scholarly journals P088 Presence versus absence of flow limitation during stable breathing in patients with obstructive sleep apnoea

2021 ◽  
Vol 2 (Supplement_1) ◽  
pp. A49-A50
Author(s):  
D Mann ◽  
T Georgeson ◽  
S Landry ◽  
A Azarbarzin ◽  
D Vena ◽  
...  
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Phenotypic Variability ◽  
Sleep Apnoea ◽  
Flow Limitation ◽  
Sleep Study ◽  
Respiratory Events ◽  
Obstructive Sleep ◽  
Ventilatory Drive ◽  
Clinical Scoring ◽  
Nasal Pressure

Abstract Introduction Flow limitation is the distinguishing characteristic of obstructive sleep apnoea. Critically, periods of flow limitation can occur without overt reductions in airflow (e.g. disproportionate increase in ventilatory drive vs. achieved ventilation), however, such periods are ignored by clinical scoring. Here we investigate flow limitation during so-called “stable breathing”, i.e. periods of sleep without scored events, by applying our recently-validated model to estimate flow limitation from the airflow signal. Methods Flow limitation was visually-scored (N=117,871 breaths) from N=40 participants attending an overnight sleep study for suspected sleep apnoea. Scoring was aided by physiological signals (e.g. intra-oesophageal diaphragm EMG). Model flow limitation classification used features extracted from the pneumotach signal (cross-validated accuracy=92.4%). We applied this method to investigate the occurrence of flow limitation during stable breathing, defined as periods of sleep >3 min duration without scored arousals or respiratory events. Results Model predicted flow limitation frequency was strongly correlated with visual scoring (R²=0.84 p<0.001). The median flow limitation frequency during stable breathing ranged from 8–91%, with an overall median of 59% (IQR 37%-75%). Flow limitation frequency during stable breathing was only modestly associated with the apnoea-hypopnea index (R²=0.12 p<0.05). Discussion Flow limitation occurs surprisingly frequently during stable breathing. While some individuals achieve stable breathing with minimal flow limitation, others demonstrate substantial flow limitation. Heterogeneity in frequency of flow limitation (within and between individuals) may provide further insights into emergent phenotypic variability within sleep disordered breathing. Finally, this model performed similarly in nasal pressure (88.2% accuracy), indicating potential application to clinical studies.

scholarly journals Palatal prolapse as a signature of expiratory flow limitation and inspiratory palatal collapse in patients with obstructive sleep apnoea

2018 ◽  
Vol 51 (2) ◽  
pp. 1701419 ◽  
Author(s):  
Ali Azarbarzin ◽  
Scott A. Sands ◽  
Melania Marques ◽  
Pedro R. Genta ◽  
Luigi Taranto-Montemurro ◽  
...  
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Sleep Apnoea ◽  
Flow Limitation ◽  
Sleep Endoscopy ◽  
Expiratory Flow Limitation ◽  
Patient Level ◽  
Obstructive Sleep ◽  
Expiratory Flow ◽  
Nasal Pressure ◽  
Lateral Walls

In some individuals with obstructive sleep apnoea (OSA), the palate prolapses into the velopharynx during expiration, limiting airflow through the nose or shunting it out of the mouth. We hypothesised that this phenomenon causes expiratory flow limitation (EFL) and is associated with inspiratory “isolated” palatal collapse. We also wanted to provide a robust noninvasive means to identify this mechanism of obstruction.Using natural sleep endoscopy, 1211 breaths from 22 OSA patients were scored as having or not having palatal prolapse. The patient-level site of collapse (tongue-related, isolated palate, pharyngeal lateral walls and epiglottis) was also characterised. EFL was quantified using expiratory resistance at maximal epiglottic pressure. A noninvasive EFL index (EFLI) was developed to detect the presence of palatal prolapse and EFL using the flow signal alone. In addition, the validity of using nasal pressure was assessed.A cut-off value of EFLI >0.8 detected the presence of palatal prolapse and EFL with an accuracy of >95% and 82%, respectively. The proportion of breaths with palatal prolapse predicted isolated inspiratory palatal collapse with 90% accuracy.This study demonstrates that expiratory palatal prolapse can be quantified noninvasively, is associated with EFL and predicts the presence of inspiratory isolated palatal collapse.

Night-to-night variability of respiratory events in obstructive sleep apnoea: a systematic review and meta-analysis

Thorax ◽  
2020 ◽  
Vol 75 (12) ◽  
pp. 1095-1102 ◽  
Author(s):  
Maurice Roeder ◽  
Matteo Bradicich ◽  
Esther Irene Schwarz ◽  
Sira Thiel ◽  
Thomas Gaisl ◽  
...  
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Evidence Synthesis ◽  
Meta Analysis ◽  
Sleep Apnoea ◽  
Study Data ◽  
Sleep Study ◽  
Diagnostic Threshold ◽  
Respiratory Events ◽  
Obstructive Sleep ◽  
Significant Difference

BackgroundIt is current practice to use a single diagnostic sleep study in the diagnostic workup of obstructive sleep apnoea (OSA). However, a relevant night-to-night variability (NtNV) of respiratory events has been reported.MethodsWe evaluated the NtNV of respiratory events in adults with suspected or already diagnosed OSA who underwent more than one diagnostic sleep study. Data sources were PubMed, Cochrane and Embase up to 23 January 2019. Random-effects models were used for evidence synthesis. For moderator analysis, mixed-effects regression analysis was performed. The study was registered with PROSPERO (CRD42019135277).ResultsOf 2143 identified papers, 24 studies, comprising 3250 participants, were included. The mean Apnoea-Hypopnoea Index (AHI) difference between the first and second night was −1.70/hour (95% CI −3.61 to 0.02). REM time differences (first to second night) were significantly positive associated with differences in mean AHI (β coefficient 0.262 (95% CI 0.096 to 0.428). On average, 41% (95% CI 27% to 57%) of all participants showed changes of respiratory events >10/hour from night to night. Furthermore, 49% (95% CI 32% to 65%) of participants changed OSA severity class (severity thresholds at 5/hour, 15/hour and 30/hour) at least once in sequential sleep studies. Depending on the diagnostic threshold (5/hour, 10/hour or 15/hour), on average 12% (95% CI 9% to 15%), 12% (95% CI 8% to 19%) and 10% (95% CI 8% to 13%) of patients would have been missed during the first night due to single night testing.ConclusionWhile there was no significant difference between mean AHI in two sequential study nights on a group level, there was a remarkable intraindividual NtNV of respiratory events, leading to misdiagnosis and misclassification of patients with suspected OSA.

scholarly journals Quantifying the magnitude of pharyngeal obstruction during sleep using airflow shape

2019 ◽  
Vol 54 (1) ◽  
pp. 1802262 ◽  
Author(s):  
Dwayne L. Mann ◽  
Philip I. Terrill ◽  
Ali Azarbarzin ◽  
Sara Mariani ◽  
Angelo Franciosini ◽  
...  
Keyword(s):  
Gold Standard ◽  
Airflow Obstruction ◽  
Sleep Apnoea ◽  
Shape Features ◽  
Sleep Study ◽  
Shape Information ◽  
Obstructive Sleep ◽  
Ventilatory Drive ◽  
Nasal Pressure ◽  
Obstruction Severity

Rationale and objectivesNon-invasive quantification of the severity of pharyngeal airflow obstruction would enable recognition of obstructiveversuscentral manifestation of sleep apnoea, and identification of symptomatic individuals with severe airflow obstruction despite a low apnoea–hypopnoea index (AHI). Here we provide a novel method that uses simple airflow-versus-time (“shape”) features from individual breaths on an overnight sleep study to automatically and non-invasively quantify the severity of airflow obstruction without oesophageal catheterisation.Methods41 individuals with suspected/diagnosed obstructive sleep apnoea (AHI range 0–91 events·h−1) underwent overnight polysomnography with gold-standard measures of airflow (oronasal pneumotach: “flow”) and ventilatory drive (calibrated intraoesophageal diaphragm electromyogram: “drive”). Obstruction severity was defined as a continuous variable (flow:drive ratio). Multivariable regression used airflow shape features (inspiratory/expiratory timing, flatness, scooping, fluttering) to estimate flow:drive ratio in 136 264 breaths (performance based on leave-one-patient-out cross-validation). Analysis was repeated using simultaneous nasal pressure recordings in a subset (n=17).ResultsGold-standard obstruction severity (flow:drive ratio) varied widely across individuals independently of AHI. A multivariable model (25 features) estimated obstruction severity breath-by-breath (R2=0.58versusgold-standard, p<0.00001; mean absolute error 22%) and the median obstruction severity across individual patients (R2=0.69, p<0.00001; error 10%). Similar performance was achieved using nasal pressure.ConclusionsThe severity of pharyngeal obstruction can be quantified non-invasively using readily available airflow shape information. Our work overcomes a major hurdle necessary for the recognition and phenotyping of patients with obstructive sleep disordered breathing.

Immediate Effect of Acupuncture on the Sleep Pattern of Patients with Obstructive Sleep Apnoea

2010 ◽  
Vol 28 (3) ◽  
pp. 115-119 ◽  
Author(s):  
Anaflávia O Freire ◽  
Gisele C M Sugai ◽  
Sônia Maria Togeiro ◽  
Luiz Eugênio Mello ◽  
Sérgio Tufik
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Placebo Treatment ◽  
Acute Effect ◽  
Sham Acupuncture ◽  
Sleep Apnoea ◽  
Sleep Pattern ◽  
Control Group ◽  
Respiratory Events ◽  
Obstructive Sleep ◽  
Before And After

Background Most patients with obstructive sleep apnoea (OSA) do not tolerate treatment with nasal continuous positive airway pressure, the ‘gold standard’ treatment for this condition. It was shown in a pilot study that acupuncture was more effective than placebo treatment (sham acupuncture) in producing significant changes in the respiratory events assessed by polysomnography (PSG). Objectives To investigate the immediate effect of manual acupuncture (MA) and electroacupuncture (EA) on the sleep pattern of patients presenting with moderate OSA. Methods 40 patients with an Apnoea–Hypopnoea Index (AHI) of 15–30/h were randomly allocated to MA treatment (n=10), EA 10 Hz treatment (n=10), EA 2 Hz treatment (n=10) and a no-treatment control group (n=10). The patients received MA or EA (2 or 10 Hz) just before the PSG study at 20:00. Results The AHI (p=0.005; p=0.005), the Apnoea Index (p=0.038; p=0.009) and the respiratory events (p=0.039; p=0.014) decreased significantly in the MA and EA 10 Hz groups, respectively (AHI (21.9, 11.2), Apnoea Index (5.15, 0.7), respiratory events (120.5, 61.0) in the MA group before and after. AHI (20.6, 9.9), Apnoea Index (8.2, 0.3), respiratory events (117.0, 56.0) in the EA 10 Hz group before and after). The micro-arousals decreased only in the MA group (146.0 vs 88.5, p=0.0002). There were no significant changes in the EA 2 Hz group or in the control group. Conclusion A single session of either MA or EA 10 Hz had an acute effect in reducing the AHI as well as the number of nocturnal respiratory events of patients presenting with moderate OSA.

Effect of a 1-week intense myofunctional training on obstructive sleep apnoea in children with Down syndrome

2018 ◽  
Vol 104 (3) ◽  
pp. 275-279 ◽  
Author(s):  
Magnus von Lukowicz ◽  
Nina Herzog ◽  
Sebastian Ruthardt ◽  
Mirja Quante ◽  
Gabriele Iven ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Obstructive Sleep Apnoea ◽  
Sleep Apnoea ◽  
Marginal Effect ◽  
Sleep Study ◽  
Desaturation Index ◽  
Intensive Training ◽  
Children With Down Syndrome ◽  
Training Camp ◽  
Obstructive Sleep

BackgroundObstructive sleep apnoea (OSA) is common in children with Down syndrome (DS), yet difficult to treat. As muscular hypotonia of the upper airway may cause OSA and is also common in DS, we tested whether intense myofunctional therapy improves OSA in children with DS.Patients and methodsForty-two children underwent cardiorespiratory sleep studies immediately before and after a 1-week intensive training camp consisting of three daily 45 min sessions of myofunctional exercises according to Padovan. Primary outcome was the mixed-obstructive-apnoea/hypopnoea index (MOAHI), secondary outcomes the ≤3% oxygen desaturation index (DI3), the ≤90% desaturation index (DI90) and the lowest pulse oximeter saturation (SpO2nadir).ResultsEighteen recordings had ≥3 hours of artefact-free recording in both the pretreatment and post-treatment sleep study and were therefore included in the analysis. Mean age was 6.3 years (SD 2.5); 83% had OSA prior to intervention. Mean MOAHI was 6.4 (SD 8.6) before and 6.4 (SD 10.8) after the intervention (p>0.05); the DI3 and SpO2nadir also did not change. Only the DI90 decreased significantly from 2.7 (SD 4.5) to 2.1 (SD 3.7) (p<0.05).ConclusionThe 1-week intense myofunctional training camp evaluated here in children with DS had only a marginal effect on OSA. Whether a longer follow-up period or duration of intervention would yield stronger effects remains to be determined.

scholarly journals Oral Appliance Therapy for Obstructive Sleep Apnoea: State of the Art

2019 ◽  
Vol 8 (12) ◽  
pp. 2121 ◽  
Author(s):  
Kate Sutherland ◽  
Peter A. Cistulli
Keyword(s):  
Health Outcomes ◽  
Obstructive Sleep Apnoea ◽  
Productivity Loss ◽  
Sleep Apnoea ◽  
World Health ◽  
Cardiometabolic Health ◽  
Accident Risk ◽  
Sleep Study ◽  
Pharyngeal Airway ◽  
Obstructive Sleep

Obstructive sleep apnoea (OSA) represents a significant global health burden, with impact on cardiometabolic health, chronic disease, productivity loss and accident risk. Oral appliances (OA) are an effective therapy for OSA and work by enlarging and stabilising the pharyngeal airway to prevent breathing obstructions during sleep. Although recommended in clinical guidelines for OSA therapy, they are often considered only as second-line therapy following positive airway pressure (PAP) therapy failure. There has been a long-standing barrier to selecting OA over PAP therapy due to the inability to be certain about the level of efficacy in individual OSA patients. A range of methods to select OSA patients for OA therapy, based on the outcome of a single sleep study night, have been proposed, although none has been widely validated for clinical use. Emergent health outcome data suggest that equivalent apnoea–hypopnea index reduction may not be necessary to produce the same health benefits of PAP. This may be related to the more favourable adherence to OA therapy, which can now be objectively verified. Data on longer term health outcomes are needed, and there are additional opportunities for device improvement and combination therapy approaches. OAs have an important role in precision care of OSA as a chronic disorder through a multi-disciplinary care team. Future studies on real-world health outcomes following OA therapy are needed.

scholarly journals Screening for obstructive sleep apnoea in professional drivers

Breathe ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 29364 ◽  
Author(s):  
Sophia E. Schiza ◽  
Izolde Bouloukaki
Keyword(s):  
Obstructive Sleep Apnoea ◽  
Early Identification ◽  
Sleep Apnoea ◽  
Screening Tools ◽  
List Type ◽  
Objective Data ◽  
Sleep Study ◽  
Professional Drivers ◽  
Obstructive Sleep ◽  
Increased Risk

Professional drivers show a higher prevalence of obstructive sleep apnoea (OSA) compared with the general population. Furthermore, there is concern about the association between OSA and car crash risk given that drivers with OSA show an increased risk for car accidents. Despite this risk, OSA is often underdiagnosed and undertreated in this population, mainly due to lack of appropriate screening and sleep study referrals. Polysomnography (PSG), the gold standard test, is inappropriate for systematic screening because of its high expense, complexity and relative inaccessibility in this population. Therefore, there is a strong demand for good screening tools, including both subjective and objective data that may assist in early identification of possible OSA among professional drivers and, thus, aid in PSG examination referral and OSA management in an accredited sleep centre. However, there is considerable disagreement over screening methods and criteria for triggering a sleep study referral in different countries. There is also a strong need for further research in the area of OSA screening of commercial drivers in order to improve the diagnostic accuracy of screening tools and ensure that patients with OSA are accurately identified.Key pointsObstructive sleep apnoea (OSA) is often undiagnosed and undertreated in professional drivers.Professional drivers often under-report and are reluctant to report OSA symptoms.Barriers to OSA diagnosis include appropriate screening and sleep study referrals.Screening tools including both subjective and objective data may assist in early identification of possible OSA among professional drivers.Educational aimsTo evaluate screening instruments currently used to identify OSA risk in professional drivers.To provide guidance for developing an assessment strategy for OSA by professional driver medical examiners.

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