High-Resolution Pulse Oximetry (HRPO): A Cost-Effective Tool in Screening for Obstructive Sleep Apnea (OSA) in Acute Stroke and Predicting Outcome

Prevalence, incidence, and the time trends of sleep-disordered breathing among patients with stroke: a systematic review and meta-analysis

BACKGROUND

Recent studies have investigated the epidemiological burden of sleep-disordered breathing (SDB) in patients with stroke; however, the results have been inconsistent, and the temporal trends of SDB after stroke remain unclear.

OBJECTIVE

To perform a systematic review and meta-analysis of the prevalence and incidence of post-stroke SDB, evaluate demographic and clinical characteristic predictors of post-stroke SDB, and examine temporal trends in the overall burden of post-stroke SDB.

METHODS

We searched PubMed, MEDLINE, Embase, Web of Science, CINAHL, and the Cochrane Library for studies reporting the burden of SDB in stroke patients published between 1 January 2010 and 30 December 2023. Two researchers independently screened the records for eligibility, extracted the data, and assessed the quality of the studies. Data were analyzed using random effects meta-analyses, and sources of heterogeneity were explored using subgroup analyses and meta-regression analyses.

RESULTS

Out of the 8,799 references retrieved, none examined the incidence of SDB after stroke. However, 85 studies from 26 countries examined the prevalence of SDB and were included. The overall prevalence of SDB, mild SDB, and moderate to severe SDB were 60.0% (95% CI, 60.0-70.0%), 30.0% (95% CI, 23.0-37.0%), and 45.0% (95% CI, 33.0-57.0%), respectively. Meta-regression revealed that sex (p < 0.0001) and sample size (p < 0.01) were sources of heterogeneity among the studies. The pooled overall prevalence of SDB remained stable over time.

CONCLUSION

SDB is common in patients with stroke, and no reduction in the high prevalence of SDB has been observed over time, suggesting that early screening and prevention of post-stroke SDB still have not received sufficient attention. Moreover, additional studies investigating the incidence of this disease are needed to inform clinical practice.

Early screening of sleep disordered breathing in hospitalized stroke patients high-resolution pulse oximetry as prognostic and early intervention tools in patients with acute stroke and sleep apnea (HOPES TRIAL)

INTRODUCTION

Sleep Disordered Breathing (SDB) has been shown to increase the risk of stroke and despite recommendations, routine evaluation for SDB in acute stroke is not consistent across institutions. The necessary logistics and expertise required to conduct sleep studies in hospitalized patients remain a significant barrier. This study aims to evaluate the feasibility of high-resolution pulse-oximetry (HRPO) for the screening of SDB in acute stroke. Secondarily, considering impact of SDB on acute stroke, we investigated whether SDB at acute stroke predicts functional outcome at discharge and at 3 months post-stroke.

METHODS

Patients with acute mild to moderate ischemic stroke underwent an overnight HRPO within 48 h of admission. Patients were divided into SDB and no-SDB groups based on oxygen desaturations index(ODI > 10/h). Stepwise multivariate logistic regression analysis was applied to identify the relevant predictors of functional outcome (favorable [mRS 1-2 points] versus unfavorable [mrS > = 3 points]).

RESULTS

Of the 142 consecutively screened patients, 96 were included in the analysis. Of these, 33/96 (34%) were identified as having SDB and were more likely to have unfavorable mRS scores as compared to those without SDB (odds ratio = 2.70, p-value = 0.032).

CONCLUSION

HRPO may be a low-cost and easily administered screening method to detect SDB among patients hospitalized for acute ischemic stroke. Patients with SDB (as defined by ODI) have a higher burden of neurological deficits as compared to those without SDB during hospitalization.

Obstructive Sleep Apnea and Stroke: Determining the Mechanisms Behind their Association and Treatment Options

Sleep-disordered breathing (SDB) can be a sequela of stroke caused by vascular injury to vital respiratory centers, cerebral edema, and increased intracranial pressure of space-occupying lesions. Likewise, obstructive sleep apnea (OSA) contributes to increased stroke risk through local mechanisms such as impaired ischemic cerebrovascular response and systemic effects such as promoting atherosclerosis, hypercoagulability, cardiac arrhythmias, vascular-endothelial dysfunction, and metabolic syndrome. The impact of OSA on stroke outcomes has been established, yet it receives less attention in national guidelines on stroke management than hyperglycemia and blood pressure dysregulation. Furthermore, whether untreated OSA worsens stroke outcomes is not well-described in the literature. This scoping review provides an updated investigation of the correlation between OSA and stroke, including inter-relational pathophysiology. This review also highlights the importance of OSA treatment and its role in stroke outcomes. Knowledge of pathophysiology, the inter-relationship between these common disorders, and the impact of OSA therapy on outcomes affect the clinical management of patients with acute ischemic stroke. In addition, understanding the relationship between stroke outcomes and pre-existing OSA will allow clinicians to predict outcomes while treating acute stroke.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Waist-To-Hip Ratio Predicts Abnormal Overnight Oximetry in Men Independent of Body Mass Index

Background: Ambulatory overnight oximetry (OXI) has emerged as a cost-effective initial test for sleep disordered breathing. Obesity is closely associated with obstructive sleep apnea (OSA); however, whether body mass index (BMI) or waist-to-hip ratio (WHR) predicts abnormal overnight OXI remains unknown. Methods: We performed a retrospective cross-sectional study of 393 men seen in the Executive Health Program at Mayo Clinic in Rochester, Minnesota who underwent ambulatory overnight OXI ordered by preventive medicine physicians between January 1, 2004 through December 31, 2010. We compared participant/spouse-reported symptoms (sleepiness, snoring), physician indications for OXI (obesity, fatigue), Epworth Sleepiness Scale scores, anthropomorphic measurements (WHR, BMI), and comorbid medical conditions (hypertension, diabetes) with OXI results. Results: 295 of the 393 men who completed OXI had abnormal results. During multivariate analysis, the strongest independent predictor of abnormal OXI for men was WHR (≥1.0, OR = 5.59) followed by BMI (≥30.0 kg/m2, OR = 2.75), age (≥55 yrs, OR = 2.06), and the presence of snoring (OR = 1.91, P < 0.05 for all). A strong association was observed between WHR and abnormal OXI in obese (BMI ≥ 30.0 kg/m2, OR = 6.28) and non-obese (BMI < 29.9 kg/m2, OR = 6.42, P < 0.01 for both) men. Furthermore, 88 men with abnormal OXI underwent polysomnography with 91% being subsequently diagnosed with OSA. Conclusions: In ambulatory, predominantly middle-aged men undergoing preventive services evaluation many physician indications for OXI were not predictors of abnormal results; however, WHR strongly predicted abnormal OXI in obese and non-obese men. As such, we suggest middle-aged men who snore and have a WHR ≥1.0 should be directly referred to a sleep clinic for polysomnography.

Hospital screening for obstructive sleep apnea in patients admitted to a rural, tertiary care academic hospital with heart failure

BACKGROUND

Rural communities represent a vulnerable population that would significantly benefit from hospital-based OSA screening given these areas tend to have significant health-care disparities and poor health outcomes. Although inpatient screening has been studied at urban hospitals, no study to date has assessed this approach in rural populations.

METHODS

This study utilized the Electronic Medical Record (EMR) to generate a list of potential candidates by employing inclusion/exclusion criteria as screening. Subjects identified were then approached and offered information regarding the study. Screening for OSA entailed a tiered approach utilizing the sleep apnea clinical score (SAC) and portable sleep testing. Individuals identified as high risk (SAC ≥ 15) for OSA underwent evaluation with a portable sleep testing system while hospitalized. All participants with an apnea-hypopnea index (AHI) ≥5 events/h confirmed by a sleep medicine physician were considered screen positive for OSA. If approved/available, subjects screening positive for OSA were provided with an auto-titrating continuous positive airway pressure (PAP). Patient characteristics were analyzed using descriptive statistics. Categorical data were described using contingency tables, including counts and percentages. Continuously scaled measures were summarized by median with range. This study was registered with ClinicalTrials.gov. Identifier: NCT03056443.

RESULTS

Nine hundred and fifty-eight potential subjects were identified. The three most common reasons for exclusion included previous OSA diagnosis or exposure to PAP therapy (n = 357), advanced illness (n = 380), and declined participation by the individual (n = 68). The remaining 31 subjects underwent further evaluation for obstructive sleep apnea. Twenty-three subjects had a high sleep apnea clinic score. Per our study protocol, 13 subjects who screened positive for OSA were initiated on APAP therapy. Conclusion: Our study provides important insight into the burden of sleep-disordered breathing (SDB) and unique challenges of hospital-based OSA screening/treatment in a rural setting. Our study identified barriers to successful screening in a rural population that may be well addressed by adapting previous research in hospital sleep medicine.

Association Between Risk of Obstructive Sleep Apnea and Cerebrovascular Reactivity in Stroke Patients

Background Obstructive sleep apnea (OSA) is present in 60% to 70% of stroke patients. Cerebral vasoreactivity in patients with stroke and OSA has not been well studied and could identify a new pathophysiologic mechanism with potential therapeutic intervention. We aimed to determine whether risk categories for OSA are associated with cerebral vasoreactivity in stroke patients. Methods and Results In this cross-sectional study of a cohort of patients with stroke, we used clinical questionnaires (Sleep Obstructive Apnea Score Optimized for Stroke [SOS] and snoring, tiredness, observed, pressure, bmi, age, neck, gender [STOP-BANG] scores) to assess the risk of OSA and transcranial Doppler to assess cerebral vasoreactivity (breath-holding index and visual evoked flow velocity response). Of the 99 patients included, 77 (78%) had medium or high risk of OSA and 80 performed transcranial Doppler. Mean breath-holding index was 0.52±0.37, and median visual evoked flow velocity response was 10.8% (interquartile range: 8.8-14.5); 54 of 78 (69%) showed impaired anterior circulation vasoreactivity (breath-holding index <0.69) and 53 of 71 (75%) showed impaired posterior circulation vasoreactivity (visual evoked flow velocity response ≤14.0%). There was a significant negative correlation between the risk of OSA calculated by STOP-BANG and the breath-holding index (r_S=-0.284, P=0.012). The following variables were associated with low anterior circulation vasoreactivity: dyslipidemia (odds ratio: 4.7; 95% CI, 1.5-14.2) and STOP-BANG score (odds ratio: 1.7 per 1-point increase; 95% CI, 1.1-1.5). Conclusions A high risk of OSA and impaired vasoreactivity exists in the population that has had stroke. Dyslipidemia and STOP-BANG sleep apnea risk categories were independently associated with impaired anterior circulation vasoreactivity.

Sleep and Stroke: New Updates on Epidemiology, Pathophysiology, Assessment, and Treatment

PURPOSE OF REVIEW

This review aims to discuss the most recent data on sleep disorders and stroke, highlighting relevant findings for the practicing neurologist or health providers who encounter patients with sleep disorders and stroke.

RECENT FINDINGS

Sleep apnea and abnormal sleep duration have the strongest association with stroke risk. Possible mechanisms include non-dipping of blood pressure during sleep, hypoxemia or reoxygenation leading to sympathetic activation, hypertension, atrial fibrillation and impaired cerebral hemodynamics. Treatment studies suggest that continuous positive airway pressure (CPAP) for sleep apnea could improve primary prevention of stroke, but data is equivocal for secondary prevention. However, CPAP could improve functional outcomes after stroke.

SUMMARY

Sleep disorders present an opportunity to improve stroke risk and functional outcomes. However, new strategies are needed to determine the patients at high-risk who would most likely benefit from targeted care. Novel methods for phenotyping sleep disorders could provide personalized stroke care to improve clinical outcomes and public health strategies.