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

Can we use biomarkers to identify those at risk of acute pain from sickle cell disease?

INTRODUCTION

Acute pain episodes, also known as vaso-occlusive crises (VOC), are a major symptom of sickle cell disease (SCD) and lead to frequent hospitalizations. The diagnosis of VOC can be challenging, particularly in adults with SCD, 50% of whom have chronic pain. Several potential biomarkers have been proposed for identifying individuals with VOC, including elevation above the baseline of various vascular growth factors, cytokines, and other markers of inflammation. However, none have been validated to date.

AREAS COVERED

We summarize prospective biomarkers for the diagnosis of acute pain in SCD, and how they may be involved in the pathophysiology of a VOC. Previous and current strategies for biomarker discovery, including the use of omics techniques, are discussed.

EXPERT OPINION

Implementing a multi-omics-based approach will facilitate the discovery of objective and validated biomarkers for acute pain.

Roles of Pharmacists in the Management of Sickle Cell Disease in Adults: A Narrative Review

Background: Sickle cell disease (SCD) is an autosomal, recessive, genetic condition of the sickle cell genes. It affects about 100 000 people in the United States where an estimated 1 out of every 365 black children and 1 out of every 13 black children will be born with SCD and sickle cell trait, respectively. Severe and unpredictable pain crisis are the leading cause of emergency department visit for adult patients with SCD and account for 90% of inpatient hospitalizations and 85% of all acute medical care, as well as high usage of medical resources. The care of patients with SCD is complex and requires a multidisciplinary approach. With a few pharmacotherapeutic options to reduce SCD complications and pain episodes, the role of pharmacists in the medication management is unclear. This article aims to outline the potential role of pharmacists in SCD management. Data sources: The authors searched Medline, PubMed, EMBASE, and Scopus from January 1, 1990 to August 31, 2022, for primary literature that assessed the role of pharmacists in managing patients with SCD. Results: The authors identified relevant studies and summarized the role of pharmacists in SCD management. Conclusions: Access to comprehensive health care is essential to ensure that patients with SCD have decreased hospitalizations and good health-related quality of life. Pharmacists are an integral part of the multidisciplinary health-care team and can help patients with SCD navigate the complexities of health care. Pharmacists are medication experts who are positioned to ensure comprehensive care in the acute and chronic SCD management.

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.

An alcohol dehydrogenase 7 gene polymorphism associates with both acute and chronic pain in sickle cell disease

Introduction: As the most distressing complication of sickle cell disease (SCD), pain is marked by considerable heterogenicity. In this study we explored the potential association of alcohol dehydrogenase 7 gene (ADH7) polymorphism rs971074 with sickle cell pain. Methods: We analyzed clinical phenotypes and the rs971074 single-nucleotide polymorphism in ADH7 by MassARRAY-iPlex analysis in a cohort of SCD patients. Results: The synonymous rs971074 was significantly associated with both acute and chronic pain in SCD. Patients with the minor T allele(s) recorded significantly more crisis episodes and severe chronic pain symptoms. Conclusion: Our study has identified the rs971074 minor T allele as a genetic biomarker potentially influencing acute and chronic pain. These findings may ultimately help inform strategies to develop precision pain therapies in SCD.

Preliminary construct validity of patient-reported outcomes to assess chronic pain in adults with sickle cell disease

Chronic pain affects 30% to 40% of individuals with sickle cell disease (SCD) and impairs patient functioning. Clinically meaningful, practical, and valid assessment tools for investigation, evaluation, and management of chronic pain are limited, representing a barrier for advancing SCD care. We sought to determine whether patient-reported outcomes (PROs) show preliminary construct validity in identifying individuals with SCD who were a priori defined as suggestive of having chronic pain based on previously published criteria. All individuals completed the Patient-Reported Outcomes Measurement Information System (PROMIS) domains: pain interference, pain behavior, pain quality (nociceptive, neuropathic), fatigue, sleep disturbance, depression, and anxiety; the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) domains: pain impact and emotional impact; and the painDETECT questionnaire. Thirty-three adults living with SCD were enrolled, and 42.4% had chronic pain. Pain-related PROs scores distinctly differentiated individuals with chronic pain from those without. Individuals with chronic pain had significantly worse pain-related PROs scores: PROMIS pain interference (64.2 vs 54.3), PROMIS pain behavior (63.2 vs 50), and ASCQ-Me pain impact (42.9 vs 53.2). According to published PROMIS clinical cut scores for the pain-related domains, individuals with chronic pain were categorized as having moderate impairment, whereas those without chronic pain had mild or no impairment. Individuals with chronic pain had PRO pain features consistent with neuropathic pain and worse scores in fatigue, depression, sleep disturbance, and emotional impact. Pain-related PROs show preliminary construct validity in differentiating individuals with and without chronic SCD pain and could be used as valuable tools for research and clinical monitoring of chronic pain.

Complementary and alternative medicine for children with sickle cell disease: A systematic review

BACKGROUND

Complementary and alternative medicine (CAM) is a popular alternative to opioid and other analgesics in sickle cell disease (SCD). We review the effectiveness, prevalence, and factors associated with CAM use in the pediatric SCD population.

METHODS

The review protocol was created based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A literature search was conducted in MEDLINE, Embase, Cochrane Library, PubMed, and Web of Science.

RESULTS

Twenty-four studies were examined. The prevalence of CAM use in pediatric patients with SCD ranged from 36 to 84.5%. Common inpatient CAM interventions were yoga, virtual reality, and acupuncture, which decreased pain scale scores. Outpatient CAMs were consisted of cognitive behavioral therapy, massage therapy, and guided-imagery, which increased pain tolerability and decreased pain scale scores.

CONCLUSIONS

CAM modalities can decrease pain scale scores. However, the impact of specific CAM modalities on emergency department visits, hospitalizations, and school absences were inconclusive.

Patient and Caregiver Perspectives on Care-Seeking During a Vaso-Occlusive Crisis in Sickle Cell Disease: Results from Qualitative Interviews in Canada

PURPOSE

There is little research on care-seeking preferences during active pain crises for sickle cell disease (SCD) patients and their caregivers. The objective of this study was to identify relevant, patient or caregiver narratives of the pain crisis experience, to understand the factors that contribute to care-seeking during a pain crisis, and to identify preferences when making care-seeking decisions during a pain crisis.

PATIENTS AND METHODS

Qualitative semi-structured interviews were conducted with Canadian residents with a self-reported SCD diagnosis, who were either ≥18 years of age or an adolescent between the ages of 12-18. Interviews were hosted virtually, audio-recorded, and transcribed verbatim.

RESULTS

A total of 23 individuals participated (74% female; 26% male), including six adolescents with parent dyads and 11 adults. Almost all (N = 21, 91.3%) participants were Black/African American. Participants mentioned many factors that influenced care-seeking decisions, mainly the symptom and pain experience; institutional factors (waiting time, the presence of and adherence to treatment guidelines, and the empathy or racial bias felt from medical staff); and subject-level factors (age and a flexibility in daily responsibilities).

CONCLUSION

This study identified important institutional and subject-level considerations involved in care-seeking decisions. Most importantly, this study highlights the racial stigma faced by many patients when care-seeking in the ER and the lack of care protocol implemented, which hinders care-seeking in a dedicated medical facility. From the patient perspective, these are clear gaps to fill to encourage patients to seek and receive the care they deserve.

Prevalence of neuropathic pain in adolescents with sickle cell disease: A single-center experience

BACKGROUND

Neuropathic pain (NP) has been previously explored in adolescents with sickle cell disease (SCD). This study aims to describe the prevalence of NP in adolescents with SCD at a single institution and to explore associated risk factors.

PROCEDURE

We used the painDETECT questionnaire, one of the few pain phenotyping questionnaires validated for adolescents. We also evaluated the relationships between painDETECT scores and frequency of acute care visits and admissions for pain in the previous 12 months, and age, respectively. Patients 12-18 years old were surveyed from June to July 2019. A retrospective approach was used to answer the remaining research questions.

RESULTS

Eighty-one and seven surveys were completed in the outpatient and inpatient settings, respectively. PainDETECT scores suggestive of NP were more prevalent in inpatient surveys than in outpatient surveys. The difference between the mean painDETECT scores of each group was significant when using a general linear mixed model. Most inpatients surveyed had ≥3 pain events in the previous 12 months. Further, older age and increased number of pain events in the previous 12 months were independently associated with higher painDETECT scores.

CONCLUSIONS

Overall, in our opinion, NP is not being evaluated for and treated sufficiently in pediatric SCD, especially in the setting of inpatient acute vaso-occlusive crisis. Age and number of acute pain events/admissions in the previous 12 months can be used to identify patients likely to be at risk for NP. It is important to continue to identify NP and develop NP-targeting treatment plans.

The eEgg: Evaluation of a New Device to Measure Pain

Aim: The aim of this study was to evaluate whether pain stimuli can be measured validly and reliably by the eEgg (electronic Egg), a new device to measure pain intensity, in comparison to the hand dynamometer.

Methods: This study consists of screening and diagnostic tests conforming to the standard criterion of handgrip strength measurement. Fifty healthy participants (25 women, 25 men; age, 39.1 ± 13.7 years) participated in this study. The approach of intermodal comparison was used to transfer different degrees of pain sensations into measurable handgrip strength values. This included an intensity comparison of 10-100% of the subjective maximum handgrip strength and an application of thermal stimuli of 34-48°C. The eEgg was compared to the numeric rating scale (NRS) as a categorization method regarding the subjective assessment of pain. An online questionnaire was distributed to test the evaluation of the product’s features.

Results: Regarding the experiment’s validity, the handgrip strength values showed significant (p < 0.05) positive correlations between the eEgg and the hand dynamometer (intensities: r=0.328 to r=0.550; thermal stimuli: r=0.353 to r=0.614). The reliability results showed good to very good correlations (p < 0.05) in the calculated ICC (intraclass correlation coefficient) values between the individual measurement devices: eEgg intensities: ICC=0.621 to 0.851; thermal stimuli: ICC=0.487 to 0.776 and hand dynamometer intensities: ICC= 0.789 to 0.974; thermal stimuli: ICC=0.716 to 0.910.

Conclusion: The new eEgg device shows strong correlations with the hand dynamometer. The central limitation focuses on the obligatory use of an arbitrary unit (AU) for the eEgg. The results of the study indicate that this device can be used in medical and therapeutic practice in the future.

Mobile Health-Collected Biophysical Markers in Children with Serious Illness-Related Pain

Context: There is an ongoing established need to develop engaging pain assessment strategies to provide more effective individualized care to pediatric patients with serious illnesses. This study explores the acceptability of wireless devices as one option. Objective: To evaluate the ability of wrist-wearable technology to collect physiological data from children with serious illnesses. Methods: Single-site prospective observational study conducted between September 2017 and September 2018 at Rady Children's Hospital, San Diego, California, inpatient wards. Pediatric patients with diagnoses of cancer and sickle cell disease admitted to the hospital for acute-on-chronic pain and taking opioid pain medications were asked to complete two 24-hour continuous monitoring periods with the Empatica E4 wristband. Results: Data collected from the device correlated with manually obtained vital signs. Children responded favorably to wearing the device. Participants with reported subjective pain versus no pain had average heart rate increased by 16.4 bpm, skin temperature decreased by 3.5°C, and electrodermal activity decreased by 0.27. Conclusions: This study shows the possibility of collecting continuous biophysical data in a nonobtrusive manner in seriously ill children experiencing acute-on-chronic pain using wearable devices. It provides the framework for larger studies to explore the utility of such data in relation to metrics of pain and suffering in this patient population.

Emergency Department Provider Survey Regarding Acute Sickle Cell Pain Management

Sickle cell disease (SCD) can lead to potentially devastating complications that occur secondary to vaso-occlusion. Current national clinical guidelines are largely based on expert opinion, resulting in significant variation of management. Provider awareness regarding emergency department (ED) management of vaso-occlusive crises (VOC) remains unknown. A 23-question assessment of VOC management was administered to all eligible ED providers at Riley Hospital for Children between September and November 2018. Univariate analyses were performed to evaluate responses between groups. Of 52 respondents comprised of ED staff attendings (27%), resident trainees (58%), and ED nurses (15%), the majority were not aware of SCD management guidelines being available. Approximately 54% of providers endorsed a high comfort level in managing VOC, with staff and nurses more likely to report this than trainees (P=0.02). Less than 10% of all providers knew the recommended timeframe from triage to initial medication administration. Prolonged time between pain assessments was reported by 25% of providers with a high comfort level in managing VOC, which was similar to providers with a lower comfort level (13%, P=0.217). Only one fourth of all respondents appropriately did not use vital signs as an indication of a patient's pain level, and >10% reported not utilizing patient-reported pain scores. This was not significantly different between provider comfort levels (P=0.285 and 0.412, relatively). Our results suggest education regarding recommended practices was inadequate regardless of reported provider comfort. Further provider education and/or standardized ED VOC management guidelines may serve as areas for improvement in SCD care.

Characteristics and potential biomarkers of adult sickle cell patients with chronic pain

OBJECTIVES

In this study, we investigated the evolution of chronic pain in sickle cell patients (SCD) as an age-dependent phenomenon and studied the frequency of vaso-occlusive episode frequency, opioid use, quantitative sensory testing (QST), and biomarkers of chronic pain (CP).

METHODS

We undertook a cross-sectional study of the evolution of CP in SCD. A total of 72 subjects (age 15-66) were enrolled. VOE frequency, presence of CP hydroxyurea (HU) therapy, opioid use, and laboratory parameters were collected. QST was performed, and plasma tryptase, substance P, and NGF (Nerve Growth Factor) levels were assayed.

RESULTS

There was an age-dependent increase in frequency of CP, VOEs, opioid use, and Von Frey monofilament values. CP patients had significantly higher opioid use (daily morphine equivalents) (52.8 mg vs 6.94 mg, P = .009), suggesting a correlation between opioid use and hyperalgesia. NGF levels were also significantly higher (P = .051). Our results confirm previous observations of an age-dependent increase in the proportion of patients with CP and support the contributing role of mast cell activation and neurogenic inflammation.

CONCLUSIONS

This is the first study of NGF as a possible biomarker of CP in SCD. If confirmed, this could provide a diagnostic marker and therapeutic target for CP in SCD.

[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.

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.

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.