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

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.


2019 ◽  
Vol 105 (3) ◽  
pp. e23-e31 ◽  
Author(s):  
Matteo Parolin ◽  
Francesca Dassie ◽  
Luigi Alessio ◽  
Alexandra Wennberg ◽  
Marco Rossato ◽  
...  

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 < 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.



2021 ◽  
Vol 9 (3) ◽  
pp. 01-06
Author(s):  
Zappelini CEM ◽  
Jeremias LA ◽  
Borba IN ◽  
Machado LZ ◽  
Nicoladelli SJ ◽  
...  

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.



2019 ◽  
Vol 8 (10) ◽  
pp. 1754 ◽  
Author(s):  
Olga Mediano ◽  
Sofia Romero-Peralta ◽  
Pilar Resano ◽  
Irene Cano-Pumarega ◽  
Manuel Sánchez-de-la-Torre ◽  
...  

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of upper airway obstruction caused by a loss of upper airway dilator muscle tone during sleep and an inadequate compensatory response by these muscles in the context of an anatomically compromised airway. The genioglossus (GG) is the main upper airway dilator muscle. Currently, continuous positive airway pressure is the first-line treatment for OSA. Nevertheless, problems related to poor adherence have been described in some groups of patients. In recent years, new OSA treatment strategies have been developed to improve GG function. (A) Hypoglossal nerve electrical stimulation leads to significant improvements in objective (apnea-hypopnea index, or AHI) and subjective measurements of OSA severity, but its invasive nature limits its application. (B) A recently introduced combination of drugs administered orally before bedtime reduces AHI and improves the responsiveness of the GG. (C) Finally, myofunctional therapy also decreases AHI, and it might be considered in combination with other treatments. Our objective is to review these therapies in order to advance current understanding of the prospects for alternative OSA treatments.



2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
K. Al Oweidat ◽  
S. A. AlRyalat ◽  
M. Al-Essa ◽  
N. Obeidat

Obstructive sleep apnea (OSA) is a common disorder that includes an intermittent mechanical obstruction of the upper airway during sleep, which can occur either during rapid eye movement (REM) phase or non-REM (NREM) phase. In this study, we aim to evaluate the differences in demographic and polysomnographic features between REM- and NREM-related OSA in a Jordanian sample, using both the broad and the restricted definitions of REM-related OSA. All patients who were referred due to clinical suspicion of OSA and underwent sleep study were screened. We included patients with a diagnosis of OSA who had Apnea-Hypopnea Index (AHI) greater than or equal to five. We classified patients into REM-related OSA according to either the broad definition (AHIREM/AHINREM ≥ 2) or the strict definition (AHIREM > 5 and AHINREM < 5 with a total REM sleep duration of at least 30 minutes), and patients with AHIREM/AHINREM less than two were classified as NREM-related OSA. A total of 478 patients were included in this study with a mean age of 55.3 years (±12.6). According to the broad definition of REM-related OSA, 86 (18%) of OSA patients were classified as having REM-related OSA compared to only 13 (2.7%) patients according to the strict definition. Significant differences were found between both NREM-related OSA and REM-related OSA according to the broad and to the strict definitions for arousal index (p<0.001 and p<0.032), respectively, duration of saturation below 90% (p<0.001 for both), and saturation nadir (p<0.036 and p<0.013), respectively. No significant differences were found between this group and other OSA patients regarding age, BMI, ESS, and snoring. Our study showed that the stricter the definition for REM-related OSA, the milder the associated clinical changes.



2013 ◽  
Vol 114 (7) ◽  
pp. 911-922 ◽  
Author(s):  
Andrew Wellman ◽  
Bradley A. Edwards ◽  
Scott A. Sands ◽  
Robert L. Owens ◽  
Shamim Nemati ◽  
...  

We previously published a method for measuring several physiological traits causing obstructive sleep apnea (OSA). The method, however, had a relatively low success rate (76%) and required mathematical modeling, potentially limiting its application. This paper presents a substantial revision of that technique. To make the measurements, continuous positive airway pressure (CPAP) was manipulated during sleep to quantify 1) eupneic ventilatory demand, 2) the level of ventilation at which arousals begin to occur, 3) ventilation off CPAP (nasal pressure = 0 cmH2O) when the pharyngeal muscles are activated during sleep, and 4) ventilation off CPAP when the pharyngeal muscles are relatively passive. These traits could be determined in all 13 participants (100% success rate). There was substantial intersubject variability in the reduction in ventilation that individuals could tolerate before having arousals (difference between ventilations #1 and #2 ranged from 0.7 to 2.9 liters/min) and in the amount of ventilatory compensation that individuals could generate (difference between ventilations #3 and #4 ranged from −0.5 to 5.5 liters/min). Importantly, the measurements accurately reflected clinical metrics; the difference between ventilations #2 and #3, a measure of the gap that must be overcome to achieve stable breathing during sleep, correlated with the apnea-hypopnea index ( r = 0.9, P < 0.001). An additional procedure was added to the technique to measure loop gain (sensitivity of the ventilatory control system), which allowed arousal threshold and upper airway gain (response of the upper airway to increasing ventilatory drive) to be quantified as well. Of note, the traits were generally repeatable when measured on a second night in 5 individuals. This technique is a relatively simple way of defining mechanisms underlying OSA and could potentially be used in a clinical setting to individualize therapy.



ORL ◽  
2021 ◽  
pp. 1-8
Author(s):  
Lifeng Li ◽  
Demin Han ◽  
Hongrui Zang ◽  
Nyall R. London

<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.



Author(s):  
Goutham Mylavarapu ◽  
Ephraim Gutmark ◽  
Sally Shott ◽  
Robert J. Fleck ◽  
Mohamed Mahmoud ◽  
...  

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.



Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Kevin R Duque ◽  
Brian Villafuerte ◽  
Fiorella Adrianzen ◽  
Rodrigo Zamudio ◽  
Andrea Mendiola ◽  
...  

Introduction: Obstructive sleep apnea (OSA) is a biological plausible risk factor for leukoaraiosis (LA). We tested the hypothesis that polysomnographic (PSG) and sleep-related variables are associated to LA in OSA patients. Methods: Cross-sectional study in which PSG records, medical histories and brain 1.5T MRI were collected from all consecutive patients who had attended a Sleep Medicine Center between 2009-2014. LA was graded from 0 to 9 with the ’Atherosclerosis Risk In Communities’ study scale. OSA was defined by The International Classification of Sleep Disorders, 2014, and its severity categorizing according to apnea-hypopnea index (AHI, <15 mild, 15 to <30 moderate, 30 to <45 severe and ≥45 very severe). A multinomial logistic regression was performed to describe the association between OSA severity and LA (divided into 2 groups: mild-to-moderate LA and non-to-minimal LA). The covariates for all regression models were age, gender, BMI, hypertension, ischemic stroke, myocardial infarction, diabetes and pack-year of smoking. Results: From 82 OSA patients (77% male; mean age 58±9 years, range 19-91), 54 (66%) had LA. Mild-to-moderate LA was found in 13 patients (8 mild and 5 moderate LA) and non-to-minimal LA in 69 (41 minimal and 28 non LA). Spearman’s correlation coefficient between AHI and LA grade was 0.41 (p<0.001). Furthermore, the higher OSA severity, the higher LA severity (p<0.001, for Jonckheere-Terpstra test for ordered alternatives). In the multinomial logistic regression model adjusted for cofounders, severe OSA patients had higher risk for mild or moderate LA (HR 12.8, 95% IC 1.2-141) compared to mild-to-moderate OSA patients. Additionally, self-reported habitual sleep duration from 7 to 9 hours (HR 0.36, 90% IC 0.14-0.90) and proportion of time in apnea/hypopnea over total sleep time (HR 1.04 for one unit increase, 90% IC 1.01-1.08) could be associated with the presence of LA (adjusted only for age and gender). In a multiple regression analysis with all the aforementioned variables, age (p=0.002), diabetes (p=0.003), and OSA severity (p=0.04) were predictors of the presence of LA. Conclusion: Patients with severe OSA had higher risk for mild to moderate LA when compared to patients with mild or moderate OSA.





Sign in / Sign up

Export Citation Format

Share Document