scholarly journals The Oxygen Desaturation Measured by Optical Sensor at Fingertip but Not at the Arm Is Diminished by Continuous Positive Airway Pressure in Obstructive Sleep Apnea

Author(s):  
Zhongxing Zhang ◽  
Ming Qi ◽  
Gordana Hügli ◽  
Ramin Khatami

Obstructive sleep apnea (OSA) is a common sleep disorder, and continuous positive airways pressure (CPAP) is the most effective treatment. Poor adherence is one of the major challenges in CPAP therapy. The recent boom of wearable optical sensors measuring oxygen saturation makes the at-home multiple-night CPAP titrations possible, which may essentially improve the adherence of CPAP therapy by optimizing its pressure in a real-life setting economically. We tested whether the oxygen desaturations (OD) measured in the arm muscle (arm_OD) by gold-standard frequency-domain multi-distance near-infrared spectroscopy (FDMD-NIRS) changes with titrated CPAP pressures in OSA patients together with polysomnography. We found that the arm_OD (2.08 ± 1.23%, mean ± standard deviation) was significantly smaller (P-value <0.0001) than the fingertip OD (finger_OD) (4.46 ± 2.37%) measured by polysomnography pulse oximeter. Linear mixed-effects models suggested that CPAP pressure was a significant predictor for finger_OD but not for arm_OD. Since FDMD-NIRS measures a mixture of arterial and venous OD, whereas fingertip pulse oximeter measures arterial OD, our results of no association between arm_OD and finger_OD indicate that the arm_OD mainly represented venous desaturation. Arm_OD measured by near-infrared optical sensors may be not a suitable indicator of the effectiveness of CPAP titration.

Biosensors ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
Zhongxing Zhang ◽  
Ming Qi ◽  
Gordana Hügli ◽  
Ramin Khatami

Obstructive sleep apnea (OSA) is a common sleep disorder, and continuous positive airway pressure (CPAP) is the most effective treatment. Poor adherence is one of the major challenges in CPAP therapy. The recent boom of wearable optical sensors measuring oxygen saturation makes at-home multiple-night CPAP titrations possible, which may essentially improve the adherence of CPAP therapy by optimizing its pressure in a real-life setting economically. We tested whether the oxygen desaturations (ODs) measured in the arm muscle (arm_OD) by gold-standard frequency-domain multi-distance near-infrared spectroscopy (FDMD-NIRS) change quantitatively with titrated CPAP pressures in OSA patients together with polysomnography. We found that the arm_OD (2.08 ± 1.23%, mean ± standard deviation) was significantly smaller (p-value < 0.0001) than the fingertip OD (finger_OD) (4.46 ± 2.37%) measured by a polysomnography pulse oximeter. Linear mixed-effects models suggested that CPAP pressure was a significant predictor for finger_OD but not for arm_OD. Since FDMD-NIRS measures a mixture of arterial and venous OD, whereas a fingertip pulse oximeter measures arterial OD, our results of no association between arm_OD and finger_OD indicate that the arm_OD mainly represented venous desaturation. Arm_OD measured by optical sensors used for wearables may not be a suitable indicator of the CPAP titration effectiveness.


2020 ◽  
Author(s):  
Zhongxing Zhang ◽  
Ming Qi ◽  
Gordana Hügli ◽  
Ramin Khatami

BACKGROUND Obstructive sleep apnea (OSA) is the most prevalent respiratory sleep disorder occurring in 9-38% of the general population. But about 90% of the suspected OSA patients go undiagnosed due to the lack of sleep laboratories/specialists and the high-cost of in-lab polysomnography (PSG) diagnosis, leading to decreased life qualities and increased healthcare burden in cardio-/cerebrovascular diseases. Wearable sleep trackers like smartwatches/armbands are booming, creating a hope of cost-efficient at-home OSA screening and assessment of treatment (e.g., continuous positive airway pressure [CPAP] therapy) effectiveness. However, such wearables currently are still not available. One of the major limitations in measuring OSA with wearables is the detection of sleep hypopnea. Because sleep apnea is defined by a complete pause/stop of breathing and many wearables can measure surrogate markers for breathing frequency, but hypopnea is defined by ≥ 30% drop in breathing and at least 3% drop in peripheral capillary oxygen saturation (SpO2) measured at fingertip. Whether the conventional measures of oxygen desaturation (OD) at the fingertip and at the arm/wrist are identical, is essentially unknown. OBJECTIVE We aimed to compare event-by-event the arm OD (arm_OD) with the fingertip OD (finger_OD) in sleep hypopneas during both naïve sleep and CPAP therapy. METHODS 30 OSA patients did the incremental stepwise CPAP titration protocol during all-night in-lab video-PSG monitoring, i.e., 1-h baseline sleep without CPAP followed by stepwise increment of 1-cmH2O pressure per-hour starting from 5-8 cmH2O depending on the individuals. The arm_OD of left bicep muscular and the finger_OD of left index fingertip in sleep hypopneas were simultaneously measured by frequency-domain near-infrared spectroscopy and video-PSG photoplethysmography, respectively. Bland-Altman plots were used to illustrate the agreements between arm_OD and finger_OD during baseline sleep and under CPAP, respectively. T-test tested whether the differences between arm_OD and finger_OD were significantly different from 0 (P<.05). RESULTS Totally 2185 hypopneas from our patients were analyzed, including 668 ones during baseline sleep and 1517 ones during CPAP. The mean difference between finger_OD and arm_OD was 2.86% (95% confidence interval [CI]: 2.67-3.06%, t-test: P<.001) during baseline sleep and 1.83% (95% CI: 1.72-1.94%, t-test: P<.001) during CPAP, with the 95% limits of agreement as [-2.27%, 8.00%] and [-2.54%, 6.19%], respectively. Using the criterion of arm_OD ≥3% can only define 16.32% (109/668) and 14.90% (226/1517) hypopneas at baseline and during CPAP, respectively. CONCLUSIONS arm_OD is 2-3% smaller than standard finger_OD in sleep hypopnea, probably because the measured arm_OD physiologically comes from arterioles, venules and capillaries thus the venous blood adversely affects its value. Our findings cannot recommend directly using a drop of ≥ 3% OD at arm/wrist as a criterion to define hypopnea because it could provide large false negative results in screening OSA and assessing the CPAP treatment effectiveness.


2021 ◽  
Vol 22 (5) ◽  
pp. 2300
Author(s):  
Ronni Baran ◽  
Daniela Grimm ◽  
Manfred Infanger ◽  
Markus Wehland

Obstructive sleep apnea (OSA) is a common disease, with approximately 3–7% of men and 2–5% of women worldwide suffering from symptomatic OSA. If OSA is left untreated, hypoxia, microarousals and increased chemoreceptor stimulation can lead to complications like hypertension (HT). Continuous positive airway pressure (CPAP) is the most common treatment for OSA, and it works by generating airway patency, which will counteract the apnea or hypopnea. More than one billion people in the world suffer from HT, and the usual treatment is pharmacological with antihypertensive medication (AHM). The focus of this review will be to investigate whether the CPAP therapy for OSA affects HT.


2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
J Hnatiak ◽  
O Ludka ◽  
L Batalik ◽  
P Winnige ◽  
F Dosbaba

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Ministry of Health Czech Republic; identification of organization 65269705 Background Although continuous positive airway pressure (CPAP) is currently still the gold standard for therapy of moderate to severe obstructive sleep apnea (OSA), another alternative or adjunct effective therapeutic options exist. Lifestyle intervention focused on nutrition and weight reduction, regular exercise, sleep hygiene, smoking and alcohol restriction represents a recommended therapeutic strategy for OSA. Though this intervention represents an effective tool for improving objective and subjective parameters of OSA, it’s effectivity depends on components of the intervention, OSA severity and gender. Comprehensive remotely-supervised cardiac rehabilitation (CR) represents possible training intervention in home conditions using elements of telemedicine. Purpose This prospective study aims to investigate the feasibility and effect of a remotely-supervised CR in patients with newly diagnosed OSA with Apnea-Hypopnea Index greater than 15 episodes per hour. Methods This monocentric study is designed as a prospective, parallel, randomised, controlled trial of remotely-supervised 12-week CR in male patients between 40-60 years old with newly diagnosed OSA indicated to CPAP therapy. The sample size is calculated by 0,05 level of significance and 80% statistical power on 25 participants in each group. The Intervention group will undergo comprehensive remotely-supervised CR in home conditions with teleconsultation (contains telecoaching, telemonitoring) via regular phone calls and e-mails at least 1-2 times a week. The intervention will include nutrition, health-related lifestyle and behavioral changes recommendations, and at least 5 times a week 30 minutes of moderate-intensity aerobic training, 10 minutes of inspiratory and expiratory muscle training with breathing device and 10 minutes of oropharyngeal exercise along with individually titrated CPAP therapy. The control group will undergo individually titrated CPAP therapy only. The participants in both groups will go through the following assessments before and after this study: polysomnography, spirometry, anthropometry and body composition examination, laboratory values examination, quality of life questionnaires, Epworth sleepiness scale, 6-min walking test. Conclusions: Comprehensive remotely-supervised CR, as mentioned in this study, may represent an adjunct therapy with a promising future in patients with OSA. The study is occupied with a current issue and can also bring new possibilities and experiences in remote rehabilitation.


SLEEP ◽  
2019 ◽  
Vol 43 (6) ◽  
Author(s):  
Sina A Gharib ◽  
Amanda L Hurley ◽  
Michael J Rosen ◽  
James C Spilsbury ◽  
Amy E Schell ◽  
...  

Abstract Obstructive sleep apnea (OSA) has been linked to dysregulated metabolic states, and treatment of sleep apnea may improve these conditions. Subcutaneous adipose tissue is a readily samplable fat depot that plays an important role in regulating metabolism. However, neither the pathophysiologic consequences of OSA nor the effects of continuous positive airway pressure (CPAP) in altering this compartment’s molecular pathways are understood. This study aimed to systematically identify subcutaneous adipose tissue transcriptional programs modulated in OSA and in response to its effective treatment with CPAP. Two subject groups were investigated: Study Group 1 was comprised of 10 OSA and 8 controls; Study Group 2 included 24 individuals with OSA studied at baseline and following CPAP. For each subject, genome-wide gene expression measurement of subcutaneous fat was performed. Differentially activated pathways elicited by OSA (Group 1) and in response to its treatment (Group 2) were determined using network and Gene Set Enrichment Analysis (GSEA). In Group 2, treatment of OSA with CPAP improved apnea-hypopnea index, daytime sleepiness, and blood pressure, but not anthropometric measures. In Group 1, GSEA revealed many up-regulated gene sets in OSA subjects, most of which were involved in immuno-inflammatory (e.g. interferon-γ signaling), transcription, and metabolic processes such as adipogenesis. Unexpectedly, CPAP therapy in Group 2 subjects was also associated with up-regulation of several immune pathways as well as cholesterol biosynthesis. Collectively, our findings demonstrate that OSA alters distinct inflammatory and metabolic programs in subcutaneous fat, but these transcriptional signatures are not reversed with short-term effective therapy.


2007 ◽  
Vol 293 (4) ◽  
pp. R1666-R1670 ◽  
Author(s):  
Walter T. McNicholas

Considerable evidence is now available of an independent association between obstructive sleep apnea syndrome (OSAS) and cardiovascular disease. The association is particularly strong for systemic arterial hypertension, but there is growing evidence of an association with ischemic heart disease and stroke. The mechanisms underlying cardiovascular disease in patients with OSAS are still poorly understood. However, the pathogenesis is likely to be a multifactorial process involving a diverse range of mechanisms, including sympathetic overactivity, selective activation of inflammatory molecular pathways, endothelial dysfunction, abnormal coagulation, and metabolic dysregulation, the latter particularly involving insulin resistance and disordered lipid metabolism. Therapy with continuous positive airway pressure (CPAP) has been associated with significant benefits to cardiovascular morbidity and mortality, both in short-term studies addressing specific aspects of morbidity, such as hypertension, and more recently in long-term studies that have evaluated major outcomes of cardiovascular morbidity and mortality. However, there is a clear need for further studies evaluating the impact of CPAP therapy on cardiovascular outcomes. Furthermore, studies on the impact of CPAP therapy have provided useful information concerning the role of basic cell and molecular mechanisms in the pathophysiology of OSAS.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A156-A157
Author(s):  
Sikawat Thanaviratananich ◽  
Hao Cheng ◽  
Maria Pino ◽  
Krishna Sundar

Abstract Introduction The apnea-hypopnea index (AHI) is used as a generic index to quantify both central sleep apnea (CSA) and obstructive sleep apnea (OSA) syndromes. Patterns of oxygenation abnormalities seen in CSA and OSA may be key to understanding differing clinical impacts of these disorders. Oxygen desaturation and resaturation slopes and durations in OSA and CSA were compared between OSA and CSA patients. Methods Polysomnographic data of patients aged 18 years or older with diagnosis of OSA and CSA, at University of Iowa Hospitals and Clinics, were analyzed and demographic data were collected. Oximetric changes during hypopneas and apneas were studied for desaturation/resaturation durations and desaturation/resaturation slopes. Desaturation and resaturation slopes were calculated as rate of change in oxygen saturation (ΔSpO2/Δtime). Comparison of hypoxemia-based parameters between patients with OSA and CSA was performed using unpaired t-test. Results 32 patients with OSA with median AHI of 15.4 (IQR 5.1 to 30.55) and median ODI of 15.47 (IQR 9.50 to 29.33) were compared to 15 patients with CSA with a median AHI of 20.4 (IQR 12.6 to 47.8) and median ODI of 27.56 (IQR 17.99 to 29.57). The mean number of desaturation and resaturation events was not significantly different between patients with OSA and CSA (OSA - 106.81±87.93; CSA - 130.67±76.88 with a p-value 0.1472). 4/15 CSA patients had Cheyne-Stokes breathing, 2/15 had treatment emergent central sleep apnea, 1/15 had methadone-associated CSA and for 8/15, no etiologies for CSA were found. Mean desaturation durations was significantly longer in OSA (20.84 s ± 5.67) compared to CSA (15.94 s ± 4.54) (p=0.0053) and consequently the desaturation slopes were steeper in CSA than OSA (-0.35%/sec ±0.180 vs. -0.243 ± 0.073; p=0.0064). The resaturation duration was not significantly longer in OSA (9.76 s ± 2.02) than CSA (9.057 s ± 2.17) (p=0.2857). Differences between desaturation duration and slopes between CSA and OSA persisted during REM and NREM sleep, and in supine sleep. Conclusion As compared to OSA, patients with CSA have different patterns of desaturations and resaturations with lesser hypoxic burden with CSA. This may have implications on the clinical outcomes seen between these two disorders. Support (if any):


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