IMPROVE trial: a randomized controlled trial of patient-controlled analgesia for sickle cell painful episodes: rationale, design challenges, initial experience, and recommendations for future studies

Sickle Cell Disease Treatment with Arginine Therapy (STArT): study protocol for a phase 3 randomized controlled trial

BACKGROUND

Despite substantial illness burden and healthcare utilization conferred by pain from vaso-occlusive episodes (VOE) in children with sickle cell disease (SCD), disease-modifying therapies to effectively treat SCD-VOE are lacking. The aim of the Sickle Cell Disease Treatment with Arginine Therapy (STArT) Trial is to provide definitive evidence regarding the efficacy of intravenous arginine as a treatment for acute SCD-VOE among children, adolescents, and young adults.

METHODS

STArT is a double-blind, placebo-controlled, randomized, phase 3, multicenter trial of intravenous arginine therapy in 360 children, adolescents, and young adults who present with SCD-VOE. The STArT Trial is being conducted at 10 sites in the USA through the Pediatric Emergency Care Applied Research Network (PECARN). Enrollment began in 2021 and will continue for 5 years. Within 12 h of receiving their first dose of intravenous opioids, enrolled participants are randomized 1:1 to receive either (1) a one-time loading dose of L-arginine (200 mg/kg with a maximum of 20 g) administered intravenously followed by a standard dose of 100 mg/kg (maximum 10 g) three times a day or (2) a one-time placebo loading dose of normal saline followed by normal saline three times per day at equivalent volumes and duration as the study drug. Participants, research staff, and investigators are blinded to the participant's randomization. All clinical care is provided in accordance with the institution-specific standard of care for SCD-VOE based on the 2014 National Heart, Lung, and Blood Institute guidelines. The primary outcome is time to SCD-VOE pain crisis resolution, defined as the time (in hours) from study drug delivery to the last dose of parenteral opioid delivery. Secondary outcomes include total parental opioid use and patient-reported outcomes. In addition, the trial will characterize alterations in the arginine metabolome and mitochondrial function in children with SCD-VOE.

DISCUSSION

Building on the foundation of established relationships between emergency medicine providers and hematologists in a multicenter research network to ensure adequate participant accrual, the STArT Trial will provide definitive information about the efficacy of intravenous arginine for the treatment of SCD-VOE for children.

TRIAL REGISTRATION

The STArT Trial was registered in ClinicalTrials.gov on April 9, 2021, and enrollment began on June 21, 2021 (NCT04839354).

Time to pain relief: A randomized controlled trial in the emergency department during vaso-occlusive episodes in sickle cell disease

OBJECTIVE

Compare time to pain relief (minimum of a 13 mm and 30% reduction) during an Emergency Department (ED) visit among patients with sickle cell disease (SCD) experiencing severe pain associated with a vaso-occlusive episode who were randomized to receive either an individualized or weight-based pain protocol.

METHODS

A randomized controlled trial in two EDs. Adults with sickle cell disease. Research staff recorded pain scores every 30 min during an ED visit (up to 6 h in the ED) using a 0-100 mm visual analogue scale. Analysis included 122 visits, representing 49 patients (individualized: 61 visits, 25 patients; standard: 61 visits, 24 patients).

RESULTS

Pain reduction across 6-h was greater for the individualized compared to the standard protocol (protocol-by-time: p = .02; 6-h adjusted pain score comparison: Individualized: M = 29.2, SD = 38.8, standard: M = 45.3, SD = 35.6; p = .03, Cohen d = 0.43). Hazards models indicated a greater probability of 13 mm (HR = 1.54, 95% CI = 1.05, 2.27, p = .03) and 30% (HR = 1.71, 95% CI = 1.11, 2.63, p = .01) reduction in the individualized relative to the standard protocol.

CONCLUSIONS

Patients who received treatment with an individualized protocol experienced a more rapid reduction in pain, including a 13 mm and 30% reduction in pain scores when compared to those that received weight-based dosing.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Age-Induced Changes in µ-Opioid Receptor Signaling in the Midbrain Periaqueductal Gray of Male and Female Rats

Opioids have decreased analgesic potency (but not efficacy) in aged rodents compared with adults; however, the neural mechanisms underlying this attenuated response are not yet known. The present study investigated the impact of advanced age and biological sex on opioid signaling in the ventrolateral periaqueductal gray (vlPAG) in the presence of chronic inflammatory pain. Assays measuring µ-opioid receptor (MOR) radioligand binding, GTPγS binding, receptor phosphorylation, cAMP inhibition, and regulator of G-protein signaling (RGS) protein expression were performed on vlPAG tissue from adult (2-3 months) and aged (16-18 months) male and female rats. Persistent inflammatory pain was induced by intraplantar injection of complete Freund's adjuvant (CFA). Adult males exhibited the highest MOR binding potential (BP) and highest G-protein activation (activation efficiency ratio) in comparison to aged males and females (adult and aged). No impact of advanced age or sex on MOR phosphorylation state was observed. DAMGO-induced cAMP inhibition was highest in the vlPAG of adult males compared with aged males and females (adult and aged). vlPAG levels of RGS4 and RGS9-2, critical for terminating G-protein signaling, were assessed using RNAscope. Adult rats (both males and females) exhibited lower levels of vlPAG RGS4 and RGS9-2 mRNA expression compared with aged males and females. The observed age-related reductions in vlPAG MOR BP, G-protein activation efficiency, and cAMP inhibition, along with the observed age-related increases in RGS4 and RGS9-2 vlPAG expression, provide potential mechanisms whereby the potency of opioids is decreased in the aged population.SIGNIFICANCE STATEMENT Opioids have decreased analgesic potency (but not efficacy) in aged rodents compared with adults; however, the neural mechanisms underlying this attenuated response are not yet known. In the present study, we observed age-related reductions in ventrolateral periaqueductal gray (vlPAG) µ-opioid receptor (MOR) binding potential (BP), G-protein activation efficiency, and cAMP inhibition, along with the observed age-related increases in regulator of G-protein signaling (RGS)4 and RGS9-2 vlPAG expression, providing potential mechanisms whereby the potency of opioids is decreased in the aged population. These coordinated decreases in opioid receptor signaling may explain the previously reported reduced potency of opioids to produce pain relief in females and aged rats.

Evaluation of Vaso-occlusive Crisis Management With Patient-Controlled Analgesia in Children With Sickle Cell Disease Requiring Hospitalization

OBJECTIVE

The aim of this study was to review the use of patient-controlled analgesia (PCA) in sickle cell disease (SCD) for pediatric patients with vaso-occlusive crisis (VOC) in our institution and to compare the effect of early vs late PCA start on pain relief and LOS.

METHODS

This retrospective study included all pediatric patients treated with PCA for a severe VOC from 2010 to 2016. "Early-PCA" was defined as start of PCA within 48 hours of arrival. Time to reach adequate analgesia was defined as the time to reach 2 consecutive pain scores less than 5/10 at 4-hour interval.

RESULTS

During the study period, 46 patients presented 87 episodes of VOC treated with PCA. Sixty-three patients with VOC were treated with Early-PCA and 24 with Late-PCA. Both groups were comparable except for median pain score at admission; the Early-PCA group had higher scores: 9.0/10 vs 7.0/10. Time to reach adequate analgesia could be evaluated only in a subset of patients (n = 32) but was shorter in the Early-PCA group with a median difference of 41.0 hours (95% CI -82.0 to -6.0). Early-PCA was associated with a median reduction in LOS of 3.4 days (95% CI -4.9 to -1.9). There was no difference between the 2 groups in terms of side effects and occurrence of acute chest syndrome during hospitalization.

CONCLUSIONS

In this study, a reduced time to reach adequate analgesia and LOS was noted in the Early-PCA group for severe VOC. A prospective study is required to confirm these results.

A non-injected opioid analgesia protocol for acute pain crisis in adolescents and adults with sickle cell disease

Initial management of the acute pain crisis (APC) of sickle cell disease (SCD) is often unsatisfactory, and might be improved by developing a standardised analgesia protocol. Here, we report the first stages in developing a standard oral protocol for adolescents and adults. Initially, we performed a dose finding study to determine the maximal tolerated dose of sublingual fentanyl (MTD SLF) given on arrival in the acute care facility, when combined with repeated doses of oral oxycodone. We used a dose escalation algorithm with two dosing ranges based on patient’s weight (<50 kg or >50 kg). We also made a preliminary evaluation of the safety and efficacy of the protocol. The study took place in a large tertiary centre in London, UK. Ninety patients in the age range 14–60 years were pre-consented and 31 treatment episodes were evaluated. The first 21 episodes constituted the dose escalation study, establishing the MTD SLF at 600 mcg (>50 kg) or 400 mcg (<50 kg). Further evaluation of the protocol indicated no evidence of severe opioid toxicity, nor increased incidence of acute chest syndrome (ACS). Between 0 and 6 hours, the overall gradient of reduction of visual analogue pain score (visual analogue scale (VAS)) was 0.32 centimetres (cm) per hour (95% confidence interval (CI) = 0.20 to 0.44, p < 0.001). For episodes on MTD SLF, there was median (interquartile range (IQR)) reduction in VAS score of 2.8 cm (0–4.2) and 59% had at least a 2.6-cm reduction. These results are supportive of further evaluation of this protocol for acute analgesia of APC in a hospital setting and potentially for supervised home management.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Advanced age attenuates the antihyperalgesic effect of morphine and decreases μ-opioid receptor expression and binding in the rat midbrain periaqueductal gray in male and female rats

The present study investigated the impact of advanced age on morphine modulation of persistent inflammatory pain in male and female rats. The impact of age, sex, and pain on μ-opioid receptor (MOR) expression and binding in the ventrolateral periaqueductal gray (vlPAG) was also examined using immunohistochemistry and receptor autoradiography. Intraplantar administration of complete Freund's adjuvant induced comparable levels of edema and hyperalgesia in adult (2-3 mos) and aged (16-18 mos) male and female rats. Morphine potency was highest in adult males, with a greater than two-fold increase in morphine EC50 observed in adult versus aged males (3.83 mg/kg vs. 10.16 mg/kg). Adult and aged female rats also exhibited significantly higher EC50 values (7.76 mg/kg and 8.74 mg/kg, respectively) than adult males. The upward shift in EC50 from adult to aged males was paralleled by a reduction in vlPAG MOR expression and binding. The observed age-related reductions in morphine potency and vlPAG MOR expression and binding have significant implications in pain management in the aged population.

Unfractionated heparin in acute chest syndrome: a pilot feasibility randomized controlled trial of unfractionated heparin vs. standard of care in acute chest syndrome

BACKGROUND

Acute chest syndrome (ACS) is the leading cause of mortality in sickle cell disease (SCD). The pathogenesis of ACS is complex and not entirely understood with multiple etiologies likely contributing simultaneously. One particular etiology is pulmonary vascular occlusion due to thrombosis. Thus, anticoagulation is an attractive therapeutic modality.

METHODS

This was a single-center, randomized controlled, open-label, pilot study to determine the feasibility of performing a larger multicenter phase III trial to assess the effects of unfractionated heparin (UFH) in ACS. Subjects were randomized within 24 h of diagnosis of ACS to one of two treatment arms, UFH, and standard of care (SOC), or no UFH and SOC. UFH was given intravenously for 7 days, or until discharge, if discharge was shorter than 7 days. SOC consisted of intravenous fluids, antibiotics, supplemental oxygen, analgesia, red blood cell transfusion, and exchange transfusion.

RESULTS

From July 2014 to June 2018, a total of 7 patients underwent randomization (four patients received UFH in addition to SOC and 3 patients received SOC only). Two of the prespecified feasibility criteria were not met: the capacity to consent eligible individuals and the timely notification of hospitalized patients with ACS necessary to permit randomization within 24 h of diagnosis; thus, as a result of poor enrollment, the study was terminated early. The duration of hospitalization was 279.43 (SD 267.98) and 127.31 (SD 137.70) h in the UFH and SOC arms, respectively. The duration of hypoxemia, leukocytosis, fever, and moderate to severe pain was 117.52 (SD 60.52), 24.90 (SD 29.69), 117.52 (SD 60.52), and 117.52 (SD 60.52) h, respectively, in the UFH group, and 51.49 (SD 44.79), 0, 53.11 (SD 25.06), and 88.68 (SD 72.77) h, respectively, in the SOC group. No major bleeding was noted in either group.

CONCLUSIONS

Our study did not achieve prespecified feasibility criteria, resulting in poor enrollment and early termination, and serves to highlight some of the pitfalls experienced in clinical research in SCD. It did show the use of UFH without any major adverse events in 7 subjects. No future large-scale study is planned.

TRIALS REGISTRATION

Registered at ClinicalTrials.gov (NCT #02098993) on March 28, 2014.

Patterns of healthcare utilization among patients with sickle cell disease hospitalized with pain crises

Background

Vaso‐occlusive crises (VOC) are the hallmark of sickle cell disease (SCD). Adults experiencing VOC often have high rates of unexpected healthcare utilization. We characterized prior and future healthcare utilization among adults hospitalized with VOC at an urban, academic medical center.

Methods

We identified 449 VOC hospitalizations among 63 patients from 2013 to 2016. Patients were categorized based on receiving established care at the medical center and prior utilization: (a) not established (n = 21); (b) newly established (n = 10); (c) established with low utilization in past 12 months (<4 VOC hospitalizations) (n = 22); and (d) established with high utilization in past 12 months (≥4 VOC hospitalizations) (n = 10). Patient and hospitalization characteristics and future utilization were compared across categories.

Results

Median age was 26 years (Q1 = 22, Q3 = 29) and 55.6% were female. Established patients with high prior utilization tended to have higher median pain scores at admission (10, P = .08). Thirty‐day readmissions were highest in established patients with high prior utilization (P = .06), but 30‐day clinic visits were highest in established patients with low prior utilization (P = .08). Adjusted linear regression found that newly established patients (β = −4.6, P < .01) and established patients with low prior utilization (β = −5.6, P < .01) had fewer VOC hospitalizations in the ensuing 12 months than established patients with high prior utilization.

Conclusion

Among patients with SCD hospitalized for VOC, there was heterogeneity in healthcare utilization, with persistence in utilization over time for some patients. Efforts are needed to shift care from the acute setting to the outpatient clinic, which may lead to improved outcomes.

What is the future of patient-reported outcomes in sickle-cell disease?

INTRODUCTION

Sickle cell disease (SCD) is a complex, chronic disease caused by abnormal polymerization of hemoglobin, which leads to severe pain episodes, fatigue, and end-organ damage. Patient reported outcomes (PROs) have emerged as a critical tool for measuring SCD disease severity and response to treatment.

AREAS COVERED

Authors review the key issues involved when deciding to use a PRO in a clinical trial. We describe the most highly recommended generic and disease-specific PRO tools in SCD and discuss the challenges of incorporating them in clinical practice.

EXPERT OPINION

PRO measures are essential to incorporate into SCD clinical trials either as primary or secondary outcomes. The use of PRO measures in SCD facilitates a patient-centered approach, which is likely to lead to improved outcomes. Significant challenges remain in adapting PRO tools to routine clinical use and in developing countries.

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

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

Analgesic management of uncomplicated acute sickle-cell pain crisis in pediatrics: a systematic review and meta-analysis

OBJECTIVES

To capture evidence of the efficacy and safety of pharmacological analgesia for uncomplicated acute sickle-cell pain in pediatric patients compared to placebo.

SOURCES OF DATA

Searches for key evidence were performed from March 1 to 31, 2018, for randomized controlled trials of pharmacological analgesia compared to placebo for uncomplicated acute sickle-cell pain in a pediatric sample. The authors searched ten scientific databases including, among others, PubMed, MEDLINE, Embase, and Clinicaltrials.gov for this systematic review and meta-analysis.

SUMMARY OF THE FINDINGS

Four trials (n=227) were selected by the inclusion criteria (intranasal fentanyl, intravenous magnesium, arginine, and inhaled nitric oxide). The quality of evidence ranged from low to moderate for each outcome. Meta-analysis of changes in the ladder of pain score (p=0.72), length-of-stay in hospital (p=0.65), and amount of narcotics used during the study (p=0.10) showed non-statistically significant differences and a lack of amelioration provided by pharmaceutical analgesics in treatment group. The adverse events reported that more participants in the intervention arm underwent pain, with statistically significant differences at the drug delivery site in studies using intranasal fentanyl and intravenous magnesium (p=0.03).

CONCLUSIONS

Pharmacological analgesia appears to be uncertain in improving the intensity and providing relief of acute pain crisis in pediatric patients with sickle-cell anemia. With respect to clinical advantage, no decisive deduction about the clinical efficacy may be made regarding these medications in acute sickle-cell pain management in the pediatric age group.

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.

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.

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

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

Patient- and Nurse-Controlled Analgesia: 22-Year Experience in a Pediatric Hospital

OBJECTIVES

Pediatric pain management has rapidly changed over the last 2 decades. In this study, we describe the changing practices and adverse events (AEs) related to patient-controlled analgesia (PCA) and/or nurse-controlled analgesia (NCA) over a 22-year period.

METHODS

After institutional review board approval, retrospective data from a single tertiary-care pediatric hospital were collected between 1994 and 2016. Subgroup analyses were done for surgical and medical case patients. We reported the number of times that PCA and/or NCA was ordered annually, the median and interquartile ranges for age, PCA and/or NCA duration and length of stay, and AE frequencies.

RESULTS

Over 22 years, 32 338 PCAs and/or NCAs were ordered in this institution. Morphine and hydromorphone were used most commonly. Between 1994 and 2006, initial orders for PCA and/or NCA increased 2.5-fold. After 2007, initial orders for PCA and/or NCA rapidly decreased; after 2013, the decrease continued at a slower rate, with a total of 1007 orders in 2016. This decrease occurred despite increased hospital admissions and surgeries. Between 2007 and 2012, peripheral nerve blocks rapidly increased (10-fold). After 2002, 146 AEs were reported (1.0%). Of those, 50.5% were nonintercepted, and 20.6% were intercepted AEs; 5.5% and 6.2% were preventable and nonpreventable AEs, respectively.

CONCLUSIONS

PCA and/or NCA usage continues to be common in pediatric patients, although usage has declined and stabilized in the setting of other emerging methods of analgesia and increases in the number of minimally invasive surgical procedures. The overall rate of AEs was extremely low. However, improvements to eliminate all errors are needed, especially with medications with a great risk of harm (such as opioids).

Key Components of Pain Management for Children and Adults with Sickle Cell Disease

Sickle cell disease pain manifests as severe acute pain episodes and a debilitating chronic pain syndrome. Acute pain episodes are the most common reason for health care use; however, acute pain episodes are also frequently managed at home. Chronic pain syndrome develops in 30% to 40% of individuals with sickle cell disease, with an increasing incidence and severity with age. We review the critical aspects of pain management that are integral to the comprehensive approach to sickle cell disease pain and are rooted in the biopsychosocial model. The review focuses on opioid pharmacology and psychosocial comorbidities.

State of the Art Management of Acute Vaso-occlusive Pain in Sickle Cell Disease

Acute vaso-occlusive crisis (VOC) is a hallmark of sickle cell disease (SCD). Multiple complex pathophysiological processes can result in pain during a VOC. Despite significant improvements in the understanding and management of SCD, little progress has been made in the management of pain in SCD, although new treatments are being explored. Opioids and non-steroidal anti-inflammatory drugs (NSAIDs) remain the mainstay of treatment of VOC pain, but new classes of drugs are being tested to prevent and treat acute pain. Advancements in the understanding of the pathophysiology of SCD and pain and the pharmacogenomics of opioids have yet to be effectively utilized in the management of VOC. Opioid tolerance and opioid-induced hyperalgesia are significant problems associated with the long-term use of opioids, and better strategies for chronic pain therapy are needed. This report reviews the mechanisms of pain associated with acute VOC, describes the current management of VOC, and describes some of the new therapies under evaluation for the management of acute VOC in SCD.

A randomized controlled trial comparing two vaso-occlusive episode (VOE) protocols in sickle cell disease (SCD)

Limited evidence guides opioid dosing strategies for acute Sickle Cell (SCD) pain. We compared two National Heart, Lung and Blood (NHBLI) recommended opioid dosing strategies (weight-based vs. patient-specific) for ED treatment of acute vaso-occlusive episodes (VOE). A prospective randomized controlled trial (RCT) was conducted in two ED's. Adults ≥ 21 years of age with SCD disease were eligible. Among the 155 eligible patients, 106 consented and 52 had eligible visits. Patients were pre-enrolled in the outpatient setting and randomized to one of two opioid dosing strategies for a future ED visit. ED providers accessed protocols through the electronic medical record. Change in pain score (0-100 mm VAS) from arrival to ED disposition, as well as side effects were assessed. 52 patients (median age was 27 years, 42% were female, and 89% black) had one or more ED visits for a VOE (total of 126 ED study visits, up to 5 visits/patient were included). Participants randomized to the patient-specific protocol experienced a mean reduction in pain score that was 16.6 points greater than patients randomized to the weight-based group (mean difference 95% CI = 11.3 to 21.9, P = 0.03). Naloxone was not required for either protocol and nausea and/or vomiting was observed less often in the patient-specific protocol (25.8% vs 59.4%, P = 0.0001). The hospital admission rate for VOE was lower for patients in the patient-specific protocol (40.3% vs 57.8% P = 0.05). NHLBI guideline-based analgesia with patient-specific opioid dosing resulted in greater improvements in the pain experience compared to a weight-based strategy, without increased side effects.

Increased theta band EEG power in sickle cell disease patients

Objective

Pain is a major issue in the care of patients with sickle cell disease (SCD). The mechanisms behind pain and the best way to treat it are not well understood. We studied how electroencephalography (EEG) is altered in SCD patients.

Methods

We recruited 20 SCD patients and compared their resting state EEG to that of 14 healthy controls. EEG power was found across frequency bands using Welch's method. Electrophysiological source imaging was assessed for each frequency band using the eLORETA algorithm.

Results

SCD patients had increased theta power and decreased beta2 power compared to controls. Source localization revealed that areas of greater theta band activity were in areas related to pain processing. Imaging parameters were significantly correlated to emergency department visits, which indicate disease severity and chronic pain intensity.

Conclusion

The present results support the pain mechanism referred to as thalamocortical dysrhythmia. This mechanism causes increased theta power in patients.

Significance

Our findings show that EEG can be used to quantitatively evaluate differences between controls and SCD patients. Our results show the potential of EEG to differentiate between different levels of pain in an unbiased setting, where specific frequency bands could be used as biomarkers for chronic pain.

Comparative Safety of Morphine Delivered via Intravenous Route vs. Patient-Controlled Analgesia Device for Pediatric Inpatients

CONTEXT

Although patient-controlled analgesia (PCA) is an effective pain control modality, there is a lack of large studies on PCA safety in pediatric patients.

OBJECTIVES

This study compared the delivery of morphine either via intravenous route (morphine IV) or via PCA device (morphine PCA) on risk of cardiopulmonary resuscitation (CPR) and mechanical ventilation (MV) using a large administrative database.

METHODS

We assembled a retrospective cohort of pediatric inpatients between five and 21 years old in 42 children's hospitals between 2007 and 2011 from the Pediatric Health Information System database. After propensity score matching, we created matched cohorts of morphine PCA and morphine IV patients, in both surgical and nonsurgical samples, who were similar on demographic, clinical, and hospital-level factors. We examined if PCA administration was associated with greater likelihood of CPR or MV up to two days after drug administration.

RESULTS

Surgical and nonsurgical patients administered morphine PCA generally had lower odds of having MV on the baseline day and up to two days after PCA exposure, although these estimates were not statistically significant. Similarly, PCA exposure was associated with about 20%-44% lower odds of same day CPR in both surgical and nonsurgical patients, with a slightly greater reduction in the odds of CPR in the surgical patients.

CONCLUSION

In this large pediatric inpatient population, morphine administered via PCA device for surgical and nonsurgical pain was not associated with an increased risk of receiving CPR or MV, and was associated with slightly better safety outcomes than intravenous morphine.

Characterization of functional brain activity and connectivity using EEG and fMRI in patients with sickle cell disease

Sickle cell disease (SCD) is a red blood cell disorder that causes many complications including life-long pain. Treatment of pain remains challenging due to a poor understanding of the mechanisms and limitations to characterize and quantify pain. In the present study, we examined simultaneously recording functional MRI (fMRI) and electroencephalogram (EEG) to better understand neural connectivity as a consequence of chronic pain in SCD patients. We performed independent component analysis and seed-based connectivity on fMRI data. Spontaneous power and microstate analysis was performed on EEG-fMRI data. ICA analysis showed that patients lacked activity in the default mode network (DMN) and executive control network compared to controls. EEG-fMRI data revealed that the insula cortex's role in salience increases with age in patients. EEG microstate analysis showed patients had increased activity in pain processing regions. The cerebellum in patients showed a stronger connection to the periaqueductal gray matter (involved in pain inhibition), and negative connections to pain processing areas. These results suggest that patients have reduced activity of DMN and increased activity in pain processing regions during rest. The present findings suggest resting state connectivity differences between patients and controls can be used as novel biomarkers of SCD pain.

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Simultaneous EEG-fMRI recordings revealed altered connectivity in sickle cell patients.

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Reduced activity observed in default mode network and executive control network.

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Patients' salience network strength increases with age; opposite seen in controls.

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EEG-fMRI parameters reflect disease severity in sickle cell patients.

Electroacupuncture in conscious free-moving mice reduces pain by ameliorating peripheral and central nociceptive mechanisms

Integrative approaches such as electroacupuncture, devoid of drug effects are gaining prominence for treating pain. Understanding the mechanisms of electroacupuncture induced analgesia would benefit chronic pain conditions such as sickle cell disease (SCD), for which patients may require opioid analgesics throughout life. Mouse models are instructive in developing a mechanistic understanding of pain, but the anesthesia/restraint required to administer electroacupuncture may alter the underlying mechanisms. To overcome these limitations, we developed a method to perform electroacupuncture in conscious, freely moving, unrestrained mice. Using this technique we demonstrate a significant analgesic effect in transgenic mouse models of SCD and cancer as well as complete Freund's adjuvant-induced pain. We demonstrate a comprehensive antinociceptive effect on mechanical, cold and deep tissue hyperalagesia in both genders. Interestingly, individual mice showed a variable response to electroacupuncture, categorized into high-, moderate-, and non-responders. Mechanistically, electroacupuncture significantly ameliorated inflammatory and nociceptive mediators both peripherally and centrally in sickle mice correlative to the antinociceptive response. Application of sub-optimal doses of morphine in electroacupuncture-treated moderate-responders produced equivalent antinociception as obtained in high-responders. Electroacupuncture in conscious freely moving mice offers an effective approach to develop a mechanism-based understanding of analgesia devoid of the influence of anesthetics or restraints.

The Benefits and Challenges of Preconsent in a Multisite, Pediatric Sickle Cell Intervention Trial

Enrollment of patients in sickle cell intervention trials has been challenging due to difficulty in obtaining consent from a legal guardian and lack of collaboration between emergency medicine and hematology. We utilized education and preconsent in a pediatric multisite sickle cell intervention trial to overcome these challenges. Overall, 48 patients were enrolled after being preconsented. Variable Institutional Review Board policies related to preconsent validity and its allowable duration decreased the advantages of preconsent at some sites. The utility of preconsent for future intervention trials largely depends on local Institutional Review Board policies. Preeducation may also benefit the consent process, regardless of site differences.

Assessment and classification of protocol deviations

INTRODUCTION

Deviations from the approved trial protocol are common during clinical trials. They have been conventionally classified as deviations or violations, depending on their impact on the trial.

METHODS

A new method has been proposed by which deviations are classified in five grades from 1 to 5. A deviation of Grade 1 has no impact on the subjects' well-being or on the quality of data. At the maximum, a deviation Grade 5 leads to the death of the subject. This method of classification was applied to deviations noted in the center over the last 3 years.

RESULTS

It was observed that most deviations were of Grades 1 and 2, with fewer falling in Grades 3 and 4. There were no deviations that led to the death of the subject (Grade 5).

DISCUSSION

This method of classification would help trial managers decide on the action to be taken on the occurrence of deviations, which would be based on their impact.

SWIM (sickle with ibuprofen and morphine) randomised controlled trial fails to recruit: lessons learnt

OBJECTIVES

Sickle With Ibuprofen and Morphine (SWIM) trial was designed to assess whether co-administration of ibuprofen (a non-steroidal anti-inflammatory drug) resulted in a reduction of opioid consumption delivered by patient-controlled analgesia (PCA) for acute pain in sickle cell disease.

DESIGN

A randomised, placebo-controlled, double-blind trial.

SETTING

UK multicentre trial in acute hospital setting.

PARTICIPANTS

Adults with sickle cell disease of any gender and phenotype aged 16 years and over.

INTERVENTIONS

Oral ibuprofen at a dose of 800 mg three times daily or placebo in addition to opioids (morphine or diamorphine) administered via PCA pump for up to 4 days.

MAIN OUTCOME MEASURES

The primary outcome measure was opioid consumption over 4 days following randomisation.

RESULTS

The SWIM trial closed early because it failed to randomise to its target of 316 patients within a reasonable time.

CONCLUSIONS

The key issues identified include the unanticipated length of time between informed consent and randomisation, difficulties in randomisation of patients in busy emergency departments, availability of trained staff at weekends and out of hours, fewer centres than expected using PCA routinely for sickle cell pain treatment, lack of research staff and support for participation, and the trial design. There are implications for future UK trials in sickle cell disease.

TRIAL REGISTRATION NUMBER

ISRCTN97241637, NCT00880373; Pre-results.

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.

Addressing challenges of clinical trials in acute pain: The Pain Management of Vaso-occlusive Crisis in Children and Young Adults with Sickle Cell Disease Study

Background/aims:

Neuropathic pain is a known component of vaso-occlusive pain in sickle cell disease; however, drugs targeting neuropathic pain have not been studied in this population. Trials of acute pain are complicated by the need to obtain consent, to randomize participants expeditiously while optimally treating pain. We describe the challenges in designing and implementing the Pain Management of Vaso-occlusive Crisis in Children and Young Adults with Sickle Cell Disease Study (NCT01954927), a phase II, randomized, double-blind, placebo-controlled trial to determine the effect of gabapentin for vaso-occlusive crisis.

Methods:

In the Pain Management of Vaso-occlusive Crisis in Children and Young Adults with Sickle Cell Disease Study, we aim to assess the analgesic effect of gabapentin during vaso-occlusive crisis. Difficulties we identified included avoiding delay of notification of study staff of potential participants which we resolved by automated notification. Concern for rapid randomization and drug dispensation was addressed through careful planning with an investigational pharmacy and a single liquid formulation. We considered obtaining consent during well-visits to avoid the time constraints with acute presentations, but the large number of patients and limited duration that consent is valid made this impractical.

Results:

In all, 79% of caregivers/children approached have agreed to participate. The trial is currently active, and enrollment is at 45.8% of that targeted (76 of 166) and expected to continue for two more years. Maintaining staff availability after-hours remains problematic, with 8% of screened patients missed for lack of available staff.

Lessons learned:

Lessons learned in designing a trial to expedite procedures in the acute pain setting include (1) building study evaluations upon a standard-of-care backbone; (2) implementing a simple study design to facilitate consent and data capture; (3) assuring ample, well-trained study staff; and (4) utilizing technology to automate procedures whenever possible.

Conclusion:

This study design has circumvented many of the logistical barriers usually associated with acute pain trials and may serve as a prototype for future studies.

Quantification of pain in sickle mice using facial expressions and body measurements

Pain is a hallmark feature of sickle cell disease (SCD). Subjects typically quantify pain by themselves, which can be biased by other factors leading to overtreatment or under-treatment. Reliable and accurate quantification of pain, in real time, might enable to provide appropriate levels of analgesic treatment. The mouse grimace scale (MGS), a standardized behavioral coding system with high accuracy and reliability has been used to quantify varied types of pain. We hypothesized that addition of the objective parameters of body length and back curvature will strengthen the reproducibility of MGS. We examined MGS scores and body length and back curvature of transgenic BERK sickle and control mice following cold treatment or following treatment with analgesic cannabinoid CP55,940. We observed that sickle mice demonstrated decreased length and increased back curvature in response to cold. These observations correlate with changes in facial expression for the MGS score. CP55,940 treatment of sickle mice showed an increase in body length and a decrease in back curvature concordant with MGS scores indicative of an analgesic effect. Thus, body parameters combined with facial expressions may provide a quantifiable unbiased method for objective measure of pain in SCD.

A multicenter randomized controlled trial of intravenous magnesium for sickle cell pain crisis in children

Magnesium, a vasodilator, anti-inflammatory, and pain reliever, could alter the pathophysiology of sickle cell pain crises. We hypothesized that intravenous magnesium would shorten length of stay, decrease opioid use, and improve health-related quality of life (HRQL) for pediatric patients hospitalized with sickle cell pain crises. The Magnesium for Children in Crisis (MAGiC) study was a randomized, double-blind, placebo-controlled trial of intravenous magnesium vs normal saline placebo conducted at 8 sites within the Pediatric Emergency Care Applied Research Network (PECARN). Children 4 to 21 years old with hemoglobin SS or Sβ(0) thalassemia requiring hospitalization for pain were eligible. Children received 40 mg/kg of magnesium or placebo every 8 hours for up to 6 doses plus standard therapy. The primary outcome was length of stay in hours from the time of first study drug infusion, compared using a Van Elteren test. Secondary outcomes included opioid use and HRQL. Of 208 children enrolled, 204 received the study drug (101 magnesium, 103 placebo). Between-group demographics and prerandomization treatment were similar. The median interquartile range (IQR) length of stay was 56.0 (27.0-109.0) hours for magnesium vs 47.0 (24.0-99.0) hours for placebo (P = .24). Magnesium patients received 1.46 mg/kg morphine equivalents vs 1.28 mg/kg for placebo (P = .12). Changes in HRQL before discharge and 1 week after discharge were similar (P > .05 for all comparisons). The addition of intravenous magnesium did not shorten length of stay, reduce opioid use, or improve quality of life in children hospitalized for sickle cell pain crisis. This trial was registered at www.clinicaltrials.gov as #NCT01197417.

Systematic review of interventional sickle cell trials registered in ClinicalTrials.gov

BACKGROUND/AIMS

The registry ClinicalTrials.gov was created to provide investigators and patients an accessible database of relevant clinical trials.

METHODS

To understand the state of sickle cell disease clinical trials, a comprehensive review of all 174 "closed," "interventional" sickle cell trials registered at ClinicalTrials.gov was completed in January 2015.

RESULTS

The majority of registered sickle cell disease clinical trials listed an academic center as the primary sponsor and were an early phase trial. The primary outcome for sickle cell disease trials focused on pain (23%), bone marrow transplant (BMT) (13%), hydroxyurea (8%), iron overload (8%), and pulmonary hypertension (8%). A total of 52 trials were listed as terminated or withdrawn, including 25 (14% of all trials) terminated for failure to enroll participants. At the time of this review, only 19 trials uploaded results and 29 trials uploaded a manuscript in the ClinicalTrials.gov database. A systematic review of pubmed.gov revealed that only 35% of sickle cell studies completed prior to 2014 resulted in an identified manuscript. In comparison, of 80 thalassemia trials registered in ClinicalTrials.gov, four acknowledged failure to enroll participants as a reason for trial termination or withdrawal, and 48 trials (60%) completed prior to 2014 resulted in a currently identified manuscript.

CONCLUSION

ClinicalTrials.gov can be an important database for investigators and patients with sickle cell disease to understand the current available research trials. To enhance the validity of the website, investigators must update their trial results and upload trial manuscripts into the database. This study, for the first time, quantifies outcomes of sickle cell disease trials and provides support to the belief that barriers exist to successful completion, publication, and dissemination of sickle cell trial results.

Usability and Feasibility of an mHealth Intervention for Monitoring and Managing Pain Symptoms in Sickle Cell Disease: The Sickle Cell Disease Mobile Application to Record Symptoms via Technology (SMART)

Patients with sickle cell disease frequently experience severe pain events that lead to unplanned healthcare utilization. Mobile health tools (mHealth) may help prevent these events by providing remote monitoring and self-management support. This article describes the feasibility of the Sickle cell disease Mobile Application to Record symptoms via Technology (SMART), an mHealth app developed to help sickle cell disease patients monitor and manage their day-to-day symptoms. Fifteen patients recorded their pain intensity using a paper visual analog scale (VAS) and then repeated this measurement using an electronic VAS pain measure on SMART. Patients continued using SMART to record clinical symptoms, pain intensity, location and perceived severity, and treatment strategies for at least 28 days. Patient median age was 29 years (range 16-54); 60.0% were male. There was a high intraclass correlation between pain measurements entered on the paper VAS and SMART on the iPhone and the iPad We found a strong association between patient perceived pain severity and pain intensity entries using SMART (b = 1.71; p < 0.01). Daily compliance with SMART entries was a mean 75.0%, with a high of 85.7% in week 1 and low of 57.9% in week 4; however, one-third (n = 5) of the patients were 100.0% compliant even in week 4. Patients who were over age 35 or used an iPad for the study had the highest compliance rates. This study showed that SMART is a useable and feasible method for monitoring daily pain symptoms among adolescents and adults with sickle cell disease-related pain.

Development and validation of the English Pain Interference Index and Pain Interference Index-Parent report

OBJECTIVE

Measurement of pain interference in children is challenged by a lack of validated measures with a parent proxy report. This study investigated the psychometric properties of the Pain Interference Index (PII), a six-item questionnaire originally developed in Swedish, in chronically ill youth.

METHODS

We adapted the PII for English-speaking participants and created a parallel parent proxy measure. Respondents indicate how much pain has interfered with the child's life in the past 2 weeks (0-6 scale); higher scores indicate more pain interference. Eligible participants included individuals 6-25 years with neurofibromatosis type 1 (NF1) and cancer. Internal consistency was assessed; validity was examined by correlating PII scores with existing measures of pain interference (Modified Brief Pain Inventory [MBPI]) and pain intensity (visual analogue scale [VAS]), and with measures of disease severity.

RESULTS

Among 60 participants (mean age 14.7 years, range 6-24) and their parents, PII internal consistency was 0.84 and 0.96, respectively. PII scores correlated with MBPI (r = 0.81, P < 0.0001) and VAS (r = 0.55, P < 0.0001) scores and differentiated between patients with mild vs moderate/severe NF1 disease severity (P < 0.05). The PII-Parent was significantly correlated with the mothers' and fathers' VAS rating of the child's pain intensity (Ps < 0.01).

CONCLUSIONS

Internal consistency of the English PII is high; validity is supported by the PII's correlations with other measures of pain interference and pain intensity, and with disease severity in patients with NF1. Preliminary data indicate that the English PII is a reliable, valid, feasible pain interference measure for youth with NF1 and cancer.

Morphine for the treatment of pain in sickle cell disease

Pain is a hallmark of sickle cell disease (SCD) and its treatment remains challenging. Opioids are the major family of analgesics that are commonly used for treating severe pain. However, these are not always effective and are associated with the liabilities of their own. The pharmacology and multiorgan side effects of opioids are rapidly emerging areas of investigation, but there remains a scarcity of clinical studies. Due to opioid-induced endothelial-, mast cell-, renal mesangial-, and epithelial-cell-specific effects and proinflammatory as well as growth influencing signaling, it is likely that when used for analgesia, opioids may have organ specific pathological effects. Experimental and clinical studies, even though extremely few, suggest that opioids may exacerbate existent organ damage and also stimulate pathologies of their own. Because of the recurrent and/or chronic use of large doses of opioids in SCD, it is critical to evaluate the role and contribution of opioids in many complications of SCD. The aim of this review is to initiate inquiry to develop strategies that may prevent the inadvertent effect of opioids on organ function in SCD, should it occur, without compromising analgesia.

Pharmacological treatment of chronic non-cancer pain in pediatric patients

Chronic pain in children and young adults occurs frequently and contributes to early disability as well as personal and familial distress. A biopsychosocial approach to evaluation and treatment is recommended. Within this approach, there is a role for pharmacologic intervention. A variety of medications are used for chronic pain conditions in pediatric patients. Medication classes include anticonvulsants, muscle relaxants, antidepressants, opioids, local anesthetics, and anti-inflammatory drugs. Data is sparse, and most medications are used without condition-specific approval by national regulatory agencies such as the Food and Drug Administration in the US and the European Medicines Agency. In the absence of evidence on which to base practice, optimal drug therapy decisions rest on understanding proposed mechanisms of pain conditions, extrapolation from adult data-when such exists, and empirical and experiential knowledge. Drug delivery systems have evolved, and practitioners have to decide amongst not only medication classes, but also routes of delivery. Opioids are not recommended for use by non-pain specialists for the treatment of pediatric chronic pain, and even then the issues are more complex than can be addressed here. This article reviews the major medications used for pediatric chronic pain conditions.

Sickle cell disease pain management in adolescents: a literature review

Sickle cell disease (SCD) pain continues to emerge in adolescents. More than 98,000 individuals are believed to have SCD in the United States. In fact, 1 in 500 Black infants will be affected by SCD. Identifying standards of care for this unique population can improve pain management and treatment. A significant effect of vaso-occlusive crisis is a decrease in the quality of life in children. Therefore, pain management is multidimensional and includes pharmacologic, physical, and psychological strategies. A review of the literature was conducted to identify best practices regarding pain management in adolescents with sickle cell anemia. Key words such as pain, pain management, adolescent sickle cell anemia, and acute sickle cell pain were entered into databases to reveal qualitative and quantitative studies from 2009 to the present. Many of the research articles identified poor SCD pain management. Studies showed that acute SCD pain management is essential and should be evaluated and robustly managed to achieve optimum pain relief for patients. Acute SCD pain usually occurs as a result of vaso-occlusive crisis. Untreated acute SCD pain can result in morbidity and mortality in adolescents. Nursing knowledge is critical to reducing the stigma and improving management of SCD pain. Nurses play a vital role in the introduction of evidence-based practice within the clinical setting. In an effort to educate nurses and other health care professionals about SCD, this article is a literature review of studies concerning SCD and pain management in emergency rooms.

Intravenous magnesium for pediatric sickle cell vaso-occlusive crisis: methodological issues of a randomized controlled trial

Multiple recent Sickle Cell Disease studies have been terminated due to poor enrollment. We developed methods to overcome past barriers and utilized these to study the efficacy and safety of intravenous magnesium for vaso-occlusive crisis (VOC). We describe the methods of the Intravenous Magnesium in Sickle Vaso-occlusive Crisis (MAGiC) trial and discuss methods used to overcome past barriers. MAGiC was a multi-center randomized double-blind placebo-controlled trial of intravenous magnesium versus normal saline for treatment of VOC. The study was a collaboration between Pediatric Hematologists and Emergency Physicians in the Pediatric Emergency Care Applied Research Network (PECARN). Eligible patients were randomized within 12 hours of receiving intravenous opioids in the Emergency Department (ED) and administered study medication every 8 hours. The primary outcome was hospital length of stay. Associated plasma studies elucidated magnesium's mechanism of action and the pathophysiology of VOC. Health-related quality of life was measured. Site-, protocol-, and patient-related barriers from prior studies were identified and addressed. Limited study staff availability, lack of collaboration with the ED, and difficulty obtaining consent were previously identified barriers. Leveraging PECARN resources, forging close collaborations between Sickle Cell Centers and EDs of participating sites, and approaching eligible patients for prior consent helped overcome these barriers. Participation in the PECARN network and establishment of collaborative arrangements between Sickle Cell Centers and their affiliated EDs are major innovative features of the MAGiC study that allowed improved subject capture. These methods could serve as a model for future studies of VOCs.