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Raanan Arens - One of the best experts on this subject based on the ideXlab platform.
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Effect of sleep on upper Airway Dynamics in obese adolescents with obstructive sleep apnea syndrome.
Sleep, 2020Co-Authors: Anna C. Bitners, Sanghun Sin, Sabhyata Agrawal, Seonjoo Lee, Jayaram K. Udupa, Yubing Tong, David M. Wootton, Kok Ren Choy, Mark E. Wagshul, Raanan ArensAbstract:STUDY OBJECTIVES The biomechanical basis of obstructive sleep apnea syndrome (OSAS) may influence upper Airway Dynamics. In this study, we investigate dynamic changes during respiration in wakefulness and sleep in obese adolescents with and without OSAS. METHODS Respiratory-gated dynamic magnetic resonance imaging (MRI) at the retropalatal and retroglossal regions was performed with simultaneous measurement of SpO2 and nasal-oral mask airflow and pressure. Airway cross-sectional area (CSA) was determined using AMIRA. Percent change in CSA was calculated from five continuous tidal breaths in states of wakefulness and sleep. Mixed effects models were used to evaluate interactions between group (OSAS/control), site (retropalatal/retroglossal), and stage (wake/sleep). RESULTS We studied 24 children with OSAS (mean age 15.49 ± 2.00 years, mean apnea-hypopnea index [AHI] 16.53 ± 8.72 events/h) and 19 controls (mean age 14.86 ± 1.75 years, mean AHI 2.12 ± 1.69 events/h). Groups were similar in age, sex, height, weight, and BMI Z-score. Participants with OSAS had a 48.17% greater increase in percent change of Airway CSA during sleep than controls (p < 0.0001), while there was no difference between groups during wakefulness (p = 0.6589). Additionally, participants with OSAS had a 48.80% increase in percent change of Airway CSA during sleep as compared with wakefulness (p < 0.0001), whereas no such relationship was observed in controls (p = 0.5513). CONCLUSIONS This study demonstrates significant effects of sleep on upper Airway Dynamics in obese children with OSAS. Dynamic MRI with physiological data can potentially provide further insight into the biomechanical basis of OSAS and assist in more effective management.
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Changes in upper Airway size during tidal breathing in children with obstructive sleep apnea syndrome.
American journal of respiratory and critical care medicine, 2005Co-Authors: Raanan Arens, Sanghun Sin, David M. Wootton, Joseph M. Mcdonough, John M. Palmer, Troy E. Dominguez, Heiko Meyer, Allan I. PackAbstract:We performed respiratory-gated magnetic resonance imaging to evaluate Airway Dynamics during tidal breathing in 10 children with obstructive sleep apnea syndrome (OSAS; age, 4.3 2.3 years) and 10matchedcontrolsubjects(age,5.02.0years).Wehypothesized that respiratory cycle fluctuations in upper Airway cross-sectional area would be larger in children with OSAS. Methods: Studies were performed under sedation. Respiratory gating was performed automatically at 10, 30, 50, 70, and 90% of inspiratory and expiratory volume.Airwaycross-sectionalareawasmeasuredatfourascending oropharyngeal levels at each increment of the respiratory cycle. Results: We noted the following in subjects with OSAS compared with control subjects: (1) a smaller upper Airway cross-sectional area, particularly during inspiration; (2) Airway narrowing occurred during inspiration without evidence of complete Airway collapse; (3) Airway dilatation occurred during expiration, particularly early inthephase;and(4)magnitudeofcross-sectionalareasfluctuations during tidal breathing noted in OSAS at levels 1 through 4 were 317, 422, 785, and 922%, compared with 19, 15 17, and 24% in control subjects (p 0.001, p 0.005, p 0.001, and p 0.001, respectively). Conclusions: Fluctuations in Airway area during tidal breathing are significantly greater in subjects with OSAS compared with control subjects. Resistive pressure loading is a probable explanation, although increased Airway compliance may be a contributing factor.
Richard Kraemer - One of the best experts on this subject based on the ideXlab platform.
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Normative Reference Equations of Airway Dynamics Assessed by Whole-Body Plethysmography During Spontaneous Breathing Transitionally Evaluated in Infants, Children and Adults
2020Co-Authors: Richard Kraemer, Hans-jürgen Smith, Heinrich MatthysAbstract:Abstract Background In contrast to the conventional parameters of Airway Dynamics mostly obtained by the two-point approximation method, the effective specific Airway resistance (sReff), its reciprocal value the effective specific Airway conductance (sGeff) resp., obtained by the integration of the entire tidal breathing loop, features promising target parameters for differentiating between individual functional disease patterns. sReff can be computed as the ratio between the integral of the area enclosed by the plethysmographic shift volume–tidal flow loop, featuring the specific aerodynamic work of breathing (sWOB), and the tidal flow–volume loop, sGeff by the ratio of the integral of the tidal flow–volume loop and the sWOB, respectively. However, normative values for sWOB, sReff and sGeff at resting level are not yet available.Methods We aimed to define reference equations in healthy infants (n=28), children (n=47) and adults (n=273), which incorporates not only the standard anthropometric measures, but also lung volume and breathing pattern indices (including both volume and time indices). Retrospectively exported data were collected from databases of 5 Swiss lung function centres, in which plethysmography (Jaeger Würzburg, Germany) was performed using standard techniques (ATS-ERS criteria) for the assessment of Airway Dynamics, static lung volumes and forced breathing flow-volume loops.Results Using multi-linear modelling, reference equations of sReff, sGeff, and sWOB could be defined taking as independent parameters apart from anthropometric parameters, also parameters given by the ratio between the tidal volume (VT) and functional residual capacity (FRCpleth), and the ratio between VT and inspiratory time (VT/TI). In addition, we examined the effect of age on the breathing pattern, the relationship between breathing pattern (tidal volume) and timing (inspiratory time).Conclusions An alternative statistical approach to define reference equations of Airway Dynamics reveals that apart from the subject’s anthropometric measurements, parameters of the magnitude of static lung volumes, the breathing pattern, and the timing of breathing are co-variants of reference equations of Airway Dynamics over a large age range.
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Alterations in static lung volumes during methacholine challenge (MCH) tests, assessed by whole-body plethysmography using the aerosol provocation system (APS)
European Respiratory Journal, 2012Co-Authors: Richard Kraemer, Gaby Giger, Thomas Sigrist, Martin FreyAbstract:Rationale. Airway hyperreactivity (AHR) is a characteristic feature of asthma, and methacholine challenge tests (MCT) are well established in asthma diagnostics and research, to quantitate AHR. Cut points have arbitrarily been selected, defining a fall of 20% in FEV 1 as PC 20 . By this technical approach, however, changes in end-expiratory resting level cannot be detected. MCT using APS technology integrated in the Jaeger whole-body plethysmograph features the possibility to evaluate changes of Airway Dynamics concomitantly with changes of lung volumes [1]. Objectives. We aimed to assess changes of FRC pleth , IC, ERV and hence RV and TLC during MCT, and comparing changes of effective specific Airway conductances (sG eff , sG 0.5 , sG tot ) in relation to changes effected to FEV 1 and MEF 50 . Methods. We retrospectively analysed data from our hospital database including 140 test persons (asthmatics and controls; 59 males; 81 females; age: 11 to 82 y), in whom MCT have been performed. Methacholine was administered during 3 consecutive cumulative challenge levels (P1:0.2 mg; P2:1.0 mg; P3:2.2 mg) computerized by the APS system. Results. During MCT not only Airway mechanics, but also static lung volumes (FRC pleth , IC) changed consistently. Conclusions. In the assessment of AHR by MCT sG eff and and sG tot qualified as most sensitive target parameter, taking into account changes of Airway Dynamics concomitantly with changes of lung volumes. Comparison between volume-time and flow-volume parameters with plethysmographically assessed sG eff , sG 0.5 during MCT is presented in abstract 850930. [1]. Matthys H, et al.: Respiration: 1975;32(2):121-134.
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Sensitivity and specificity of Airway hyperreactivity (AHR) based on methacholine challenge (MCH) tests - Comparison of sGeff with FEV1 and MEF50 as target parameter
European Respiratory Journal, 2012Co-Authors: Richard Kraemer, Thomas Sigrist, Gabi Giger, Martin FreyAbstract:Rationale. Airway hyperreactivity (AHR) is a characteristic feature of asthma, and methacholine challenge tests (MCT) are well established, mostly defining a fall of 20% in FEV 1 as PC 20 . In contrast to this spirometric technique, whole-body plethysmography features the possibility to evaluate changes of Airway Dynamics concomitantly with changes of lung volumes (see also abstract 850929). Objectives. Assessment of sensitivity and specificity of MCT, comparing changes of effective specific Airway conductances (sG eff , sG 0.5 , sG tot ) with changes effected to FEV 1 and MEF 50 . Methods. Data from 140 test persons (asthmatics and controls; 59 males; 81 females; age: 11 to 82 y), in whom MCH was administered during 3 consecutive cumulative challenge levels (P1:0.2 mg; P2:1.0 mg; P3:2.2 mg) computerized by the APS system, were retrospectively evaluated. Results. Highest response rates were found for sG eff PD , 50 (82.1%) and sG tot PD , 50 (77.1%), lowest for FEV 1 PD 20 (34.3%), and intermediate for MEF 50 PD 50 (45%). sG eff reached its PD 50 at 0.56±0.48 mg, FEV 1 its PD 20 only at .94±.57 mg MCH. Sensitivity of MCH-tests (s) and specificity (f) were obtained as follows: sG eff (s: 95.7%; f: 80.0%), sG tot (s: 91.3%; f: 88.0%), FEV 1 (s: 38.3%; f: 84.0%) and MEF 50 : (s: 48.7%; f: 72.0%). Conclusions. In comparison to FEV 1 , assessment of AHR by sG eff and sG tot reached their PD at much lower MCH doses, in a much higher percentage of tests. The advantage of MCT by plethysmography, measuring changes of Airway Dynamics in relation to changes of the volume history, features the advantage to perform MCT with better safety for the patients.
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An isoflow-volume technique for assessing Airway Dynamics in children and adults.
Respiration; international review of thoracic diseases, 2001Co-Authors: Andreas Schibler, Urs Frey, Richard KraemerAbstract:Background: We propose a new approach to the measurement of small Airway function as an alternative to recordings of maximal expiratory flow-volume (MEFV) curves. Objective
David M. Wootton - One of the best experts on this subject based on the ideXlab platform.
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Effect of sleep on upper Airway Dynamics in obese adolescents with obstructive sleep apnea syndrome.
Sleep, 2020Co-Authors: Anna C. Bitners, Sanghun Sin, Sabhyata Agrawal, Seonjoo Lee, Jayaram K. Udupa, Yubing Tong, David M. Wootton, Kok Ren Choy, Mark E. Wagshul, Raanan ArensAbstract:STUDY OBJECTIVES The biomechanical basis of obstructive sleep apnea syndrome (OSAS) may influence upper Airway Dynamics. In this study, we investigate dynamic changes during respiration in wakefulness and sleep in obese adolescents with and without OSAS. METHODS Respiratory-gated dynamic magnetic resonance imaging (MRI) at the retropalatal and retroglossal regions was performed with simultaneous measurement of SpO2 and nasal-oral mask airflow and pressure. Airway cross-sectional area (CSA) was determined using AMIRA. Percent change in CSA was calculated from five continuous tidal breaths in states of wakefulness and sleep. Mixed effects models were used to evaluate interactions between group (OSAS/control), site (retropalatal/retroglossal), and stage (wake/sleep). RESULTS We studied 24 children with OSAS (mean age 15.49 ± 2.00 years, mean apnea-hypopnea index [AHI] 16.53 ± 8.72 events/h) and 19 controls (mean age 14.86 ± 1.75 years, mean AHI 2.12 ± 1.69 events/h). Groups were similar in age, sex, height, weight, and BMI Z-score. Participants with OSAS had a 48.17% greater increase in percent change of Airway CSA during sleep than controls (p < 0.0001), while there was no difference between groups during wakefulness (p = 0.6589). Additionally, participants with OSAS had a 48.80% increase in percent change of Airway CSA during sleep as compared with wakefulness (p < 0.0001), whereas no such relationship was observed in controls (p = 0.5513). CONCLUSIONS This study demonstrates significant effects of sleep on upper Airway Dynamics in obese children with OSAS. Dynamic MRI with physiological data can potentially provide further insight into the biomechanical basis of OSAS and assist in more effective management.
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Changes in upper Airway size during tidal breathing in children with obstructive sleep apnea syndrome.
American journal of respiratory and critical care medicine, 2005Co-Authors: Raanan Arens, Sanghun Sin, David M. Wootton, Joseph M. Mcdonough, John M. Palmer, Troy E. Dominguez, Heiko Meyer, Allan I. PackAbstract:We performed respiratory-gated magnetic resonance imaging to evaluate Airway Dynamics during tidal breathing in 10 children with obstructive sleep apnea syndrome (OSAS; age, 4.3 2.3 years) and 10matchedcontrolsubjects(age,5.02.0years).Wehypothesized that respiratory cycle fluctuations in upper Airway cross-sectional area would be larger in children with OSAS. Methods: Studies were performed under sedation. Respiratory gating was performed automatically at 10, 30, 50, 70, and 90% of inspiratory and expiratory volume.Airwaycross-sectionalareawasmeasuredatfourascending oropharyngeal levels at each increment of the respiratory cycle. Results: We noted the following in subjects with OSAS compared with control subjects: (1) a smaller upper Airway cross-sectional area, particularly during inspiration; (2) Airway narrowing occurred during inspiration without evidence of complete Airway collapse; (3) Airway dilatation occurred during expiration, particularly early inthephase;and(4)magnitudeofcross-sectionalareasfluctuations during tidal breathing noted in OSAS at levels 1 through 4 were 317, 422, 785, and 922%, compared with 19, 15 17, and 24% in control subjects (p 0.001, p 0.005, p 0.001, and p 0.001, respectively). Conclusions: Fluctuations in Airway area during tidal breathing are significantly greater in subjects with OSAS compared with control subjects. Resistive pressure loading is a probable explanation, although increased Airway compliance may be a contributing factor.
Sanghun Sin - One of the best experts on this subject based on the ideXlab platform.
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Effect of sleep on upper Airway Dynamics in obese adolescents with obstructive sleep apnea syndrome.
Sleep, 2020Co-Authors: Anna C. Bitners, Sanghun Sin, Sabhyata Agrawal, Seonjoo Lee, Jayaram K. Udupa, Yubing Tong, David M. Wootton, Kok Ren Choy, Mark E. Wagshul, Raanan ArensAbstract:STUDY OBJECTIVES The biomechanical basis of obstructive sleep apnea syndrome (OSAS) may influence upper Airway Dynamics. In this study, we investigate dynamic changes during respiration in wakefulness and sleep in obese adolescents with and without OSAS. METHODS Respiratory-gated dynamic magnetic resonance imaging (MRI) at the retropalatal and retroglossal regions was performed with simultaneous measurement of SpO2 and nasal-oral mask airflow and pressure. Airway cross-sectional area (CSA) was determined using AMIRA. Percent change in CSA was calculated from five continuous tidal breaths in states of wakefulness and sleep. Mixed effects models were used to evaluate interactions between group (OSAS/control), site (retropalatal/retroglossal), and stage (wake/sleep). RESULTS We studied 24 children with OSAS (mean age 15.49 ± 2.00 years, mean apnea-hypopnea index [AHI] 16.53 ± 8.72 events/h) and 19 controls (mean age 14.86 ± 1.75 years, mean AHI 2.12 ± 1.69 events/h). Groups were similar in age, sex, height, weight, and BMI Z-score. Participants with OSAS had a 48.17% greater increase in percent change of Airway CSA during sleep than controls (p < 0.0001), while there was no difference between groups during wakefulness (p = 0.6589). Additionally, participants with OSAS had a 48.80% increase in percent change of Airway CSA during sleep as compared with wakefulness (p < 0.0001), whereas no such relationship was observed in controls (p = 0.5513). CONCLUSIONS This study demonstrates significant effects of sleep on upper Airway Dynamics in obese children with OSAS. Dynamic MRI with physiological data can potentially provide further insight into the biomechanical basis of OSAS and assist in more effective management.
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Changes in upper Airway size during tidal breathing in children with obstructive sleep apnea syndrome.
American journal of respiratory and critical care medicine, 2005Co-Authors: Raanan Arens, Sanghun Sin, David M. Wootton, Joseph M. Mcdonough, John M. Palmer, Troy E. Dominguez, Heiko Meyer, Allan I. PackAbstract:We performed respiratory-gated magnetic resonance imaging to evaluate Airway Dynamics during tidal breathing in 10 children with obstructive sleep apnea syndrome (OSAS; age, 4.3 2.3 years) and 10matchedcontrolsubjects(age,5.02.0years).Wehypothesized that respiratory cycle fluctuations in upper Airway cross-sectional area would be larger in children with OSAS. Methods: Studies were performed under sedation. Respiratory gating was performed automatically at 10, 30, 50, 70, and 90% of inspiratory and expiratory volume.Airwaycross-sectionalareawasmeasuredatfourascending oropharyngeal levels at each increment of the respiratory cycle. Results: We noted the following in subjects with OSAS compared with control subjects: (1) a smaller upper Airway cross-sectional area, particularly during inspiration; (2) Airway narrowing occurred during inspiration without evidence of complete Airway collapse; (3) Airway dilatation occurred during expiration, particularly early inthephase;and(4)magnitudeofcross-sectionalareasfluctuations during tidal breathing noted in OSAS at levels 1 through 4 were 317, 422, 785, and 922%, compared with 19, 15 17, and 24% in control subjects (p 0.001, p 0.005, p 0.001, and p 0.001, respectively). Conclusions: Fluctuations in Airway area during tidal breathing are significantly greater in subjects with OSAS compared with control subjects. Resistive pressure loading is a probable explanation, although increased Airway compliance may be a contributing factor.
C Tantucci - One of the best experts on this subject based on the ideXlab platform.
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Upper Airway Dynamics during negative expiratory pressure in apneic and non-apneic awake snorers
Respiratory Research, 2006Co-Authors: A Ferretti, P Giampiccolo, S Redolfi, S Mondini, F Cirignotta, A Cavalli, C TantucciAbstract:Background The ability of negative expiratory pressure (NEP) technique to differentiate between awake snorers with and without obstructive sleep apnea-hypopnea (OSAH) was investigated. Methods Forty-eight subjects with sleep disordered breathing (SDB) and 7 healthy subjects, as non-snorer controls, underwent the NEP application of -5 and -7 cmH_2O in the seated and supine position during wakefulness, after performing a sleep study. The upper Airway collapsibility was assessed by computing the volume exhaled during the first 0.5 sec. (V,NEP_0.5) and 1 sec. (V,NEP_1) following the NEP start. Results Patients with severe (AHI ≥ 30) (n = 19) and mild-to-moderate (AHI 5) (n = 15) OSAH had lower V,NEP_0.5 (340 ± 88 ml) as compared to snorers (AHI ≤ 5) (n = 14) (427 ± 101 ml; p < 0.01) and controls (n = 7) (492 ± 69 ml; p < 0.001) in the supine position with NEP -5 cmH_2O. Less significant differences among the different groups were observed for V,NEP_0.5 in the seated position with NEP -5 cmH_2O and in both positions with NEP -7 cmH_2O (only OSAH patients vs controls, p < 0.001). Similar results were obtained for V,NEP_1 in either position by using both NEP -5 cmH_2O and -7 cmH_2O. In spite of this, a substantial overlapping of V,NEP_0.5 and V,NEP_1 between snorers and OSAH patients did not allow to identify a reliable diagnostic cut-off level. An inverse correlation with AHI was found for V,NEP_0.5 in the supine position with NEP -5 cmH_2O (r_s = -0.46, p < 0.05) in severe OSAH patients. Conclusion The awake OSAH patients exhibit values of V,NEP_0.5 and V,NEP_1 lesser than those of awake snorers. The NEP technique, however, appears to have a limited usefulness as clinical tool for routine screening of the OSAH patients during wakefulness.
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Upper Airway Dynamics during negative expiratory pressure in apneic and non-apneic awake snorers
Respiratory research, 2006Co-Authors: A Ferretti, P Giampiccolo, S Redolfi, S Mondini, F Cirignotta, A Cavalli, C TantucciAbstract:Background The ability of negative expiratory pressure (NEP) technique to differentiate between awake snorers with and without obstructive sleep apnea-hypopnea (OSAH) was investigated.