Opioids, sleep architecture and sleep-disordered breathing

A Review of the Toxicologic Implications of Obesity

The increasing prevalence of obesity in developed nations has far-reaching implications for medical toxicology. The management of obese patients is complicated by comorbid illnesses, changes in cardiovascular and respiratory physiology, alterations in pharmacokinetics, and a lack of studies to identify appropriate dosing for current therapeutics and antidotes. In this review article, we examine obesity-associated physiologic and pharmacokinetic changes that may increase the vulnerability of obese patients to overdose. Further research is needed to characterize the relationship between drug toxicity and obesity.

Clinical Efficacy of Traditional Chinese Medicine, Suan Zao Ren Tang, for Sleep Disturbance during Methadone Maintenance: A Randomized, Double-Blind, Placebo-Controlled Trial

Methadone maintenance therapy is an effective treatment for opiate dependence, but more than three-quarters of persons receiving the treatment report sleep quality disturbances. In this double-blind, randomized, controlled trial, we recruited 90 individuals receiving methadone for at least one month who reported sleep disturbances and had Pittsburgh Sleep Quality Index (PSQI) scores > 5. The purpose of this study was to determine whether Suan Zao Ren Tang, one of the most commonly prescribed traditional Chinese medications for treatment of insomnia, improves subjective sleep among methadone-maintained persons with disturbed sleep quality. Ninety patients were randomly assigned to intervention group (n = 45) and placebo group (n = 45), and all participants were analyzed. Compared with placebo treatment, Suan Zao Ren Tang treatment for four weeks produced a statistically significant improvement in the mean total PSQI scores (P = 0.007) and average sleep efficiency (P = 0.017). All adverse events (e.g., lethargy, diarrhea, and dizziness) were mild in severity. Suan Zao Ren Tang is effective for improving sleep quality and sleep efficiency among methadone-maintained patients with sleep complaints.

Sleep and fatigue in pediatric oncology: A review of the literature

Cancer in children has detrimental effects on sleep patterns and sleep quality, which in turn impacts on the perception of, and the ability to cope with, the emotional and physical challenges associated with both the disease and its treatment. This places an added burden on their quality of life that can last many years beyond diagnosis and treatment. In addition to the effect of the cancer itself, surgery, chemotherapy and radiotherapy can all contribute both short and long term to sleep disruption. Sleep disorders have also been associated with pain, fatigue, medication and hospitalisation in children suffering from cancer. This review will explore the relationship between childhood cancer and associated sleep disorders, in the acute stage of diagnosis, during treatment and in the years following. We will discuss the possible causes and the current treatment modalities used to treat sleep disorders in children with cancer, and in childhood cancer survivors. It has been estimated that the recent advances in treatment have improved the overall five year survival rate for all childhood cancers to over 80%, with some cancers achieving a near 100% cure rate such as early stage Wilms' tumour. Thus, recognition and appropriate treatment of associated sleep disorders is essential to optimise long term quality of life.

Incorporating measures of sleep quality into cancer studies

INTRODUCTION/BACKGROUND

Sleep disturbance may influence the development of cancer and responses to treatment. It is also closely tied to recovery and quality of life in cancer patients, survivors, and caregivers, and recent studies have begun to show beneficial effects of sleep-promoting interventions. Despite the importance of sleep to cancer and its treatment and the availability of numerous tools for measuring sleep quality and quantity, sleep measurements are underutilized in cancer studies.

METHODS

This review, written for cancer researchers interested in incorporating sleep measures into their studies, is designed to raise awareness about the importance of sleep and suggests strategies for including sleep evaluation in cancer studies.

CONCLUSIONS

Inclusion of readily available sleep measures may ultimately improve cancer care by facilitating studies that lead to a greater understanding of how sleep and sleep disturbance influence all aspects of cancer care and the patient experience.

Sleep-disordered breathing and psychiatric disorders

Sleep-disordered breathing, the commonest form of which is obstructive sleep apnoea (OSA) is increasingly recognised as a treatable cause of morbidity. It shares many risk factors with psychiatric disorders including behaviours such as smoking and physical comorbidity. Many symptoms of the two overlap, leaving OSA often undetected and undertreated. In the few studies that assess the two, OSA is commonly comorbid with depression (17-45%) and schizophrenia (up to 55%) and possibly bipolar. There is some limited evidence that treating OSA can ameliorate psychiatric symptoms. Some psychotropics, such as narcotics, cause sleep-disordered breathing (SDB), whilst weight-inducing neuroleptics may exacerbate it. An extreme form of SDB, sudden infant death syndrome (SIDS), is a risk in mothers with substance abuse. Being aware of these common comorbidities may help improve psychiatric patient's treatment and quality of life.

Rethinking the role of opioids in the outpatient management of chronic nonmalignant pain

OBJECTIVE

Opioid analgesics are commonly and increasingly prescribed by physicians for the management of chronic pain. However, strong evidence supports the need for strategies that reduce opioid use. The objective of this review is to outline limitations associated with opioid use and discuss therapeutic techniques that can be adopted to optimize the use of opioids in the management of chronic nonmalignant pain.

SCOPE

Literature searches through MEDLINE and Cochrane databases were used to identify relevant journal articles. The search was limited to articles published from January 1980 to January 2014. Additional references were obtained from articles extracted during the database search. Relevant search terms included opioid, opioid abuse, chronic pain management, written care agreements, urine drug testing, and multimodal therapy.

FINDINGS

Opioids exhibit a well established abuse potential and evidence supporting the efficacy of opioids in chronic pain management is limited. In addition, opioid exposure is associated with adverse effects on multiple organ systems. Effective strategies designed to mitigate opioid abuse and diversion and optimize clinical outcomes should be employed.

CONCLUSIONS

Appropriate patient selection through identification of risk factors, urine drug testing, and access to prescription monitoring programs has been shown to effectively improve care. Structured opioid therapy in a multimodal platform, including use of a low initial dose, prescription of alternative non-opioid analgesics including non-steroidal anti-inflammatory drugs and acetaminophen, as well as development of written care agreements to individualize and guide therapy has also been shown to improve patient outcomes. Implementation of opioid allocation strategies has the potential to encourage appropriate opioid use and improve patient care.

Sleep disturbances and pain among individuals with prescription opioid dependence

BACKGROUND

Poor sleep quality has been observed in individuals with substance use disorders and is often a trigger for relapse. To date, little research has investigated sleep quality among individuals with prescription opioid (PO) dependence. The present study aimed to address this gap in the literature by examining subjective and objective sleep disturbances among PO dependent individuals.

METHODS

Subjects were 68 non-treatment seeking individuals (33 PO dependent, 35 healthy controls). Subjective sleep was assessed with the Pittsburgh Sleep Quality Index (PSQI) and Insomnia Severity Index (ISI). Subjects were admitted for an overnight inpatient hospital stay during which objective sleep data was collected using an actigraphy device. Self-report pain was measured with the Brief Pain Inventory.

RESULTS

Significant group differences in subjective sleep quality were revealed in the PSQI (p<0.01) and ISI (p<0.01). Poor sleep quality (i.e., PSQI total score>5) was identified in 80.6% of the PO group, as compared to 8.8% of the control group (p<.001). Significant group differences in sleep quality were identified in five of six actigraphy variables: total time asleep, sleep efficiency, latency of onset of sleep, total time awake and time mobile. Furthermore, significant associations between pain severity and sleep quality were observed.

CONCLUSIONS

Results indicate high rates of sleep impairment and poor sleep quality among PO dependent individuals. Pain severity was significantly correlated with sleep quality. Although preliminary, the findings highlight the importance of assessing and treating sleep disturbances, as well as pain, among patients with PO dependence.

Fighting insomnia and battling lethargy: the yin and yang of palliative care

There is an interdependent relationship between insomnia and fatigue in the medical literature, but both remain distinct entities. Insomnia entails problematic sleep initiation, maintenance, or restoration with an accompanying decrease in perceived daytime function. Lethargy is a symptom that has a wide differential diagnosis that heavily overlaps with cancer-related fatigue; however, insomnia may contribute to worsened fatigue and lethargy in cancer patients. Insomnia is a major risk factor for mood disturbances such as depression, which may also contribute to lethargy in this at-risk population. The pathophysiology of fatigue and insomnia is discussed in this review, including their differential diagnoses as well as the emerging understanding of the roles of neurotransmitters, branched-chain amino acids, and inflammatory cytokines. Treatment approaches for insomnia and fatigue are also discussed and reviewed, including the role of hypnotics, psychotropics, hormonal agents, and alternative therapies.

Adaptive servoventilation for treatment of opioid-associated central sleep apnea

RATIONALE

Opioids have become part of contemporary treatment in the management of chronic pain. Although severe daytime ventilatory depression is uncommon, chronic use of opioids could be associated with severe central and obstructive sleep apnea.

OBJECTIVES

To determine the acute efficacy, and prolonged use of adaptive servoventilation (ASV) to treat central sleep apnea in patients on chronic opioids.

METHODS

Twenty patients on opioid therapy referred for evaluation of obstructive sleep apnea (OSA) were found to have central sleep apnea (CSA). The first 16 patients underwent continuous positive airway pressure (CPAP) titration, which showed persistent CSA. With the notion that CSA will be eliminated with continued use of CPAP, 4 weeks later, 9 of the 16 patients underwent a second CPAP titration which proved equally ineffective. Therefore, therapy with CPAP was abandoned. All patients underwent ASV titration.

MAIN RESULTS

Diagnostic polysomnography showed an average apnea-hypopnea index (AHI) of 61/h and a central-apnea index (CAI) of 32/h. On CPAP 1, AHI was 34/h and CAI was 20/h. Respective indices on CPAP 2 were AHI 33/h and CAI 19/h. During titration with ASV, CAI was 0/h and the average HI was 11/h on final pressures. With a reduction in AHI, oxyhemoglobin saturation nadir increased from 83% to 90%, and arousal index decreased from 29/h of sleep to 12/h on final ASV pressures. Seventeen patients were followed for a minimum of 9 months and up to 6 years. The mean long-term adherence was 5.1 ± 2.5 hours.

CONCLUSIONS

Chronic use of opioids could be associated with severe CSA which remains resistant to CPAP therapy. ASV device is effective in the treatment of CSA and over the long run, most patients remain compliant with the device. Randomized long-term studies are necessary to determine if treatment of sleep apnea with ASV improves quality of life and the known mortality associated with opioids.

Interactions between disordered sleep, post-traumatic stress disorder, and substance use disorders

Disordered sleep is associated with a number of adverse health consequences and is an integral component of many psychiatric disorders. Rates of substance use disorders (SUDs) are markedly higher among individuals with post-traumatic stress disorder (PTSD), and this relationship may be partly mediated by disturbed sleep. Sleep disturbances (e.g. insomnia, daytime sleepiness, vivid nightmares) are hallmark features of PTSD and there is evidence that individuals with PTSD engage in substance use as a means of coping with these symptoms. However, prolonged substance use can lead to more severe sleep disturbances due to the development of tolerance and withdrawal. Behavioural or pharmacological treatment of disordered sleep is associated with improved daytime symptoms and psychosocial functioning among individuals who have developed PTSD. Initial research also suggests that improving sleep could be similarly beneficial in reducing coping oriented substance use and preventing relapse among those seeking treatment for SUDs. Together, these findings suggest that ameliorating sleep disturbance among at-risk individuals would be a viable target for the prevention and treatment of PTSD and associated SUDs, but prospective research is needed to examine this hypothesis. Enhanced understanding of the interrelation between sleep, PTSD, and SUDs may yield novel prevention and intervention approaches for these costly, prevalent and frequently co-occurring disorders.

Postoperative Changes in Sleep-disordered Breathing and Sleep Architecture in Patients with Obstructive Sleep Apnea

Background:

Anesthetics, analgesics, and surgery may profoundly affect sleep architecture and aggravate sleep-related breathing disturbances. The authors hypothesized that patients with preoperative polysomnographic evidence of obstructive sleep apnea (OSA) would experience greater changes in these parameters than patients without OSA.

Methods:

After obtaining approvals from the Institutional Review Boards, consented patients underwent portable polysomnography preoperatively and on postoperative nights (N) 1, 3, 5, and 7 at home or in hospital. The primary and secondary outcome measurements were polysomnographic parameters of sleep-disordered breathing and sleep architecture.

Results:

Of the 58 patients completed the study, 38 patients had OSA (apnea hypopnea index [AHI] &gt;5) with median preoperative AHI of 18 events per hour and 20 non-OSA patients had median preoperative AHI of 2. AHI was increased after surgery in both OSA and non-OSA patients (P &lt; 0.05), with peak increase on postoperative N3 (OSA vs. non-OSA, 29 [14, 57] vs. 8 [2, 18], median [25th, 75th percentile], P &lt; 0.05). Hypopnea index accounted for 72% of the postoperative increase in AHI. The central apnea index was low (median = 0) but was significantly increased on postoperative N1 in only non-OSA patients. Sleep efficiency, rapid eye movement sleep, and slow-wave sleep were decreased on N1 in both groups, with gradual recovery.

Conclusions:

Postoperatively, sleep architecture was disturbed and AHI was increased in both OSA and non-OSA patients. Although the disturbances in sleep architecture were greatest on postoperative N1, breathing disturbances during sleep were greatest on postoperative N3.

Obstructive Sleep Apnea and Surgery: Quality Improvement Imperatives and Opportunities

Obstructive sleep apnea (OSA) is more common in surgical candidates than in the general population and may increase susceptibility to perioperative complications that range from transient desaturation to catastrophic injuries. Understanding the potential impact of OSA on patients' surgical risk profile is of particular interest to otolaryngologists, who routinely perform airway procedures-including surgical procedures for treatment of OSA. Whereas the effects of OSA on long-term health outcomes are well documented, the relationship between OSA and surgical risk is not collinear, and clear consensus on the nature of the association is lacking. Better guidelines for optimization of pain control, perioperative monitoring, and surgical decision making are potential areas for quality improvement efforts. Many interventions have been suggested to mitigate the risk of adverse events in surgical patients with OSA, but wide variations in clinical practice remain. We review the current literature, emphasizing recent progress in understanding the complex pathophysiologic interactions noted in OSA patients undergoing surgery and outlining potential strategies to decrease perioperative risks.

Neural control of the upper airway: integrative physiological mechanisms and relevance for sleep disordered breathing

The various neural mechanisms affecting the control of the upper airway muscles are discussed in this review, with particular emphasis on structure-function relationships and integrative physiological motor-control processes. Particular foci of attention include the respiratory function of the upper airway muscles, and the various reflex mechanisms underlying their control, specifically the reflex responses to changes in airway pressure, reflexes from pulmonary receptors, chemoreceptor and baroreceptor reflexes, and postural effects on upper airway motor control. This article also addresses the determinants of upper airway collapsibility and the influence of neural drive to the upper airway muscles, and the influence of common drugs such as ethanol, sedative hypnotics, and opioids on upper airway motor control. In addition to an examination of these basic physiological mechanisms, consideration is given throughout this review as to how these mechanisms relate to integrative function in the intact normal upper airway in wakefulness and sleep, and how they may be involved in the pathogenesis of clinical problems such obstructive sleep apnea hypopnea.

Is cognitive behavioural therapy for insomnia effective in treating insomnia and pain in individuals with chronic non-malignant pain?

AIM

This paper systematically reviews clinical trials investigating the effectiveness of cognitive behavioural therapy for insomnia and pain in patients with chronic non-malignant pain.

METHOD

A systematic search of MEDLINE, PSYCINFO, EMBASE, CINHAL and Cochrane library and register of trials was conducted.

RESULTS

Essential components of cognitive behavioural therapy for insomnia were included in all studies except for the cognitive restructuring component, which was not considered an intervention in one study. Interventions were provided by adequately trained clinicians. Significant within-group effect sizes (> 1) were observed in the intervention groups as compared with the control groups. Improvements were noted in sleep latency, sleep efficiency and wake after sleep onset times. Although improvements were noted in pain experienced by the participants, this was not a significant finding.

CONCLUSIONS

These clinical trials demonstrate that cognitive behavioural therapy for insomnia is effective as an intervention for insomnia in individuals suffering from chronic non-malignant pain. Although pain and disturbed sleep are linked, cognitive behavioural therapy for insomnia alone may not be an effective solution for addressing chronic non-malignant pain. Trials of cognitive behavioural therapy for insomnia on a variety of chronic pain patients with disturbed sleep and with long-term follow-up are required to ascertain whether cognitive behavioural therapy for insomnia is an effective intervention to reduce pain and to add to increasing evidence that it is an effective intervention for insomnia in the chronic pain population.

Chronic opioid use in fibromyalgia syndrome: a clinical review

Chronic opioid therapy in the treatment of chronic nonmalignant pain has increased drastically over the past decade. This is a worrisome trend in general, but specifically, given pathophysiologic characteristics seen in fibromyalgia (FM) syndrome patients, the use of this class of medication deserves special scrutiny. We first describe the current understanding of the etiology and pathophysiology of FM, including the role of genetic and environmental factors in the development of this syndrome. We then discuss the biologic effects of opioid use. Next, we review the pharmaceutical treatment options for FM, including 3 Food and Drug Administration-approved medications, and the evolution of treatment guidelines since 2004. We then highlight the various consequences associated with the mechanism of action of opioids and the specific concerns for FM patients.Finally, summarizing the existing literature, we make the case that chronic opioid use is inappropriate in the treatment of FM because of the interaction of unique pathophysiologic characteristics of the patients and effects associated with chronic opioid use.

Delirium in the fast-track surgery setting

Postoperative delirium (PD) and postoperative cognitive dysfunction (POCD) are two separate syndromes of cognitive decline after major surgery, especially in the elderly. Pathogenesis is multifactorial with some common risk factors, and to reduce the risk, a multimodal approach is necessary. The fast-track methodology is becoming a well-established perioperative care regime with possible preventive effects for postoperative cognitive decline, including reduced pain and use of opioids, and early mobilisation with early discharge (≤3 days) to preoperative environment after total hip/knee arthroplasty (THA/TKA). The fast-track set-up seems to be associated with a lower frequency of PD and early POCD after THA/TKA. Thus, in a series of 225 patients ≥60 years, no cases of PD were seen and the incidence of POCD was reduced by more than 50% at 1 week postoperatively compared to previous studies. In conclusion, the fast-track methodology may reduce the incidence of postoperative cognitive decline after surgery.

Morphine has latent deleterious effects on the ventilatory responses to a hypoxic challenge

The aim of this study was to determine whether morphine depresses the ventilatory responses elicited by a hypoxic challenge (10% O₂, 90% N₂) in conscious rats at a time when the effects of morphine on arterial blood gas (ABG) chemistry, Alveolar-arterial (A-a) gradient and minute ventilation (V_M) had completely subsided. In vehicle-treated rats, each episode of hypoxia stimulated ventilatory function and the responses generally subsided during each normoxic period. Morphine (5 mg/kg, i.v.) induced an array of depressant effects on ABG chemistry, A-a gradient and V_M (via decreases in tidal volume). Despite resolution of these morphine-induced effects, the first episode of hypoxia elicited substantially smaller increases in V_M than in vehicle-treated rats, due mainly to smaller increases in frequency of breathing. The pattern of ventilatory responses during subsequent episodes of hypoxia and normoxia changed substantially in morphine-treated rats. It is evident that morphine has latent deleterious effects on ventilatory responses elicited by hypoxic challenge.

Morphine has latent deleterious effects on the ventilatory responses to a hypoxic-hypercapnic challenge

This study explored the concept that morphine has latent deleterious actions on the ventilatory control systems that respond to a hypoxic-hypercapnic challenge. In this study, we examined the ventilatory responses elicited by hypoxic-hypercapnic challenge in conscious rats at a time when the effects of morphine (10 mg/kg) on arterial blood-gas chemistry and minute ventilation had subsided. Morphine induced pronounced changes in arterial blood-gas chemistry (e.g., an increase in pCO₂, decreases in pO₂ and sO₂) and decreases in minute ventilation. Despite the complete resolution of the morphine-induced changes in arterial blood-gas chemistry and minute ventilation and almost complete resolution of the effects on peak inspiratory flow and peak expiratory flow, subsequent exposure to hypoxic-hypercapnic challenge elicited markedly blunted increases in minute ventilation and in peak inspiratory and expiratory flows. These findings demonstrate that (1) the changes in arterial blood-gas chemistry elicited by morphine parallel changes in minute ventilation rather than PIF and PEF, and (2) morphine has latent untoward effects on the ventilatory responses to hypoxic-hypercapnic challenge. These novel findings raise the possibility that patients deemed to have recovered from the acute ventilatory depressant effects of morphine may still be susceptible to the latent effects of this opioid analgesic. The mechanisms underlying these latent effects remain to be elucidated.

The development of fast-track principles in gynecological surgery

Fast-track is a multimodal strategy aimed at reducing the physiological burden of surgery to achieve an enhanced postoperative recovery. The strategy combines unimodal evidence-based interventions in the areas of preoperative preparation, anesthesia, surgical factors and postoperative care. The advantages of fast-track most likely extend to gynecology, although so far have scarcely been reported. This review summarizes current evidence concerning use of fast-track in general and in gynecological surgery. The main findings of this review are that there are benefits within elective gynecological surgery, but studies of quality of life, patient satisfaction and health economics in elective surgery are needed. Studies of fast-track within the field of non-elective gynecological surgery are lacking. Widespread education is needed to improve the rate of implementation of fast-track. Close involvement of the entire surgical team is imperative to ensure a structured perioperative care aiming for enhanced postoperative recovery.

Augmented breaths ('sighs') are suppressed by morphine in a dose-dependent fashion via naloxone-sensitive pathways in adult rats

Morphine treatment can eliminate augmented breaths (ABs; 'sighs') during spontaneous breathing. In the present study, unanesthetized rats were studied to: (1) determine the involvement of naloxone-sensitive receptor pathways, and (2) establish the dose-response relationship of this side effect. At a dosage of 5mg/kg (2-10mg/kg is recommended range for analgesia) morphine eliminated ABs from the breathing rhythm across nearly 100 min post-administration (vs. 6.2 ± 1.6 ABs in 15 min, control condition, p<0.001). This occurred despite no apparent effect on indices of ventilation. By contrast, when naloxone was co-administered with morphine, the occurrence of ABs was not different compared to control. The suppression of ABs by morphine followed a sigmoidal pattern across the low-mid dosage range (R(2)=0.83), whereas tidal volume and breathing frequency were unaffected. We conclude that the opioid-induced suppression of ABs is mediated by naloxone-sensitive opioid receptor pathways, and that this side effect is potent across the low-mid dosage range, and cannot be simply avoided by restricting dosage.

Obstructive sleep apnea and severe mental illness: evolution and consequences

Sleep complaints are commonly encountered in psychiatric clinics. Underlying medical disorders or sleep disorders need to be identified and treated to optimize treatment of the mental illness. Excessive daytime sleepiness, which is the main symptom of obstructive sleep apnea (OSA), overlaps with those of many severe mental illnesses. Medication side effects or the disorder itself maybe account for daytime sleepiness but comorbid OSA is a possibility that should not be overlooked. The diagnosis of OSA is straightforward but treatment compliance is problematic in psychiatric patients. This article summarizes studies concerning comorbid OSA in patients with severe mental illness and includes suggestions for future investigations.

Response inhibition and psychomotor speed during methadone maintenance: impact of treatment duration, dose, and sleep deprivation

BACKGROUND

In opiate-dependent individuals, abstinence results in deficits in cognitive functioning, which may be exacerbated by medication-associated sleep disruption.

METHOD

To assess cognitive function and the influence of sleep deprivation (SD), 14 healthy control (HC) and 22 methadone maintained (MM) participants completed the continuous performance task (CPT) after a baseline night, a night of total SD, and two recovery sleep nights. The digit symbol substitution task (DSST) was administered at bedtime and in the morning. Secondary analyses separated MM participants into short- (< 12 months; n=8) and long-term (≥ 12 months; n=14) treatment duration groups, and into low- (< 80 mg; n=9) and high-dose (≥ 80 mg; n=13) groups.

RESULTS

Linear mixed model ANOVAs revealed that there was no effect of SD. Across all days MM participants had more errors of omission, fewer correct responses, and slower reaction times (RTs) on the CPT, and fewer accurate substitutions on the evening and morning DSST. Short-term MM participants exhibited slower RTs on the CPT, and fewer correct substitutions on the evening DSST compared to long-term MM participants. Low-dose MM participants had slower RTs on the CPT than HCs and high-dose MM participants.

CONCLUSION

These data demonstrate that methadone-maintained individuals exhibit poorer performance on tasks of psychomotor speed and selective attention/impulsivity, but with longer-term treatment, performance appears to return toward control levels. Furthermore, while one day of SD was enough to alter subjective reports of sleep quality, cognitive function may be more resilient.

Medical and psychological risks and consequences of long-term opioid therapy in women

BACKGROUND

Long-term opioid use has increased substantially over the past decade for U.S. women. Women are more likely than men to have a chronic pain condition, to be treated with opioids, and may receive higher doses. Prescribing trends persist despite limited evidence to support the long-term benefit of this pain treatment approach.

PURPOSE

To review the medical and psychological risks and consequences of long-term opioid therapy in women.

METHOD

Scientific literature containing relevant keywords and content were reviewed.

RESULTS AND CONCLUSIONS

Long-term opioid use exposes women to unique risks, including endocrinopathy, reduced fertility, neonatal risks, as well as greater risk for polypharmacy, cardiac risks, poisoning and unintentional overdose, among other risks. Risks for women appear to vary by age and psychosocial factors may be bidirectionally related to opioid use. Gaps in understanding and priorities for future research are highlighted.

The impact of quality of sleep on recovery from fast-track abdominal hysterectomy

STUDY OBJECTIVES

To examine the impact of mode of anesthesia on perceived quality of sleep and to analyze the perceived quality of sleep in affecting recovery from surgery.

METHODS

A randomized, controlled, open multicenter trial was conducted in 5 hospitals in Southeast Sweden. One-hundred eighty women scheduled for fast-track abdominal hysterectomy for benign conditions were randomized to spinal anesthesia or general anesthesia; 162 women completed the trial; 82 allocated to spinal anesthesia and 80 to general anesthesia. Symptoms and perceived quality of sleep after surgery were registered daily in the Swedish Postoperative Symptoms Questionnaire.

RESULTS

Women in the general anesthesia group experienced bad quality of sleep the night after surgery significantly more often than the women who had spinal anesthesia (odds ratio [OR] 2.45; p = 0.03). This was almost exclusively attributed to a significantly higher consumption of opioids postoperatively in the general anesthesia group. Risk factors for bad quality of sleep during the first night postoperatively were: opioids (OR 1.07; p = 0.03); rescue antiemetics (OR 2.45; p = 0.05); relative weight gain (OR 1.47; p = 0.04); summary score of postoperative symptoms (OR 1.13; p = 0.02); and stress coping capacity (OR 0.98; p = 0.01). A longer hospital stay was strongly associated with a poorer quality of sleep the first night postoperatively (p = 0.002).

CONCLUSIONS

The quality of sleep the first night after abdominal hysterectomy is an important factor for recovery. In fast-track abdominal hysterectomy, it seems important to use anesthesia and multimodal analgesia reducing the need for opioids postoperatively and to use strategies that diminish other factors that may interfere negatively with sleep. Efforts to enhance quality of sleep postoperatively by means of preventive measures and treatment of sleep disturbances should be included in fast-track programs.

Sleep disturbances after fast-track hip and knee arthroplasty

BACKGROUND

Major surgery is followed by pronounced sleep disturbances after traditional perioperative care potentially leading to prolonged recovery. The aim was to evaluate the rapid eye movement (REM) sleep duration and sleep architecture before and after fast-track hip and knee replacement with length of stay (LOS) <3 days. The primary endpoint was REM sleep duration on the first postoperative night compared with before operation.

METHODS

Ten subjects (≥60 yr) receiving spinal anaesthesia and multimodal opioid-sparing postoperative analgesia for total hip or knee arthroplasty were included. Ambulatory polysomnography was performed one night before operation at home, continuously during hospitalization, and on the fourth postoperative night at home. Sleep staging was performed according to the American Academy of Sleep Medicine manual. Opioid use, pain, and inflammatory response (C-reactive protein) were also evaluated.

RESULTS

The mean LOS was 1.5 (1-2) days. The mean REM sleep time decreased from a mean of 18.2 (9.5-23.5)% of total sleep time to 1.2 (0-5.8)% on the first postoperative night (P=0.002); awake time increased from 19.1 (3.7-44.4)% to 44.3 (12.2-70.6)% (P=0.009); and sleep architecture on the first postoperative night was more disturbed than before operation. Sleep architecture normalized on the fourth postoperative night. There was no association between opioid use, pain scores, and inflammatory response with a disturbed sleep pattern.

CONCLUSIONS

Despite ultra-short LOS and provision of spinal anaesthesia with multimodal opioid-sparing analgesia, REM sleep was almost eliminated on the first postoperative night after fast-track orthopaedic surgery but returned to pre-admission levels when at home on the fourth postoperative night.

Genetic adaptation of the hypoxia-inducible factor pathway to oxygen pressure among eurasian human populations

Research into the mechanisms of human adaptation to the hypoxic environment of high altitude is of great interest to the fields of human physiology and clinical medicine. Recently, the gene EGLN1, from the hypoxia-inducible factor (HIF) pathway, was identified as being involved in the hypoxic adaptation of highland Andeans and Tibetans. Both highland Andeans and Tibetans have adapted to an extremely hypoxic habitat and less attention has been paid to populations living in normoxic conditions at sea level and mild-hypoxic environments of moderate altitude, thus, whether a common adaptive mechanism exists in response to quantitative variations of environmental oxygen pressure over a wide range of residing altitudes is unknown. Here, we first performed a genome-wide association study of 35 populations from the Human Genome Diversity-CEPH Panel who dwell at sea level to moderate altitude in Eurasia (N = 691; 0-2,500 m) to identify the genetic adaptation profile of normoxic and mild-hypoxic inhabitants. In addition, we systematically compared the results from the present study to six previously published genome-wide scans of highland Andeans and Tibetans to identify shared adaptive signals in response to quantitative variations of oxygen pressure. For normoxic and mild-hypoxic populations, the strongest adaptive signal came from the mu opioid receptor-encoding gene (OPRM1, 2.54 × 10(-9)), which has been implicated in the stimulation of respiration, while in the systematic survey the EGLN1-DISC1 locus was identified in all studies. A replication study performed with highland Tibetans (N = 733) and sea level Han Chinese (N = 748) confirmed the association between altitude and SNP allele frequencies in OPRM1 (in Tibetans only, P < 0.01) and in EGLN1-DISC1 (in Tibetans and Han Chinese, P < 0.01). Taken together, identification of the OPRM1 gene suggests that cardiopulmonary adaptation mechanisms are important and should be a focus in future studies of hypoxia adaptation. Furthermore, the identification of the EGLN1 gene from the HIF pathway suggests a common adaptive mechanism for Eurasian human populations residing at different altitudes with different oxygen pressures.

Sleep deprivation in critical illness: its role in physical and psychological recovery

Critically ill patients frequently experience poor sleep, characterized by frequent disruptions, loss of circadian rhythms, and a paucity of time spent in restorative sleep stages. Factors that are associated with sleep disruption in the intensive care unit (ICU) include patient-ventilator dysynchrony, medications, patient care interactions, and environmental noise and light. As the field of critical care increasingly focuses on patients' physical and psychological outcomes following critical illness, understanding the potential contribution of ICU-related sleep disruption on patient recovery is an important area of investigation. This review article summarizes the literature regarding sleep architecture and measurement in the critically ill, causes of ICU sleep fragmentation, and potential implications of ICU-related sleep disruption on patients' recovery from critical illness. With this background information, strategies to optimize sleep in the ICU are also discussed.

Trazodone for sleep disturbance during methadone maintenance: a double-blind, placebo-controlled trial

BACKGROUND

To test whether trazodone, one of the most commonly prescribed medications for treatment of insomnia, improves subjective and/or objective sleep among methadone-maintained persons with sleep complaints, we performed a randomized, double-blind, placebo-controlled trial with 6-month follow-up.

METHODS

From eight methadone maintenance programs in the northeastern United States, we recruited 137 persons receiving methadone for at least 1 month who reported a Pittsburgh Sleep Quality Index (PSQI) score of six or higher. Two-night home polysomnography (PSG) was completed at baseline and 1 month later, with morning surveys and urine drug toxicologies. Interviews assessed sleep over the past 30 days at baseline and 1-, 3-, and 6-month follow-ups.

RESULTS

Participants averaged 38 years of age, were 47% male, and had a mean PSQI total score of 12.9 (±3.1). At baseline, intervention groups did not significantly differ on 10 PSG-derived objective sleep measures and 11 self-reported measures. Over 88% (n=121) of participants completed the PSG at 1-month. Without adjusting p-values for multiple comparisons, only 1 of 21 sleep measure comparisons was statistically significant (p<.05). The effect of trazodone on mean PSQI scores during the 6-month follow-up was not statistically significant (p=.10). Trazodone neither significantly increased nor decreased illicit drug use relative to placebo.

CONCLUSIONS

Trazodone did not improve subjective or objective sleep in methadone-maintained persons with sleep disturbance. Other pharmacologic and non-pharmacologic treatments should be investigated for this population with high rates of insomnia.

[Outpatient anesthesia for patients with obstructive sleep apnea: results of a national survey]

BACKGROUND

In Germany there is currently no national standard for the management of patients with obstructive sleep apnea syndrome (OSAS). The object of this survey was to obtain information on the treatment concept for patients with OSAS and to report on the current practice in Germany.

METHODS

Data collection was obtained through an online questionnaire. A total of 12,113 members of the supporting anesthesia societies from all over Germany were invited to participate via e-mail. Additionally an announcement was made in a professional journal.

RESULTS

A total of 1,671 questionnaires were analyzed. The average age of the respondents was 45 years, 64% were male and 36% were female. The average work experience was 16 years and 85% of the respondents were consultants. In total 85% of anesthesiologists were predominantly working in inpatient care and 12% were predominantly active in outpatient care. Of the respondents 63% preferred regional anesthesia, 20% preferred general anesthesia for patients with OSAS and 17% did not have a preference for a specific anesthesia procedure. Outpatient surgery for patients with OSAS was performed by 72% of the respondents using regional anesthesia and by 55% of the respondents using local anesthesia with sedation. Of the anesthesiologists 49% consented to outpatient surgery using general anesthesia and 14% to interventions involving the airways. Compared to anesthesiologists working predominantly in inpatient departments, those working predominantly in outpatient departments treated patients with OSAS more frequently on an outpatient basis, used general anesthesia significantly more often, discharged those patients significantly earlier and observed less complications.

CONCLUSIONS

This survey shows that outpatient surgery for patients with sleep apnea is common practice in Germany. It is also performed when patients have moderate or severe OSAS and for respiratory tract surgery. This means that the management is not conform to the guidelines of the American Society of Anesthesiologists (ASA).

No change of sleep after 6 and 12 months of methadone maintenance treatment

OBJECTIVE

To determine whether the methadone maintenance treatment (MMT) affects sleep.

METHODS

We prospectively followed up the sleep pattern of 23 opiate addicts when admitted to MMT and after 6 and 12 months of treatment. Pittsburgh Sleep Quality Index, pain self-report questionnaires, urine for drug abuse, and one-night sleep polysomnography were assessed.

RESULTS

The baseline sleep indices (sleep time [5.5 ± 1.1 hours], sleep efficiency [80.6% ± 10.5%], rapid eye movement [REM] stage percent of sleep [14.3% ± 8.4%], percent of non-REM stage 3-4 [6.7% ± 8.6%], and Pittsburgh Sleep Quality Index Scores [11.4 ± 4.8]) did not change at 6 and 12 months. Proportion of patients with absent non-REM stage 3-4 reduced (47.8%, 34.8%, 13%, P = 0.03), and mean REM density increased (P = 0.04). Body mass index increased (24 ± 4.2 kg/m, 25.7 ± 4 kg/m, 27.1 ± 4.8 kg/m, P < 0.0005) with no change in the rate of benzodiazepine abuse or chronic pain. No patient had central sleep apnea. The Respiratory Disturbance Index (apnea or hypopnea numbers/sleep hr) increased among 5 patients who increased ≥25% of their entry weight (3.4 ± 4.1, 11.8 ± 10.1, 29.6 ± 30.4 Respiratory Disturbance Index's) but not with the other 18 (3.9 ± 4.8, 6.2 ± 6.2, 7.8 ± 7.4).

CONCLUSIONS

We conclude that MMT did not negatively affect the opiate addicts' baseline poor perceived and objective sleep. Only extensive weight gain (evident in a minority of patients) was associated with obstructive sleep apnea.

Sleep among opioid users

Use of opioids in the treatment of both acute and chronic pain has increased significantly in the past 2 decades. Recent literature suggests that chronic opioid use is related to sleep-related breathing disorders, particularly central sleep apnea of both the periodic and nonperiodic breathing pattern. The clinical significance, pathogenesis, and treatment options of these sleep-related breathing disorders are not well understood. This article summarizes the current literature on the effects of both acute and chronic opioid use on sleep, sleep-disordered breathing, and the current evidence on various treatment options for breathing disorders related to chronic opioid use.

Opioids, Ventilation and Acute Pain Management

Despite the increasing use of a variety of different analgesic strategies, opioids continue as the mainstay for management of moderate to severe acute pain. However, concerns remain about their potential adverse effects on ventilation. The most commonly used term, respiratory depression, only describes part of that risk. Opioid-induced ventilatory impairment (OIVI) is a more complete term encompassing opioid-induced central respiratory depression (decreased respiratory drive), decreased level of consciousness (sedation) and upper airway obstruction, all of which, alone or in combination, may result in decreased alveolar ventilation and increased arterial carbon dioxide levels.

Concerns about OIVI are warranted, as deaths related to opioid administration in the acute pain setting continue to be reported. Risks are often said to be higher in patients with obstructive sleep apnoea. However, the tendency to use the term ‘obstructive sleep apnoea’ to encompass the much broader spectrum of sleep- and obesity-related hypoventilation syndromes and the related misuse of terminology in papers relating to obstructive sleep apnoea and sleep-disordered breathing remain significant problems in discussions of opioid-related effects.

Opioids given for management of acute pain must be titrated to effect for each patient. However, strategies aiming for better pain scores alone, without highlighting the need for appropriate monitoring of OIVI, can and will lead to an increase in adverse events. Therefore, all patients must be monitored appropriately for OIVI (at the very least using sedation scores as a ‘6th vital sign’) so that it can be detected at an early stage and appropriate interventions triggered.

Sleep problems in children and adolescents with common medical conditions

Untreated sleep disturbances and sleep disorders pose significant adverse daytime consequences and place children at considerable risk for poor health outcomes. Sleep disturbances occur at a greater frequency in children with acute and chronic medical conditions compared with otherwise healthy peers. Sleep disturbances in medically ill children can be associated with sleep disorders, comorbid with acute and chronic conditions, or secondary to underlying disease-related mechanisms, treatment regimens, or hospitalization. Clinical management should include a multidisciplinary approach with particular emphasis on routine, regular sleep assessments and prevention of daytime consequences, and promotion of healthy sleep habits and health outcomes.

Electroacupuncture treatment normalized sleep disturbance in morphine withdrawal rats

Sleep disturbance is considered as an important symptom of acute and protracted opiate withdrawal. Current results suggest that sleep disturbance may be taken as a predictor of relapse. Appropriate sleep enhancement therapy will be in favor of the retention in treatment for opiate addicts. Our previous studies have shown that electroacupuncture (EA) is effective in suppressing morphine withdrawal syndrome. The aim of the present study is to investigate the effect of 2 and 100 Hz EA on the sleep disturbance during morphine withdrawal. Rats were made dependent on morphine by repeated morphine injections (escalating doses of 5-80 mg kg(-1), subcutaneously, twice a day) for 5 days. EA of 2 or 100 Hz was given twice a day for 3 days, starting at 48 h after the last morphine injection. Electroencephalogram and electromyogram were monitored at the end of the first and the last EA treatments, respectively. Results showed that non-rapid eye movement (NREM) sleep, REM sleep and total sleep time decreased dramatically, while the sleep latency prolonged significantly during acute morphine withdrawal. Both 2 and 100 Hz EA produced a significant increase in NREM sleep, REM sleep and total sleep time. It was suggested that EA could be a potential treatment for sleep disturbance during morphine withdrawal.

[Cannabis withdrawal syndrome in patients with cannabis dependence only, and in patients with cannabis and opioid dependence]

BACKGROUND

The cannabis withdrawal syndrome occurs after cannabis cessation in more than 50% of dependent smokers. But although opioid-dependent patients are more frequently cannabis users and cannabis-dependent than the general population, the frequency and phenomenology of cannabis withdrawal symptoms in this specific population is unknown. Our hypothesis was that cannabis-dependent patients with current opioid dependence would experience the same withdrawal syndrome after cannabis cessation.

OBJECTIVE

To describe cannabis withdrawal symptoms in cannabis-only dependent patients and in cannabis-dependent patients with current opioid dependence.

METHODS

Using retrospective interviews, we evaluated the number and duration of six cannabis withdrawal symptoms in two groups: 56 cannabis-dependent patients without and 43 cannabis dependent patients with current opioid dependence. Cannabis and opioid dependence diagnoses were defined with DSM IV criteria using the MINI structured interview.

RESULTS

The two groups were not different in terms of age of onset of cannabis use, and number of cannabis joints smoked at the time of the cannabis cessation attempt. The frequency of a cannabis withdrawal syndrome (defined as at least two different symptoms) did not differ in the two groups (65%). Neither was the proportion of subjects with the following symptoms: appetite or weight loss (30.8%), irritability (45.1%), anxiety (56%), aggression (36.3%) and restlessness (45.1%). Patients with cannabis dependence and current opioid dependence were more likely to report sleep disturbances (79.1 vs. 53.6%, chi(2)=6.91, P=0.007). The median duration of this cannabis withdrawal syndrome was 20 days post-cessation.

CONCLUSION

This is, to our knowledge, the first study describing cannabis withdrawal syndrome in cannabis-dependent patients with current opioid dependence. These patients experience a cannabis withdrawal syndrome as often as cannabis-only dependent subjects, but describe more frequently sleep disturbances. This high rate of sleep disturbances may cause relapse to cannabis use.