Computational analysis of airflow dynamics for predicting collapsible sites in the upper airways: a preliminary study

The present study aimed to detail the relationship between the flow and structure characteristics of the upper airways and airway collapsibility in obstructive sleep apnea. Using a computational approach, we performed simulations of the flow and structure of the upper airways in two patients having different facial morphologies: retruding and protruding jaws, respectively. First, transient flow simulation was performed using a prescribed volume flow rate to observe flow characteristics within upper airways with an unsteady effect. In the retruding jaw, the maximum magnitude of velocity and pressure drop with velocity shear and vortical motion was observed at the oropharyngeal level. In contrast, in the protruding jaw, the overall magnitude of velocity and pressure was relatively small. To identify the cause of the pressure drop in the retruding jaw, pressure gradient components induced by flow were examined. Of note, vortical motion was highly associated with pressure drop. Structure simulation was performed to observe the deformation and collapsibility of soft tissue around the upper airways using the surface pressure obtained from the flow simulation. At peak flow rate, the soft tissue of the retruding jaw was highly expanded, and a collapse was observed at the oropharyngeal and epiglottis levels. NEW & NOTEWORTHY Aerodynamic characteristics have been reported to correlate with airway occlusion. However, a detailed mechanism of the phenomenon within the upper airways and its impact on airway collapsibility remain poorly understood. This study provides in silico results for aerodynamic characteristics, such as vortical structure, pressure drop, and exact location of the obstruction using a computational approach. Large deformation of soft tissue was observed in the retruding jaw, suggesting that it is responsible for obstructive sleep apnea.

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Upper Airway Collapsibility During REM Sleep in Children with the Obstructive Sleep Apnea Syndrome

SLEEP ◽

10.1093/sleep/32.9.1173 ◽

2009 ◽

Vol 32 (9) ◽

pp. 1173-1181 ◽

Cited By ~ 12

Author(s):

Jingtao Huang ◽

Laurie R. Karamessinis ◽

Michelle E. Pepe ◽

Stephen M. Glinka ◽

John M. Samuel ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Obstructive Sleep Apnea Syndrome ◽

Rem Sleep ◽

Sleep Apnea Syndrome ◽

Upper Airway ◽

Obstructive Sleep ◽

Airway Collapsibility ◽

Apnea Syndrome ◽

Upper Airway Collapsibility

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Evaluation of tongue/mandible volume ratio in children with obstructive sleep apnea

Dental Press Journal of Orthodontics ◽

10.1590/2177-6709.23.4.072-078.oar ◽

2018 ◽

Vol 23 (4) ◽

pp. 72-78 ◽

Cited By ~ 3

Author(s):

Kavita Hotwani ◽

Krishna Sharma ◽

Arpan Jaiswal

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Soft Tissue ◽

Volume Ratio ◽

Radiology Department ◽

Control Group ◽

Mr Images ◽

Early Screening ◽

Obstructive Sleep ◽

Tongue Volume

ABSTRACT Objective: The present study was an attempt to investigate tongue/mandible volume ratio in children, using volumetric magnetic resonance imaging (MRI) for early screening and to aid in treatment planning. Methods: Volumetric evaluation of tongue volume/mandible volume ratio (TV/MV ratio) in children with obstructive sleep apnea (OSA) using MRI was carried out retrospectively on available DICOM MR images of children in the age group of 10-14 years. MRI image records of patients diagnosed with OSA were obtained from interventional radiology department records, at Sharad Pawar Dental College and Hospital (Datta Meghe Institute of Medical Sciences, Nagpur/India). The age, gender, height and weight of the subjects were retrieved from patient database and registered. For the control group, available MRI images of healthy subjects without OSA were retrieved. Body mass index (BMI) was also calculated using the height and the weight present in the records. Measurements from MR images were made using DICOM image processing software. Soft tissue and bony structure segmentation was performed by manual tracing. The tongue volume and mandible volume were directly computed using the software. The tongue volume/mandible volume ratio (TV/MV) was generated using the above values and expressed as a percentage for both groups. Results: The difference between OSA group and control group with respect to TV/MV ratio was found to be highly significant at 0.05 level of significance. There was no significant correlation between BMI and TV/MV ratio in OSA group (p= 0.451) as well as in control group (p= 0.094). Conclusion: TV/MV ratio may be an appropriate variable to evaluate the risk of OSA, representing the balance between skeletal morphology and soft tissue morphology in craniofacial complex.

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Obstructive sleep apnea syndrome and cognitive impairment: effects of CPAP

Reviews in Health Care ◽

10.7175/rhc.5224209-227 ◽

2011 ◽

Vol 2 (4) ◽

pp. 209

Author(s):

Alessandra Giordano ◽

Alessandro Cicolin ◽

Roberto Mutani

Keyword(s):

Obstructive Sleep Apnea ◽

Cognitive Impairment ◽

Sleep Apnea ◽

Executive Functions ◽

Obstructive Sleep Apnea Syndrome ◽

Sleep Apnea Syndrome ◽

Muscular Activity ◽

Upper Airways ◽

Obstructive Sleep ◽

Apnea Syndrome

Obstructive Sleep Apnea Syndrome (OSAS) is a sleep disorder characterised by repetitive episodes of upper airway obstruction (apnea) or reduced airflow (hypopnoea) despite persistent respiratory effort. Apnea is defined as the cessation of breathing for at least 10 seconds during sleep, while hypopnoea is defined as at least 30% reduction in airflow for 10 seconds associated with oxygen desaturation and sleep fragmentation. The presence in the general population is about 4%. The principal symptoms are: excessive daytime sleepiness (EDS), snoring, dry throat, morning headache, night sweats, gastro-esophageal reflux, and increased blood pressure.Long term complications can be: increased cardio-cerebrovascular risk and cognitive impairment such as deficiency in attention, vigilance, visual abilities, thought, speech, perception and short term memory.Continuous Positive Airway Pressure (CPAP) is currently the best non-invasive therapy for OSAS.CPAP guarantees the opening of upper airways using pulmonary reflexive mechanisms increasing lung volume during exhalation and resistance reduction, decreasing electromyografical muscular activity around airways.The causes of cognitive impairments and their possible reversibility after CPAP treatment have been analysed in numerous studies. The findings, albeit controversial, show that memory, attention and executive functions are the most compromised cognitive functions.The necessity of increasing the patient compliance with ventilotherapy is evident, in order to prevent cognitive deterioration and, when possible, rehabilitate the compromised functions, a difficult task for executive functions.

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An assessment of a simple clinical technique to estimate pharyngeal collapsibility in people with obstructive sleep apnea

SLEEP ◽

10.1093/sleep/zsaa067 ◽

2020 ◽

Vol 43 (10) ◽

Cited By ~ 2

Author(s):

Amal M Osman ◽

Benjamin K Tong ◽

Shane A Landry ◽

Bradley A Edwards ◽

Simon A Joosten ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Characteristic Curve ◽

Upper Airway ◽

Clinical Intervention ◽

Apnea Hypopnea Index ◽

Cpap Titration ◽

Obstructive Sleep ◽

Airway Collapsibility ◽

Upper Airway Collapsibility

Abstract Study Objectives Quantification of upper airway collapsibility in obstructive sleep apnea (OSA) could help inform targeted therapy decisions. However, current techniques are clinically impractical. The primary aim of this study was to assess if a simple, novel technique could be implemented as part of a continuous positive airway pressure (CPAP) titration study to assess pharyngeal collapsibility. Methods A total of 35 participants (15 female) with OSA (mean ± SD apnea–hypopnea index = 35 ± 19 events/h) were studied. Participants first completed a simple clinical intervention during a routine CPAP titration, where CPAP was transiently turned off from the therapeutic pressure for ≤5 breaths/efforts on ≥5 occasions during stable non-rapid eye movement (non-REM) sleep for quantitative assessment of airflow responses (%peak inspiratory flow [PIF] from preceding 5 breaths). Participants then underwent an overnight physiology study to determine the pharyngeal critical closing pressure (Pcrit) and repeat transient drops to zero CPAP to assess airflow response reproducibility. Results Mean PIF of breaths 3–5 during zero CPAP on the simple clinical intervention versus the physiology night were similar (34 ± 29% vs. 28 ± 30% on therapeutic CPAP, p = 0.2; range 0%–90% vs. 0%–95%). Pcrit was −1.0 ± 2.5 cmH2O (range −6 to 5 cmH2O). Mean PIF during zero CPAP on the simple clinical intervention and the physiology night correlated with Pcrit (r = −0.7 and −0.9, respectively, p < 0.0001). Receiver operating characteristic curve analysis indicated significant diagnostic utility for the simple intervention to predict Pcrit < −2 and < 0 cmH2O (AUC = 0.81 and 0.92), respectively. Conclusions A simple CPAP intervention can successfully discriminate between patients with and without mild to moderately collapsible pharyngeal airways. This scalable approach may help select individuals most likely to respond to non-CPAP therapies.

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Facial soft tissue response to maxillo-mandibular advancement in obstructive sleep apnea syndrome patients

Head & Face Medicine ◽

10.1186/s13005-017-0149-x ◽

2017 ◽

Vol 13 (1) ◽

Author(s):

Julio Cifuentes ◽

Christian Teuber ◽

Alfredo Gantz ◽

Ariel Barrera ◽

Gholamreza Danesh ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Soft Tissue ◽

Sleep Apnea Syndrome ◽

Tissue Response ◽

Mandibular Advancement ◽

Facial Soft Tissue ◽

Obstructive Sleep ◽

Apnea Syndrome ◽

Soft Tissue Response

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Craniofacial Structures And Upper Airway Soft Tissue Differences Between Caucasian And African American Females With Obstructive Sleep Apnea

10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a2203 ◽

2010 ◽

Author(s):

Francois-Louis COMYN ◽

R.J. Schwab ◽

S.J. Ratcliffe ◽

E.A. Beothy ◽

C. Kim ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

African American ◽

Sleep Apnea ◽

Soft Tissue ◽

Upper Airway ◽

African American Females ◽

Obstructive Sleep ◽

Tissue Differences

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Adherence to the Mediterranean lifestyle is inversely associated with insomnia presence and severity: cross-sectional analysis in obstructive sleep apnea patients

Proceedings of The Nutrition Society ◽

10.1017/s0029665120005042 ◽

2020 ◽

Vol 79 (OCE2) ◽

Author(s):

Ioanna Kechribari ◽

Meropi Kontogianni ◽

Michael Georgoulis ◽

Kallirroi Lamprou ◽

Antonia Kalogera ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Healthy Lifestyle ◽

Well Being ◽

Sleep Habits ◽

Upper Airways ◽

Lifestyle Habits ◽

Obstructive Sleep ◽

The Mediterranean ◽

Insomnia Symptoms

AbstractInsomnia is the most prevalent sleep disorder and frequently co-occurs with obstructive sleep apnea (OSA), a chronic disease characterized by repetitive pauses of breathing during sleep due to obstructions of the upper airways. The link between lifestyle and sleep quantity and quality is an area of intensive research, however data exploring associations between lifestyle habits and insomnia symptoms are still scarce. The aim of the present study was to investigate the potential association between the level of adherence to the Mediterranean lifestyle (ML), a healthy lifestyle pattern incorporating the prudent Mediterranean diet, adequate physical activity and healthy sleep habits, and insomnia presence and severity. The study sample consisted of 243 adult patients with polysomnography-diagnosed OSA. Participants’ insomnia-related disorders were evaluated through the Athens Insomnia Scale (AIS), an 8-item index ranging from 0 (absence of any sleep-related problem) to 24 (severe degree of insomnia); AIS values of > 6 were used to establish the diagnosis of insomnia. All patients were evaluated with regard to anthropometric indices and lifestyle habits, and adherence to the ML was estimated through the MEDLIFE index, a 28-item index ranging from 0 to 28, with higher values indicating greater proximity to the healthy lifestyle of the Mediterranean region. An inverse correlation was observed between the MEDLIFE index and total AIS (rho = -0.22, p = 0.001), as well as most individual components of AIS, including difficulty in sleep induction (rho = -0.14, p = 0.03), awakenings during the night (rho = -0.2, p = 0.008), short sleep duration (rho = -0.16, p = 0.01), low quality of sleep (rho = -0.13, p = 0.05), low well-being during the day (rho = -0.16, p = 0.02), and low functioning capacity during the day (rho = -0.15, p = 0.02). Patients with insomnia (AIS > 6), compared to those without (AIS ≤ 6), exhibited lower MEDLIFE index values [13 (11–15) vs. 14 (12–15), P = 0.002], had more severe OSA as assessed by the apnea-hypopnea index (AHI) [55 (24–87) vs. 35 (17–57) events/hour, P < 0.001] and tended to have higher body mass index (BMI) [35.0 (30.6–39.7) vs. 32.4 (29.5–38.6) kg/m2, P = 0.06]. According to logistic regression analysis, MEDLIFE index was inversely associated with the presence of insomnia (OR: 0.89, 95%CI: 0.80–0.99, P = 0.04) after adjustment for age, sex, smoking, BMI, daily energy intake and AHI. In conclusion, a higher adherence to the ML is inversely associated with insomnia presence and severity in patients with obstructive sleep apnea. Future research should assess whether this association applies in other samples, as well as whether the ML could be an efficient therapeutic tool alleviating or treating insomnia symptoms.

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Upper airway collapsibility measured using a simple wakefulness test closely relates to the pharyngeal critical closing pressure during sleep in obstructive sleep apnea

SLEEP ◽

10.1093/sleep/zsz080 ◽

2019 ◽

Vol 42 (7) ◽

Cited By ~ 5

Author(s):

Amal M Osman ◽

Jayne C Carberry ◽

Peter G R Burke ◽

Barbara Toson ◽

Ronald R Grunstein ◽

...

Keyword(s):

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Airway Pressure ◽

Pressure Sensors ◽

Upper Airway ◽

Apnea Hypopnea Index ◽

Pharyngeal Airway ◽

Obstructive Sleep ◽

Airway Collapsibility ◽

Upper Airway Collapsibility

AbstractStudy ObjectivesA collapsible or crowded pharyngeal airway is the main cause of obstructive sleep apnea (OSA). However, quantification of airway collapsibility during sleep (Pcrit) is not clinically feasible. The primary aim of this study was to compare upper airway collapsibility using a simple wakefulness test with Pcrit during sleep.MethodsParticipants with OSA were instrumented with a nasal mask, pneumotachograph and two pressure sensors, one at the choanae (PCHO), the other just above the epiglottis (PEPI). Approximately 60 brief (250 ms) pulses of negative airway pressure (~ –12 cmH2O at the mask) were delivered in early inspiration during wakefulness to measure the upper airway collapsibility index (UACI). Transient reductions in the continuous positive airway pressure (CPAP) holding pressure were then performed during sleep to determine Pcrit. In a subset of participants, the optimal number of replicate trials required to calculate the UACI was assessed.ResultsThe UACI (39 ± 24 mean ± SD; range = 0%–87%) and Pcrit (–0.11 ± 2.5; range: –4 to +5 cmH2O) were quantified in 34 middle-aged people (9 female) with varying OSA severity (apnea–hypopnea index range = 5–92 events/h). The UACI at a mask pressure of approximately –12 cmH2O positively correlated with Pcrit (r = 0.8; p < 0.001) and could be quantified reliably with as few as 10 replicate trials. The UACI performed well at discriminating individuals with subatmospheric Pcrit values [receiver operating characteristic curve analysis area under the curve = 0.9 (0.8–1), p < 0.001].ConclusionsThese findings indicate that a simple wakefulness test may be useful to estimate the extent of upper airway anatomical impairment during sleep in people with OSA to direct targeted non-CPAP therapies for OSA.

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