Current issues in sickle cell pain and its management

Inpatient Management of Pain Episodes in Children with Sickle Cell Disease: A Review

Sickle cell disease (SCD) is the most common hemoglobinopathy in the world. Sickle cell vaso-occlusive episodes (VOEs) are very painful acute events and the most common complication as well as reason for hospitalization. SCD pain is best evaluated holistically with a pain functional assessment to aid in focusing pain management on reducing pain in addition to improving function. Patients with SCD have long endured structural racism and negative implicit bias surrounding the management of pain. Thus, it is important to approach the management of inpatient pain systematically with the use of multi-modal medications and nonpharmacologic treatments. Furthermore, equitable pain management care can be better achieved with standardized pain plans for an entire system and individualized pain plans for patients who fall outside the scope of the standardized pain plans. In this article, we discuss the best practices to manage SCD VOEs during an inpatient hospitalization.

Epidemiological profile trends and cost of pediatric sickle cell disease in Brazil from 2008 to 2022

OBJECTIVE

This study aimed to investigate the epidemiological trends of Pediatric Sickle Cell Disease (SCD) in Brazil over the period 2008-2022, with a focus on understanding the incidence, mortality rates, and associated healthcare costs. The study explored potential associations between patient characteristics and the occurrence of crises in pediatric SCD cases.

METHODS

A cross-sectional study was conducted, analyzing national annual rates of pediatric SCD hospitalizations using data from the FioCruz platform. Descriptive and inferential analyses, including time series and ARIMA regression, were employed. Economic dimensions were assessed using cost categorization. The study followed STROBE reporting guidelines.

RESULTS

Data on 81,942 pediatric SCD hospitalizations were collected, with a predominance of crisis-related cases (74.08 %). Males and children under five years old were most affected. Regional disparities were observed, with the Southwest region recording the highest hospitalization rates. ICU costs were higher for crisis-related hospitalizations. Mortality rates were significantly higher for crisis-related cases (p < 0.001), with ARIMA regression indicating a significant association between hospitalizations for crisis-related cases and mortality.

CONCLUSION

This study highlights the significant burden of pediatric SCD in Brazil, particularly crisis-related cases, suggesting a need for focused interventions. By prioritizing early detection, equitable access to healthcare, and evidence-based interventions, Brazil can mitigate the burden of SCD and improve patient outcomes. These findings contribute to informing public health policies and interventions aimed at addressing the challenges of pediatric SCD management in Brazil.

Costs and impact of disease in adults with sickle cell disease: a pilot study

ABSTRACT

We assessed the feasibility to estimate illness burden in adults with SCD, investigated factors associated with health-related quality of life (HRQoL), and estimated societal burden. We recruited 32 participants and collected data on fatigue, HRQoL, and work productivity and activity impairment via patient survey. Health care utilization was abstracted for the 12 months before enrollment using medical chart review. Mean age was 36.7 years; 84.4% of participants had hemoglobin SS or Sβthal0 disease, and 81.3% reported chronic pain (experiencing pain on ≥3 days per week in the past 6 months). Mean EQ-5D-3L visual analogue scale score was 63.4 and the index score was 0.79. The mean fatigue score was 57.9. Higher fatigue score was correlated with lower EQ-5D index score (correlation coefficient r = -0.35; P = .049) and Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) scores, including pain (r = -0.47; P = .006), sleep (r = -0.38; P = .03), and emotion scores (r = -0.79; P < .0001). The number of hospitalizations was negatively correlated with HRQoL (all P < .05). Patients who reported chronic pain had significantly lower mean ASCQ-Me sleep scores (48.3 vs 57.1; P = .04) and EQ-5D index scores (0.72 vs 0.89; P = .002) than those without chronic pain. Mean estimated annual per person costs were $51 779 (median, $36 366) for total costs, $7619 ($0) for indirect costs (estimated from lost earnings of participants), and $44 160 ($31 873) for medical costs. Fatigue, SCD complications, hospitalization, and chronic pain negatively affected HRQoL. This sample experienced a high economic burden, largely from outpatient doctor visits.

Hospitalization Events Among Adolescents and Adults With Sickle Cell Disease in a Tertiary Care Center in Central India

BACKGROUND

Sickle cell disease (SCD) is an inherited red blood cell disorder, wherein mutation causes the substitution of glutamic acid to valine at the sixth position of the β-globin chain. These include sickle cell anemia (homozygous sickle mutation), sickle-beta thalassemia, and hemoglobin SCD. The clinical manifestations of SCD are protean. Individuals with SCD suffer from both acute and chronic complications, which include recurring episodes of pain commonly called vaso-occlusive crisis (VOC) - acute chest syndrome (ACS); aseptic necrosis of the bone; micro-infarction of the spleen, brain, and kidney; infections; stroke; and organ damage affecting every part of the body. SCD necessitates frequent hospitalizations because of severe complications, which pose a significant burden on caregivers and economic strain on healthcare systems. The pattern of hospital admission with SCD varies in different parts of the world.

OBJECTIVE

This study aimed to determine the causes of hospitalization among adolescent and adult patients with SCD and to determine factors associated with their hospital stay.

METHODS

The study was a hospital-based prospective observational study comprising adolescent and adult patients diagnosed with SCD, aged 15-45 years, who were hospitalized in the Department of General Medicine at All India Institute of Medical Sciences in Raipur from August 2021 to August 2022.

RESULT

According to our study, the primary reason for hospitalization was a painful crisis, accounting for 63% of cases, followed by infection (17%), ACS (11%), and acute hemolytic crisis (9%). Notably, we did not observe any significant differences between genders and causes of admission (p > 0.05). Joint pain (p = 0.005), back pain (p = 0.001), and chest pain (p = 0.001) were more frequently reported by adults over the age of 19. In addition, our analysis of the duration of hospital stays and various factors revealed that patients admitted for infections had a significantly longer mean hospital stay duration (p = 0.040).

CONCLUSION

Acute painful crises were the primary cause of hospital admission among individuals with SCD; many patients also encountered infections and ACS. Furthermore, patients who experienced infections and VOC had a lengthier duration of hospital stay. Therefore, it is essential to provide them with comprehensive instructions on various preventive measures against infections and the factors that trigger painful crises.

Management of Acute Sickle Cell Disease Pain

Pain is a common complication of sickle cell disease. Sickle cell pain can often be effectively managed by pediatricians in outpatient and hospital settings. Acute pain management should be initiated quickly. Patients need to be evaluated for sickle cell complications and other causes of pain. Nonsteroidal anti-inflammatory drugs and opioids are the mainstay of pain treatment, but additional therapies include hydration, local pain control, muscle relaxants, and nonpharmacologic approaches. Healthy lifestyle habits and good behavioral and mental health are important for preventing and coping with sickle cell disease pain. Disease-modifying therapies, such as hydroxyurea, can help prevent sickle hemoglobin polymerization and acute pain episodes. Because sickle cell disease largely affects people who are racialized minorities in the United States, health-care providers need to be aware of how their own personal biases may affect care of these patients.

Descending Facilitation of Nociceptive Transmission From the Rostral Ventromedial Medulla Contributes to Hyperalgesia in Mice with Sickle Cell Disease

Sickle cell disease (SCD) is an inherited blood disorder that is associated with acute episodic and chronic pain. Mice with SCD have robust hyperalgesia mediated, in part, by sensitization of spinal dorsal horn neurons. However, underlying mechanisms are not fully understood. Since the rostral ventromedial medulla (RVM) is a major component of descending circuitry that modulates nociceptive transmission in the spinal cord, we examined if the RVM contributes to hyperalgesia in mice with SCD. Injection of lidocaine, but not vehicle, into the RVM eliminated mechanical and heat hyperalgesia in sickle (HbSS-BERK) mice without altering mechanical and heat sensitivity in naïve C57B mice. These data indicate that the RVM contributes to the maintenance of hyperalgesia in mice with SCD. In electrophysiological studies, we determined the changes in response properties of RVM neurons that might contribute to hyperalgesia in sickle mice. Recordings were made from single ON, OFF, and Neutral cells in the RVM of sickle and control (HbAA-BERK) mice. Spontaneous activity and responses of ON, OFF and Neutral cells evoked by heat (50 °C) and mechanical (26 g) stimuli applied to the hind paw were compared between sickle and control mice. Although there were no differences in the proportions of functionally-identified neurons or spontaneous activity between sickle and control mice, evoked responses of ON cells to heat and mechanical stimuli were increased approximately 3-fold in sickle mice as compared to control mice. Thus, the RVM contributes to hyperalgesia in sickle mice via a specific ON cell-dependent descending facilitation of nociceptive transmission.

A case report and review of literature on the role of automated red cell exchange in managing sickle cell crisis in India

Red cell exchanges (RCE) help in the treatment of complications of sickle cell anemia (SCA) by reducing the viscosity of blood and improving the oxygen-carrying capacity. We present a case of sickle cell crisis (SCC) managed with automated RCE and also reviewed the literature to assess the utilization and clinical efficiency of this therapy in India. A 19-year-old gentleman diagnosed with SCA presented with acute chest syndrome. Hemoglobin (Hb) was 8.8 g%, hematocrit (HCT) was 24%, and HbS was 90%. As there was worsening of symptoms with conventional management, the patient underwent two procedures of automated RCE. The clinical condition of the patient was improved, HbS was reduced to 16% and HCT was remained at 21% postprocedure. Articles on automated RCE in SCA conducted in India were reviewed and four articles were analyzed based on the search strategy. All the included articles concluded automated RCE as an effective procedure for complications of SCA. Common indication in India was SCA patients undergoing surgery as a prophylactic measure. Automated RCEs are promising as an acute treatment for indicated sickle cell complications. This therapy is underutilized in the Indian scenario, especially in patients with SCC.

Identifying Chronic Pain Subgroups in Pediatric Sickle Cell Disease: A Cluster-Analytic Approach

OBJECTIVES

Youth with sickle cell disease (SCD) and chronic pain, defined in this study as pain on most days for 3 months, experience variability in daily pain and physical and psychosocial functioning. This study aimed to (1) empirically derive chronic pain subgroups based on pain characteristics among youth with chronic SCD pain; and (2) investigate derived subgroups for differences in sociodemographics, clinical characteristics, and psychosocial and functional outcomes.

MATERIALS AND METHODS

Youth with chronic SCD pain (n=62, Mage =13.9, SD=2.5, 10 to 18 y; 58% female, 60% HbSS) completed a battery of questionnaires. Clinical characteristics (eg, medications, treatments) and health care utilization were abstracted from electronic medical records. Hierarchical cluster analysis informed the number of clusters at the patient level. k-means cluster analysis used multidimensional pain assessment to identify and assign patients to clusters.

RESULTS

Cluster 1 (n=35; Moderate Frequency, Moderate Pain) demonstrated significantly lower worst pain intensity, number of pain days per month, number of body sites affected by pain, and pain quality ratings. Cluster 2 (n=27; Almost Daily, High Pain) reported high ratings of worst pain intensity, almost daily to daily pain, greater number of body sites affected by pain, and higher ratings of pain quality (all P 's <0.05). There were no differences between subgroups by sociodemographics, clinical characteristics, or health care utilization. The Almost Daily, High Pain subgroup reported significantly higher pain interference, depressive symptoms, and pain catastrophizing than the Moderate Frequency, Moderate Pain subgroup.

DISCUSSION

Identifying chronic SCD pain subgroups may inform tailored assessment and intervention to mitigate poor pain and functional outcomes.

Inhaled nitric oxide for treating pain crises in people with sickle cell disease

BACKGROUND

In people with sickle cell disease, sickled red blood cells cause the occlusion of small blood vessels, which presents as episodes of severe pain known as pain crises or vaso-occlusive crises. The pain can occur in the bones, chest, or other parts of the body, and may last several hours to days. Pain relief during crises includes both pharmacologic and non-pharmacologic treatments. The efficacy of inhaled nitric oxide in pain crises has been a subject of controversy; hypotheses have been made suggesting a beneficial response due to its vasodilator properties, yet no conclusive evidence has been presented. This review aimed to evaluate the available randomised controlled studies addressing this topic.

OBJECTIVES

To capture the body of evidence evaluating the efficacy and safety of the use of inhaled nitric oxide in treating pain crises in people with sickle cell disease, and to assess the relevance, robustness, and validity of the treatment to better guide medical practice in the fields of haematology and palliative care (since the recent literature seems to favour the involvement of palliative care for such people).

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Trials Register. We searched for unpublished work in the abstract books of the European Haematology Association conference, the American Society of Hematology conference, the British Society for Haematology Annual Scientific Meeting, the Caribbean Health Research Council Meetings, and the National Sickle Cell Disease Program Annual Meeting. The most recent search was conducted on 1 September 2021. We also searched ongoing study registries on 19 November 2021.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing inhaled nitric oxide with placebo for treating pain crises in people with sickle cell disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data (including adverse event data), with any disagreements resolved by consulting a third review author. When the data were not reported in the text, we attempted to extract the data from available tables or figures. We contacted trial authors for additional information. We assessed the certainty of the evidence using the GRADE criteria.

MAIN RESULTS

We included three trials involving a total of 188 participants in the review. There were equal numbers of males and females. Most participants were adults, although one small trial was conducted in a children's hospital and recruited children over the age of 10 years. All three parallel trials compared inhaled nitric oxygen (80 parts per million (ppm)) to placebo (nitrogen gas mixed with oxygen or room air) for four hours; one trial continued administering nitric oxide (40 ppm) for a further four hours. This extended trial had an overall low risk of bias; however, we had concerns about risk of bias for the remaining two trials due to their small sample size, and additionally a high risk of bias due to financial conflicts of interest in one of these smaller trials. We were only able to analyse some limited data from the eight-hour trial, reporting the remaining results narratively. Evidence from one trial (150 participants) suggested that inhaled nitric oxide may not reduce the time to pain resolution: inhaled nitric oxide median 73.0 hours (95% confidence interval (CI) 46.0 to 91.0) and with placebo median 65.5 hours (95% CI 48.1 to 84.0) (low-certainty evidence). No trial reported on the duration of the initial pain crisis. Only one large trial reported on the frequency of pain crises in the follow-up period and found there may be little or no difference between the inhaled nitric oxide and placebo groups for return to the emergency department (risk ratio (RR) 0.73, 95% CI 0.31 to 1.71) and rehospitalisation (RR 0.53, 95% CI 0.25 to 1.11) (150 participants; low-certainty evidence). There may be little or no difference between treatment and placebo in terms of reduction in pain score at any time point up to eight hours (150 participants). The two smaller trials reported a beneficial effect of inhaled nitric oxide in reducing the visual analogue pain score after four hours of the intervention. Analgesic use was reported not to differ greatly between the inhaled nitric oxide group and placebo group in any of the three trials, but no analysable data were provided. Two trials reported the median duration of hospitalisation: in the largest trial the placebo group had the shorter duration, whilst in the second smaller (paediatric) trial hospitalisation was shorter in the treatment group. Only the largest trial (150 participants) reported serious adverse events, with no increase in the inhaled nitric oxide group during or after the intervention compared to the control group (acute chest syndrome occurred in 5 out of 75 participants from each group, pyrexia in 1 out of 75 participants from each group, and dysphagia and a drop in haemoglobin were each reported in 1 out of 75 participants in the inhaled nitric oxide group) (low-certainty evidence).

AUTHORS' CONCLUSIONS

The currently available evidence is insufficient to determine the effects (benefits or harms) of using inhaled nitric oxide to treat pain (vaso-occlusive) crises in people with sickle cell disease. Large-scale, long-term trials are needed to provide more robust data in this area. Patient-important outcomes (e.g. measures of pain and time to pain resolution and amounts of analgesics used), as well as use of healthcare services, should be measured and reported in a standardised manner.

Zinc in sickle cell disease: A narrative review

Sickle cell disease (SCD) is an inherited disease caused by hemoglobin S mutated hemoglobin S. It is characterized by chronic hemolysis, intermittent vaso-occlusive crises followed by ischemia-reperfusion, and organ damage. These patients have an increased risk of multiple micronutrient deficiencies, such as zinc. The reduced zinc bioavailability in sickle cell patients may lead to several complications such as growth retardation, delayed wound healing, increased vaso-occlusive crises, and infections. This narrative review aims to analyze the literature concerning the zinc status in SCD and their possible consequences on the patients' clinical evolution. We found in children and adolescents a direct association between zinc insufficiencies/deficiencies with increased disease severity in SCD. Monitoring zinc status in children and adolescent SCD appears essential for reducing disease-associated morbidity and infections. Zinc supplementation is a safe therapeutic modality for treating SCD patients. New research must be carried out, especially for adults, to ensure more remarkable survival for this population.

Drug Repositioning: Antimalarial Activities of GABA Analogs in Mice Infected with Plasmodium berghei

BACKGROUND

Drug repositioning is becoming popular due to the development of resistance to almost all the recommended antimalarials. Pregabalin and gabapentin are chemical analogs of gamma- aminobutyric acid (GABA) approved for the treatment of epilepsy and neuropathic pain.

OBJECTIVE

This study investigates acute toxicities and antimalarial activities of pregabalin and gabapentin in the murine malarial model.

METHODS

Acute toxicities were assessed using the method of Lorke, while curative activities were assessed by the administration of serial doses of pregabalin and gabapentin to Plasmodium berghei infected mice. Pregabalin was further investigated for its prophylactic activity, and curative potential when combined with either artesunate or amodiaquine. All drugs were freshly prepared and administered orally. Thin films were collected, stained, and observed under the microscope for the estimation of parasitemia and calculation of percentage chemoinhibition or chemoprevention. In pregabalin -artesunate or -amodiaquine combination aspect of this study, survival day post-infection (SDPI) was recorded, while parasitemia was re-estimated for animals that survived till day 28.

RESULTS

The oral LD50 of gabapentin, as well as pregabalin, was >5,000 mg/kg. Gabapentin at 100 and 200 mg/Kg demonstrated 35.64% and -12.78% chemoinhibition, respectively, while pregabalin demonstrated 75.60% and 100.00% chemoinhibition at doses of 12.5 and 25 mg/Kg, respectively. Moreover, pregabalin at individual doses of 25, 50 mg/Kg, and in combination with either artesunate or amodiaquine demonstrated 100.00% chemoinhibition. In its prophylactic study, pregabalin was found to be 100% chemopreventive at individual doses of 12.5 and 25 mg/Kg.

CONCLUSION

Both GABA analogs have antimalarial properties, but pregabalin proved to be more efficacious.

Neuropathic Pain and Sickle Cell Disease: a Review of Pharmacologic Management

PURPOSE OF REVIEW

Sickle cell disease (SCD) remains among the most common and severe monogenic disorders present in the world today. Although sickle cell pain has been traditionally characterized as nociceptive, a significant portion of sickle cell patients has reported neuropathic pain symptoms. Our review article will discuss clinical aspects of SCD-related neuropathic pain, epidemiology of neuropathic pain among individuals with SCD, pain mechanisms, and current and future potential pharmacological interventions.

RECENT FINDINGS

Neuropathic pain in SCD is a complicated condition that often has a lifelong and significant negative impact on life; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous, and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Our review article outlines several pharmacological modalities which may be employed to treat neuropathic pain in SCD patients.

Association between Vaso-occlusive Crises and Opioid Prescriptions among Patients with Sickle Cell Disease: A Retrospective Claims-based Study

BACKGROUND/OBJECTIVES

Among sickle cell disease (SCD) patients, vaso-occlusive crises (VOCs) are recurrent and unpredictable attacks of acute pain. These pain crises are often treated with analgesics, including opioids, which have been associated with misuse and overdose. The aim of this study was to examine the association between VOC events and opioid use and assess the association between opioid prescriptions and health care resource utilization among SCD patients.

METHODS

This was a retrospective cohort study using Texas Medicaid medical and prescription claims between September 2011 and August 2016. The index date was the first SCD diagnosis. Patients (2-63 years) with at least one inpatient or two outpatient SCD diagnoses, who were continuously enrolled during 12 months postindex, were included in the study. The primary outcome was number of opioid prescriptions, while the independent variable was number of VOC events. Covariates included age, gender, nonopioid medication use, nonstudy SCD-related medication (penicillin and folic acid) use, evidence of blood transfusions, number of SCD-related complications, number of SCD-related comorbid conditions, and Charlson Comorbidity Index score. Negative binomial regression analysis was used to address study objectives.

RESULTS

Of 3368 included patients, 1978 (58.7%) had at least one opioid prescription with a mean of 4.2 (SD=7.2). Overall, 2071 (61.5%) had at least one VOC event with an average of 2.9 (SD=4.4). The results from the negative binomial regression showed that for every increase in VOC events, the number of opioid prescriptions increased by 9.5% (Incidence rate ratio=1.095, 95% CI: 1.078-1.111; P ≤ 0.0001). Other significant covariates associated with higher opioid use included age (13 and older compared to 2-12) and increase in the number of nonopioid pain medications, nonstudy SCD-related medications, and SCD-related complications.

CONCLUSIONS

The majority of SCD patients had at least one VOC event and were prescribed opioids during the 12-month study period. We found that each VOC event was associated with a 9.5% increase in the use of opioids. SCD guidelines recommend opioids for the treatment of VOC-related pain. Payers and providers should be aware of opioid use in this population, consider appropriate VOC prevention measures, and provide SCD patients with access to appropriate pain management.

Metabolomic Profiling of Plasma and Erythrocytes in Sickle Mice Points to Altered Nociceptive Pathways

Few data-driven metabolomic approaches have been reported in sickle cell disease (SCD) to date. We performed a metabo-lipidomic study on the plasma and red blood cells of a steady-state mouse model carrying the homozygous human hemoglobin SS, compared with AS and AA genotypes. Among the 188 metabolites analyzed by a targeted quantitative metabolomic approach, 153 and 129 metabolites were accurately measured in the plasma and red blood cells, respectively. Unsupervised PCAs (principal component analyses) gave good spontaneous discrimination between HbSS and controls, and supervised OPLS-DAs (orthogonal partial least squares-discriminant analyses) provided highly discriminant models. These models confirmed the well-known deregulation of nitric oxide synthesis in the HbSS genotype, involving arginine deficiency and increased levels of dimethylarginines, ornithine, and polyamines. Other discriminant metabolites were newly evidenced, such as hexoses, alpha-aminoadipate, serotonin, kynurenine, and amino acids, pointing to a glycolytic shift and to the alteration of metabolites known to be involved in nociceptive pathways. Sharp remodeling of lysophosphatidylcholines, phosphatidylcholines, and sphingomyelins was evidenced in red blood cells. Our metabolomic study provides an overview of the metabolic remodeling induced by the sickle genotype in the plasma and red blood cells, revealing a biological fingerprint of altered nitric oxide, bioenergetics and nociceptive pathways.

Mechanisms of pain in sickle cell disease

Objectives

The hallmark of sickle cell disease (SCD) is acute and chronic pain, and the pain dominates the clinical characteristics of SCD patients. Although pharmacological treatments of SCD targeting the disease mechanisms have been improved, many SCD patients suffer from pain. To overcome the pain of the disease, there have been renewed requirements to understand the novel molecular mechanisms of the pain in SCD.

Methods

We concisely summarized the molecular mechanisms of SCD-related acute and chronic pain, focusing on potential drug targets to treat pain.

Results

Acute pain of SCD is caused by vaso-occulusive crisis (VOC), impaired oxygen supply or infarction-reperfusion tissue injuries. In VOC, inflammatory cytokines include tryptase activate nociceptors and transient receptor potential vanilloid type 1. In tissue injury, the secondary inflammatory response is triggered and causes further tissue injuries. Tissue injury generates cytokines and pain mediators including bradykinin, and they activate nociceptive afferent nerves and trigger pain. The main causes of chronic pain are from extended hyperalgesia after a VOC and central sensitization. Neuropathic pain could be due to central or peripheral nerve injury, and protein kinase C might be associated with the pain. In central sensitization, neuroplasticity in the brain and the activation of glial cells may be related with the pain.

Discussion

In this review, we summarized the molecular mechanisms of SCD-related acute and chronic pain. The novel treatments targeting the disease mechanisms would interrupt complications of SCD and reduce the pain of the SCD patients.

Factors Influencing Motivation and Engagement in Mobile Health Among Patients With Sickle Cell Disease in Low-Prevalence, High-Income Countries: Qualitative Exploration of Patient Requirements

Background

Sickle cell disease (SCD) is a hematological genetic disease affecting over 25 million people worldwide. The main clinical manifestations of SCD, hemolytic anemia and vaso-occlusion, lead to chronic pain and organ damages. With recent advances in childhood care, high-income countries have seen SCD drift from a disease of early childhood mortality to a neglected chronic disease of adulthood. In particular, coordinated, preventive, and comprehensive care for adults with SCD is largely underresourced. Consequently, patients are left to self-manage. Mobile health (mHealth) apps for chronic disease self-management are now flooding app stores. However, evidence remains unclear about their effectiveness, and the literature indicates low user engagement and poor adoption rates. Finally, few apps have been developed for people with SCD and none encompasses their numerous and complex self-care management needs.

Objective

This study aimed to identify factors that may influence the long-term engagement and user adoption of mHealth among the particularly isolated community of adult patients with SCD living in low-prevalence, high-income countries.

Methods

Semistructured interviews were conducted. Interviews were audiotaped, transcribed verbatim, and analyzed using thematic analysis. Analysis was informed by the Braun and Clarke framework and mapped to the COM-B model (capability, opportunity, motivation, and behavior). Results were classified into high-level functional requirements (FRs) and nonfunctional requirements (NFRs) to guide the development of future mHealth interventions.

Results

Overall, 6 males and 4 females were interviewed (aged between 21 and 55 years). Thirty FRs and 31 NFRs were extracted from the analysis. Most participants (8/10) were concerned about increasing their physical capabilities being able to stop pain symptoms quickly. Regarding the psychological capability aspects, all interviewees desired to receive trustworthy feedback on their self-care management practices. About their physical opportunities, most (7/10) expressed a strong desire to receive alerts when they would reach their own physiological limitations (ie, during physical activity). Concerning social opportunity, most (9/10) reported wanting to learn about the self-care practices of other patients. Relating to motivational aspects, many interviewees (6/10) stressed their need to learn how to avoid the symptoms and live as normal a life as possible. Finally, NFRs included inconspicuousness and customizability of user experience, automatic data collection, data shareability, and data privacy.

Conclusions

Our findings suggest that motivation and engagement with mHealth technologies among the studied population could be increased by providing features that clearly benefit them. Self-management support and self-care decision aid are patients’ major demands. As the complexity of SCD self-management requires a high cognitive load, pervasive health technologies such as wearable sensors, implantable devices, or inconspicuous conversational user interfaces should be explored to ease it. Some of the required technologies already exist but must be integrated, bundled, adapted, or improved to meet the specific needs of people with SCD.

Transcutaneous electrical nerve stimulation (TENS) for pain management in sickle cell disease

BACKGROUND

Sickle cell disease (SCD), one of the most common inherited disorders, is associated with vaso-occlusive pain episodes and haemolysis leading to recurrent morbidity, hospital admissions and work or school absenteeism. The crises are conventionally treated with opioids, non-opioids and other adjuvants with the risk of developing complications, addictions and drug-seeking behaviour. Different non-pharmacological treatments, such as transcutaneous electrical nerve stimulation (TENS) have been used for managing pain in other painful conditions. Hence, the efficacy of TENS for managing pain in SCD needs to be reviewed.

OBJECTIVES

To assess the benefits and harms of TENS for managing pain in people with SCD who experience pain crises or chronic pain (or both).

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Haemoglobinopathies Register, comprising of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also searched online trial registries and the reference lists of relevant articles and reviews. Date of the last search: 26 Febraury 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs, where TENS was evaluated for managing pain in people with SCD.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of the trials identified by the literature searches according to the inclusion criteria. Two review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using the GRADE guidelines.

MAIN RESULTS

One double-blind cross-over RCT with 22 participants with SCD (aged 12 to 27 years) was eligible for inclusion. Following stratification into four pain crises severity grades, participants were then randomised to receive TENS or placebo (sham TENS). The trial was concluded after 60 treatment episodes (30 treatment episodes of each treatment group). There is a lack of clarity regarding the trial design and the analysis of the cross-over data. If a participant was allocated to TENS treatment for an episode of pain and subsequently returned with a further episode of a similar degree of pain, they would then receive the sham TENS treatment (cross-over design). For those experiencing a pain episode of a different severity, it is not clear whether they were re-randomised or given the alternate treatment. Reporting and analysis was based on the total number pain events and not on the number of participants. It is unclear how many participants were crossed over from the TENS group to the sham TENS group and vice versa. The trial had a high risk of bias regarding random sequence generation and allocation concealment; an unclear risk regarding the blinding of participants and personnel; and a low risk regarding the blinding of the outcome assessors and selective outcome reporting. The trial was small and of very low quality; furthermore, given the issue with trial design we were unable to quantitatively analyse the data. Therefore, we present only a narrative summary and caution is advised in interpreting the results. In relation to our pre-defined primary outcomes, the included trial did not report pain relief at two to four weeks post intervention. The trial authors reported that no difference was found in the changes in pain ratings (recorded at one hour and four hours post intervention) between the TENS and the placebo groups. In relation to our secondary outcomes, the analgesic usage during the trial also did not show any difference between groups. Given the quality of the evidence, we are uncertain whether TENS improves overall satisfaction as compared to sham TENS. The ability to cope with activities of daily living was not evaluated. Regarding adverse events, although one case of itching was reported in the TENS group, the site and nature of itching was not clearly stated; hence it cannot be clearly attributed to TENS. Also, two participants receiving 'sham' TENS reported a worsening of pain with the intervention.

AUTHORS' CONCLUSIONS

Since we have only included one small and very low-quality trial, with a high risk of bias across several domains, we are unable to conclude whether TENS is harmful or beneficial for managing pain in people with SCD. There is a need for a well-designed, adequately-powered, RCT to evaluate the role of TENS in managing pain in people with SCD.

Sleep Moderating the Relationship Between Pain and Health Care Use in Youth With Sickle Cell Disease

OBJECTIVES

The purpose of the current study was to investigate the influence of sleep on the relationship between pain and health care use (HCU) in youth with sickle cell disease (SCD). It was hypothesized that poor sleep would be related to higher HCU and would strengthen the relationship between high pain frequency and more HCU among youth with SCD.

MATERIALS AND METHODS

Ninety-six youth with SCD (aged 8 to 17 y) and their guardians were recruited from 3 regional pediatric SCD clinics. Guardians reported on the youth's pain frequency and HCU using the Structured Pain Interview for parents, and youth wore a sleep actigraph for up to 2 weeks to assess sleep duration and sleep efficiency. A series of regression models were calculated with the following outcomes: emergency department visits, hospitalizations, and health care provider contacts.

RESULTS

Inconsistent with hypotheses, poor sleep was not directly related to HCU. Also, higher sleep duration appeared to strengthen the relationship between high pain frequency and more emergency department visits.

CONCLUSIONS

Findings suggest that good sleep may serve as a protective factor for better matching pain to HCU. Results should be interpreted in the context of study limitations. Research is needed to investigate possible mechanisms linking sleep duration to HCU in response to pain and to ascertain if sleep patterns influence the relationship between pain and other functional outcomes in youth with SCD. Clinically, these findings support the need to acknowledge and address the role that sleep plays in responding to SCD pain in pediatric populations.

Pharmacological interventions for painful sickle cell vaso-occlusive crises in adults

BACKGROUND

Sickle cell disease (SCD) is a group of inherited disorders of haemoglobin (Hb) structure in a person who has inherited two mutant globin genes (one from each parent), at least one of which is always the sickle mutation. It is estimated that between 5% and 7% of the world's population are carriers of the mutant Hb gene, and SCD is the most commonly inherited blood disorder. SCD is characterized by distorted sickle-shaped red blood cells. Manifestations of the disease are attributed to either haemolysis (premature red cell destruction) or vaso-occlusion (obstruction of blood flow, the most common manifestation). Shortened lifespans are attributable to serious comorbidities associated with the disease, including renal failure, acute cholecystitis, pulmonary hypertension, aplastic crisis, pulmonary embolus, stroke, acute chest syndrome, and sepsis. Vaso-occlusion can lead to an acute, painful crisis (sickle cell crisis, vaso-occlusive crisis (VOC) or vaso-occlusive episode). Pain is most often reported in the joints, extremities, back or chest, but it can occur anywhere and can last for several days or weeks. The bone and muscle pain experienced during a sickle cell crisis is both acute and recurrent. Key pharmacological treatments for VOC include opioid analgesics, non-opioid analgesics, and combinations of drugs. Non-pharmacological approaches, such as relaxation, hypnosis, heat, ice and acupuncture, have been used in conjunction to rehydrating the patient and reduce the sickling process.

OBJECTIVES

To assess the analgesic efficacy and adverse events of pharmacological interventions to treat acute painful sickle cell vaso-occlusive crises in adults, in any setting.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online, MEDLINE via Ovid, Embase via Ovid and LILACS, from inception to September 2019. We also searched the reference lists of retrieved studies and reviews, and searched online clinical trial registries.

SELECTION CRITERIA

Randomized, controlled, double-blind trials of pharmacological interventions, of any dose and by any route, compared to placebo or any active comparator, for the treatment (not prevention) of painful sickle cell VOC in adults.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed studies for eligibility. We planned to use dichotomous data to calculate risk ratio (RR) and number needed to treat for one additional event, using standard methods. Our primary outcomes were participant-reported pain relief of 50%, or 30%, or greater; Patient Global Impression of Change (PGIC) very much improved, or much or very much improved. Our secondary outcomes included adverse events, serious adverse events, and withdrawals due to adverse events. We assessed GRADE and created three 'Summary of findings' tables.

MAIN RESULTS

We included nine studies with data for 638 VOC events and 594 participants aged 17 to 42 years with SCD presenting to a hospital emergency department in a painful VOC. Three studies investigated a non-steroidal anti-inflammatory drug (NSAID) compared to placebo. One study compared an opioid with a placebo, two studies compared an opioid with an active comparator, two studies compared an anticoagulant with a placebo, and one study compared a combination of three drugs with a combination of four drugs. Risk of bias across the nine studies varied. Studies were primarily at an unclear risk of selection, performance, and detection bias. Studies were primarily at a high risk of bias for size with fewer than 50 participants per treatment arm; two studies had 50 to 199 participants per treatment arm (unclear risk). Non-steroidal anti-inflammatory drugs (NSAID) compared with placebo No data were reported regarding participant-reported pain relief of 50% or 30% or greater. The efficacy was uncertain regarding PGIC very much improved, and PGIC much or very much improved (no difference; 1 study, 21 participants; very low-quality evidence). Very low-quality, uncertain results suggested similar rates of adverse events across both the NSAIDs group (16/45 adverse events, 1/56 serious adverse events, and 1/56 withdrawal due to adverse events) and the placebo group (19/45 adverse events, 2/56 serious adverse events, and 1/56 withdrawal due to adverse events). Opioids compared with placebo No data were reported regarding participant-reported pain relief of 50% or 30%, PGIC, or adverse events (any adverse event, serious adverse events, and withdrawals due to adverse events). Opioids compared with active comparator No data were reported regarding participant-reported pain relief of 50% or 30% or greater. The results were uncertain regarding PGIC very much improved (33% of the opioids group versus 19% of the placebo group). No data were reported regarding PGIC much or very much improved. Very low-quality, uncertain results suggested similar rates of adverse events across both the opioids group (9/66 adverse events, and 0/66 serious adverse events) and the placebo group (7/64 adverse events, 0/66 serious adverse events). No data were reported regarding withdrawal due to adverse events. Quality of the evidence We downgraded the quality of the evidence by three levels to very low-quality because there are too few data to have confidence in results (e.g. too few participants per treatment arm). Where no data were reported for an outcome, we had no evidence to support or refute (quality of the evidence is unknown).

AUTHORS' CONCLUSIONS

This review identified only nine studies, with insufficient data for all pharmacological interventions for analysis. The available evidence is very uncertain regarding the efficacy or harm from pharmacological interventions used to treat pain related to sickle cell VOC in adults. This area could benefit most from more high quality, certain evidence, as well as the establishment of suitable registries which record interventions and outcomes for this group of people.

Inhaled nitric oxide for treating pain crises in people with sickle cell disease

BACKGROUND

In people with sickle cell disease, sickled red blood cells cause the occlusion of small blood vessels which presents as episodes of severe pain known as pain crises or vaso-occlusive crises. The pain can occur in the bones, chest, or other parts of the body, and may last several hours to days. Pain relief during crises includes both pharmacologic and non-pharmacologic treatments. The efficacy of inhaled nitric oxide in pain crises has been a controversial issue and hypotheses have been made suggesting a beneficial response due to its vasodilator properties. Yet no conclusive evidence has been presented.This review aims to evaluate the available randomised controlled studies which address this topic.

OBJECTIVES

To capture the available body of evidence evaluating the efficacy and safety of the use of inhaled nitric oxide in treating pain crises in people with sickle cell disease; and to assess the treatment's relevance, robustness, and validity, in order to better guide medical practice in the fields of haematology and palliative care (since recent literature seems to favour the involvement of palliative care for those people).

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. Unpublished work is identified by searching the abstract books of the European Haematology Association conference; the American Society of Hematology conference; the British Society for Haematology Annual Scientific Meeting; the Caribbean Health Research Council Meetings; and the National Sickle Cell Disease Program Annual Meeting.Date of most recent search: 19 September 2019.We also searched ongoing study registries, date of most recent search: 26 September 2019.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing inhaled nitric oxide with placebo, or standardized way of treatment of pain crises in people with sickle cell disease.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data (including adverse event data). A third author helped clarify any disagreement. When the data were not reported in the text, we attempted to extract the data from any table or figure available. We contacted trial authors for additional information. We assessed the quality of the evidence using the GRADE criteria MAIN RESULTS: We identified six trials, three of which (188 participants) were eligible for inclusion in the review. There were equal numbers of males and females; and most participants were adults, although one small trial was conducted in a children's hospital and recruited children over the age of 10 years. All three parallel trials compared inhaled nitric oxygen (80 ppm) to placebo (room air) for four hours; one trial continued administering nitric oxide (40 ppm) for a further four hours. This extended trial had an overall low risk of bias; however, in the remaining two trials we had concerns about the risk of bias from the small sample size and additionally a high risk of bias due to financial conflicts of interest in one of these smaller trials. We were only able to analyse some limited data from the eight-hour trial and report the remaining results narratively.The time to pain resolution was only reported in one trial (150 participants), showing there may be little or no difference between the two groups: with inhaled nitric oxide median 73.0 hours (95% confidence interval (CI) 46.0 to 91.0) and with placebo median 65.5 hours (95% CI 48.1 to 84.0) (low-quality evidence). No trial reported on the duration of the initial pain crisis. Only one large trial reported on the frequency of pain crises in the follow-up period and found there may be little or no difference between the inhaled nitric oxide and placebo groups for a return to the ED, risk ratio 0.73 (95% CI 0.31 to 1.71) or for re-hospitalisation, risk ratio 0.53 (95% CI 0.25 to 1.11) (150 participants; low-quality evidence).There may be little or no difference between treatment and placebo in terms of reduction in pain score at any time point up to eight hours (150 participants). The two smaller trials reported a beneficial effect of inhaled nitric oxide in reducing the visual analogue pain score after four hours of the intervention, but these trials were small and limited compared to the first trial.Analgesic use was reported not to differ greatly between the inhaled nitric oxide group and placebo group in any of the three trials, but no analysable data were provided. The median duration of hospitalisation was reported by two trials, in the largest trial the placebo group had the shorter duration and in the second smaller (paediatric) trial hospitalisation was shorter in the treatment group.Only the largest trial (150 participants) reported serious adverse events, with no increase in the inhaled nitric oxide group during or after the intervention compared to the control group (acute chest syndrome occurred in 5 out of 75 participants from each group, pyrexia in 1 out of 75 participants from each group, dysphagia and a drop in haemoglobin were each reported in 1 out of 75 participants in the inhaled nitric oxide group, but not in the placebo group) (low-quality evidence).

AUTHORS' CONCLUSIONS

The currently available trials do not provide sufficient evidence to determine the effects (benefits or harms) of using inhaled nitric oxide to treat pain (vaso-occlusive) crises in people with sickle cell disease. Large-scale, long-term trials are needed to provide more robust data in this area. Patient-important outcomes (e.g. measures of pain and time to pain resolution and amounts of analgesics used), as well as use of healthcare services should be measured and reported in a standardized form.

Gabapentin alleviates chronic spontaneous pain and acute hypoxia-related pain in a mouse model of sickle cell disease

Pain is the main complication of sickle cell disease (SCD). Individuals with SCD experience acute pain episodes and chronic daily pain, both of which are managed with opioids. Opioids have deleterious side effects and use-associated stigma that make them less than ideal for SCD pain management. After recognizing the neuropathic qualities of SCD pain, clinically-approved therapies for neuropathic pain, including gabapentin, now present unique non-opioid based therapies for SCD pain management. These experiments explored the efficacy of gabapentin in relieving evoked and spontaneous chronic pain, and hypoxia/reoxygenation (H/R)-induced acute pain in mouse models of SCD. When administered following H/R, a single dose of gabapentin alleviated mechanical hypersensitivity in SCD mice by decreasing peripheral fibre activity. Gabapentin treatment also alleviated spontaneous ongoing pain in SCD mice. Longitudinal daily administration of gabapentin failed to alleviate H/R-induced pain or chronic evoked mechanical, cold or deep tissue hypersensitivity in SCD mice. Consistent with this observation, voltage-gated calcium channel (VGCC) α2 δ1 subunit expression was similar in sciatic nerve, dorsal root ganglia and lumbar spinal cord tissue from SCD and control mice. Based on these data, gabapentin may be an effective opioid alternative for the treatment of chronic spontaneous and acute H/R pain in SCD.

Zinc for Infection Prevention in Sickle Cell Anemia (ZIPS): study protocol for a randomized placebo-controlled trial in Ugandan children with sickle cell anemia

BACKGROUND

Sickle cell anemia (SCA) is the most common inherited hemoglobinopathy worldwide. Infection is a major cause of illness and death in children with SCA, especially in sub-Saharan Africa where an estimated 50-90% of affected children die before their fifth birthday. Interventions to reduce the incidence and severity of infections are needed urgently. A high proportion of adults and children with SCA are zinc-deficient, and zinc deficiency leads to impaired immunity and an increased risk of infection. Zinc supplementation has been shown to decrease the risk of infection in adolescents and adults, but there are no data on the effectiveness of zinc for prevention of infection in children < 5 years of age with SCA.

METHODS/DESIGN

The study will be a randomized, placebo-controlled, double-blind clinical trial in which 250 Ugandan children 1.00-4.99 years of age with SCA will receive daily zinc supplementation (10 mg oral dispersible tablet) or identical placebo for 12 months.

DISCUSSION

If this trial shows a reduction in severe or invasive infection incidence, it would be the basis for a multi-site, multi-country clinical trial to assess real-world safety and efficacy of zinc in African children with SCA. Since zinc is safe, inexpensive, and easy to administer, this trial has the potential to improve the health of hundreds of thousands of African children with SCA through reduction of infection-related morbidity and mortality.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03528434. Registered on May 17, 2018 Protocol Version: 1.0. Date: Dec 11, 2017 Sponsor: Indiana University. Sponsor's protocol identifier, 1712339562.

Interventions for treating neuropathic pain in people with sickle cell disease

BACKGROUND

Pain is the hallmark of sickle cell disease (SCD) and it can be severe, frequent and unpredictable. Although nociceptive pain is more common, at times, people with SCD may have neuropathic pain. The latter can occur due to peripheral or central nerve injury. This review is focused on identifying treatment of only painful sensory neuropathy in people with SCD.

OBJECTIVES

To determine the effectiveness and safety of any pharmacological or non-pharmacological therapies for treating neuropathic pain in people with SCD.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched trial registries, the reference lists of relevant articles and reviews and contacted experts in the field.Date of last search: 31 January 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs) (parallel or cross-over in design), quasi-RCTs of pharmacological or non-pharmacological therapies for treating neuropathic pain in people with SCD compared to placebo or another intervention in any category (i.e. pharmacological or non-pharmacological).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all trials identified by the searches and extracted relevant data. Two authors independently assessed the risk of bias in the selected trials using the Cochrane risk of bias tool. Two review authors independently rated the quality of the evidence for each outcome using the GRADE guidelines.

MAIN RESULTS

One RCT of 22 participants with SCD, conducted in the USA was included in this review. Participants were randomly assigned to either pregabalin (n = 11) or placebo (n = 11). Oral pregabalin was administered at an initial dose of 75 mg twice daily. The drug was titrated at increments of 75 mg to a maximum of 600 mg daily or decreased by 75 mg per day if necessary, based on clinical presentation and pain level. Neuropathic pain was assessed using self-reports on the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANNS) scale and the Neuropathic Pain Symptom Inventory (NPSI), where higher scores were indicative of more pain. Outcomes included self-reported pain, quality of life and withdrawal due to adverse effects measured at baseline and monthly for three months post-intervention. The overall risk of bias was low with a high risk of bias due to attrition.In relation to this reviews primary outcomes, for self-reported neuropathic pain relief, given the paucity of data, we are very uncertain whether there is a difference between the pregabalin and placebo groups at the end of three months as measured by the S-LANSS scale, mean difference (MD) -2.00 (95% confidence interval (CI) -9.18 to 5.18), or the NPSI scale, MD -11.10 (95% CI -33.97 to 11.77) (very low-quality evidence). There was no report of 'Patient Global Impression of Change' in the included trial.Although the mean quality of life scores (Short Form-36) at three months showed small increases in seven of the eight domains post-intervention in the pregabalin group as compared to the placebo group, this was very low-quality evidence and we are very uncertain whether pregabalin increases quality of life. Neither of our pre-defined outcomes of 'time to improvement of symptoms' or 'changes in sleep quality', were measured in the included trial.While treatment-related adverse effects appeared higher in pregabalin group than the placebo group at three months, this was very low-quality evidence and we are very uncertain whether there is a difference, RR 1.33 (95% CI 0.39 to 4.62) (very low-quality evidence). There was one withdrawal for adverse effects in the pregabalin group while three people withdrew or dropped out from the placebo group due to adverse effects and complications and hospitalisation related to SCD.

AUTHORS' CONCLUSIONS

The included trial provided very low-quality evidence. Self-reported pain relief was greater in the pregabalin group compared to the placebo control group but only using the S-LANSS scale and we are very unsure whether there is a difference. While the pregabalin group tended to have improved quality of life over the duration of the trial, this was very low-quality evidence and we are uncertain whether there is a difference. Adverse effects and withdrawals were similar across the treatment and placebo control group in trial. There are both insufficient trials addressing this review question and insufficient outcomes addressed in the single included RCT. Therefore, there is still a significant gap in evidence on interventions for neuropathic pain in people with SCD.

Screening for neuropathic pain in patients with sickle cell disease: is a single assessment scale sufficient?

Background

The objectives of this study were to delineate the clinical-epidemiological profile of patients with neuropathic pain (NP) in the groups of SCD patients, from each of the three questionnaires used DN-4, painDETECT - PDQ, LANSS and to compare these three questionnaires in NP evaluation in SCD carriers. This cross-sectional study evaluated 83 patients with symptomatic SCD, aged 14 years or older. Clinical and laboratory data were extracted from the patients’ charts and from information obtained from the patients during the interview before the application of the questionnaire. The calculations were performed using the statistical software Epi InfoTM 7. Pearson’s correlation coefficient was used to compare the neuropathic pain evaluation scales with the software BioEstat 5.3.

Results

The use of two or more questionnaires may increase the suspicion of NP in patients with SCD and, with a confirmed diagnosis, adequate treatments will benefit patients.

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.

Investigating the Sleep-Pain Relationship in Youth with Sickle Cell Utilizing mHealth Technology

OBJECTIVES

The current study utilized mHealth technologies that were objective (e.g., sleep actigraphy and pulse oximetry) and time-sensitive (e.g., ecological momentary assessments [EMAs]) to characterize sleep in youth with sickle cell disease (SCD) and investigate the relationships between sleep variables and pain. It also investigated the influence of age on sleep and the sleep-pain relationship.

METHODS

Eighty-eight youth with SCD (aged 8-17 years) were recruited from three regional pediatric SCD clinics. Youth completed twice daily EMAs for up to 4 weeks to assess nighttime subjective sleep quality and daily pain. They also wore a sleep actigraph for 2 weeks to assess sleep duration, sleep efficiency, and sleep latency, and a wrist-worn pulse oximeter for two nights to assess whether they had sleep apnea. Multilevel models were calculated predicting daily SCD pain using the sleep variables, age, and the interaction between age and the sleep variables.

RESULTS

None of the sleep variables were related to one another. Poor subjective sleep quality during the night was related to high pain severity the next day, and high pain was related to poor subjective sleep quality that night. Older age was associated with poorer subjective sleep quality, shorter duration of nighttime sleep, and high sleep latency. Also, findings indicated that as age increased, the strength of the relationship between poor continuous subjective sleep quality and high pain severity increased.

CONCLUSIONS

Future research is needed to examine possible mechanisms connecting subjective sleep quality to high pain.

Sensitization of nociceptors by prostaglandin E2-glycerol contributes to hyperalgesia in mice with sickle cell disease

Pain is a characteristic feature of sickle cell disease (SCD), 1 of the most common inherited diseases. Patients may experience acute painful crises as well as chronic pain. In the Berkley transgenic murine model of SCD, HbSS-BERK mice express only human hemoglobin S. These mice share many features of SCD patients, including persistent inflammation and hyperalgesia. Cyclooxygenase-2 (COX-2) is elevated in skin, dorsal root ganglia (DRG), and spinal cord in HbSS-BERK mice. In addition to arachidonic acid, COX-2 oxidizes the endocannabinoid 2-arachidonoylglycerol (2-AG) to produce prostaglandin E₂ (PGE₂)-glycerol (PGE₂-G); PGE₂-G is known to produce hyperalgesia. We tested the hypotheses that PGE₂-G is increased in DRGs of HbSS-BERK mice and sensitizes nociceptors (sensory neurons that respond to noxious stimuli), and that blocking its synthesis would decrease hyperalgesia in HbSS-BERK mice. Systemic administration of R-flurbiprofen preferentially reduced production of PGE₂-G over that of PGE₂ in DRGs, decreased mechanical and thermal hyperalgesia, and decreased sensitization of nociceptors in HbSS-BERK mice. The same dose of R-flurbiprofen had no behavioral effect in HbAA-BERK mice (the transgenic control), but local injection of PGE₂-G into the hind paw of HbAA-BERK mice produced sensitization of nociceptors and hyperalgesia. Coadministration of a P2Y6 receptor antagonist blocked the effect of PGE₂-G, indicating that this receptor is a mediator of pain in SCD. The ability of R-flurbiprofen to block the synthesis of PGE₂-G and to normalize levels of 2-AG suggests that R-flurbiprofen may be beneficial to treat pain in SCD, thereby reducing the use of opioids to relieve pain.

Improving Uptake of Hydroxyurea in Patients with Sickle Cell Disease: A Retrospective Study of a Clinic-based Change in Consenting Practices

INTRODUCTION

Sickle cell disease (SCD) can shorten lives and may result in severe clinical complications. Hydroxyurea (HU) is inexpensive, widely available, and National Institutes of Health (NIH) recommends HU for SCD. Despite these benefits, utilization of HU is low. Barriers to taking HU include inaccurate perceptions of serious side effects such as hair loss, a significant barrier in the African American community. However, at doses for treating SCD, the incidence of side effects is extremely low. Using a retrospective medical record review, the impact of a revised consent procedure for HU that addressed these barriers was evaluated.

METHODS

SCD patients 2-20yo eligible for HU were examined. Patients prescribed HU versus those not prescribed HU were compared one year before and one year after revising consent procedures.

RESULTS

Change in clinic practice (including revised consent procedures) resulted in 158% more patients agreeing to HU therapy (p<.001).

DISCUSSION

The revised consent procedures are not resource intensive and easy to implement. Future research should address treatment acceptability, intimidation, and cultural sensitivity.

The Effects of a Single Electronic Music Improvisation Session on the Pain of Adults with Sickle Cell Disease: A Mixed Methods Pilot Study

Background

Adults with sickle cell disease (SCD) experience acute pain that is multidimensional. Despite recent improvements in treatment, pain management remains a significant challenge for these individuals. Music therapy interventions have the potential to address several dimensions of SCD pain, but they require systematic investigation.

Objective

This study investigated feasibility and preliminary efficacy of a single-session electronic music improvisation with a music therapist to diminish pain intensity and improve pain relief and mood in adults with SCD.

Methods

Using a three-group mixed methods intervention design, we randomized 60 adults with SCD to standard care plus one of three 20-minute study conditions: 1) electronic music improvisation with a music therapist (MT); 2) recorded music listening (ML); or 3) no intervention (control). Measures of pain intensity (VASPI), pain relief (VASPR), and mood (VASMOOD) were assessed before and after the study conditions, with a subset of MT and ML participants interviewed after measure completion.

Results

Compared to control, MT produced significant improvements in VASPI (odds ratio (OR) = 5.12, P = 0.035) and VASMOOD (OR = 11.60, P = 0.005). ML produced significant improvements in VASMOOD compared to control (OR = 5.76, P = 0.040). Qualitatively, there were two prominent themes directly related to music: 1) ML and MT offered many positive and few negative effects; and 2) music therapists provided comfort beyond the music.

Conclusions

Preliminary findings were promising and support the need for additional studies evaluating improvisational music therapy interventions for acute pain management in adults with SCD.

Sleep Problem Risk for Adolescents With Sickle Cell Disease: Sociodemographic, Physical, and Disease-related Correlates

The aims of the current study were to investigate whether SCD incurs an additional risk for poor sleep over and above the influence of sociodemographic factors (ie, race and sex) during adolescence, and to explore the relationships between sociodemographic, physical (ie, age and pubertal status), and disease-related factors (ie, SCD genotype and hydroxyurea use) on sleep problem risk during adolescence. Black adolescents (age, 12 to 17 y) with SCD (n=53) were recruited from regional pediatric SCD clinics in the southeast and a sample of healthy black adolescents (n=160) were recruited from middle and high schools. Regression analyses indicated that SCD was uniquely related to sleeping more, and worse sleep quality over and above the influence of sociodemographic factors. Having a more severe SCD genotype was related to worse sleep quality and higher pubertal status was related to sleeping longer during the week. Results indicate the need for systematic assessments of sleep problems, with more a focus on youth with more severe genotypes and higher pubertal status. Future research should focus on characterizing trajectories of sleep problems in this population, identifying key risk factors, and elucidating mechanisms linking risk factors to sleep problem risk to aid in tailoring interventions for this population.

Interventions for treating neuropathic pain in people with sickle cell disease

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To determine the effectiveness and safety of any pharmacological or non‐pharmacological therapies for treating neuropathic pain in people with SCD.

Widespread Pain Among Youth With Sickle Cell Disease Hospitalized With Vasoocclusive Pain: A Different Clinical Phenotype?

OBJECTIVES

The purpose of this study was to describe the clinical phenotype of widespread pain (WSP) among youth with sickle cell disease (SCD) hospitalized with vasoocclusive pain.

MATERIALS AND METHODS

One hundred fifty-six youth with SCD, between 7 and 21 years of age hospitalized at 4 children's hospitals for a vasoocclusive episode were evaluated. Data were collected during 1 day of the hospitalization.

RESULTS

Using the 2010 American College of Rheumatology guidelines, 21.8% of patients were identified as having WSP (pain in 7 or more unique body locations). Patients classified as having WSP had higher pain intensity (6.5 vs. 5.6; t=2.19, P=0.03) higher pain burden (13.0 vs. 9.8; t=3.09, P=0.002), higher acute functional disability (22.1 vs. 16.5; t=2.43, P=0.016), higher chronic functional disability (30.4 vs. 22.2; t=2.31, P=0.02), lower positive affect (22.9 vs. 27.6; t=2.23, P=0.027), and lower quality of life (56.2 vs. 62.9; t=1.99, P=0.049) than those youth with SCD without WSP.

DISCUSSION

Assessment of WSP may identify a unique clinical phenotype of youth with SCD with differing treatment needs.

Perceived Racial Bias and Health-Related Stigma Among Youth with Sickle Cell Disease

OBJECTIVE

Little is known about the role of perceived racial bias and health-related stigma on the health of youth with sickle cell disease (SCD). The purpose of this study was to investigate the occurrence of perceived racial bias and health-related stigma among youth with SCD and its relationship with psychological and physical well-being.

METHODS

Twenty-eight youth with SCD, ages 13 to 21, were recruited from outpatient and inpatient settings at an urban children's medical center. Participants completed measures of perceived racial bias, perceived health-related stigma, depression, quality of life, and pain burden.

RESULTS

Most participants endorsed occurrences of racial bias and health-related stigma. The findings indicate that greater perceived racial bias was associated with greater pain burden, and greater perceived health-related stigma was related to lower quality of life.

CONCLUSION

Perceived racial bias and health-related stigma may be important to consider for future research investigating the psychological and physiological features of SCD for youth.

Pain Management for Sickle Cell Disease in the Pediatric Emergency Department: Medications and Hospitalization Trends

The majority of emergency department (ED) visits and hospitalizations for patients with sickle cell disease (SCD) are pain related. Adequate and timely pain management may improve quality of life and prevent worsening morbidities. We conducted a retrospective chart review of pediatric patients with SCD seen in the ED, selected by sickle cell-related ICD-9 codes. A total of 176 encounters were reviewed from 47 patients to record ED pain management and hospitalization trends. Mean time to pain medication administration was 63 minutes. Patients received combination (nonsteroidal anti-inflammatory drug [NSAID] + narcotic) pain medications for initial treatment at a minority of ED encounters (19%). A higher percentage of patients who received narcotics alone as initial treatment were hospitalized as compared with those who received combination treatment initially ( P= 0.0085). Improved patient education regarding home pain management as well as standardized ED guidelines for assessment and treatment of sickle cell pain may result in superior and more consistent patient care.

Fluid replacement therapy for acute episodes of pain in people with sickle cell disease

BACKGROUND

Treating vaso-occlusive painful crises in people with sickle cell disease is complex and requires multiple interventions. Extra fluids are routinely given as adjunct treatment, regardless of the individual's state of hydration with the aim of slowing or stopping the sickling process and thereby alleviating pain. This is an update of a previously published Cochrane Review.

OBJECTIVES

To determine the optimal route, quantity and type of fluid replacement for people with sickle cell disease with acute painful crises.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.We also conducted searches of Embase (November 2007), LILACS, www.ClinicalTrials.gov (05 January 2010), and the WHO ICTRP (30 June 2017).Date of most recent search of the Group's Haemoglobinopathies Trials Register: 16 February 2017.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the administration of supplemental fluids adjunctive to analgesics by any route in people with any type of sickle cell disease during an acute painful episode, under medical supervision (inpatient, day care or community).

DATA COLLECTION AND ANALYSIS

No relevant trials have yet been identified.

MAIN RESULTS

Sixteen trials were identified by the searches, all of which were not eligible for inclusion in the review.

AUTHORS' CONCLUSIONS

Treating vaso-occlusive crises is complex and requires multiple interventions. Extra fluids, generally oral or intravenous, are routinely administered during acute painful episodes to people with sickle cell disease regardless of the individual's state of hydration. Reports of their use during these acute painful episodes do not state the efficacy of any single route, type or quantity of fluid compared to another. However, there are no randomised controlled trials that have assessed the safety and efficacy of different routes, types or quantities of fluid. This systematic review identifies the need for a multicentre randomised controlled trial assessing the efficacy and possible adverse effects of different routes, types and quantities of fluid administered to people with sickle cell disease during acute painful episodes.

Does Attendance at a Sickle Cell Educational Conference Improve Clinician Knowledge and Attitude Toward Patients with Sickle Cell Disease?

Sickle cell disease (SCD) is a genetic disease associated with both chronic pain and acute painful events referred to as vaso-occlusive crises. Individuals with SCD suffer from a multitude of medical complications in addition to pain. Patients often are stigmatized as "drug-seeking" and receive inadequate pain management. The purpose of this study was to compare clinicians' SCD knowledge and attitudes toward patients with SCD before attending a 2-day conference on SCD (T1) with knowledge and attitudes immediately postconference (T2) and 2 months postconference (T3). A prospective, descriptive survey design was used. The authors administered surveys to assess SCD knowledge and clinicians' attitudes toward patients with SCD at three time points: T1 (N = 59), T2 (N = 38), and T3 (N = 30). SCD knowledge was measured using a 20-item survey, and clinicians' attitudes toward patients with SCD were measured with the General Perceptions About Sickle Cell Patients Scale, which included items on four independent subscales: positive attitudes, negative attitudes, concern-raising behaviors, and red-flag behaviors. The authors compared changes in knowledge and attitude scores between T1-T2 and T1-T3. Overall, knowledge scores were significantly improved (p < .001) and significantly increased between T1-T2 (p < .0001) and T1-T3 (p = .01). Negative attitudes trended lower over the three time points (p = .07), but a significant decrease in the negative attitudes score was only noted for T1-T3 (Z = -2.16.17, p = .03). Attendance at an educational SCD conference was an effective means to improve knowledge and decrease negative attitudes among clinicians. These differences were maintained at 2 months postconference.

Clinical and Laboratory Predictors of Frequency of Painful Crises among Sickle Cell Anaemia Patients in Nigeria

INTRODUCTION

The severity of Sickle Cell Anaemia (SCA) in terms of frequency of painful Vaso-Occlusive Crises (VOC) may be affected by clinical and haematological parameters amongst others. Elucidation of these factors in a given disease prevalent environment is necessary for prompt and effective management of patients with frequent painful VOC.

AIM

This study aimed at determining the clinical and laboratory predictors of frequency of painful VOC among SCA patients in Enugu, Southeastern Nigeria.

MATERIALS AND METHODS

It was a cross-sectional study of 100 consecutive SCA patients receiving care at the University of Nigeria Teaching Hospital, Enugu, Nigeria between May 2012 and February 2014. The eligible patients were categorized into two groups namely; Group A and Group B. Group A/study group (severe disease) comprised SCA patients who had experienced three or more painful crises (≥3 crises) in the last one year preceding the study but, currently in steady state, while Group B/control group (mild-moderate disease), comprised SCA patients matched for age, sex, highest educational status, and occupation but who have had no painful crisis or had only one or two painful crises (0-2 crises) in the last one year preceding the study and currently in steady state.

RESULTS

The overall mean age of the patients was 18.4±12.2 (range=2-52) years. The mean values of the haematological parameters including haemoglobin concentration, white cell count, platelet count, and neutrophil count were significantly higher in those with severe crises than mild-moderate crises (p<0.05). Sickle cell related complications including Avascular Necrosis (AVN) and leg ulcers were significantly higher in the study group than the control group (p<0.05).

CONCLUSION

There was significant association between the frequency of crises and haemogblobin level, platelet and neutrophil counts and some clinical parameters: AVN, nephropathy and stroke. Future preventive interventions for reduction in frequency of crisis amongst patients with SCA could be targeted at controlling the blood levels of the identified haematological parameters.

Multiple Levels of Suffering: Discrimination in Health-Care Settings is Associated With Enhanced Laboratory Pain Sensitivity in Sickle Cell Disease

OBJECTIVE

People living with sickle cell disease (SCD) experience severe episodic and chronic pain and frequently report poor interpersonal treatment within health-care settings. In this particularly relevant context, we examined the relationship between perceived discrimination and both clinical and laboratory pain.

METHODS

Seventy-one individuals with SCD provided self-reports of experiences with discrimination in health-care settings and clinical pain severity, and completed a psychophysical pain testing battery in the laboratory.

RESULTS

Discrimination in health-care settings was correlated with greater clinical pain severity and enhanced sensitivity to multiple laboratory-induced pain measures, as well as stress, depression, and sleep. After controlling for relevant covariates, discrimination remained a significant predictor of mechanical temporal summation (a marker of central pain facilitation), but not clinical pain severity or suprathreshold heat pain response. Furthermore, a significant interaction between experience with discrimination and clinical pain severity was associated with mechanical temporal summation; increased experience with discrimination was associated with an increased correlation between clinical pain severity and temporal summation of pain.

DISCUSSION

Perceived discrimination within health-care settings was associated with pain facilitation. These findings suggest that discrimination may be related to increased central sensitization among SCD patients, and more broadly that health-care social environments may interact with pain pathophysiology.

Pharmacological interventions for painful sickle cell vaso‐occlusive crises in adults

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the analgesic efficacy, and adverse events, of pharmacological interventions used to treat acute painful sickle cell vaso‐occlusive crises in adults, aged 18 and over, in any setting.

Novel insights in the management of sickle cell disease in childhood

Sickle cell disease (SCD) is a life-threatening genetic disorder characterized by chronic hemolytic anemia, vascular injury and multiorgan dysfunctions. Over the last few decades, there have been significant improvements in SCD management in Western countries, especially in pediatric population. An early onset of prophylaxis with Penicillin and a proper treatment of the infections have increased the overall survival in childhood. Nevertheless, management of painful episodes and prevention of organ damage are still challenging and more efforts are needed to better understand the mechanisms behind the development of chronic organ damages. Hydroxyurea (Hydroxycarbamide, HU), the only medication approved as a disease-modifying agent by the United States Food and Drug Administration and the European Medicines Agency, is usually under-used, especially in developing countries. Currently, hematopoietic stem-cell transplantation is considered the only curative option, although its use is limited by lack of donors and transplant-related toxicity. SCD symptoms are similar in children and adults, but complications and systemic organ damages increase with age, leading to early mortality worldwide. Experts in comprehensive care of young patients with SCD, especially those approaching the transition age to adulthood, are missing, leading people to rely on urgent care, increasing health care utilization costs and inappropriate treatments. It would be important to establish programs of comprehensive healthcare for patients with SCD from birth to adulthood, to improve their quality and expectancy of life.

Hospitalization Events among Children and Adolescents with Sickle Cell Disease in Basra, Iraq

Objectives. Despite improvements in the management of sickle cell disease (SCD), many patients still experience disease-related complications requiring hospitalizations. The objectives of this study were to identify causes of hospitalization among these patients and factors associated with the length of hospital stay (LOS) and readmission. Methods. Data from 160 patients (<14 years old) with SCD who were admitted to the Basra Maternity and Children's Hospital from the first of January 2012 through July 2012 were analyzed. Results. The main causes of hospitalization were acute painful crises (73.84%), infections (9.28%), acute chest syndrome (8.02%), and acute splenic sequestration crisis (6.32%). The mean LOS was 4.34 ± 2.85 days. The LOS for patients on hydroxyurea (3.41 ± 2.64 days) was shorter than that for patients who were not (4.59 ± 2.86 days), P < 0.05. The readmission rate (23.1%) was significantly higher among patients with frequent hospitalizations in the previous year (OR 9.352, 95% CI 2.011–43.49), asthma symptoms (OR 4.225, 95% CI 1.125–15.862), and opioid use (OR 6.588, 95% CI 1.104–30.336). Patients on hydroxyurea were less likely to be readmitted (OR 0.082, 95% CI 0.10–0.663). Conclusions. There is a relatively high readmission rate among patients with SCD in Basra. The use of hydroxyurea significantly decreases the LOS and readmission rate.

Adult sickle cell quality-of-life measurement information system (ASCQ-Me): conceptual model based on review of the literature and formative research

OBJECTIVES

Research-derived evidence about the impact of sickle cell disease (SCD) on the lives of affected adults is lacking. We conducted formative research to provide the basis for a comprehensive description of how SCD affects the lives of adults, with the goal of developing a SCD-specific quality-of-life measurement system.

METHODS

We conducted a comprehensive literature review of patient-reported outcomes, followed by a series of focus groups and structured individual interviews with adults with SCD (n=122) and their health care providers (n=15).

RESULTS

We reviewed 473 abstracts and included 86 articles in the final review. The literature revealed broad categories of the impact of SCD and its treatment on the lives of adults-pain; emotional distress; social-role functioning; overall quality-of-life; and quality of care. We classified 1213 incidents from the focus groups and interviews into a taxonomy (16 domains) that met the criterion for saturation and was demonstrated to be reliable for the classification of incidents. The final conceptual model was built upon the taxonomy.

DISCUSSION

Our conceptual model was similar to previous models with the effects of pain predominating, interwoven with emotional distress, quality of care, and stigmatization. We found a broad range of emotions reflected, including positive effects of SCD. Items for the quality-of-life measure were derived from the taxonomy and the conceptual model may be of use in generating hypotheses for clinical research and improving understanding for clinicians of the lived experience of adults with SCD.

Fluid replacement therapy for acute episodes of pain in people with sickle cell disease

BACKGROUND

Treating vaso-occlusive painful crises in people with sickle cell disease is complex and requires multiple interventions. Extra fluids are routinely given as adjunct treatment, regardless of the individual's state of hydration with the aim of slowing or stopping the sickling process and thereby alleviating pain. This is an update of a previously published Cochrane Review.

OBJECTIVES

To determine the optimal route, quantity and type of fluid replacement for people with sickle cell disease with acute painful crises.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.We also conducted searches of Embase (November 2007), LILACS and www.ClinicalTrials.gov (05 January 2010).Date of most recent search of the Group's Haemoglobinopathies Trials Register: 24 September 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared the administration of supplemental fluids adjunctive to analgesics by any route in people with any type of sickle cell disease during an acute painful episode, under medical supervision (inpatient, day care or community).

DATA COLLECTION AND ANALYSIS

No relevant trials have yet been identified.

MAIN RESULTS

Sixteen trials were identified by the searches, all of which were not eligible for inclusion in the review.

AUTHORS' CONCLUSIONS

Treating vaso-occlusive crises is complex and requires multiple interventions. Extra fluids, generally oral or intravenous, are routinely administered during acute painful episodes to people with sickle cell disease regardless of the individual's state of hydration. Reports of their use during these acute painful episodes do not state the efficacy of any single route, type or quantity of fluid compared to another. However, there are no randomised controlled trials that have assessed the safety and efficacy of different routes, types or quantities of fluid. This systematic review identifies the need for a multicentre randomised controlled trial assessing the efficacy and possible adverse effects of different routes, types and quantities of fluid administered to people with sickle cell disease during acute painful episodes.