scholarly journals Computational Modeling of Airway Obstruction in Sleep Apnea in Down Syndrome

2016 ◽  
Vol 155 (1) ◽  
pp. 184-187 ◽  
Author(s):  
Goutham Mylavarapu ◽  
Dhananjay Subramaniam ◽  
Raghuvir Jonnagiri ◽  
Ephraim J. Gutmark ◽  
Robert J. Fleck ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Obstructive Sleep Apnea ◽  
Down Syndrome ◽  
Sleep Apnea ◽  
Airway Resistance ◽  
Upper Airway ◽  
Apnea Hypopnea Index ◽  
Virtual Surgery ◽  
Obstructive Apnea ◽  
Obstructive Sleep

Current treatment options are successful in 40% to 60% of children with persistent obstructive sleep apnea after adenotonsillectomy. Residual obstruction assessments are largely subjective and do not clearly define multilevel obstruction. We endeavor to use computational fluid dynamics to perform virtual surgery and assess airflow changes in patients with Down syndrome and persistent obstructive sleep apnea. Three-dimensional airway models were reconstructed from respiratory-gated computed tomography and magnetic resonance imaging. Virtual surgeries were performed on 10 patients, mirroring actual surgeries. They demonstrated how surgical changes affect airflow resistance. Airflow and upper airway resistance was calculated from computational fluid dynamics. Virtual and actual surgery outcomes were compared with obstructive apnea-hypopnea index values. Actual surgery successfully treated 6 of 10 patients (postoperative obstructive apnea-hypopnea index <5). In 8 of 10 subjects, both apnea-hypopnea index and the calculated upper airway resistance after virtual surgery decreased as compared with baseline values. This is a feasibility and proof-of-concept study. Further studies are needed before using these techniques in surgical planning.

scholarly journals Upper airway resistance syndrome: evaluation of patients with excessive day time sleepiness non-invasively

2017 ◽  
Vol 5 (6) ◽  
pp. 2753
Author(s):  
Vaibhav Kumar Ingle
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Airway Resistance ◽  
Upper Airway ◽  
Driving Ability ◽  
Apnea Hypopnea Index ◽  
Upper Airway Resistance Syndrome ◽  
Oesophageal Manometry ◽  
Upper Airway Resistance ◽  
Obstructive Sleep

Background: Upper airway resistance syndrome (UARS) is a recent concept introduced among sleep disordered breathing (chronic snoring and Obstructive sleep apnea) disorders. UARS also presents with excessive daytime sleepiness (EDS), which is associated with impaired social functioning, work performance and driving ability. However, UARS is not merely a continuum between chronic snoring and obstructive sleep apnea (OSA). Not only UARS patients have equal gender distribution and thin body habitus but they also do not fulfil Polysomnographic criteria of OSA. UARS diagnosis requires oesophageal manometry for diagnosing increased respiratory efforts against increased upper airway resistance (without complete cessation of airflow or hypoxia) and correlating it with EEG arousals to mark an event. Oesophageal manometry is invasive and uncomfortable, therefore, non-invasive means are desirable for evaluation of UARS. The aim of the study is to evaluate the patients with EDS for UARS non-invasively.Methods: 25 consecutive patients with EDS (Epworth Sleepiness Score >9) visiting sleep clinic at a tertiary level hospital in North India were enrolled after informed consent. It was a non-blinded, interventional trial. All enrolled patients underwent nocturnal polysomnography using VIASYS healthcare sleep screen apnea screen cardio polysomnography machine. After PSG, those patients satisfying criteria for OSA were not analysed further. In remaining patients, greater than 10 alpha EEG arousals/h (Spontaneous Arousals) along with flattening or plateau of inspiratory flow contour (by nasal cannula) was employed to diagnose UARS non-invasively. Epi-info software was used in statistical analysis.Results: Out of 25 patients with EDS, 60% (15) were diagnosed as OSA based on Apnea-Hypopnea Index (AHI) > 10/hr. Among 15 OSA patients,10 patients had severe (AHI >30); 2 had moderate (AHI 15-30) and 3 had mild OSAS (AHI 10-15). Only one patient was provisionally diagnosed as UARS based on nasal air flow graph and spontaneous arousals/hr >10.Conclusions: Upper airway resistance syndrome (UARS) is a distinct sleep disorder from obstructive sleep apnea syndrome (OSAS) with unique pathophysiology and it need be evaluated in all patients with unexplained arousals.

Aerodynamics Analysis of the Impact of Nasal Surgery on Patients with Obstructive Sleep Apnea and Nasal Obstruction

ORL ◽  
2021 ◽  
pp. 1-8
Author(s):  
Lifeng Li ◽  
Demin Han ◽  
Hongrui Zang ◽  
Nyall R. London
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Nasal Obstruction ◽  
Upper Airway ◽  
Apnea Hypopnea Index ◽  
Nasal Surgery ◽  
Subjective Sleep Quality ◽  
Obstructive Sleep ◽  
Significant Difference ◽  
The Impact

<b><i>Objective:</i></b> The purpose of this study was to evaluate the effects of nasal surgery on airflow characteristics in patients with obstructive sleep apnea (OSA) by comparing the alterations of airflow characteristics within the nasal and palatopharyngeal cavities. <b><i>Methods:</i></b> Thirty patients with OSA and nasal obstruction who underwent nasal surgery were enrolled. A pre- and postoperative 3-dimensional model was constructed, and alterations of airflow characteristics were assessed using the method of computational fluid dynamics. The other subjective and objective clinical indices were also assessed. <b><i>Results:</i></b> By comparison with the preoperative value, all postoperative subjective symptoms statistically improved (<i>p</i> &#x3c; 0.05), while the Apnea-Hypopnea Index (AHI) changed little (<i>p</i> = 0.492); the postoperative airflow velocity and pressure in both nasal and palatopharyngeal cavities, nasal and palatopharyngeal pressure differences, and total upper airway resistance statistically decreased (all <i>p</i> &#x3c; 0.01). A significant difference was derived for correlation between the alteration of simulation metrics with subjective improvements (<i>p</i> &#x3c; 0.05), except with the AHI (<i>p</i> &#x3e; 0.05). <b><i>Conclusion:</i></b> Nasal surgery can decrease the total resistance of the upper airway and increase the nasal airflow volume and subjective sleep quality in patients with OSA and nasal obstruction. The altered airflow characteristics might contribute to the postoperative reduction of pharyngeal collapse in a subset of OSA patients.

Tongue-Based Procedures in Treating Refractory Obstructive Sleep Apnea in Down Syndrome Patients: A Systematic Review and Meta-Analysis

FACE ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 65-70
Author(s):  
Paul B. Lee ◽  
Michael T. Chung ◽  
Jared Johnson ◽  
Jordyn Lucas ◽  
Caitlin R. Priest ◽  
...  
Keyword(s):  
Systematic Review ◽  
Obstructive Sleep Apnea ◽  
Down Syndrome ◽  
Sleep Apnea ◽  
Nerve Stimulation ◽  
Hypoglossal Nerve ◽  
Meta Analysis ◽  
Apnea Hypopnea Index ◽  
Hypoglossal Nerve Stimulation ◽  
Obstructive Sleep

Objective: There is a high prevalence of obstructive sleep apnea (OSA) in pediatric and adult Down Syndrome (DS) patients that is refractory to adenotonsillectomy and continuous positive airway pressure. Newer treatment modalities have emerged with improved outcomes. The objective is to provide an updated systematic review and meta-analysis to analyze the clinical outcomes of OSA in pediatric and adult DS patients with hypoglossal nerve stimulation using Inspire, midline posterior glossectomy plus lingual tonsillectomy (MPG + LT), and combined genioglossus advancement plus radiofrequency (GGS + RF). Methods: A comprehensive literature search of PubMed and Google Scholar was performed followed by a meta-analysis. Studies with preoperative and post-operative Apnea Hypopnea Index (AHI) values were included with patients serving as their own control. Results: Across 5 studies, 56 patients were analyzed. The mean reduction in AHI was statistically significant before vs. after procedure ( P < .001 for hypoglossal nerve stimulation using Inspire with a paired 2-tailed t-test and P = .031 for MPG + LT). Although individual patient AHI values were unavailable in the GGS + RF study, the standard difference in mean AHI was also significant for GGS + RF with P = .001. Device malfunction was the most common complication for Inspire while postoperative bleeding was observed for MPG + LT and nasopharyngeal obstruction and retropalatal collapse were observed for GGS + RF. Conclusion: This review reveals significant improvement in AHI with Inspire, MPG + LT, and GGS + RF for DS patients with refractory OSA. Further investigation is needed for comparison between these 3 therapies.

Predicting critical closing pressure in children with obstructive sleep apnea using fluid structure interaction simulations

2021 ◽  
Author(s):  
Goutham Mylavarapu ◽  
Ephraim Gutmark ◽  
Sally Shott ◽  
Robert J. Fleck ◽  
Mohamed Mahmoud ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Dynamic Mri ◽  
Patient Specific ◽  
Apnea Hypopnea Index ◽  
Structure Interaction ◽  
Obstructive Sleep ◽  
Mri Scans ◽  
Closing Pressure

Surgical treatment of obstructive sleep apnea (OSA) in children requires knowledge of upper airway dynamics, including the closing pressure (Pcrit), a measure of airway collapsibility. We applied a Flow-Structure Interaction (FSI) computational model to estimate Pcrit in patient-specific upper airway models obtained from magnetic resonance imaging (MRI) scans. We sought to examine the agreement between measured and estimated Pcrit from FSI models in children with Down syndrome. We hypothesized that the estimated Pcrit would accurately reflect measured Pcrit during sleep and therefore reflect the severity of OSA as measured by the obstructive apnea hypopnea index (AHI). All participants (n=41) underwent polysomnography and sedated sleep MRI scans. We used Bland Altman Plots to examine the agreement between measured and estimated Pcrit. We determined associations between estimated Pcrit and OSA severity, as measured by AHI, using regression models. The agreement between passive and estimated Pcrit showed a fixed bias of -1.31 (CI=-2.78, 0.15) and a non-significant proportional bias. A weaker agreement with active Pcrit was observed. A model including AHI, gender, an interaction term for AHI and gender and neck circumference explained the largest variation (R2 = 0.61) in the relationship between AHI and estimated Pcrit. (P <0.0001). Overlap between the areas of the airway with lowest stiffness, and areas of collapse on dynamic MRI, was 77.4%±30% for the nasopharyngeal region and 78.6%±33% for the retroglossal region. The agreement between measured and estimated Pcrit and the significant association with AHI supports the validity of Pcrit estimates from the FSI model.

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