Opioids, sleep architecture and sleep-disordered breathing

Sleep and Delirium in Older Adults

Purpose of Review

Poor sleep and delirium are common in older patients but recognition and management are challenging, particularly in the intensive care unit (ICU) setting. The purpose of this review is to highlight current research on these conditions, their inter-relationship, modes of measurement, and current approaches to management.

Recent Findings

Sleep deprivation and delirium are closely linked, with shared clinical characteristics, risk factors, and neurochemical abnormalities. Acetylcholine and dopamine are important neurochemicals in the regulation of sleep and wakefulness and their dysregulation has been implicated in development of delirium. In the hospital setting, poor sleep and delirium are associated with adverse outcomes; non-pharmacological interventions are recommended, but tend to be resource intensive and hindered by a lack of reliable sleep measurement tools. Delirium is easier to identify, with validated tools available in both ICU and non-ICU settings; however, an optimal treatment approach remains unclear. Antipsychotics are used widely to prevent and treat delirium, although the efficacy data are equivocal. Bundled non-pharmacologic approaches represent a promising framework for prevention and management.

Summary

Poor sleep and delirium are common problems in older patients. While these phenomena appear linked, a causal relationship is not clearly established. At present, there are no established sleep-focused guidelines for preventing or treating delirium. Novel interventions are needed that address poor sleep and delirium, particularly in older adults.

Study protocol for a randomised controlled trial evaluating the effects of the orexin receptor antagonist suvorexant on sleep architecture and delirium in the intensive care unit

INTRODUCTION

Insomnia frequently occurs in patients admitted to an intensive care unit (ICU). Sleep-promoting agents may reduce rapid eye movement sleep and have deliriogenic effects. Suvorexant (Belsomra) is an orexin receptor antagonist with Food and Drug Administration (FDA) approval for the treatment of adult insomnia, which improves sleep onset and maintenance as well as subjective measures of quality of sleep. This trial will evaluate the efficacy of postoperative oral suvorexant treatment on night-time wakefulness after persistent sleep onset as well as the incidence and duration of delirium among adult cardiac surgical patients.

METHODS AND ANALYSIS

In this single-centre, randomised, double-blind, placebo-controlled trial, we will enrol 120 patients, aged 60 years or older, undergoing elective cardiac surgery with planned postoperative admission to the ICU. Participants will be randomised to receive oral suvorexant (20 mg) or placebo one time a day starting the night after extubation. The primary outcome will be wakefulness after persistent sleep onset. The secondary outcome will be total sleep time. Exploratory outcomes will include time to sleep onset, incidence of postoperative in-hospital delirium, number of delirium-free days and subjective sleep quality.

ETHICS AND DISSEMINATION

Ethics approval was obtained through the 'Committee on Clinical Investigations' at Beth Israel Deaconess Medical Center (protocol number 2019P000759). The findings will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

This trial has been registered at clinicaltrials.gov on 17 September 2019 (NCT04092894).

Sleep and pain management: a review

There is a complex interplay between sleep disturbance and patients in pain. There is an increasing appreciation of the direct effects of analgesic drugs and sleep quality. This review provides an overview of the effects of different analgesic drugs and their effects on phases of sleep. The effects of different pain conditions and their direct effects on sleep physiology are also discussed. A structured search of the scientific literature using MEDLINE and PubMed databases. Original human and animal studies were included. A multi-search term strategy was employed. An appreciation of the physiological effects of these drugs will allow a more considered prescription of them to better manage sleep disturbance.

Prevalence of sleep-disordered breathing in opioid users with chronic pain: a systematic review and meta-analysis

STUDY OBJECTIVES

Opioids have been reported to increase the risk for sleep-disordered breathing (SDB) in patients with noncancer chronic pain on opioid therapy. This study aims to determine the pooled prevalence of SDB in opioid users with chronic pain and compare it with patients with pain:no opioids and no pain:no opioids.

METHODS

A literature search of PubMed, Medline, Embase, and Cochrane Central Register of Controlled Trials was conducted. We included all observational studies that reported the prevalence of SDB in patients with chronic pain on long-term opioid therapy (≥3 months). The primary outcome was the pooled prevalence of SDB in opioid users with chronic pain (pain:opioids group) and a comparison with pain:no opioids and no pain:no opioids groups. The meta-analysis was performed using a random-effects model.

RESULTS

After screening 1,404 studies, 9 studies with 3,791 patients were included in the meta-analysis (pain:opioids group, n = 3181 [84%]; pain:no opioids group, n = 359 [9.4%]; no pain:no opioids group, n = 251 [6.6%]). The pooled prevalence of SDB in the pain:opioids, pain:no opioids, and no pain:no opioids groups were 91%, 83%, and 72% in sleep clinics and 63%, 10%, and 75% in pain clinics, respectively. Furthermore, in the pain: opioids group, central sleep apnea prevalence in sleep and pain clinics was 33% and 20%, respectively.

CONCLUSIONS

The pooled prevalence of SDB in patients with chronic pain on opioid therapy is not significantly different compared with pain:no opioids and no pain:no opioids groups and varies considerably depending on the site of patient recruitment (ie, sleep vs pain clinics). The prevalence of central sleep apnea is high in sleep and pain clinics in the pain:opioids group. Clinical Trial Registration: Registry: PROSPERO: International prospective register of systematic reviews; Name: Prevalence of sleep disordered breathing, hypoxemia and hypercapnia in patients on oral opioid therapy for chronic pain management; URL: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42018103298; Identifier: CRD42018103298.

Targeting the Orexin System for Prescription Opioid Use Disorder

Prescription opioids are potent analgesics that are used for clinical pain management. However, the nonmedical use of these medications has emerged as a major concern because of dramatic increases in abuse and overdose. Therefore, effective strategies to prevent prescription opioid use disorder are urgently needed. The orexin system has been implicated in the regulation of motivation, arousal, and stress, making this system a promising target for the treatment of substance use disorder. This review discusses recent preclinical studies that suggest that orexin receptor blockade could be beneficial for the treatment of prescription opioid use disorder.

Patient reported outcomes and neuropsychological testing in patients with chronic non-cancer pain in long-term opioid therapy: a pilot study

Background and aims Opioid consumption has increased dramatically in patients with chronic non-cancer pain (CNCP), but long-term consequences are still unclear. The aim of this study is to investigate the effects of long-term opioid treatment on pain, cognition, mood, sleep and quality of life in CNCP patients. Methods In this cross-sectional pilot study, two groups of patients with CNCP treated in a multidisciplinary pain center were selected: (1) opioid group: ≥30 mg morphine equivalent/day for >4 weeks, and (2) control group: no opioid consumption for >4 weeks. Socio-demographic data, alcohol consumption, smoking habits and body mass index (BMI) were registered and pain (brief pain inventory), mood (Hospital Anxiety and Depression Scale), sleep (Pittsburgh Sleep Quality Index) and quality of life (RAND 36-Item Health Survey) were assessed. Continuous Reaction Time and the Digit Span Test were used to evaluate cognitive function. Data was analyzed with a Fisher's exact test and Wilcoxon two-sample test. Results Forty-two patients with CNCP were included (21 in each group). No differences regarding socio-demographics, smoking/alcohol habits and duration, type, or intensity of pain were found. More patients in the opioid group had significantly higher BMI (62% above BMI 25 vs. 33.3%, p = 0.042). Consequently, the subsequent data analyses were controlled for BMI. The two groups did not differ in pain, cognition, anxiety, depression, sleep or quality of life but both showed lower values than the normal standards. Further, the opioid group presented a tendency to lower ratings regarding pain and social function and performed below the normal cut off in the continuous reaction time. Conclusions No significant differences between the two groups were found regarding any of the above-mentioned variables. Interestingly, the patients assessed, regardless of taking opioids or not, could be classified with moderate pain intensity, anxiety and low quality of sleep and life compared to norm standards. Implications The findings of this pilot study suggested that long-term opioid treatment may influence pain and quality of life among CNCP patients. A larger cohort is needed to verify these findings.

Morphine alters respiratory control but not other key obstructive sleep apnoea phenotypes: a randomised trial

Accidental opioid-related deaths are increasing. These often occur during sleep. Opioids such as morphine may worsen obstructive sleep apnoea (OSA). Thus, people with OSA may be at greater risk of harm from morphine. Possible mechanisms include respiratory depression and reductions in drive to the pharyngeal muscles to increase upper airway collapsibility. However, the effects of morphine on the four key phenotypic causes of OSA (upper airway collapsibility (pharyngeal critical closure pressure; Pcrit), pharyngeal muscle responsiveness, respiratory arousal threshold and ventilatory control (loop gain) during sleep) are unknown.

21 males with OSA (apnoea–hypopnoea index range 7–67 events·h−1) were studied on two nights (1-week washout) according to a double-blind, randomised, cross-over design (ACTRN12613000858796). Participants received 40 mg of MS-Contin on one visit and placebo on the other. Brief reductions in continuous positive airway pressure (CPAP) from the therapeutic level were delivered to induce airflow limitation during non-rapid eye movement (REM) sleep to quantify the four phenotypic traits. Carbon dioxide was delivered via nasal mask on therapeutic CPAP to quantify hypercapnic ventilatory responses during non-REM sleep.

Compared to placebo, 40 mg of morphine did not change Pcrit (−0.1±2.4 versus −0.4±2.2 cmH2O, p=0.58), genioglossus muscle responsiveness (−2.2 (−0.87 to −5.4) versus −1.2 (−0.3 to −3.5) μV·cmH2O−1, p=0.22) or arousal threshold (−16.7±6.8 versus −15.4±6.0 cmH2O, p=0.41), but did reduce loop gain (−10.1±2.6 versus −4.4±2.1, p=0.04) and hypercapnic ventilatory responses (7.3±1.2 versus 6.1±1.5 L·min−1, p=0.006).

Concordant with recent clinical findings, 40 mg of MS-Contin does not systematically impair airway collapsibility, pharyngeal muscle responsiveness or the arousal threshold in moderately severe OSA patients. However, consistent with blunted chemosensitivity, ventilatory control is altered.

A Wearable RF Sensor for Monitoring Respiratory Patterns

We present a non-invasive approach for continuous monitoring of respiration dynamics using a wearable radio-frequency (RF) sensor based on near-field coherent sensing. A continuous-wave RF signal at 1.8 GHz is generated by a software-defined radio, with both transmitter (Tx) and receiver (Rx) antennas placed close to the xiphoid process. The experimental prototype of the mobile sensor can modulate the internal organ motion in the near-field region of the Tx antenna and is then received by the nearby Rx antenna to be demodulated and sampled. Through peak detection, we have identified inhalation and exhalation peaks of each breath cycle to estimate the breath rate and the lung volume. The extracted respiratory parameters are compared with the conventional chest belts data for various simulated respiratory conditions including voluntary deep, fast-shallow and slow-shallow breathing. We also characterized simulated central sleep apneas, Cheyne-Stokes, Biot's, ataxic and coughing conditions. To accurately identify obstructive apnea, we presented a two-sensor approach that can capture paradoxical movement of thorax and abdomen. The on-line recognition of these respiratory patterns can be employed not only to continuously monitor patients with chronic respiratory disorders but also to provide real-time feedback for future therapeutic purposes.

Multimodal assessment of sleep in men and women during treatment for opioid use disorder

BACKGROUND

Sleep disturbance is common in patients with opioid use disorder (OUD) receiving medication for addiction treatment. Differences between patients on the two primary agonist medications-methadone and buprenorphine-are not well understood.

METHODS

In patients receiving either methadone or buprenorphine treatment for OUD, we examined sleep continuity and architecture using ambulatory monitoring to gather both an objective measure (daily sleep EEG; M = 5.76 days, SD = 1.46) and a subjective measure (daily sleep diary; M = 54.10 days, SD = 25.10) of sleep.

RESULTS

Patients treated with buprenorphine versus methadone did not differ on any measure of sleep continuity or architecture. Women had longer EEG-derived total sleep time than men (d = -0.68, 95 % CI -1.32 to -0.09), along with lower %N2 (d = 0.94, 95 % CI 0.34-1.64) and greater %N3 (d = -0.94, 95 % CI -1.61 to -0.32). Self-reported sleep differed from EEG-derived estimates: wake after sleep onset was greater by EEG than by diary (d = 2.58, 95 % CI 1.74-3.63), and total sleep time and sleep efficiency were lower by EEG than by diary (d for sleep time = 2.93, 95 % CI 2.06-4.14; d for efficiency = 1.69, 95 % CI 0.98-2.49).

CONCLUSIONS

Patients treated with buprenorphine or methadone did not substantively differ in ambulatory measures of sleep. With both medications, there was a discrepancy between objective and subjective sleep measures. Further confirmatory evidence would inform the development of sleep-related recommendations for OUD patients undergoing agonist treatment.

Alcohol use disorder and sleep disturbances: a feed-forward allostatic framework

The development of alcohol use disorder (AUD) involves binge or heavy drinking to high levels of intoxication that leads to compulsive intake, the loss of control in limiting intake, and a negative emotional state when alcohol is removed. This cascade of events occurs over an extended period within a three-stage cycle: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These three heuristic stages map onto the dysregulation of functional domains of incentive salience/habits, negative emotional states, and executive function, mediated by the basal ganglia, extended amygdala, and frontal cortex, respectively. Sleep disturbances, alterations of sleep architecture, and the development of insomnia are ubiquitous in AUD and also map onto the three stages of the addiction cycle. During the binge/intoxication stage, alcohol intoxication leads to a faster sleep onset, but sleep quality is poor relative to nights when no alcohol is consumed. The reduction of sleep onset latency and increase in wakefulness later in the night may be related to the acute effects of alcohol on GABAergic systems that are associated with sleep regulation and the effects on brain incentive salience systems, such as dopamine. During the withdrawal/negative affect stage, there is a decrease in slow-wave sleep and some limited recovery in REM sleep when individuals with AUD stop drinking. Limited recovery of sleep disturbances is seen in AUD within the first 30 days of abstinence. The effects of withdrawal on sleep may be related to the loss of alcohol as a positive allosteric modulator of GABAA receptors, a decrease in dopamine function, and the overactivation of stress neuromodulators, including hypocretin/orexin, norepinephrine, corticotropin-releasing factor, and cytokines. During the preoccupation/anticipation stage, individuals with AUD who are abstinent long-term present persistent sleep disturbances, including a longer latency to fall asleep, more time awake during the night, a decrease in slow-wave sleep, decreases in delta electroencephalogram power and evoked delta activity, and an increase in REM sleep. Glutamatergic system dysregulation that is observed in AUD is a likely substrate for some of these persistent sleep disturbances. Sleep pathology contributes to AUD pathology, and vice versa, possibly as a feed-forward drive to an unrecognized allostatic load that drives the addiction process.

Electrocortical changes associating sedation and respiratory depression by the opioid analgesic fentanyl

Opioid drugs are the mainstay of pain management but present the side-effect of respiratory depression that can be lethal with overdose. In addition to their respiratory effect, opioids also induce a profound sedative state and produce electrocortical features characteristic of a state of reduced brain arousal, similar to anaesthesia or sleep. In such states, respiratory activity depends more on the integrity of the brainstem respiratory network than it does during wakefulness. Accordingly, we propose that sedation by fentanyl induces specific electrocortical changes consistent with reduced brain arousal, and that the magnitude of respiratory depression is associated with distinct electrocortical changes. To these aims, we determined the effects of systemic injections of fentanyl (dosage 100 µg ·kg) versus control on electrocortical  and respiratory activities of freely-behaving rats. We found that fentanyl induced electrocortical changes that differed from those observed in sleep or wakefulness. Fentanyl increased δ (1-3 Hz) frequency power (P < 0.001), but reduced α (7.5-13.5 Hz) and β2 (20-30 Hz) powers (P = 0.012 and P < 0.001, respectively), when compared to wakefulness. Interestingly, respiratory rate depression by fentanyl was significantly correlated with increased θ power (R = 0.61, P < 0.001), therefore showing a clear association between electrocortical activity and the magnitude of respiratory rate depression. Overall, we provide new evidence linking specific electrocortical changes to the severity of respiratory depression by opioids, which highlights the importance of considering the cortical and subcortical effects of opioids in addition to their impacts on breathing when evaluating opioid-induced respiratory depression.

Nonpeptide Orexin-2 Receptor Agonist Attenuates Morphine-induced Sedative Effects in Rats

BACKGROUND

Sleepiness and decrease in attention are dose-limiting side effects of opioids. The orexin/hypocretin system plays an important role in maintaining wakefulness. This study aimed to explore the potential of a nonpeptide orexin receptor agonist to alleviate morphine-induced sedative effects.

METHODS

Morphine sedative effects were evaluated as changes in electroencephalogram (EEG), locomotor activity, and acoustic startle response in rats (n = 5 to 9 per group). Effects of intracerebroventricular orexin-A and systemic orexin type-2 receptor agonist, YNT-185, on EEG changes induced by morphine were examined. Furthermore, the authors examined effects of morphine administered with or without YNT-185 on locomotor activity and on acoustic startle response.

RESULTS

Morphine-induced, frequent, short epochs of increased power (total epoch duration: 0.5 [0.0 to 8.0] s/10 min during baseline vs. 74.0 [49.0 to 115.0] s/10 min during the post-morphine administration period; P = 0.012). EEG analyses revealed that morphine-induced, high-amplitude, slow activity (increase in spectral power of frequencies less than 15 Hz, baseline vs. postmorphine; P < 0.001). Orexin-A and YNT-185 attenuated these changes. Locomotor activity decreased after morphine (268 [103 to 889] ambulatory movement counts during baseline period [20 min] vs. 138 [7 to 434] counts during 40 to 59 min postadministration; P = 0.012), but did not change after morphine with YNT-185 (363 [121 to 636] vs. 864 [381 to 1092] counts, difference within morphine + YNT-185 group; P = 0.071). Startle response latency was longer after morphine (26 [20 to 28] ms) than after morphine with YNT-185 (17 [16 to 18] ms; P = 0.012).

CONCLUSIONS

Orexin-A and/or YNT-185 attenuated morphine-induced sedative effects assessed by EEG changes and behavioral measures in rats. The authors' results suggest that orexin-2 receptor activation alleviates morphine-induced sedative effects.

Intensity of Withdrawal Symptoms During Opioid Taper in Patients with Chronic Pain—Individualized or Fixed Starting Dosage?

Objective

Controlled opioid withdrawal is recommended for patients with chronic noncancer pain (CNCP) with insufficient pain reduction or intolerable side effects while on opioid treatment. Few studies have investigated the management of opioid withdrawal (OW). Most common are protocols with an individualized starting dosage (ISD), calculated from the last opioid intake. After two cases of overdose, we introduced a novel withdrawal protocol using a low fixed starting dosage (FSD) for safety reasons. The present study compares the intensity of withdrawal symptoms using the Subjective Opioid Withdrawal Scale (SOWS) and incidences of serious adverse events (SAE) and dropouts in each taper schedule in 195 CNCP patients with OW in an inpatient facility.

Methods

Two protocols were compared: FSD (2014–2016): N = 68, starting dose: 90 mg morphine/d; and ISD (2010–2014): N = 127, starting dose: 70% of the patient’s daily morphine equivalent dose (MED). Outcome criteria: primary: mean daily SOWS score during the first 10 days (16 questions, daily score 0–64); secondary: change in pain intensity on a numeric rating scale (0–10), rate of dropouts and SAEs. Statistics: Student test, Mann-Whitney U test, chi-square test, analysis of variance, P &lt; 0.05.

Results

The mean daily SOWS score was lower in the FSD group (14.9 ± 9.4 vs 16.1 ± 10, P &lt; 0.05) due to a lower rate of high-intensity withdrawal symptoms (12.4% vs 17.6%, P &lt; 0.01), particularly in patients on &gt;180 mg MED (9.7% vs 18.4%, P &lt; 0.01). Pain intensity decreased after withdrawal, and the incidence of SAEs and dropouts was low in both groups.

Conclusions

The FSD protocol provides a lesser burden of withdrawal symptoms and equal patient safety. It can be recommended for OW in CNCP patients.

Meta-Analysis for Correlating Structure of Bioactive Peptides in Foods of Animal Origin with Regard to Effect and Stability

Amino acid (AA) sequences of 807 bioactive peptides from foods of animal origin were examined in order to correlate peptide structure with activity (antihypertensive, antioxidative, immunomodulatory, antimicrobial, hypolipidemic, antithrombotic, and opioid) and stability in vivo. Food sources, such as milk, meat, eggs, and marine products, show different frequencies of bioactive peptides exhibiting specific effects. There is a correlation of peptide structure and effect, depending on type and position of AA. Opioid peptides contain a high percentage of aromatic AA residues, while antimicrobial peptides show an excess of positively charged AAs. AA residue position is significant, with those in the first and penultimate positions having the biggest effects on peptide activity. Peptides that have activity in vivo contain a high percentage (67%) of proline residues, but the positions of proline in the sequence depend on the length of the peptide. We also discuss the influence of processing on activity of these peptides, as well as methods for predicting release from the source protein and activity of peptides.

The Pain Divide: a cross-sectional analysis of chronic pain prevalence, pain intensity and opioid utilisation in England

OBJECTIVES

Our central research question was, in England, are geographical inequalities in opioid use driven by health need (pain)? To answer this question, our study examined: (1) if there are regional inequalities in rates of chronic pain prevalence, pain intensity and opioid utilisation in England; (2) if opioid use and chronic pain are associated after adjusting for individual-level and area-level confounders.

DESIGN

Cross-sectional study design using data from the Health Survey for England 2011.

SETTING

England.

PRIMARY AND SECONDARY OUTCOME MEASURES

Chronic pain prevalence, pain intensity and opioid utilisation.

PARTICIPANTS

Participant data relating to chronic pain prevalence, pain intensity and opioid usage data were obtained at local authority level from the Health Survey for England 2011; in total, 5711 respondents were included in our analysis.

METHODS

Regional and local authority data were mapped, and a generalised linear model was then used to explore the relationships between the data. The model was adjusted to account for area-level and individual-level variables.

RESULTS

There were geographical variations in chronic pain prevalence, pain intensity and opioid utilisation across the English regions-with evidence of a 'pain divide' between the North and the South, whereby people in the North of England more likely to have 'severely limiting' or 'moderately limiting' chronic pain. The intensity of chronic pain was significantly and positively associated with the use of opioid analgesics.

CONCLUSIONS

There are geographical differences in chronic pain prevalence, pain intensity and opioid utilisation across England-with evidence of a 'pain divide'. Given the public health concerns associated with the long-term use of opioid analgesics-and their questionable activity in the management of chronic pain-more guidance is needed to support prescribers in the management of chronic pain, so the initiation of opioids can be avoided.

Discrepancies in sleep diary and actigraphy assessments in adults with fibromyalgia: Associations with opioid dose and age

Sleep diary and actigraphy assessments of insomnia symptoms in patients with fibromyalgia (FM) are often discrepant. We examined whether opioid dose and age interact in predicting magnitude or direction of discrepancies. Participants (N = 199, M = 51.5 years, SD = 11.7) with FM and insomnia completed 14 days of diaries and actigraphy. Multiple regressions determined whether average opioid dose and its interaction with age predicted magnitude or direction of diary/actigraphy discrepancies in sleep onset latency (SOL), wake after sleep onset (WASO) and sleep efficiency (SE), controlling for sex, use of sleep medication, evening pain and total sleep time. Higher opioid dose predicted greater magnitude of discrepancy in SOL and SE. Opioid dose interacted with age to predict direction but not magnitude of discrepancy in SOL and SE. Specifically, higher opioid use was associated with better subjective (shorter SOL, higher SE) than objective reports of sleep among younger adults, and longer subjective than objectively measured SOL among older adults. Opioid dose did not predict magnitude or direction of WASO discrepancies. In FM, a higher opioid dose increases diary/actigraphy SOL and SE discrepancies, and direction of discrepancies may depend on age. We speculate that increased opioid use combined with age-related factors, such as slow wave sleep disruption, increased awakenings and/or cognitive decline, may impact perceived sleep.

Sleep quality with WHO Step III opioid use for cancer pain

OBJECTIVE

Sleep is often disturbed in patients with advanced cancer. There is limited knowledge about sleep in patients with cancer treated with strong opioids. This study examines sleep quality in patients with advanced cancer who are treated with a WHO Step III opioid for pain.

METHODS

An international, multicentre, cross-sectional study with 604 adult patients with cancer pain using WHO Step III opioids. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI) global score (range; 0-21; score >5 indicates poor sleep). PSQI includes sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medications and daytime dysfunction. Pain and quality of life were assessed by Brief Pain Inventory and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core30.

RESULTS

The median age was 62 years, 42% were female, mean Karnofsky performance score (KPS) was 62.5 (±14.2) and mean oral daily morphine equivalent dose was 303 mg/24 hours (±543.8 mg). The mean PSQI global score was 8.8 (±4.2) (range 0-20). Seventy-eight per cent were poor sleepers. All PSQI components were affected, and 44% reported trouble sleeping caused by pain. In the multiple regression model, predictors of PSQI global scores were pain intensity, emotional function, constipation, financial difficulties and KPS (adjusted R²=0.21).

CONCLUSION

The majority (78%) of these patients with cancer treated with Step III opioids experienced poor sleep quality. Pain intensity, emotional function, constipation, financial difficulties and KPS predicted poor PSQI global scores. The clinical implication is that healthcare personnel should routinely assess and treat sleep disturbance in patients with advanced cancer disease.

Prospective evaluation of chronic pain disorders and treatments

BACKGROUND

The incidence of chronic pain is variable among individuals who have sustained traumatic or surgical injury. Also, treatments for pain rarely are effective consistently for a procedure or agent, and no therapies are considered effective for pain that is chronic.

NEW METHOD

Difficulties with standard methods for conducting clinical trials call attention to a need for protocols that provide a new understanding of the development of and control over chronic pain. Prospective single-subject research designs can document varieties of pain progression over time for individuals. Subsequent grouping of individuals with common characteristics directs a mechanism-based approach to therapy.

RESULTS

Tracking of individuals' pain and associated influences over time is consistent with clinical practice, noting and adapting to changes that occur.

COMPARISON WITH EXISTING METHODS

Grouping patients with diverse characteristics and variable effects of therapy is problematic. Conventional evaluation of pain assesses patients with similar injuries or surgery without characterizations of individuals who develop chronic pain or recover over time. Also, classical evaluation of therapies involves comparison of groups receiving treatment or a placebo without characterization of patients with successful and unsuccessful results.

CONCLUSIONS

Single-subject prospective studies can inform clinical trials according to individual differences that would be obscured by comparison of groups with unknown variation in characteristics that influence pain and therapeutic effectiveness.

Life-time history of insomnia and hypersomnia symptoms as correlates of alcohol, cocaine and heroin use and relapse among adults seeking substance use treatment in the United States from 1991 to 1994

AIMS

To examine the association between a life-time history of insomnia and hypersomnia compared with no sleep disturbance and substance use patterns and amounts before and after a substance use treatment episode.

DESIGN

Secondary analysis of data from the Drug Abuse Treatment Outcome Studies conducted from 1991 to 1994.

SETTING

Data were collected at 96 substance use treatment programs in 11 United States cities, including short-term in-patient, long-term residential, methadone maintenance and out-patient drug-free treatment modalities.

PARTICIPANTS

Study samples included 7168 adults at treatment entry and 2965 at 12 months post-treatment entry whose primary substance use at entry was alcohol (14.7%), cocaine (62.7%) or heroin (22.6%).

MEASUREMENTS

Life-time history of insomnia and hypersomnia was assessed via self-report. Type and frequency of substance use were assessed at treatment entry. Substance use was also assessed 12 months following treatment completion. Associations were examined using linear and logistic regression with age, sex, race, education level, depression history, treatment modality and in-treatment substance use as covariates.

FINDINGS

Life-time history of insomnia, hypersomnia, both or neither was reported by 26.3, 9.5, 28.0 and 36.2% of participants, respectively. Compared with no sleep disturbance, life-time insomnia and hypersomnia were associated at treatment entry with unique substance use patterns and a higher frequency of any substance use (P < 0.001). All types of sleep disturbance were associated with higher rates of cocaine use at 12-month post-entry (odds ratios: 1.30-1.57).

CONCLUSIONS

There is evidence of an adverse association between substance use and sleep disturbance including higher frequency of all substance use before substance abuse treatment and higher rates of cocaine use after a treatment episode.

Propofol and sufentanil may affect the patients' sleep quality independently of the surgical stress response: a prospective nonrandomized controlled trial in 1033 patients' undergone diagnostic upper gastrointestinal endoscopy

Background

It is unknown whether sedative per se contributes to the postoperative sleep disturbance. Diagnostic upper gastrointestinal endoscopy (UGE) is a minimally invasive procedure which is not likely to cause tissue trauma and pain. The purpose of this study was to evaluate the sleep quality of patients undergoing routine (without sedative) diagnostic UGE or UGE with sedative, before, 1 week, and 1 month after the procedure.

Methods

One thousand and thirty-three patients undergoing UGE were enrolled. Patients chose sedative or without sedative. Propofol and sufentanil were administered to the sedative group, not allowed for the routine group. The Pittsburgh Sleep Quality Index (PSQI) was measured before, 1 week and 1 month after the procedure.

Results

Five hundred and ten patients were enrolled in the sedative group and 523 in the routine group. One week after the procedure, patients in the sedative group showed significantly higher PSQI scores (worse sleep quality) than the baseline PSQI scores (p < 0.001), but there was no significant change for the routine group in the same period (p = 0.096). One month after the procedure, there was no significant difference in PSQI scores between the two groups compared with the baseline values (p = 0.358 for sedative group, p = 0.161 for routine group). There were also no significant difference in the PSQI scores between the two groups in the entire 1 month follow-up period (p = 0.885).

Conclusions

The sedative group showed impaired sleep quality 1 week after diagnostic UGE. Propofol and sufentanil may independently affect the sleep quality of patients after sedative of diagnostic UGE for only one week.

Trial registration

This study is registered on Chinese Clinical Trial Registry (IDChiCTR-OCH-13003128). Registered 2 April 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0341-3) contains supplementary material, which is available to authorized users.

Daily sleep quality affects drug craving, partially through indirect associations with positive affect, in patients in treatment for nonmedical use of prescription drugs

OBJECTIVE

Sleep disturbance has been identified as a risk factor for relapse in addiction to a range of substances. The relationship between sleep quality and treatment outcome has received relatively little attention in research on nonmedical use of prescription drugs (NMUPD). This study examined the within-person association between sleep quality and craving in medically detoxified patients in residence for the treatment of NMUPD.

METHOD

Participants (n=68) provided daily reports of their sleep quality, negative affect (NA), positive affect (PA), and craving for an average of 9.36 (SD=2.99) days. Within-person associations of sleep quality and craving were examined using multilevel modeling. Within-person mediation analyses were used to evaluate the mediating roles of NA and PA in the relationship between sleep quality and craving.

RESULTS

Greater cravings were observed on days of lower than usual sleep quality (γ₁₀=-0.10, p=0.003). Thirty-one percent of the overall association between sleep quality and craving was explained by PA, such that poorer sleep quality was associated with lower PA and, in turn, lower PA was associated with greater craving. No evidence emerged for an indirect association between sleep quality and craving through NA.

CONCLUSIONS

Daily fluctuations in sleep quality were associated with fluctuations in craving, an association partially explained by the association between sleep quality and daily PA. These data encourage further research on the relationship between sleep, affect, and craving in NMUPD patients, as well as in patients with other substance use disorders.

Rethinking chronic pain in a primary care setting

Chronic pain substantially impacts patient function and quality of life and is a burden to society at large in terms of increased health care utilization and loss of productivity. As a result, there is an increasing recognition of chronic pain as a public health crisis. However, there remains wide variability in clinical practices related to the prevention, assessment, and treatment of chronic pain. Certain fundamental aspects of chronic pain are often neglected including the contribution of the psychological, social, and contextual factors associated with chronic pain. Also commonly overlooked is the importance of understanding the likely neurobiological mechanism(s) of the presenting pain and how they can guide treatment selection. Finally, physicians may not recognize the value of using electronic medical records to systematically capture data on pain and its impact on mood, function, and sleep. Such data can be used to monitor onset and maintenance of treatments effects at the patient level and evaluate costs at the systems level. In this review we explain how these factors play a critical role in the development of a coordinated, evidence-based treatment approach tailored to meet specific needs of the patient. We also discuss some practical approaches and techniques that can be implemented by clinicians in order to enhance the assessment and management of individuals with chronic pain in primary care settings.

Distinct Cortical Signatures Associated with Sedation and Respiratory Rate Depression by Morphine in a Pediatric Population

Background

Opioid analgesia is an essential component of perioperative care, but effective analgesia can be limited by excessive sedation and respiratory depression. The cortical signatures associated with sedation by opioids and the relationship between changes in cortical activity and respiratory function are not well understood. The objectives of this study were to identify the electroencephalogram signatures of sedation and respiratory changes induced by morphine in a pediatric population after elective surgery.

Methods

After otologic surgery, patients (14.8 ± 2.8 yr, n = 10) stayed overnight for pain relief with morphine (3 to 10 mg), hydration, and clinical observation. Electroencephalogram activity and polysomnography were performed before and after morphine, and electroencephalogram spectral properties and cardiorespiratory activities were analyzed.

Results

Compared to wakefulness and non–rapid eye movement sleep, morphine reduced high-frequency β1 (13.5 to 20 Hz) and β2 (20 to 30Hz) electroencephalogram powers (n = 10) and decreased coherence between frontal and occipital β2 electroencephalogram activities (n = 9), therefore indicating that morphine induced a deep sedative state. Morphine also reduced respiratory rate by 8.3% (n = 10). Interestingly, there was a significant correlation between the reduction in β1 electroencephalogram activity and the depression in respiratory rate induced by morphine (R = 0.715, n = 10). With significant reduction in β1 power, respiratory rate was decreased by more than 25%, suggesting that reduction in cortical arousal is associated with the severity of respiratory rate depression.

Conclusions

Analgesic doses of morphine are associated with reduction in respiratory rate when accompanied by reduction in β1 electroencephalogram power, indicating a powerful effect of cortical arousal state per se in respiratory rate depression by morphine.

Sleep and Pain in Pediatric Illness: A Conceptual Review

BACKGROUND

Sleep disruption is a common comorbidity of pediatric pain. Consequences of pain and disrupted sleep, evidence for the pain-sleep relation, and how aspects of illness, treatment, and pharmacological pain management may contribute to or exacerbate these issues are presented.

AIMS

This conceptual review explored the relation between pain and sleep in children diagnosed with chronic medical or developmental conditions. The goal of this review is to expand upon the literature by examining common themes in sleep disturbances associated with painful conditions across multiple pediatric illnesses. Populations reviewed include youth with intellectual and developmental disabilities (IDD), migraines, cystic fibrosis (CF), sickle cell disease (SCD), cancer, juvenile idiopathic arthritis (JIA), juvenile fibromyalgia (JFM), and functional gastrointestinal disorders (FGIDs).

RESULTS

Consistent evidence demonstrates that children with medical or developmental conditions are more vulnerable to experiencing pain and subjective sleep complaints than healthy peers. Objective sleep concerns are common but often under-studied. Evidence of the pain-sleep relationship exists, particularly in pediatric SCD, IDD, and JIA, with a dearth of studies directly examining this relation in pediatric cancer, JFM, CF, and FGIDs. Findings suggest that assessing and treating pain and sleep disruption is important when optimizing functional outcomes.

CONCLUSION

It is essential that research further examine objective sleep, elucidate the pain-sleep relationship, consider physiological and psychosocial mechanisms of this relationship, and investigate nonpharmacological interventions aimed at improving pain and sleep in vulnerable pediatric populations.

Evaluation and Management of Sleep Disorders in the Hand Surgery Patient

Despite posing a significant public health threat, sleep disorders remain poorly understood and often underdiagnosed and mismanaged. Although sleep disorders are seemingly unrelated, hand surgeons should be mindful of these because numerous conditions of the upper extremity have known associations with sleep disturbances that can adversely affect patient function and satisfaction. In addition, patients with sleep disorders are at significantly higher risk for severe, even life-threatening medical comorbidities, further amplifying the role of hand surgeons in the recognition of this condition.

Multifaceted impairments in impulsivity and brain structural abnormalities in opioid dependence and abstinence

BACKGROUND

Chronic opioid exposure, as a treatment for a variety of disorders or as drug of misuse, is common worldwide, but behavioural and brain abnormalities remain under-investigated. Only a small percentage of patients who receive methadone maintenance treatment (MMT) for previous heroin misuse eventually achieve abstinence and studies on such patients are rare.

METHOD

The Cambridge Neuropsychological Test Automated Battery and T1 weighted magnetic resonance imaging (MRI) were used to study a cohort of 122 male individuals: a clinically stable opioid-dependent patient group receiving MMT (n = 48), an abstinent previously MMT maintained group (ABS) (n = 24) and healthy controls (n = 50).

RESULTS

Stable MMT participants deliberated longer and placed higher bets earlier in the Cambridge Gambling Task (CGT) and showed impaired strategic planning compared with healthy controls. In contrast, ABS participants showed impairment in choosing the least likely outcome, delay aversion and risk adjustment on the CGT, and exhibited non-planning impulsivity compared with controls. MMT patients had widespread grey matter reductions in the orbitomedial prefrontal cortex, caudate, putamen and globus pallidus. In contrast, ABS participants showed midbrain-thalamic grey matter reductions. A higher methadone dose at the time of scanning was associated with a smaller globus pallidus in the MMT group.

CONCLUSIONS

Our findings support an interpretation of heightened impulsivity in patients receiving MMT. Widespread structural brain abnormalities in the MMT group and reduced brain structural abnormality with abstinence suggest benefit of cessation of methadone intake. We suggest that a longitudinal study is required to determine whether abstinence improves abnormalities, or patients who achieve abstinence have reduced abnormalities before methadone cessation.

Cognitive Effects and Sedation

OBJECTIVE

Cognitive effects and sedation (CES) are prevalent in chronic nonmalignant pain populations receiving long-term opioid therapy and are among the most common reasons patients discontinue opioid use. In this narrative review, we describe the phenomenology, epidemiology, mechanisms, assessment, and management of opioid-related CES.

DESIGN

We reviewed the empirical and theoretical literature on CES in opioid-treated populations with chronic pain. Data on long-term opioid therapy (≥ 3 months in duration) in chronic nonmalignant pain patients were sought.

RESULTS

The phenomenology of CES includes: inattention, concentration difficulties, memory deficits, psychomotor dysfunction, perceptual distortions, and executive dysfunction and somnolence, sleep disorders, and lethargy. Deficits may be caused by unrelieved pain or opioid therapy alone, or from a combination of these and other factors. Mechanisms include central nervous system effects, for example, direct toxic effects on neurons resulting in decreased consciousness; direct effects on processing and reaction resulting in cognitive or psychomotor impairment, and inhibitory effects on cholinergic activity. Pharmacological management approaches may include opioid dose reduction and rotation or psychostimulant use. Nonpharmacological approaches may include cognitive-behavioral therapy, mindfulness-based stress reduction, acupuncture, exercise, and yoga.

CONCLUSIONS

The most prevalent CES include: memory deficits (73-81%), sleep disturbance (35-57%), and fatigue (10%). At its most severe, extreme cognitive dysfunction can result in frank delirium and decreased alertness can result in coma. Emotional distress, sleep disorders, and other comorbidities and treatments can worsen CES, particularly among the elderly. Conclusions about the neuropsychological domains affected by opioids are limited due to the heterogeneity of studies and methodological issues.

Pain Intensity and Opioid Utilization in Response to CPAP Therapy in Veterans with Obstructive Sleep Apnea on Chronic Opioid Treatment

STUDY OBJECTIVES

Sleep fragmentation has been linked to poor pain tolerance and lowered pain threshold. Little evidence exists on whether continuous positive airway pressure (CPAP) adherence in veterans with obstructive sleep apnea (OSA) who are taking opioids for non-malignant pain would ameliorate pain and reduce consumption of opioids.

METHODS

A retrospective case-control study was performed at a VA sleep center. Pain intensity was assessed using the Numerical Categorical Scale prior to CPAP treatment and 12-mo follow-up. Opioids intake was assessed using the morphine equivalent daily dose (MEDD). Adherence to CPAP was evaluated with the built-in meter.

RESULTS

We reviewed 113 patients with OSA (apnea-hypopnea index [AHI] 35.9 ± 29.5) using a MEDD of 61.6 mg (range 5-980 mg) and a control group of 113 veterans with OSA (AHI 33.4 ± 27.3) on no opioids treatment. CPAP adherence was significantly lower at 12 mo in opioid-treated patients compared to controls (37% versus 55%; p = 0.01). Greater pain intensity was the only independent variable associated with CPAP non-adherence at 12-mo follow-up (p = 0.03). Compared to baseline, no significant difference was observed in pain intensity or consumption of opioids in CPAP adherent patients.

CONCLUSIONS

CPAP treatment did not reduce pain intensity or consumption of opioids in veterans with chronic pain who have coexisting OSA. CPAP adherence was lower in opioid-treated veterans with OSA compared to opioid-free veterans with OSA. Pain intensity was the only determinant of CPAP adherence. Future studies are needed to evaluate pain management program on adherence to CPAP.

Plasticity in respiratory motor neurons in response to reduced synaptic inputs: A form of homeostatic plasticity in respiratory control?

For most individuals, the respiratory control system produces a remarkably stable and coordinated motor output-recognizable as a breath-from birth until death. Very little is understood regarding the processes by which the respiratory control system maintains network stability in the presence of changing physiological demands and network properties that occur throughout life. An emerging principle of neuroscience is that neural activity is sensed and adjusted locally to assure that neurons continue to operate in an optimal range, yet to date, it is unknown whether such homeostatic plasticity is a feature of the neurons controlling breathing. Here, we review the evidence that local mechanisms sense and respond to perturbations in respiratory neural activity, with a focus on plasticity in respiratory motor neurons. We discuss whether these forms of plasticity represent homeostatic plasticity in respiratory control. We present new analyses demonstrating that reductions in synaptic inputs to phrenic motor neurons elicit a compensatory enhancement of phrenic inspiratory motor output, a form of plasticity termed inactivity-induced phrenic motor facilitation (iPMF), that is proportional to the magnitude of activity deprivation. Although the physiological role of iPMF is not understood, we hypothesize that it has an important role in protecting the drive to breathe during conditions of prolonged or intermittent reductions in respiratory neural activity, such as following spinal cord injury or during central sleep apnea.

Sleep abnormalities associated with alcohol, cannabis, cocaine, and opiate use: a comprehensive review

Sleep abnormalities are associated with acute and chronic use of addictive substances. Although sleep complaints associated with use and abstinence from addictive substances are widely recognized, familiarity with the underlying sleep abnormalities is often lacking, despite evidence that these sleep abnormalities may be recalcitrant and impede good outcomes. Substantial research has now characterized the abnormalities associated with acute and chronic use of alcohol, cannabis, cocaine, and opiates. This review summarizes this research and discusses the clinical implications of sleep abnormalities in the treatment of substance use disorders.

A prospective, longitudinal study of sleep disturbance and comorbidity in opiate dependence (the ANRS Methaville study)

RATIONALE/OBJECTIVES

Sleep disturbance is frequent in opioid-dependent patients. To date, no data are available about the impact of methadone maintenance treatment on sleep disturbance. Using 1-year follow-up data from the Methaville trial, we investigated the impact of methadone initiation and other correlates on sleep disturbance in opioid-dependent patients.

METHODS

Sleep disturbance severity was evaluated using two items from different scales (Center for Epidemiological Studies Depression Scale for depression and Opiate Treatment Index). We assessed the effect of methadone and other correlates on sleep disturbance severity during follow-up (months 0, 6, and 12) using a mixed multinomial logistic regression model.

RESULTS

We included 173 patients who had 1-year follow-up data on sleep disturbance, corresponding to 445 visits. At enrolment, 60.5 % reported medium to severe sleep disturbance. This proportion remained stable during methadone treatment: 54.0 % at month 6 and 55.4 % at month 12. The final multivariate model indicated that younger patients (odds ratio (OR) [95 % CI] 0.95 [0.90-1.00]), patients with pain (OR [95 % CI] 2.45 [1.13-5.32]), patients with high or very high nicotine dependence (OR [95 % CI] 5.89 [2.41-14.39]), and patients at suicidal risk (2.50 [1.13-5.52]) had a higher risk of severe sleep disturbance. Because of collinearity between suicidal risk and attention deficit hyperactivity disorder (ADHD) symptoms, ADHD was not associated with sleep disturbance in the final model. Receiving methadone treatment had no significant effect on sleep disturbance.

CONCLUSIONS

Sleep disturbance is frequent among opioid-dependent patients. It can be regarded as an important signal of more complex psychiatric comorbidities such as suicidal risk and ADHD. However, sleep disturbance should not be considered an obstacle to methadone maintenance treatment (MMT) initiation or continuation.

Sleep Disturbances in Patients With Advanced Cancer in Different Palliative Care Settings

CONTEXT

Information regarding sleep disturbances in the population with advanced cancer is meager.

OBJECTIVES

To assess the prevalence of sleep disturbances and possible correlations with associated factors in a large number of patients with advanced cancer admitted to different palliative care settings.

METHODS

This was an observational study performed in different settings of palliative care. A consecutive sample of patients with advanced cancer was prospectively assessed for a period of six months. Epidemiological and clinical data, treatments received in the last month, Karnofsky status, Edmonton Symptom Assessment System scores, and concomitant medical treatment were recorded. Patients were administered the Athens Insomnia Scale and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

A total of 820 patients were surveyed. Mean age was 69.7 years (SD 12.7), and 429 patients were males. Consistent sleep disturbances (moderate to maximum) were found in 60.8% of patients. Aged patients were less likely to have sleep disturbances, whereas a poor Karnofsky level was significantly associated with sleep problems. Breast, gastrointestinal, head and neck, lung, and prostate cancers were associated with sleep problems. Patients who had a secondary school or undergraduate education had less sleep disturbances. Hormone therapy and use of opioids and corticosteroids were positively associated with sleep disturbances, and there was a positive correlation of HADS-Anxiety and HADS-Depression scores with sleep disturbances.

CONCLUSION

More than 60% of palliative care patients have relevant sleep disturbances. Several factors associated with sleep disorders have been identified and should prompt physicians to make a careful examination and subsequent treatment of these disturbances.

Diagnostic approaches to respiratory sleep disorders

Sleep disordered breathing (SDB) comprises a number of breathing disturbances occurring during sleep including snoring, the obstructive sleep apnoea/hypopnea syndrome (OSAHS), central sleep apnoea (CSA) and hypoventilation syndromes. This review focuses on sleep disordered breathing and diagnostic approaches in adults, in particular clinical assessment and overnight assessment during sleep. Although diagnostic approaches to respiratory sleep disorders are reasonably straightforward, they do require a degree of clinical acumen when it comes to assessing severity and management options. Diagnosing respiratory sleep disorders on clinical features alone has limitations. Monitoring and measuring respiration during sleep has undergone many advances in the last 40 years in respect of quality and validity, largely regarding OSAHS. Despite the improvement in our diagnostic standards and recognition of sleep disordered breathing, many limitations still need to be overcome. Apart from assessing the individual patient, population screening for sleep disorders continues to preoccupy health professionals and policy makers in many countries. Research in the field is pushing current boundaries in terms of simplifying diagnosis and enhancing screening for sleep disordered breathing in large populations. At present, a number of these newer approaches require further validation.

Polysomnographic sleep disturbances in nicotine, caffeine, alcohol, cocaine, opioid, and cannabis use: A focused review

BACKGROUND AND OBJECTIVES

In the United States, approximately 60 million Americans suffer from sleep disorders and about 22 million Americans report substance dependence or use disorders annually. Sleep disturbances are common consequences of substance use disorders and are likely found in primary care as well as in specialty practices. The aim of this review was to evaluate the effects of the most frequently used substances-nicotine, alcohol, opioids, cocaine, caffeine, and cannabis-have on sleep parameters measured by polysomnography (PSG) and related clinical manifestations.

METHODS

We used electronic databases such as PubMED and PsycINFO to search for relevant articles. We only included studies that assessed sleep disturbances using polysomnography and reviewed the effects of these substances on six clinically relevant sleep parameters: Total sleep time, sleep onset latency, rapid-eye movement, REM latency, wake after sleep onset, and slow wave sleep.

RESULTS

Our review indicates that these substances have significant impact on sleep and that their effects differ during intoxication, withdrawal, and chronic use. Many of the substance-induced sleep disturbances overlap with those encountered in sleep disorders, medical, and psychiatric conditions. Sleep difficulties also increase the likelihood of substance use disorder relapse, further emphasizing the need for optimizing treatment interventions in these patients.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

Our review highlights the importance of systematically screening for substance use in patients with sleep disturbances and highlights the need for further research to understand mechanisms underlying substances-induced sleep disturbances and on effective interventions addressing these conditions.