A retrospective review of sleep-disordered breathing, hypertenstion and cardiovascular diseases in spinal cord injury patients

Intensive support does not improve positive-airway pressure use in spinal cord injury/disease: a randomized clinical trial

STUDY OBJECTIVE

Treatment of sleep-disordered breathing (SDB) with positive airway pressure (PAP) therapy has unique clinical challenges in individuals living with spinal cord injuries and diseases (spinal cord injury [SCI]/D). Interventions focused on increasing PAP use have not been studied in this population. We aimed to evaluate the benefits of a program to increase PAP use among Veterans with SCI/D and SDB.

METHODS

Randomized controlled trial comparing a behavioral Intervention (n = 32) and educational control (n = 31), both including one face-to-face and five telephone sessions over 3 months. The intervention included education about SDB and PAP, goal setting, troubleshooting, and motivational enhancement. The control arm included non-directive sleep education only.

RESULTS

Primary outcomes were objective PAP use (nights ≥4 hours used within 90 days) and sleep quality (Pittsburgh Sleep Quality Index [PSQI] at 3 months). These did not differ between intervention and control (main outcome timepoint; mean difference 3.5 [-9.0, 15.9] nights/week for PAP use; p = .578; -1.1 [-2.8, 0.6] points for PSQI; p = .219). Secondary outcomes included fatigue, depression, function, and quality of life. Only fatigue improved significantly more in the intervention versus the control group (p = .025). Across groups, more PAP use was associated with larger improvements in sleep quality, insomnia, sleepiness, fatigue, and depression at some time points.

CONCLUSIONS

PAP use in Veterans with SCI/D and SDB is low, and a 3-month supportive/behavioral program did not show significant benefit compared to education alone. Overall, more PAP use was associated with improved symptoms suggesting more intensive support, such as in-home assistance, may be required to increase PAP use in these patients.

CLINICAL TRIALS INFORMATION

Title: "Treatment of Sleep Disordered Breathing in Patients with SCI." Registration number: NCT02830074. Website: https://clinicaltrials.gov/study/NCT02830074?cond=Sleep%20Apnea&term=badr&rank=5.

Management of Sleep-Disordered Breathing in a Spinal Cord Injury Rehabilitation Center: Model of Care Adaptation and Implementation

Background

Obstructive sleep apnea (OSA) is highly prevalent and poorly managed in spinal cord injury (SCI). Alternative management models are urgently needed to improve access to care. We previously described the unique models of three SCI rehabilitation centers that independently manage uncomplicated OSA.

Objectives

The primary objective was to adapt and implement a similar rehabilitation-led model of managing OSA in an SCI rehabilitation center in Australia. Secondary objectives were to identify the local barriers to implementation and develop and deliver tailored interventions to address them.

Methods

A clinical advisory group comprised of rehabilitation clinicians, external respiratory clinicians, and researchers adapted and developed the care model. A theory-informed needs analysis was performed to identify local barriers to implementation. Tailored behavior change interventions were developed to address the barriers and prepare the center for implementation.

Results

Pathways for ambulatory assessments and treatments were developed, which included referral for specialist respiratory management of complicated cases. Roles were allocated to the team of rehabilitation doctors, physiotherapists, and nurses. The team initially lacked sufficient knowledge, skills, and confidence to deliver the OSA care model. To address this, comprehensive education and training were provided. Diagnostic and treatment equipment were acquired. The OSA care model was implemented in July 2022.

Conclusion

This is the first time a rehabilitation-led model of managing OSA has been implemented in an SCI rehabilitation center in Australia. We describe a theory-informed method of adapting the model of care, assessing the barriers, and delivering interventions to overcome them. Results of the mixed-methods evaluation will be reported separately.

The Clinical Relevance of Autonomic Dysfunction, Cerebral Hemodynamics, and Sleep Interactions in Individuals Living With SCI

A myriad of physiological impairments is seen in individuals after a spinal cord injury (SCI). These include altered autonomic function, cerebral hemodynamics, and sleep. These physiological systems are interconnected and likely insidiously interact leading to secondary complications. These impairments negatively influence quality of life. A comprehensive review of these systems, and their interplay, may improve clinical treatment and the rehabilitation plan of individuals living with SCI. Thus, these physiological measures should receive more clinical consideration. This special communication introduces the under investigated autonomic dysfunction, cerebral hemodynamics, and sleep disorders in people with SCI to stakeholders involved in SCI rehabilitation. We also discuss the linkage between autonomic dysfunction, cerebral hemodynamics, and sleep disorders and some secondary outcomes are discussed. Recent evidence is synthesized to make clinical recommendations on the assessment and potential management of important autonomic, cerebral hemodynamics, and sleep-related dysfunction in people with SCI. Finally, a few recommendations for clinicians and researchers are provided.

Prevalence of central sleep apnea in people with tetraplegic spinal cord injury: a retrospective analysis of research and clinical data

STUDY OBJECTIVES

Over 80% of people with tetraplegia have sleep-disordered breathing (SDB), but whether this is predominantly obstructive or central is unclear. This study aimed to estimate the prevalence of central sleep apnea (CSA) in tetraplegia and the contributions of central, obstructive, and hypopnea respiratory events to SDB summary indices in tetraplegia.

METHODS

Research and clinical data from 606 individuals with tetraplegia and full overnight polysomnography were collated. The proportions of different respiratory event types were calculated; overall and for mild, moderate, and severe disease. The prevalence of Predominant CSA (Central Apnea Index [CAI] ≥ 5 and more central than obstructive apneas) and Any CSA (CAI ≥ 5) was estimated. Prevalence of sleep-related hypoventilation (SRH) was estimated in a clinical sub-cohort.

RESULTS

Respiratory events were primarily hypopneas (71%), followed by obstructive (23%), central (4%), and mixed apneas (2%). As severity increased, the relative contribution of hypopneas and central apneas decreased, while that of obstructive apneas increased. The prevalence of Predominant CSA and Any CSA were 4.3% (26/606) and 8.4% (51/606) respectively. Being male, on opiates and having a high tetraplegic spinal cord injury were associated with CSA. SRH was identified in 26% (26/113) of the clinical sub-cohort.

CONCLUSIONS

This is the largest study to characterize SDB in tetraplegia. It provides strong evidence that obstructive sleep apnea is the predominant SDB type; 9-18 times more prevalent than CSA. The prevalence of CSA was estimated to be 4%-8%, significantly lower than previously reported.

The impact of sleep quality on health, participation and employment outcomes in people with spinal cord injury: Analyses from a large cross-sectional survey

BACKGROUND

Poor sleep is common in people with spinal cord injury (SCI), yet little is known about its impact on employment and participation outcomes.

OBJECTIVES

This study aimed to (1) describe the sleep quality of a large sample of Australians with SCI and compare the results to data from an adult control and other clinical populations; (2) examine associations between sleep quality and participant characteristics; and (3) explore the relationship between sleep and outcomes.

METHODS

Cross-sectional data from the Australian arm of the International Spinal Cord Injury (Aus-InSCI) survey from 1579 community-dwelling people aged >18 years with SCI were analysed. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). Relationships between participant characteristics, sleep quality and other outcomes were examined with linear and logistic regression.

RESULTS

The PSQI was completed by 1172 individuals; 68% reported poor sleep (global PSQI score >5). Subjective sleep quality in people with SCI was poor (mean PSQI = 8.5, SD 4.5) when compared to adults without SCI (PSQI = 5.00, SD 3.37) and with traumatic brain injury (PSQI = 5.54, SD 3.94). Financial hardship and problems with secondary health conditions were significantly associated with worse sleep quality (p < 0.05). Poor sleep quality was strongly associated with lower emotional wellbeing and energy, and greater problems with participation (p < 0.001). Individuals engaged in paid work reported better sleep quality (mean PSQI = 8.1, SD 4.3) than unemployed individuals (mean PSQI = 8.7, SD 4.6; p < 0.05). Following adjustment for age, pre-injury employment, injury severity and years of education, better sleep quality remained strongly associated with being employed (OR 0.95, 95% CI 0.92 to 0.98; p = 0.003).

CONCLUSIONS

This study demonstrated pervasive and impactful relationships between sleep quality and important SCI outcomes. Poor sleep quality was strongly associated with worse emotional wellbeing and vitality, unemployment and lower participation. Future studies should aim to determine whether treating sleep problems can improve outcomes for people living with SCI.

Management of sleep-disordered breathing in three spinal cord injury rehabilitation centres around the world: a mixed-methods study

STUDY DESIGN

Mixed-methods observational study.

OBJECTIVE

To describe the sleep-disordered breathing (SDB) management models of three spinal cord injury (SCI) rehabilitation centres that are screening, diagnosing and treating uncomplicated SDB, and to determine their common elements.

SETTING

Three specialist SCI rehabilitation centres.

METHODS

Data collection at each site included direct observations and interviews with lead clinical staff and an audit of SDB-related clinical practice in 2019. Detailed descriptions of the models of care, including process maps, were developed. A theory-based analysis of the common elements of the three care models was undertaken.

RESULTS

At each centre a multidisciplinary team, consisting of medical, allied health and/or nursing staff, provided a comprehensive SDB management service that included screening, diagnosis and treatment. Inpatients with SCI were assessed for SDB with overnight oximetry and/or polygraphy. Further assessment of patient symptoms, respiratory function, and hypercapnia supported the diagnostic process. Treatment with positive airway pressure was initiated on the ward. Having a collaborative, skilled team with strong leadership and adequate resources were the key, common enablers to providing the service.

CONCLUSION

It is feasible for multi-disciplinary SCI rehabilitation teams to independently diagnose and treat uncomplicated SDB without referral to specialist sleep services provided they are adequately resourced with equipment and skilled staff. Similar models of care could substantially improve access to SDB treatment for people with SCI. Further research is required to determine the non-inferiority of these alternatives to specialist care.

Is Sleep Disordered Breathing Confounding Rehabilitation Outcomes in Spinal Cord Injury Research?

The purpose of this article is to highlight the importance of considering sleep-disordered breathing (SDB) as a potential confounder to rehabilitation research interventions in spinal cord injury (SCI). SDB is highly prevalent in SCI, with increased prevalence in individuals with higher and more severe lesions, and the criterion standard treatment with continuous positive airway pressure remains problematic. Despite its high prevalence, SDB is often untested and untreated in individuals with SCI. In individuals without SCI, SDB is known to negatively affect physical function and many of the physiological systems that negatively affect physical rehabilitation in SCI. Thus, owing to the high prevalence, under testing, low treatment adherence, and known negative effect on the physical function, it is contended that underdiagnosed SDB in SCI may be confounding physical rehabilitation research studies in individuals with SCI. Studies investigating the effect of treating SDB and its effect on physical rehabilitation in SCI were unable to be located. Thus, studies investigating the likely integrated relationship among physical rehabilitation, SDB, and proper treatment of SDB in SCI are needed. Owing to rapid growth in both sleep medicine and physical rehabilitation intervention research in SCI, the authors contend it is the appropriate time to begin the conversations and collaborations between these fields. We discuss a general overview of SDB and physical training modalities, as well as how SDB could be affecting these studies.

Prevalence of sleep-disordered breathing in people with tetraplegia-a systematic review and meta-analysis

STUDY DESIGN

Systematic review with meta-analysis.

OBJECTIVES

To determine the prevalence of sleep-disordered breathing (SDB) in people with tetraplegia and to identify the characteristics associated with SDB.

METHODS

A systematic literature search using Medline, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) and grey literature sources was conducted using a combination of spinal cord injury (SCI) and SDB related terms. Articles were restricted to publication dates between 1/1/2000 and 4/9/2020 and with objectively measured SDB with an overnight sleep study. The frequency of SDB stratified by the apnoea hypopnea index (AHI) was extracted and weighted averages, using a random effects model, were calculated with 95% confidence intervals. Sub-group analyses were performed where possible.

RESULTS

Twelve articles were included in the review; of these nine were included in meta-analysis (combined sample = 630). Sample sizes and case detection methods varied. Reported SDB prevalence rates ranged from 46 to 97%. The prevalence of at least mild (AHI ≥ 5), moderate (AHI ≥ 15) and severe (AHI ≥ 30) SDB were 83% (95% CI = 73-91), 59% (46-71) and 36% (26-46), respectively. Sub-group analyses found that prevalence increased with age (p < 0.001). There were no statistically significant differences in SDB prevalence by sex (p = 0.06), complete/incomplete SCI (p = 0.06), body mass index (p = 0.07), acute/chronic SCI (p = 0.73) or high/low level of cervical SCI (p = 0.90).

CONCLUSION

Our results confirm that SDB is highly prevalent in people with tetraplegia, and prevalence increases with age. The high prevalence suggests that routine screening and subsequent treatment should be considered in both acute and community care.

Sleep Complaints and Sleep Quality in Spinal Cord Injury: A Web-Based Survey

STUDY OBJECTIVES

The purpose of this study was to determine sleep quality and presence of sleep disorders in participants with spinal cord injury (SCI).

METHODS

A web-based survey, available online from February 2011 to July 2013, using validated sleep questionnaires, advertised via the internet and locally through SCI consumer organizations in the United States, Australia, New Zealand, and Canada, was designed to evaluate sleep in adults with self-reported SCI. Demographic characteristics and medical history were obtained from participant self-report.

RESULTS

In our study population, 70% of the 304 participants were male with a mean age of 45 ± 13 years. The mean duration of injury was 16 ± 12 years. Cervical injuries were reported by 49% and thoracic injuries noted in 40% of participants. Increased sleep apnea risk was noted in 31% of participants, with 66% reporting snoring. Insomnia symptoms were reported by 54% of the respondents. Almost 40% of participants ranked their sleep quality as "fairly bad" to "very bad" in the previous month, 29% reported "often" or "almost always" waking up because of pain, and 22% had difficulty falling asleep because of leg cramps. In the past year, 27% of the respondents reported daily uncomfortable leg sensations and 28% found these leg symptoms to be "moderately to extremely distressing."

CONCLUSIONS

This study increases the awareness that insomnia, sleep apnea, and poor sleep quality are common in individuals with chronic SCI; often coexisting. There is a need for increased screening for sleep problems by healthcare providers taking care of individuals living with SCI.

Berberine protects myocardial cells against anoxia-reoxygenation injury via p38 MAPK-mediated NF-κB signaling pathways

Ischemic heart disease is a leading cause of mortality and occurs due to coronary arterial atherosclerosis, vascular cavity stenosis and occlusion. It has previously been demonstrated that berberine treatment may ameliorate and help to prevent cardiovascular diseases due to its anti-inflammatory and anti-apoptotic effects in myocardial cells. However, the potential signaling mechanisms mediated by berberine in the progression of myocardial injury remain to be elucidated. The aim of the present study was to investigate the therapeutic effects of berberine and its potential mechanism in a mouse model of myocardial cell injury. The results revealed that berberine treatment downregulated the serum expression of inflammatory factors, including interleukin (IL)-6, tumor necrosis factor-α, IL-10 and IL-17A in mice with anoxia-reoxygenation injury. Berberine treatment also decreased myocardial cell apoptosis following anoxia-reoxygenation injury via regulating the expression of apoptosis-associated genes. Histological analysis revealed that the area, circumference fragmentation and segmentation of myocardial cells were significantly decreased by berberine treatment compared with the control group. The body weight, blood lipid levels, blood pressure and heart rate were markedly improved in mice with anoxia-reoxygenation injury following berberine treatment compared with untreated mice. The expression of p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB expression was downregulated in myocardial cells from in mice with anoxia-reoxygenation injury following berberine treatment compared with untreated mice. However, p38 MAPK overexpression ameliorated the berberine-induced decrease in NF-κB activity and expression, as well as the berberine-induced inhibition of myocardial apoptosis in myocardial cells isolated from experimental mice. In conclusion, the results of the present study indicate that berberine is able to decrease the expression of inflammatory cytokines expression and inhibit myocardial cell apoptosis via downregulating the p38 MAPK-mediated NF-κB signaling pathway. These results suggest that berberine may be an effective treatment for anoxia-reoxygenation injury.

Sleep-Disordered Breathing and Spinal Cord Injury: A State-of-the-Art Review

Individuals living with spinal cord injury or disease (SCI/D) are at increased risk for sleep-disordered breathing (SDB), with a prevalence that is three- to fourfold higher than the general population. The main features of SDB, including intermittent hypoxemia and sleep fragmentation, have been linked to adverse cardiovascular outcomes including nocturnal hypertension in patients with SCI/D. The relationship between SDB and SCI/D may be multifactorial in nature given that level and completeness of injury can affect central control of respiration and upper airway collapsibility differently, promoting central and/or obstructive types of SDB. Despite the strong association between SDB and SCI/D, access to diagnosis and management remains limited. This review explores the role of SCI/D in the pathogenesis of SDB, poor sleep quality, the barriers in diagnosing and managing SDB in SCI/D, and the alternative approaches and future directions in the treatment of SDB, such as novel pharmacologic and nonpharmacologic treatments.

Relationship between autonomic cardiovascular control and obstructive sleep apnoea in persons with spinal cord injury: a retrospective study

Study design

Retrospective study.

Objective

To determine if there is an association between obstructive sleep apnoea (OSA) and blood pressure (BP) pattern or heart rate variability (HRV) in people with spinal cord injury (SCI).

Setting

A state-based spinal cord service in Victoria, Australia.

Methods

We identified 42 subjects who had ambulatory BP monitoring (ABPM) within 6 months of a diagnostic sleep study at Austin Hospital between 2009 and 2014. Markers for autonomic function, including circadian BP pattern and HRV were extracted from the ABPM study database. Apnoea/hypopnoea index (AHI), arousals/hour and oxygen desaturation index were extracted from the sleep study database. Subjects with a nocturnal systolic BP dipping more than 10% of daytime value were defined as dippers, between 10 and 0% were non-dippers and those with a higher night than day systolic BP were reverse dippers. Severity of OSA is classified as non-OSA (AHI < 5), mild (AHI 5-15), moderate (AHI 15-30) and severe (AHI > 30).

Results

Subjects (n = 42) were predominantly male (85.7%), aged 44 ± 15.4 (mean ± SD), with a BMI of 24.4 ± 5.7 (mean ± SD) and mainly tetraplegic (92.9%). There was no difference in AHI, oxygen desaturation index or arousals/hour between dippers, non-dippers and reverse dippers. None of the HRV parameters differed between dippers, non-dippers and reverse dippers. No differences were found in 24 h, night-time, daytime or nocturnal dip in BP between subjects with non-OSA, mild, moderate and severe OSA.

Conclusion

We found no relationship between BP pattern or HRV and the severity of OSA in persons with SCI.

Sleep Disordered Breathing and Spinal Cord Injury: Challenges and Opportunities

Purpose of review

This paper focuses on the sleep disorders in patients with spinal cord injury (SCI/D), particularly mechanism of sleep disordered breathing (SDB) and challenges in diagnosis and management. Based on a review of recent literatures and studies the paper summarizes some main challenges with respect to management of SDB in patients with SCI; and what are the responsible mechanisms of disease? What are the barriers in diagnosing and treating SDB using standard treatment such as positive airway pressure (CPAP)?.

Recent findings

Previous studies have shown that most SCI/D patients have SDB with heterogeneity in prevalence mainly related to using different definition or methods of diagnosing SDB, while recent studies using new definition of SDB based on recommended criteria from the American Academy of Sleep Medicine (AASM) and also include the data on effect of SCI/D level on prevalence and describe different type of SDB. Furthermore, recent data describes simplified method of diagnosing SDB by using a combination of home sleep apnea testing and transcutaneous CO2 monitoring. Finally, emerging data has been pointing at strong relationship between SDB and cardiovascular disease including nocturnal hypertension in patients with SCI/D.

Summary

The findings indicate that early testing for SDB and associated cardiovascular disease in patients with SCI is recommended and could be beneficial in reduced the high morbidity and mortality in this group of patients with disability. In addition, studies on treatment of other sleep disorders in SCI/D are not available to inform clinical decision making. Understanding the pathophysiology of sleep disorders in SCI/D is critical for the development of new effective therapies. This review provides evidence for best practices; highlights new discoveries for the diagnosis and management of sleep disorders in SCI/D, and discuss challenges and future directions.

Coronary artery disease presenting with left upper quadrant pain in a patient with chronic cervical tetraplegia

INTRODUCTION

This single-subject case report aims to describe and discuss a case of a patient with established C5 tetraplegia with acute coronary syndrome presenting with left upper quadrant pain and tenderness.

CASE PRESENTATION

A 65-year-old male with chronic C5 American Spinal Injury Association Impairment Scale (AIS) A tetraplegia presented to the emergency department with severe left upper quadrant pain radiating across the chest to the right upper limb with associated dyspnoea and diaphoresis. Prior to his emergency department admission, he had experienced progressive worsening of left upper quadrant pain and tenderness over several months. He was a non-smoker and swam regularly. He underwent coronary angiography and was found to have significant coronary artery disease. Drug-eluting stents were placed to critical coronary artery lesions followed by an uneventful hospital course with complete symptom resolution and discharge home.

DISCUSSION

Patients with tetraplegia are known to have higher rates of cardiovascular disease compared to ambulatory patients. Their cardiovascular risk profile may include atypical risk factors, for example, sleep disordered breathing, relative immobility and autonomic dysfunction. A high index of suspicion for cardiac pathology is warranted in those with cervical tetraplegia with persistent 'atypical' symptoms, including within the abdomen (especially when no specific abdominal organ dysfunction is evident). Sleep apnoea and significantly impaired mobility are potential cardiac risk factors in this patient group and should alert the emergency physician to cardiac disease (as in this case) irrespective of their complex past medical history and symptomatology.