Influences of the breathing route on upper airway dynamics properties in normal awake subjects with constant mouth opening

2006 ◽  
Vol 111 (5) ◽  
pp. 349-355 ◽  
Author(s):  
Wei Wang ◽  
Eric Verin ◽  
Frédéric Sériès
Keyword(s):  
Polynomial Regression ◽  
Dynamic Properties ◽  
Mouth Opening ◽  
Upper Airway ◽  
Nasal Breathing ◽  
Airway Collapsibility ◽  
Flow Pressure ◽  
Upper Airway Collapsibility ◽  
Male Subjects ◽  
Closing Pressure

MB (mouth breathing) promotes the occurrence of sleep-disordered breathing even in non-apnoeic subjects. Considering that MO (mouth opening) contributes to an increase in UA (upper airway) collapsibility independently of MB, the aim of the present study was to assess the influence of breathing route on UA dynamics in the presence of MO. Bilateral anterior magnetic phrenic nerve stimulation was performed 2 s after expiratory onset in 12 healthy male subjects during wakefulness (age, 50±5 years; body mass index, 27.8±2.4 kg/m2) during MB through a mouthpiece and during exclusive NB (nasal breathing) with the same mouthpiece in place. Twitch-induced V̇I (instantaneous flow), Pph and Pes (pharyngeal and oesophageal pressures respectively) were recorded and the corresponding resistances were measured. A polynomial regression model, V̇I=k1Pd+k2Pd2, was used to characterize flow–pressure relationship and to determine the Pd value at which UA collapses. There was no difference in UA dynamic properties between NB and MB when UA collapse occurred above the pharyngeal catheter. For twitches where UA collapse occurred lower in the UA, pharyngeal resistance decreased from NB to MB (2.0±0.3 and 1.5±0.2 cmH2O·l−1·s respectively; P=0.02; values are means±S.D.), whereas closing pressure increased (−25.7±10.1 and −18.0±3.0 cmH2O respectively; P=0.04). We conclude that (i) in the presence of MO the dynamic properties of the proximal UA free of phasic activity do not differ between NB and MB, and (ii) MB decreases the upstream resistance and increases collapsibility of the distal UA.

scholarly journals Effect of Head Elevation on Passive Upper Airway Collapsibility in Normal Subjects during Propofol Anesthesia

2011 ◽  
Vol 115 (2) ◽  
pp. 273-281 ◽  
Author(s):  
Masato Kobayashi ◽  
Takao Ayuse ◽  
Yuko Hoshino ◽  
Shinji Kurata ◽  
Shunji Moromugi ◽  
...  
Keyword(s):  
Upper Airway ◽  
Normal Subjects ◽  
Target Concentration ◽  
Airway Patency ◽  
Head Elevation ◽  
Jaw Opening ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility ◽  
Head Flexion ◽  
Male Subjects

Background Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia. Method Twenty male subjects were studied, randomized to one of two experimental groups: fixed-jaw or free-jaw. Propofol infusion was used for induction and to maintain blood at a constant target concentration between 1.5 and 2.0 μg/ml. Nasal mask pressure (PN) was intermittently reduced to evaluate the upper airway collapsibility (passive PCRIT) and upstream resistance (RUS) at each level of head elevation (0, 3, 6, and 9 cm). The authors measured the Frankfort plane (head flexion) and the mandible plane (jaw opening) angles at each level of head elevation. Analysis of variance was used to determine the effect of head elevation on PCRIT, head flexion, and jaw opening within each group. Results In both groups the Frankfort plane and mandible plane angles increased with head elevation (P < 0.05), although the mandible plane angle was smaller in the free-jaw group (i.e., increased jaw opening). In the fixed-jaw group, head elevation decreased upper airway collapsibility (PCRIT ~ -7 cm H₂O at greater than 6 cm elevation) compared with the baseline position (PCRIT ~ -3 cm H₂O at 0 cm elevation; P < 0.05). Conclusion : Elevating the head position by 6 cm while ensuring mouth closure (centric occlusion) produces substantial decreases in upper airway collapsibility and maintains upper airway patency during anesthesia.

Time of day affects the frequency and duration of breathing events and the critical closing pressure during NREM sleep in participants with sleep apnea

2015 ◽  
Vol 119 (6) ◽  
pp. 617-626 ◽  
Author(s):  
Mohamad El-Chami ◽  
David Shaheen ◽  
Blake Ivers ◽  
Ziauddin Syed ◽  
M. Safwan Badr ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Nrem Sleep ◽  
Time Of Day ◽  
Obstructive Sleep ◽  
Airway Collapsibility ◽  
Critical Closing Pressure ◽  
Upper Airway Collapsibility ◽  
Closing Pressure

We investigated if the number and duration of breathing events coupled to upper airway collapsibility were affected by the time of day. Male participants with obstructive sleep apnea completed a constant routine protocol that consisted of sleep sessions in the evening (10 PM to 1 AM), morning (6 AM to 9 AM), and afternoon (2 PM to 5 PM). On one occasion the number and duration of breathing events was ascertained for each sleep session. On a second occasion the critical closing pressure that demarcated upper airway collapsibility was determined. The duration of breathing events was consistently greater in the morning compared with the evening and afternoon during N1 and N2, while an increase in event frequency was evident during N1. The critical closing pressure was increased in the morning (2.68 ± 0.98 cmH2O) compared with the evening (1.29 ± 0.91 cmH2O; P ≤ 0.02) and afternoon (1.25 ± 0.79; P ≤ 0.01). The increase in the critical closing pressure was correlated to the decrease in the baseline partial pressure of carbon dioxide in the morning compared with the afternoon and evening ( r = −0.73, P ≤ 0.005). Our findings indicate that time of day affects the duration and frequency of events, coupled with alterations in upper airway collapsibility. We propose that increases in airway collapsibility in the morning may be linked to an endogenous modulation of baseline carbon dioxide levels and chemoreflex sensitivity (12), which are independent of the consequences of sleep apnea.

Mouth-opening Increases Upper-airway Collapsibility without Changing Resistance during Midazolam Sedation

2004 ◽  
Vol 83 (9) ◽  
pp. 718-722 ◽  
Author(s):  
T. Ayuse ◽  
T. Inazawa ◽  
S. Kurata ◽  
I. Okayasu ◽  
E. Sakamoto ◽  
...  
Keyword(s):  
Maxillofacial Surgery ◽  
Mouth Opening ◽  
Upper Airway ◽  
Airflow Limitation ◽  
Airway Patency ◽  
Anesthetic Agents ◽  
Airway Collapsibility ◽  
Maximal Mouth Opening ◽  
Inspiratory Airflow Limitation ◽  
Upper Airway Collapsibility

Sedative doses of anesthetic agents affect upper-airway function. Oral-maxillofacial surgery is frequently performed on sedated patients whose mouths must be as open as possible if the procedures are to be accomplished successfully. We examined upper-airway pressure-flow relationships in closed mouths, mouths opened moderately, and mouths opened maximally to test the hypothesis that mouth-opening compromises upper-airway patency during midazolam sedation. From these relationships, upper-airway critical pressure (Pcrit) and upstream resistance (Rua) were derived. Maximal mouth-opening increased Pcrit to −3.6 ± 2.9 cm H2O compared with −8.7 ± 2.8 (p = 0.002) for closed mouths and −7.2 ± 4.1 (p = 0.038) for mouths opened moderately. In contrast, Rua was similar in all three conditions (18.4 ± 6.6 vs. 17.7 ± 7.6 vs. 21.5 ± 11.6 cm H2O/L/sec). Moreover, maximum mouth-opening produced an inspiratory airflow limitation at atmosphere that was eliminated when nasal pressure was adjusted to 4.3 ± 2.7 cm H2O. We conclude that maximal mouth-opening increases upper-airway collapsibility, which contributes to upper-airway obstruction at atmosphere during midazolam sedation.

Effects of Depth of Propofol and Sevoflurane Anesthesia on Upper Airway Collapsibility, Respiratory Genioglossus Activation, and Breathing in Healthy Volunteers

2016 ◽  
Vol 125 (3) ◽  
pp. 525-534 ◽  
Author(s):  
Jeroen C. P. Simons ◽  
Eric Pierce ◽  
Daniel Diaz-Gil ◽  
Sanjana A. Malviya ◽  
Matthew J. Meyer ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Upper Airway ◽  
Sevoflurane Anesthesia ◽  
Pressure Drops ◽  
Airway Occlusion ◽  
Airway Collapsibility ◽  
Dose Dependent Fashion ◽  
Upper Airway Collapsibility ◽  
Dose Dependent ◽  
Closing Pressure

Abstract Background Volatile anesthetics and propofol impair upper airway stability and possibly respiratory upper airway dilator muscle activity. The magnitudes of these effects have not been compared at equivalent anesthetic doses. We hypothesized that upper airway closing pressure is less negative and genioglossus activity is lower during deep compared with shallow anesthesia. Methods In a randomized controlled crossover study of 12 volunteers, anesthesia with propofol or sevoflurane was titrated using a pain stimulus to identify the threshold for suppression of motor response to electrical stimulation. Measurements included bispectral index, genioglossus electromyography, ventilation, hypopharyngeal pressure, upper airway closing pressure, and change in end-expiratory lung volume during mask pressure drops. Results A total of 393 attempted breaths during occlusion maneuvers were analyzed. Upper airway closing pressure was significantly less negative at deep versus shallow anesthesia (−10.8 ± 4.5 vs. −11.3 ± 4.4 cm H2O, respectively [mean ± SD]) and correlated with the bispectral index (P < 0.001), indicating a more collapsible airway at deep anesthesia. Respiratory genioglossus activity during airway occlusion was significantly lower at deep compared with light anesthesia (26 ± 21 vs. 35 ± 24% of maximal genioglossus activation, respectively; P < 0.001) and correlated with bispectral index (P < 0.001). Upper airway closing pressure and genioglossus activity during airway occlusion did not differ between sevoflurane and propofol anesthesia. Conclusions Propofol and sevoflurane anesthesia increased upper airway collapsibility in a dose-dependent fashion with no difference at equivalent anesthetic concentrations. These effects can in part be explained by a dose-dependent inhibiting effect of anesthetics on respiratory genioglossus activity.

Mechanisms contributing to the response of upper-airway muscles to changes in airway pressure

2015 ◽  
Vol 118 (10) ◽  
pp. 1221-1228 ◽  
Author(s):  
Jayne C. Carberry ◽  
Hanna Hensen ◽  
Lauren P. Fisher ◽  
Julian P. Saboisky ◽  
Jane E. Butler ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Airway Pressure ◽  
Upper Airway ◽  
Nasal Breathing ◽  
Quiet Breathing ◽  
Surface Receptors ◽  
Reflex Responses ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility ◽  
Pressure Changes

This study assessed the effects of inhaled lignocaine to reduce upper airway surface mechanoreceptor activity on 1) basal genioglossus and tensor palatini EMG, 2) genioglossus reflex responses to large pulses (∼10 cmH2O) of negative airway pressure, and 3) upper airway collapsibility in 15 awake individuals. Genioglossus and tensor palatini muscle EMG and airway pressures were recorded during quiet nasal breathing and during brief pulses (250 ms) of negative upper-airway pressure. Lignocaine reduced peak inspiratory (5.6 ± 1.5 vs. 3.8 ± 1.1% maximum; mean ± SE, P < 0.01) and tonic (2.8 ± 0.8 vs. 2.1 ± 0.7% maximum; P < 0.05) genioglossus EMG during quiet breathing but had no effect on tensor palatini EMG (5.0 ± 0.8 vs. 5.0 ± 0.5% maximum; P = 0.97). Genioglossus reflex excitation to negative pressure pulses decreased after anesthesia (60.9 ± 20.7 vs. 23.6 ± 5.2 μV; P < 0.05), but not when expressed as a percentage of the immediate prestimulus baseline. Reflex excitation was closely related to the change in baseline EMG following lignocaine ( r2 = 0.98). A short-latency genioglossus reflex to rapid increases from negative to atmospheric pressure was also observed. The upper airway collapsibility index (%difference) between nadir choanal and epiglottic pressure increased after lignocaine (17.8 ± 3.7 vs. 28.8 ± 7.5%; P < 0.05). These findings indicate that surface receptors modulate genioglossus but not tensor palatini activity during quiet breathing. However, removal of input from surface mechanoreceptors has minimal effect on genioglossus reflex responses to large (∼10 cmH2O), sudden changes in airway pressure. Changes in pressure rather than negative pressure per se can elicit genioglossus reflex responses. These findings challenge previous views and have important implications for upper airway muscle control.

Effect of Mandibular Position on Upper Airway Collapsibility and Resistance

2005 ◽  
Vol 84 (6) ◽  
pp. 554-558 ◽  
Author(s):  
T. Inazawa ◽  
T. Ayuse ◽  
S. Kurata ◽  
I. Okayasu ◽  
E. Sakamoto ◽  
...  
Keyword(s):  
Airway Pressure ◽  
Upper Airway ◽  
Mandibular Advancement ◽  
Neutral Position ◽  
Airway Patency ◽  
Airway Collapsibility ◽  
Critical Closing Pressure ◽  
Mandibular Position ◽  
Upper Airway Collapsibility ◽  
Closing Pressure

It has been proposed that advancement of the mandible is a useful method for decreasing upper airway collapsibility. We carried out this study to test the hypothesis that mandibular advancement induces changes in upper airway patency during midazolam sedation. To explore its effect, we examined upper airway pressure-flow relationships in each of 4 conditions of mouth position in normal, healthy subjects (n = 9). In the neutral position, Pcrit ( i.e., critical closing pressure, an index of upper airway collapsibility) was −4.2 cm H2O, and upstream resistance (Rua) was 21.2 cm H2O/L/sec. In the centric occlusal position, Pcrit was −7.1 cm H2O, and Rua was 16.6 cm H2O/L/sec. In the incisor position, Pcrit was significantly reduced to −10.7 cm H2O, and Rua was significantly reduced to 14.0 cm H2O/L/sec. Mandibular advancement significantly decreased Pcrit to −13.3 cm H2O, but did not significantly influence Rua (22.1 cm H2O/L/sec). We conclude that the mandibular incisors’ position improved airway patency and decreased resistance during midazolam sedation.

Supplemental Carbon Dioxide Stabilizes the Upper Airway in Volunteers Anesthetized with Propofol

2018 ◽  
Vol 129 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Katarina Jennifer Ruscic ◽  
Janne Bøgh Stokholm ◽  
Johann Patlak ◽  
Hao Deng ◽  
Jeroen Cedric Peter Simons ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Deep Level ◽  
Muscle Tone ◽  
Secondary Analysis ◽  
Upper Airway ◽  
Dependent Manner ◽  
Genioglossus Muscle ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility ◽  
Closing Pressure

Abstract Background Propofol impairs upper airway dilator muscle tone and increases upper airway collapsibility. Preclinical studies show that carbon dioxide decreases propofol-mediated respiratory depression. We studied whether elevation of end-tidal carbon dioxide (Petco2) via carbon dioxide insufflation reverses the airway collapsibility (primary hypothesis) and impaired genioglossus muscle electromyogram that accompany propofol anesthesia. Methods We present a prespecified, secondary analysis of previously published experiments in 12 volunteers breathing via a high-flow respiratory circuit used to control upper airway pressure under propofol anesthesia at two levels, with the deep level titrated to suppression of motor response. Ventilation, mask pressure, negative pharyngeal pressure, upper airway closing pressure, genioglossus electromyogram, bispectral index, and change in end-expiratory lung volume were measured as a function of elevation of Petco2 above baseline and depth of propofol anesthesia. Results Petco2 augmentation dose-dependently lowered upper airway closing pressure with a decrease of 3.1 cm H2O (95% CI, 2.2 to 3.9; P &lt; 0.001) under deep anesthesia, indicating improved upper airway stability. In parallel, the phasic genioglossus electromyogram increased by 28% (23 to 34; P &lt; 0.001). We found that genioglossus electromyogram activity was a significant modifier of the effect of Petco2 elevation on closing pressure (P = 0.005 for interaction term). Conclusions Upper airway collapsibility induced by propofol anesthesia can be reversed in a dose-dependent manner by insufflation of supplemental carbon dioxide. This effect is at least partly mediated by increased genioglossus muscle activity.

scholarly journals Upper Airway Collapsibility During Wakefulness in Children with Sleep Disordered Breathing, as Determined by the Negative Expiratory Pressure Technique

SLEEP ◽  
2011 ◽  
Vol 34 (6) ◽  
pp. 717-724 ◽  
Author(s):  
Helena Larramona Carrera ◽  
Joseph M. McDonough ◽  
Paul R. Gallagher ◽  
Swaroop Pinto ◽  
John Samuel ◽  
...  
Keyword(s):  
Sleep Disordered Breathing ◽  
Upper Airway ◽  
Airway Collapsibility ◽  
Upper Airway Collapsibility ◽  
Disordered Breathing
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