MRI study of regional variations of pharyngeal wall compliance in cats

1998 ◽  
Vol 85 (5) ◽  
pp. 1884-1897 ◽  
Author(s):  
Michael J. Brennick ◽  
Malcolm D. Ogilvie ◽  
Susan S. Margulies ◽  
Luke Hiller ◽  
Warren B. Gefter ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Three Dimensional ◽  
Upper Airway ◽  
Cross Sectional ◽  
Pharyngeal Wall ◽  
Regional Variations ◽  
Pharyngeal Airway ◽  
Obstructive Sleep ◽  
Mri Study

Upper airway compliance indicates the potential of the airway to collapse and is relevant to the pathogenesis of obstructive sleep apnea. We hypothesized that compliance would vary over the rostral-to-caudal extent of the pharyngeal airway. In a paralyzed isolated upper airway preparation in cats, we controlled static upper airway pressure during magnetic resonance imaging (MRI, 0.391-mm resolution). We measured cross-sectional area and anteroposterior and lateral dimensions from three-dimensional reconstructed MRIs in axial slices orthogonal to the airway centerline. High-retropalatal (HRP), midretropalatal (MRP), and hypopharyngeal (HYP) regions were defined. Regional compliance was significantly increased from rostral to caudal regions as follows: HRP < MRP < HYP ( P < 0.0001), and compliance differences among regions were directly related to collapsibility. Thus our findings in the isolated upper airway of the cat support the hypothesis that regional differences in pharyngeal compliance exist and suggest that baseline regional variations in compliance and collapsibility may be an important factor in the pathogenesis and treatment of obstructive sleep apnea.

scholarly journals Three-dimensional analyses of palatal morphology and its relation to upper airway area in obstructive sleep apnea

2016 ◽  
Vol 87 (2) ◽  
pp. 300-306 ◽  
Author(s):  
Defne Kecik
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Three Dimensional ◽  
Upper Airway ◽  
Control Group ◽  
Pharyngeal Airway ◽  
Obstructive Sleep ◽  
Lateral Cephalograms ◽  
Airway Morphology ◽  
Pharyngeal Area

ABSTRACT Objective: To evaluate the relationship between palatal morphology and pharyngeal airway morphology in patients who have obstructive sleep apnea (OSA) and compare with a nonsnoring and nonapneic control group. Materials and Methods: Three-dimensional maxillary dental cast measurements from 25 OSA patients (6 women, 19 men) with a mean age of 41.5 (4.8) years, and 25 control group participants (14 women, 11 men) without any symptom of OSA with a mean age of 38.3 (3.7) were correlated with an analysis of pharyngeal area evaluated with lateral cephalograms. Intermolar and intercanine widths and palatal volumes were calculated on the dental casts, and the upper airway area measurements were performed on lateral cephalograms. Results: OSA patients had smaller oropharyngeal volume and upper airway when compared with controls (P &lt; .001). Palatal area measurements were significantly smaller in OSA (P &lt; .001). OSA patients had significantly narrower maxilla with smaller intermolar and intercanine widths (P &lt; .001). A positive correlation was found between the palatal morphology and pharyngeal dimensions. Conclusions: A significant correlation exists between palatal morphology and pharyngeal airway.

scholarly journals Anatomical Balance of the Upper Airway and Obstructive Sleep Apnea

2008 ◽  
Vol 108 (6) ◽  
pp. 1009-1015 ◽  
Author(s):  
Satoru Tsuiki ◽  
Shiroh Isono ◽  
Teruhiko Ishikawa ◽  
Yoshihiro Yamashiro ◽  
Koichiro Tatsumi ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Adult Male ◽  
Upper Airway ◽  
Cross Sectional ◽  
Pharyngeal Airway ◽  
Soft Tissue Volume ◽  
Obstructive Sleep ◽  
Lateral Cephalograms ◽  
Maxilla And Mandible

Background Obesity and craniofacial abnormalities such as small maxilla and mandible are common features of patients with obstructive sleep apnea (OSA). The authors hypothesized that anatomical imbalance between the upper airway soft-tissue volume and the craniofacial size (rather than each alone) may result in pharyngeal airway obstruction during sleep, and therefore development of OSA. Methods Blind measurements of tongue cross-sectional area and craniofacial dimensions were performed through lateral cephalograms in 50 adult male patients with OSA and 55 adult male non-OSA subjects with various craniofacial dimensions. Results Maxillomandibular dimensions were matched between OSA and non-OSA groups. While the tongue was significantly larger in subjects with larger maxillomandible dimensions, OSA patients had a significantly larger tongue for a given maxillomandible size than non-OSA subjects. The hypothesis was also supported in subgroups matched for both body mass index and maxillomandible dimensions. Conclusions Upper airway anatomical imbalance is involved in the pathogenesis of OSA.

Obstructive Sleep Apnea in Acromegaly and the Effect of Treatment: A Systematic Review and Meta-Analysis

2019 ◽  
Vol 105 (3) ◽  
pp. e23-e31 ◽  
Author(s):  
Matteo Parolin ◽  
Francesca Dassie ◽  
Luigi Alessio ◽  
Alexandra Wennberg ◽  
Marco Rossato ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Meta Analysis ◽  
Upper Airway ◽  
Apnea Hypopnea Index ◽  
Cross Sectional ◽  
Obstructive Sleep ◽  
Before And After ◽  
The Difference

Abstract Background Obstructive sleep apnea (OSA) is a common disorder characterized by upper airway collapse requiring nocturnal ventilatory assistance. Multiple studies have investigated the relationship between acromegaly and OSA, reporting discordant results. Aim To conduct a meta-analysis on the risk for OSA in acromegaly, and in particular to assess the role of disease activity and the effect of treatments. Methods and Study Selection A search through literature databases retrieved 21 articles for a total of 24 studies (n = 734). Selected outcomes were OSA prevalence and apnea-hypopnea index (AHI) in studies comparing acromegalic patients with active (ACT) vs inactive (INACT) disease and pretreatment and posttreatment measures. Factors used for moderator and meta-regression analysis included the percentage of patients with severe OSA, patient sex, age, body mass index, levels of insulin-like growth factor 1, disease duration and follow-up, and therapy. Results OSA prevalence was similar in patients with acromegaly who had ACT and INACT disease (ES = −0.16; 95% CI, −0.47 to 0.15; number of studies [k] = 10; P = 0.32). In addition, AHI was similar in ACT and INACT acromegaly patients (ES = −0.03; 95% CI, −0.49 to 0.43; k = 6; P = 0.89). When AHI was compared before and after treatment in patients with acromegaly (median follow-up of 6 months), a significant improvement was observed after treatment (ES = −0.36; 95% CI, −0.49 to −0.23; k = 10; P &lt; 0.0001). In moderator analysis, the percentage of patients with severe OSA in the populations significantly influenced the difference in OSA prevalence (P = 0.038) and AHI (P = 0.04) in ACT vs INACT patients. Conclusion Prevalence of OSA and AHI is similar in ACT and INACT patients in cross-sectional studies. However, when AHI was measured longitudinally before and after treatment, a significant improvement was observed after treatment.

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

SLEEP ◽  
2019 ◽  
Vol 42 (7) ◽  
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.

Sniffing Position Improves Pharyngeal Airway Patency in Anesthetized Patients with Obstructive Sleep Apnea

2005 ◽  
Vol 103 (3) ◽  
pp. 489-494 ◽  
Author(s):  
Shiroh Isono ◽  
Atsuko Tanaka ◽  
Teruhiko Ishikawa ◽  
Yugo Tagaito ◽  
Takashi Nishino
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Static Pressure ◽  
Cross Sectional ◽  
Airway Patency ◽  
Neck Position ◽  
Pharyngeal Airway ◽  
Obstructive Sleep ◽  
Pressure Area ◽  
Closing Pressure

Background Appropriate bag-and-mask ventilation with patent airway is mandatory during induction of general anesthesia. Although the sniffing neck position is a traditionally recommended head and neck position during this critical period, knowledge of the influences of this position on the pharyngeal airway patency is still inadequate. Methods Total muscle paralysis was induced with general anesthesia in 12 patients with obstructive sleep apnea, eliminating neuromuscular factors contributing to pharyngeal patency. The cross-sectional area of the pharynx was measured endoscopically at different static airway pressures. Comparison of static pressure-area plot between the neutral and sniffing neck positions allowed assessment of the influence of the neck position change on the mechanical properties of the pharynx. Results The static pressure-area curves of the sniffing position were above those of neutral neck position, with increasing maximum cross-sectional area and decreasing the closing pressure at both retropalatal and retroglossal airways. The beneficial effects of the sniffing position were greater in obstructive sleep apnea patients with higher closing pressure and smaller body mass index. Conclusions Sniffing position structurally improves maintenance of the passive pharyngeal airway in patients with obstructive sleep apnea and may be beneficial for both mask ventilation and tracheal intubation during anesthesia induction.

Retropalatal Cross-Sectional Area Is Predictive of Obstructive Sleep Apnea in Patients With Syndromic Craniosynostosis

2019 ◽  
Vol 57 (5) ◽  
pp. 560-565 ◽  
Author(s):  
Cory M. Resnick ◽  
Jason K. Middleton ◽  
Carly E. Calabrese ◽  
Karan Ganjawalla ◽  
Bonnie L. Padwa
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Cross Sectional Area ◽  
Secondary Outcome ◽  
Outcome Variable ◽  
Sectional Area ◽  
Cross Sectional ◽  
Syndromic Craniosynostosis ◽  
Obstructive Sleep

Objective: There is a high rate of obstructive sleep apnea (OSA) in patients with syndromic craniosynostosis (SCS). Little is known about the airway anatomy in this population. The purpose of this study is to characterize the 3 dimensional (3D) upper airway in patients with SCS with and without OSA. Design: This is a retrospective study of patients with SCS treated at Boston Children’s Hospital from 2000 to 2015. Patients were divided into OSA and no-OSA groups based on polysomnography. Predictor variables included age, sex, body mass index (BMI), and 3D upper airway measurements. The primary outcome variable was the presence or absence of OSA. Secondary outcome variables were apnea–hypopnea index and oxygen saturation nadir. Descriptive and bivariate statistics were computed, and significance was set as P < .05. Results: There were 24 patients: 16 in the OSA group and 8 in the no-OSA group. The 2 groups did not differ significantly by age, BMI, or syndromic diagnosis. The presence of OSA was associated with a smaller minimum retropalatal cross-sectional area (minRPCSA; P < .001). In a logistic regression model controlling for age, sex, and upper airway length, minRPCSA was the primary predictor of OSA ( P ≤ .002). Receiver operating characteristic analysis determined minRPCSA = 55.3 mm2 to be the optimal diagnostic threshold for OSA, with sensitivity = 100% and specificity = 87.5% ( P < .001). Conclusion: A minRPCSA ≤55.3 mm2 is predictive of the presence of OSA in patients with SCS.

Association between Flexible Nasal Endoscopy, Polysonography Findins and Obstructive Sleep Apnea Severety

2021 ◽  
Vol 9 (3) ◽  
pp. 01-06
Author(s):  
Zappelini CEM ◽  
Jeremias LA ◽  
Borba IN ◽  
Machado LZ ◽  
Nicoladelli SJ ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Rem Sleep ◽  
Sleep Stage ◽  
Upper Airway ◽  
Inverse Correlation ◽  
Apnea Hypopnea Index ◽  
Upper Airways ◽  
Cross Sectional ◽  
Obstructive Sleep

Introduction: Obstructive Sleep Apnea (OSA) is a condition with recurrent collapses of the pharyngeal region that result in partial or total reduction in airflow. Its diagnosis and severity depends on the Apnea-Hypopnea Index (AHI), data from the polysomnography exam (PSG). Its pathophysiology includes anatomical disorders of the upper airways that can be assessed through Flexible Nasofibroscopy (FN). Objective: To identify the alterations present in the tests of FN and PSG in patients with OSA and correlate with the AHI. Methods: Cross-sectional study, with data collected from reports of the FN and PSG exams of 81 patients with OSA, seen at an otorhinolaryngology clinic in Tubarão - SC. It was verified the association between the outcome –AHI- and other exposure variables - sociodemographic and clinical. Results: Among the 81 patients, 75.31% were male, 41.98% had mild apnea, 30.86% moderate and 27.16% severe apnea. There was no correlation between FN findings and AHI (p> 0.05). There was a difference between the mean age, number of obstructive episodes per hour of sleep and minimum saturation between the groups with severe and mild apnea (p <0.05). Patients with severe apnea had a higher percentage of sleep phase one and a shorter REM sleep time compared to the mild apnea group (p <0.05). A positive correlation was obtained between: obstructive episodes with sleep stage 1 (p <0.01) and age (p <0.05); between minimum saturation and sleep stage 3 (p <0.05). There was an inverse correlation between obstructive episodes with minimal saturation (p <0.001), with sleep stage 3 (p <0.01) and with REM sleep (p <0.01); between age and minimum saturation (p <0.01). Conclusion: OSA directly interferes with sleep architecture. The present study did not find association between upper airway alterations and OSA severity.

Tracheal hysteresis in sleep apnea

1989 ◽  
Vol 67 (4) ◽  
pp. 1349-1353 ◽  
Author(s):  
I. Katz ◽  
N. Zamel ◽  
A. S. Slutsky ◽  
A. S. Rebuck ◽  
V. Hoffstein
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Muscle Tone ◽  
Upper Airway ◽  
Lung Parenchyma ◽  
Apnea Hypopnea Index ◽  
Cross Sectional ◽  
Acoustic Reflection ◽  
Obstructive Sleep ◽  
Pharyngeal Muscles

The collapsibility of pharyngeal walls, characteristic of patients with obstructive sleep apnea, likely results from reduced tone of the pharyngeal muscles. This reduction in the upper airway muscle tone may not end at the pharynx but may extend further distally, e.g., into the trachea. Because tracheal tone cannot be measured directly in conscious humans, we inferred the tone from the relative hysteresis of the tracheal area compared with the lung. Relative hysteresis was measured by plotting the cross-sectional area of a tracheal segment obtained by the acoustic reflection technique vs. lung volume. All measurements were performed during wakefulness. We found that in 42 patients with obstructive sleep apnea (apnea/hypopnea index greater than 10), relative hysteresis of the proximal trachea was predominantly clockwise, i.e., smaller than that of the lung parenchyma; in the 33 nonapneic patients (apnea/hypopnea index less than or equal to 10), it was predominantly counter-clockwise, i.e., larger than that of the lung parenchyma. For the distal trachea all patients, apneic and nonapneic, had similar, clockwise, relative hysteresis. We conclude that reduction in the upper airway muscle tone in patients with obstructive sleep apnea extends into the trachea.

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