Computational Modeling of Upper Airway Before and After Adenotonsillectomy for Obstructive Sleep Apnea

2008 ◽  
Vol 118 (2) ◽  
pp. 360-362 ◽  
Author(s):  
Mihai Mihaescu ◽  
Shanmugam Murugappan ◽  
Ephraim Gutmark ◽  
Lane F. Donnelly ◽  
Maninder Kalra
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.


1997 ◽  
Vol 38 (2) ◽  
pp. 214-221 ◽  
Author(s):  
Y. Tsushima ◽  
J. Antila ◽  
E. Laurikainen ◽  
E. Svedström ◽  
O. Polo ◽  
...  

Purpose: to study the changes in pharyngeal behavior after laser uvulopalatopharyngoplasty (LUPPP). Material and Methods: the dynamic changes in the upper airway size were evaluated with digital fluoroscopy in 24 patients with obstructive sleep apnea (OSA) before and after LUPPP and in 16 normal controls, while they were awake and breathing normally. Cephalometric measurements were also made. the patients were classified into the categories of good and poor responders by means of a static-charge-sensitive bed. Results: Following LUPPP, collapsibility at the velopharyngeal level was within the normal range in 15 of 17 good responders, but only in 2 of 7 poor responders (p=0.0086). the minimum airway size at the same level showed a similar trend. in 3 of 7 poor responders the hyoid bone was positioned more caudally than in the good responders (p=0.017). Conclusion: Digital fluoroscopy provides information on the change in upper airway behavior after LUPPP.


1996 ◽  
Vol 81 (2) ◽  
pp. 643-652 ◽  
Author(s):  
A. R. Schwartz ◽  
D. W. Eisele ◽  
A. Hari ◽  
R. Testerman ◽  
D. Erickson ◽  
...  

The influence of lingual muscle activity on airflow dynamics in the upper airway was examined in nine patients with obstructive sleep apnea. Muscles that retract the tongue (hyoglossus and styloglossus) and protrude the tongue (genioglossus) were selectively stimulated electrically during sleep with fine wire electrodes placed intramuscularly transorally. We confirmed that stimulation with 50 Hz and 40-microseconds pulse duration did not elicit changes in electroencephalographic patterns or heart rate or alter airflow after the stimulation burst had ceased. The highest stimulus intensity that did not arouse patients from sleep was then utilized to examine the effect of lingual muscle recruitment on airflow dynamics during steady-state periods of inspiratory airflow limitation. When applying a stimulus burst during single inspirations, maximal inspiratory airflow decreased by 239 +/- 177 ml/s (P < 0.05) during retractor stimulation, whereas maximal inspiratory airflow increased by 217 +/- 93 ml/s during protrusor stimulation (P < 0.001) compared with breaths immediately before and after the stimulated breath. When consecutive inspirations were stimulated repeatedly, protrusor stimulation decreased the frequency of obstructive breathing episodes in four patients breathing at 3.9 +/- 3.4 (SD) cmH2O nasal pressure. The findings suggest that stimulation of the lingual muscles can increase or decrease airflow depending on the specific muscles stimulated without arousing patients from sleep.


2003 ◽  
Vol 95 (5) ◽  
pp. 1761-1766 ◽  
Author(s):  
Jason P. Kirkness ◽  
Melanie Madronio ◽  
Rosie Stavrinou ◽  
John R. Wheatley ◽  
Terence C. Amis

Lowering surface tension (γ) of upper airway lining liquid (UAL) reduces upper airway opening (anesthetized humans) and closing (anesthetized rabbits) pressures. We now hypothesize that in sleeping obstructive sleep apnea hypopnea syndrome (OSAHS) patients lowering γ of UAL will enhance upper airway stability and decrease the severity of sleep-disordered breathing. Nine OSAHS patients [respiratory disturbance index (RDI): 49 ± 8 (SE) events/h, diagnostic night] participated in a two-part, one-night, polysomnography study. In the first part, upper airway closing pressures (during non-rapid eye movement sleep, Pcrit) were measured and samples of UAL (awake) were obtained before and after 2.5 ml of surfactant (Exosurf, Glaxo Smith Kline) was instilled into the posterior pharynx. The γ of UAL was determined with the use of the “pull-off” force technique. In the second part, subjects received a second application of 2.5 ml of surfactant and then slept the remainder of the night (205 ± 30 min). Instillation of surfactant decreased the γ of UAL from 60.9 ± 3.1 mN/m (control) to 45.2 ± 2.5 mN/m (surfactant group) ( n = 9, P < 0.001). Pcrit decreased from 1.19 ± 1.14 cmH2O (control) to -0.56 ± 1.15 cmH2O (surfactant group) ( n = 7, P < 0.02). Compared with the second half of diagnostic night, surfactant decreased RDI from 51 ± 8 to 35 ± 8 events/h ( n = 9, P < 0.03). The fall in RDI (ΔRDI) correlated with the fall in γ of UAL (Δγ) (ΔRDI = 1.8 × Δγ, r = 0.68, P = 0.04). Hypopneas decreased ∼50% from 42 ± 8 to 20 ± 5 events/h ( n = 9, P < 0.03, paired t-test). The γ of UAL measured the next morning remained low at 49.5 ± 2.7 mN/m ( n = 9, P < 0.001, ANOVA, compared with control). In conclusion, instillation of surfactant reduced the γ of UAL in OSAHS patients and decreased Pcrit and the occurrence of hypopneas. Therapeutic manipulation of γ of UAL may be beneficial in reducing the severity of sleep-disordered breathing in OSAHS patients.


2007 ◽  
Vol 103 (3) ◽  
pp. 911-916 ◽  
Author(s):  
James A. Rowley ◽  
Ihab Deebajah ◽  
Swapna Parikh ◽  
Ali Najar ◽  
Rajib Saha ◽  
...  

We have previously shown that in subjects with obstructive sleep apnea, repetitive hypoxia is associated with long-term facilitation as manifested by decreased upper airway resistance (Rua). Our objective was to study the influence of long-term facilitation on upper airway collapsibility as measured by the critical closing pressure (Pcrit) model and to determine whether changes in Rua correlated with changes in collapsibility. We studied 13 subjects (10 men, 3 women) with a mean apnea-hypopnea index of 43.9 ± 24.0 events/h. In the first protocol with 11 subjects, we measured collapsibility using a Pcrit protocol before and after episodic hypoxia. Brief (3 min) isocapnic hypoxia (inspired O2 fraction = 8%) followed by 5 min of room air was induced 10 times. A sham study without hypoxia was performed on eight subjects. Ventilatory parameters, Rua, and Pcrit before and after episodic hypoxia were measured. At 20 min of recovery, there was no change in minute ventilation but there was a significant decrease in Rua compared with the control period (control, 8.6 ± 4.8 cmH2O·l−1·s vs. recovery, 5.9 ± 3.8 cmH2O·l−1·s; P < 0.05). However, there was no change in Pcrit between the control (2.3 ± 1.9 cmH2O) and recovery (2.7 ± 3.2 cmH2O) periods. No changes in Rua or Pcrit were observed in the sham protocol. We conclude that long-term facilitation of upper airway dilators is not associated with changes in upper airway collapsibility in subjects with obstructive sleep apnea. These results corroborate previous evidence that changes in upper airway resistance and caliber can be dissociated from changes in upper airway collapsibility.


2021 ◽  
Vol 2 ◽  
Author(s):  
Eung-Kwon Pae ◽  
Ronald M. Harper

The objective was to determine whether hyoid bone elevation induced by an anterior mandibular positioning appliance (AMP) predicts the effectiveness of the AMP in patients with obstructive sleep apnea (OSA). Fifteen patients (12 males and 3 females) underwent polysomnographic recordings and lateral cephalograms before and after AMP use of at least 6 months. Measurements of sleep variables and upper airway morphology were compared between pre-AMP and with-AMP states. The AMP appliance reduced apnea-hypopnea indices (AHI) ~53% (33.77 ± 3.29 vs. 15.85 ± 3.78, P = 0.0013). Cephalograms of the oropharyngeal airway showed that the hyoid bone moved superiorly toward the inferior mandibular border (Δ H-MP) ~5 mm (23.4 ± 1.44 vs. 18.27 ± 1.86, P = 0.0377), with the AMP inserted in the oral cavity; no airway measurement other than hyoid bone position changed. No significant correlations emerged between AHI improvement (Δ AHI) and amounts of hyoid elevation (Δ H-MP) when all patients were pooled. However, when the samples were subcategorized, the correlation coefficients increased significantly (P &lt; 0.01) in both subgroups. This outcome suggests the presence of two distinct types among the “Good-Responders” to AMP appliance use. Overall use of the AMP appliance is effective; however, the effectiveness of the appliance appears to depend on the mode of hyoid elevations, likely resulting from muscle responsiveness in patients with AMP use. The results suggest that Δ H-MP measurements may be a useful marker to segregate patients with tongue and hyoid muscles responsive to AMP from those not-so-responsive.


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