to target BA skills to support self-management of AYA with SCD.

How I Treat Acute and Persistent Sickle Cell Pain

Sickle pain is the hallmark of sickle cell disease (SCD). It could be acute, persistent/relapsing, chronic, or neuropathic. Although there is a general consensus that pain is a major manifestation of SCD, there is a controversy as to the types of pain and their interrelationship between acute, chronic, relapsing, persistent, etc. This report first reviews the general approach to the management of acute vaso-occlusive crisis (VOC) pain, including education, counseling, pharmacotherapy, non-pharmacotherapy, and fluid therapy. This is followed by the presentation of five patients that represent typical issues that are commonly encountered in the management of patients with SCD. These issues are: individualized treatment of pain, bilaterality of pain, use of illicit drugs, tolerance to opioids, opioid-induced hyperalgesia, and withdrawal syndrome. The clinical aspects and management of each of these issues are described. Moreover, such complications as tolerance and withdrawal may persist after discharge and may be mistaken as chronic pain rather than resolving, persistent or relapsing pain.

Medical marijuana certification for patients with sickle cell disease: a report of a single center experience

More than one-third of adults with sickle cell disease (SCD) report using cannabis-based products. Many states list SCD or pain as qualifying conditions for medical marijuana, but there are few data to guide practitioners whether or whom should be certified. We postulated that certifying SCD patients may lead to a reduction in opioid use and/or health care utilization. Furthermore, we sought to identify clinical characteristics of patients who would request this intervention. Retrospective data obtained over the study period included rates of health care and opioid utilization for 6 months before certification and after certification. Patients who were certified but failed to obtain medical marijuana were compared with those who obtained it. Patients who were certified were invited to participate in a survey regarding their reasons for and thoughts on certification. Patients who were certified for medical marijuana were compared with 25 random patients who did not request certification. Fifty adults with SCD were certified for medical marijuana and 29 obtained it. Patients who obtained medical marijuana experienced a decrease in admission rates compared with those who did not and increased use of edible cannabis products. Neither group had changes in opioid use. Patients who were certified for medical marijuana had higher rates of baseline opioid use and illicit cannabis use compared with those who did not request certification. Most patients with SCD who requested medical marijuana were already using cannabis illicitly. Obtaining medical marijuana decreased inpatient hospitalizations.

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.

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.

Chronic Pain Does Not Impact Baseline Circulating Cytokine Levels in Adults with Sickle Cell Disease

Chronic pain affects 50% of adults with sickle cell disease (SCD). Although inflammation is thought to contribute to the pathogenesis of chronic pain, no studies have examined the differences in circulating cytokines between patients with SCD with and without chronic pain. We performed an observational cohort study using blood and urine samples from adults with SCD with and without chronic pain at their usual state of health. We tested the hypothesis that, compared to those without chronic pain, those with chronic pain would have significantly higher baseline circulating proinflammatory cytokines. A total of 61 adults with SCD, 40 with chronic pain and 21 without chronic pain were tested. When SCD patients with chronic pain were compared to those without chronic pain, no significant differences in cytokine levels were noted. The variables most associated with the diagnosis of chronic pain in this population were opioid dose and subject age.

[Pain management in sickle cell disease]

Sickle cell disease is associated with numerous symptoms and complications. Acute painful crisis is the most characteristic manifestation of the disease. In addition, many patients report chronic pain. As both acute and chronic pain severely diminish quality of life, adequate pain management is crucial. Recommendations for the treatment of acute painful crises are based on the World Health Organization analgesic ladder, which has been developed for cancer-related pain. Chronic pain can be treated with basic long-acting opioids and on-demand short-acting opioids. If patients show signs of neuropathic pain, administration of anticonvulsants, antidepressants or possibly ketamine should be considered.

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.

Depression and Anxiety as Moderators of the Pain-Social Functioning Relationship in Youth with Sickle Cell Disease

Purpose

Youth with sickle cell disease (SCD), a genetic disorder of red blood cells, may experience acute pain episodes lasting 2 to 3 days on average. While existing research has demonstrated associations between SCD pain and poor social functioning in youth with SCD, there are no data on whether symptoms of depression and anxiety modify the relationship between pain and functional outcomes in pediatric pain populations. It was hypothesized that more symptoms of depression and anxiety would exacerbate the relationship between high pain and poor social functioning in youth with SCD.

Patients and Methods

We conducted a cross-sectional study of 114 youth with SCD and their guardians assessing the youth’s pain, social functioning, and symptoms of depression and anxiety.

Results

Analyses indicated that elevated levels of depressive symptoms were related to poorer self-reported interpersonal skills. More anxiety symptoms were related to better guardian-reported social skills and weakened the relationship between high pain frequency and poor self-reported interpersonal skills.

Conclusion

Findings build on previous work supporting the need for multidisciplinary approaches to care for youth with SCD who experience pain, and provide rationale for future studies to investigate the direct and possible moderating effects of depression and anxiety symptoms on other functional outcomes in youth with SCD and other pediatric pain populations.

A Comprehensive Review of the Treatment and Management of Pain in Sickle Cell Disease

PURPOSE OF REVIEW

Sickle cell disease (SCD) is a hematological disorder which leads to serious complications in multiple organ systems. While significant research has addressed many of the effects of acute pain episodes and end-organ damage connected to this disease, little has approached the chronic pain state associated with this condition.

RECENT FINDINGS

Associated chronic pain represents a significant detractor from the quality of life experienced by these patients, affecting over half of those with SCD on more days than not. Current treatment typically is centered upon preventing and responding to acute vasoocclusive crises, presumably because this is the most common reason for hospitalization in these patients. The lack of management of chronic pain symptoms leaves many with SCD in a state of suffering. In this review, the treatment methodologies of SCD patients are examined including alternative treatments, both pharmaceutical and non-pharmaceutical, as well as procedural approaches specifically aimed at reducing chronic pain in these patients.

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.

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.

Enhancing Pain Assessment in Pediatric Sickle Cell Disease by Applying Quality Improvement Science

Objective

Standardized pain assessment and interventions are recommended for youth hospitalized for pain. This quality improvement (QI) project integrated into a pediatric psychology service aimed to increase the standardized assessment of pain-related functional ability for youth with sickle cell disease (SCD) hospitalized for pain.

Methods

Children and adolescents (n=102) with SCD referred for psychology consultation for poor coping in response to pain during hospitalization completed a validated self-report of functional ability in addition to pain intensity during inpatient psychology visits. At the time of the quality initiative, routine and standardized assessment of pain-related functional ability was not integrated into standard clinical care. Plan, Do, Study, Act (PDSA) cycles determined the feasibility and addressed common barriers of routine assessment and documentation of pain-related functional ability among youth with SCD during inpatient psychology visits with the primary goal to increase assessment of functional ability to at least 85% among patients with SCD referred for pediatric psychology consultation to address pain management within 1 year.

Results

Through iterative PDSA cycles, routine assessment of pain-related functional ability during psychology visits increased to an average of 93% over the course of 12 months. Routine, standardized assessment of functional ability was considered feasible within a pediatric psychology service.

Conclusions/Lessons Learned

This project supported the feasibility of integrating standardized assessment of functional ability to enhance pain assessment for youth hospitalized for SCD pain as part of routine clinical care in a multidisciplinary setting regardless of psychology referral.

Assessment of health-related quality of life among adults hospitalized with sickle cell disease vaso-occlusive crisis

Sickle cell disease (SCD) is characterized by painful vaso-occlusive crises (VOCs). Self-reported pain intensity is often assessed with the Numeric Rating Scale (NRS), whereas newer patient-reported outcome measures (PROMs) assess multidimensional pain in SCD. We describe pain experiences among hospitalized adults with VOCs, using 2 PROMs: the Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health and the Adult Sickle Cell Quality of Life Measurement System (ASCQ-Me). Adults with SCD hospitalized with VOCs at 2 academic centers in Boston, Massachusetts, from April 2016 to October 2017 were eligible. Participants completed the NRS and PROMs at admission and 7 days postdischarge. PROM scores were described and compared with population norms. Length of stay (LOS) and 30-day readmission rates were assessed. Forty-two (96%) of 44 eligible patients consented and completed admission assessments. Mean age was 30.2 years (standard deviation, 9.1), 60% were women, 76% were non-Hispanic black, and 64% had hemoglobin SS. Twenty-seven participants (64%) completed postdischarge assessments. Sixty percent had ≥4 VOCs in the last year. Nearly all PROMIS Global Health and ASCQ-Me scores were worse than population norms. NRS and PROMIS Global Physical Health scores improved after discharge, the latter driven principally by improvements in pain. Overall median LOS was 7 days, and 30-day readmission rate was 40.5%. Administration of PROMs among adults with SCD hospitalized for VOCs is feasible and demonstrates participants experienced recurrent, prolonged, and severe VOCs. PROMIS Global and ASCQ-Me scores indicated substantial suffering, and the striking 30-day readmission rate highlights the vulnerability of these patients.

Physical Activity and Pain in Youth With Sickle Cell Disease

Study objectives were to examine the relationships between physical activity, pain, and psychological distress in youth 8 to 17 years of age with sickle cell disease. Participants were 206 youth with sickle cell disease (M = 11.73 years, 54.9% female, 99.5% African American). Caregivers and youth completed a clinical psychosocial screening battery. Results revealed frequent pain (37.6%), moderate median pain intensity, and elevated median pain interference in youth. Lower caregiver-reported physical activity was associated with worse pain outcomes. Increased anxiety was also associated with worse pain outcomes. A better understanding of the relationship between physical activity/inactivity and pain will guide multifactorial treatment interventions.

Using Deep Learning and Resting-State fMRI to Classify Chronic Pain Conditions

Chronic pain is known as a complex disease due to its comorbidities with other symptoms and the lack of effective treatments. As a consequence, chronic pain seems to be under-diagnosed in more than 75% of patients. At the same time, the advance in brain imaging, the popularization of machine learning techniques and the development of new diagnostic tools based on these technologies have shown that these tools could be an option in supporting decision-making of healthcare professionals. In this study, we computed functional brain connectivity using resting-state fMRI data from one hundred and fifty participants to assess the performance of different machine learning models, including deep learning (DL) neural networks in classifying chronic pain patients and pain-free controls. The best result was obtained by training a convolutional neural network fed with data preprocessed using the MSDL probabilistic atlas and using the dynamic time warping (DTW) as connectivity measure. DL models had a better performance compared to other less costly models such as support vector machine (SVM) and RFC, with balanced accuracy ranged from 69 to 86%, while the area under the curve (ROC) ranged from 0.84 to 0.93. Also, DTW overperformed correlation as connectivity measure. These findings support the notion that resting-state fMRI data could be used as a potential biomarker of chronic pain conditions.

Osteonecrosis in sickle cell disease: an update on risk factors, diagnosis, and management

Osteonecrosis, a form of ischemic bone injury that leads to degenerative joint disease, affects ∼30% of people with sickle cell disease. Although osteonecrosis most commonly affects the femoral head (often bilaterally, with asymmetric clinical and radiographic progression), many people with sickle cell disease also present with multifocal joint involvement. We present the case of a young woman with bilateral osteonecrosis of the femoral head at varying stages of progression; we also highlight other important comorbid complications (eg, chronic pain requiring long-term opioids, debility, and social isolation) and postoperative outcomes. In this review, partly based on recommendations on osteonecrosis management from the 2014 evidence-based report on sickle cell disease from the National Heart, Lung and Blood Institutes, we also discuss early signs or symptoms of osteonecrosis of the femoral head, radiographic diagnosis and staging criteria, hydroxyurea effect on progression to femoral head collapse, and surgical outcomes of total hip arthroplasty in the modern era. In summary, we failed to find an association between hydroxyurea use and femoral head osteonecrosis; we also showed that evidence-based perioperative sickle cell disease management resulted in superior postoperative outcomes after cementless total hip arthroplasty in sickle cell-related osteonecrosis of the femoral head.

Urinary cross-linked carboxyterminal telopeptide, a bone resorption marker, decreases after vaso-occlusive crises in adults with sickle cell disease

People with sickle cell disease often report severe bone pain with repeated bouts of vaso-occlusive crises, but the extent of skeletal injury incurred during these painful episodes remain unclear. We sought to quantify bone degradation by comparing urinary concentrations of carboxyterminal cross-linked telopeptide of type I collagen (CTX-1), a well-described marker of bone resorption, in a prospective cohort of 52 adults with sickle cell disease enrolled in the Sickle Cell Pain Markers Study. We also questioned if changes in urinary CTX-1 concentrations correlated with changes in hemolysis and inflammatory markers measured both during and after resolution of a painful vaso-occlusive episode. Thirty-one of the 52 adults enrolled in the study had paired urine samples for CTX-1 analysis. Urinary CTX-1, corrected for urine creatinine, significantly decreased from a mean of 3.45 μg/mmol during vaso-occlusive crises to 2.62 μg/mmol at recovery (p = 0.01). Thus, increased bone loss appears to correlate with acute vaso-occlusive crises in sickle cell disease. Our finding that urinary CTX-1 can be used to probe bone degradation in sickle cell disease provides an important new tool for diagnosing and monitoring response to therapy for people with sickle cell-related bone loss.

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.

The controversial role of red cell transfusions for sickle cell pain

PURPOSE OF REVIEW

Red cell transfusions are one of the most common and important therapies used for patients with sickle cell disease (SCD). For prevention of strokes, there is abundant evidence that transfusions are efficacious, whereas for other indications, such as prevention of pain, there are less data. Nonetheless, with few therapeutic options, the use of transfusion for prevention of acute pain has increased in children and adults with SCD without a clear understanding of its benefits.

RECENT FINDINGS

Although it makes conceptual sense that red cell transfusions would prevent pain that arises from vaso-occlusion, we now know that the mechanism of pain is more complex than vaso-occlusion alone. Recent taxonomies recognize a chronic pain syndrome that is both common in adults with SCD and affects the presentation of acute pain. It is not known if acute pain on the background of chronic pain responds differently to sickle cell therapies, such as hydroxyurea and blood transfusion.

SUMMARY

In this review, we will examine the studies that have investigated whether red cell transfusions are efficacious for preventing pain. In the absence of high-quality data that specifically addresses this question, we will outline our approach, which might soon change with new drugs and curative therapies on the horizon.

Increased acute care utilization in a prospective cohort of adults with sickle cell disease

The ESCAPED (Examining Sickle Cell Acute Pain in the Emergency vs Day Hospital) trial is an ongoing prospective study comparing outcomes of people with sickle cell disease (SCD) seeking care for acute pain management in either an emergency department or specialty infusion clinic. The objective of this paper is to describe the baseline characteristics and health care utilization of patients in the trial. This is a multicenter study across 4 US cities that enrolled all adults with SCD living within 60 miles (96.6 km) of a study site who were expected to have acute care utilization over the study period. Twenty-one percent of participants had no acute care visits in the first 12 months of follow-up. Using negative binomial regression, we describe subject characteristics that predict acute care utilization. Three hundred ninety-one subjects have completed 12 months of follow-up with a mean age of 34.5 years (standard deviation, 11.4), 60% are female. Fifty-four percent of subjects with hemoglobin SS disease and 46% with hemoglobin SC disease had 3 or more acute visits over the study period. The prevalence of chronic pain in this cohort was 68%. Predictors of higher rates of acute care utilization included being unemployed, having chronic pain, being on chronic transfusion therapy, having a history of stroke, and being on disability or on Medicaid. This is the first prospective cohort in the modern era, and it demonstrates much higher rates of acute care utilization than reported in the Cooperative Study of Sickle Cell Disease.

Acute Care Utilization at End of Life in Sickle Cell Disease: Highlighting the Need for a Palliative Approach

Background: People with sickle cell disease (SCD) have a life expectancy of <50 years, so understanding their end-of-life care is critical. Objective: We aimed to determine where individuals with SCD were dying and their patterns of care in the year preceding death to highlight end-of-life research priorities and possible opportunities for intervention. Design: Using the California SCD Data Collection Program database (containing administrative data, vital records, and Medicaid claims), we examined people with SCD who died between 2006 and 2015 (cases) at age <80 years and examined their hospital and emergency department (ED) utilization in their last year of life. Comparators included living controls with SCD matched 1:1 based on age, analysis year, insurance, and income. Results: We identified 486 people with SCD (cases) who died at a median age of 45 years (SD: 16 years). Most died in the hospital (63%) and ED (15%). In their last year of life, people with SCD were hospitalized for an average of 42 days (SD: 49 days) over five admissions. Inpatient admissions and ED visits were stable throughout the year until the month before death when acute care utilization sharply increased. In their last year of life, cases had more hospitalizations than controls, but similar ED utilization. Conclusions: People with SCD are dying acutely at a young age and most die in the hospital and the ED. Since clinicians caring for people with SCD currently cannot predict which acute events may be life-threatening, a comprehensive palliative approach to people with SCD must extend beyond chronic pain management and psychosocial support to include advance care planning.

New and emerging treatments for vaso-occlusive pain in sickle cell disease

Introduction: Acute pain from episodic vaso-occlusion (VOC) spans the lifespan of almost everyone with sickle cell disease (SCD), while additional chronic pain develops in susceptible individuals in early adolescences. Frequent acute pain with chronic pain causes significant physical and psychological morbidity, and frequent health-care utilization. Available pharmacologic therapies reduce acute pain frequency but few evidence-based therapies are available for chronic pain. Areas covered: An extensive PubMed literature search was performed with appropriate search criteria. The pathophysiology of acute pain from VOC in SCD is very complex with many events subsequent to sickle polymer formation. Sensitization of pain pathways and alterations of brain networks contributes to the experience of chronic pain. Numerous therapies targeting putative VOC mechanisms are in clinical trials, and show considerable promise. Alternative analgesic treatments for acute and chronic pain have been examined in small patient cohorts, but formal clinical trials are lacking. Expert opinion: Childhood is likely a critical window for prevention of acute and later chronic pain. New multimodal analgesic therapies are needed, particularly for chronic pain, and should be examined in clinical trials. Given the multifactorial nature of both pain and VOC, simultaneously targeting multiple mechanisms may be the optimal approach for effective preventive therapies.

Chronic pain persists in adults with sickle cell disease despite regular red cell transfusions

BACKGROUND

Pain affects over 50% of adults with sickle cell disease (SCD), and this pain is largely managed outside of the hospital. While chronic transfusion therapy is used to decrease the rate of acute pain events in patients with SCD, less is known about its impact on the day-to-day experience of pain. To address this knowledge gap, we provided pain diaries to patients with SCD receiving chronic transfusion.

PATIENTS AND METHODS

A convenience sample of chronically-transfused adults with SCD successfully completed a diary over the course of at least 2 transfusion events. Patients receiving simple transfusions and red cell exchanges were included. Pain was rated on a scale of 0 to 10 each day, and patient laboratory values, co-morbidities, and hospital utilization were also obtained using the electronic medical record. The mean pain scores pre- and post-transfusion were evaluated using both a random effects-expectation maximization regression tree analysis and a generalized linear mixed regression model.

RESULTS

Ten subjects (63%) in this cohort were defined as having chronic pain, while the remaining four (27%) subjects had episodic pain. Despite chronic transfusion and a suppressed HbS% (22.5% (16.5-25.9)), 10 patients (63%) continued to report nearly daily pain, and on almost 70% of diary days, the pain was significant (≥5/10). When the relationship between HbS% and reported pain intensity was examined, no association was found.

DISCUSSION

These results suggest that, even with regular transfusions and a low HbS%, daily pain persists in many adults with SCD.