Inspiratory coactivation of the genioglossus enlarges retroglossal space in laryngectomized humans

1996 ◽  
Vol 80 (5) ◽  
pp. 1595-1604 ◽  
Author(s):  
I. Kobayashi ◽  
A. Perry ◽  
J. Rhymer ◽  
B. Wuyam ◽  
P. Hughes ◽  
...  
Keyword(s):  
Upper Airway ◽  
Dependent Manner ◽  
Tongue Movement ◽  
Forward Movement ◽  
Upper Airways ◽  
Posterior Aspect ◽  
Airway Patency ◽  
Significant Movement ◽  
Tongue Position ◽  
Tracheal Stoma

To investigate the relationship between the electrical activity of the genioglossus (GG-EMG) and associated tongue movement, seven laryngectomized subjects breathing through a tracheal stoma (without pressure or flow change in the upper airway) were studied in the supine position. Tongue movement, with the use of lateral fluoroscopy, and GG-EMG expressed as a percentage of maximum voluntary genioglossal activation were monitored simultaneously during 1) spontaneous inspiration (SI), 2) resistive loaded inspiration (LI), and 3) rapid inspiration (RI). Tongue position during each maneuver was compared with its position during spontaneous expiration. Peak GG-EMG during the three maneuvers was significantly different from each other (SI: 5.4 +/- 1.6, LI: 11.9 +/- 1.8, and RI: 51.6 +/- 9.4 (SE) %, respectively). Associated forward movement of the posterior aspect of the tongue was minimum during SI; however, significant movement was observed during LI, and this was increased during RI. Significant covariance existed between peak GG-EMG and this movement. Genioglossal coactivation with inspiration enlarges the glossopharyngeal airway, particularly in its caudal part. In subjects with intact upper airways, this activation may protect or enhance upper airway patency in an effort-dependent manner.

Mouth and nose resistance in newborn kittens and puppies

1981 ◽  
Vol 51 (3) ◽  
pp. 641-645 ◽  
Author(s):  
J. P. Mortola ◽  
J. T. Fisher
Keyword(s):  
Mechanical Properties ◽  
Airway Obstruction ◽  
Flow Rate ◽  
Muscle Tone ◽  
Upper Airway ◽  
Upper Airway Obstruction ◽  
Upper Airways ◽  
Airway Patency ◽  
The Difference ◽  
Adult Cats

Newborn mammals, including infants, have difficulties in mouth breathing when the nasal passages are occluded. In this study we examined the possibility that differences in the passive mechanical properties of the upper airways could fully explain this behavior. Steady inspiratory flows through the upper airways in anesthetized supine newborn kittens and puppies resulted in upper airway obstruction, even at flows less than those occurring during resting breathing, suggesting that in the unanesthetized condition muscle tone plays an important role in maintaining upper airway patency. Mouth (Rm) and nose (Rn) resistances have been measured during steady expiratory flows with nostrils closed and mouth passively open or nostrils open and mouth closed. In all the newborns, Rn was substantially smaller than Rm. In contrast, the Rn/Rm in adult dogs is greater than unity. In adult cats Rn/Rm is above or below unity depending upon the flow rate, but the ratio is always larger than in newborn kittens. The difference between newborns and adults is entirely due to the small Rn of the newborn, as Rm is not greater in the newborn than in the adult. We conclude that the obligatory nose breathing behavior of newborns is not fully explained by the passive mechanical properties of the upper airways.

The effect of diaphragm contraction on upper airway collapsibility

2013 ◽  
Vol 115 (3) ◽  
pp. 337-345 ◽  
Author(s):  
David R. Hillman ◽  
Jennifer H. Walsh ◽  
Kathleen J. Maddison ◽  
Peter R. Platt ◽  
Alan R. Schwartz ◽  
...  
Keyword(s):  
Nerve Stimulation ◽  
Lung Volume ◽  
Phrenic Nerve ◽  
Upper Airway ◽  
Dependent Manner ◽  
Phrenic Nerve Stimulation ◽  
Airway Patency ◽  
Airway Collapsibility ◽  
The Difference ◽  
Upper Airway Collapsibility

Increasing lung volume increases upper airway patency and decreases airway resistance and collapsibility. The role of diaphragm contraction in producing these changes remains unclear. This study was undertaken to determine the effect of selective diaphragm contraction, induced by phrenic nerve stimulation, on upper airway collapsibility and the extent to which any observed change was attributable to lung volume-related changes in pressure gradients or to diaphragm descent-related mediastinal traction. Continuous bilateral transcutaneous cervical phrenic nerve stimulation (30 Hz) was applied to nine supine, anesthetized human subjects during transient decreases in airway pressure to levels sufficient to produce flow limitation when unstimulated. Stimulation was applied at two intensities (low and high) and its effects on lung volume and airflow quantified relative to unstimulated conditions. Lung volume increased by 386 ± 269 ml (means ± SD) and 761 ± 556 ml during low and high stimulation, respectively ( P < 0.05 for the difference between these values), which was associated with peak inspiratory flow increases of 69 ± 57 and 137 ± 108 ml/s, respectively ( P < 0.05 for the difference). Stimulation-induced change in lung volume correlated with change in peak flow ( r = 0.65, P < 0.01). Diaphragm descent-related outward displacement of the abdominal wall produced no change in airflow unless accompanied by lung volume change. We conclude that phrenic nerve stimulation-induced diaphragm contraction increases lung volume and reduces airway collapsibility in a dose-dependent manner. The effect appears primarily mediated by changes in lung volume rather than mediastinal traction from diaphragm descent. The study provides a rationale for use of continuous phrenic stimulation to treat obstructive sleep apnea.

scholarly journals Pre- and postsynaptic modulations of hypoglossal motoneurons by α-adrenoceptor activation in wild-type and Mecp2−/Y mice

2013 ◽  
Vol 305 (10) ◽  
pp. C1080-C1090 ◽  
Author(s):  
Xiao-Tao Jin ◽  
Ningren Cui ◽  
Weiwei Zhong ◽  
Xin Jin ◽  
Zhongying Wu ◽  
...  
Keyword(s):  
Synaptic Transmission ◽  
Upper Airway ◽  
Membrane Properties ◽  
Compensatory Mechanism ◽  
Tongue Movement ◽  
Wild Type ◽  
Airway Patency ◽  
Hypoglossal Motoneurons ◽  
Therapeutical Modalities ◽  
Intrinsic Membrane Properties

Hypoglossal motoneurons (HNs) control tongue movement and play a role in maintenance of upper airway patency. Defects in these neurons may contribute to the development of sleep apnea and other cranial motor disorders including Rett syndrome (RTT). HNs are modulated by norepinephrine (NE) through α-adrenoceptors. Although postsynaptic mechanisms are known to play a role in this effect, how NE modulates the synaptic transmissions of HNs remains poorly understood. More importantly, the NE system is defective in RTT, while how the defect affects HNs is unknown. Believing that information of NE modulation of HNs may help the understanding of RTT and the design of new therapeutical interventions to motor defects in the disease, we performed these studies in which glycinergic inhibitory postsynaptic currents and intrinsic membrane properties were examined in wild-type and Mecp2 −/Y mice, a mouse of model of RTT. We found that activation of α1-adrenoceptor facilitated glycinergic synaptic transmission and excited HNs. These effects were mediated by both pre- and postsynaptic mechanisms. The latter effect involved an inhibition of barium-sensitive G protein-dependent K+ currents. The pre- and postsynaptic modulations of the HNs by α1-adrenoceptors were not only retained in Mecp2-null mice but also markedly enhanced, which appears to be a compensatory mechanism for the deficiencies in NE and GABAergic synaptic transmission. The existence of the endogenous compensatory mechanism is an encouraging finding, as it may allow therapeutical modalities to alleviate motoneuronal defects in RTT.

Changes in upper airway resistance with lung inflation and positive airway pressure

1990 ◽  
Vol 68 (3) ◽  
pp. 1075-1079 ◽  
Author(s):  
F. Series ◽  
Y. Cormier ◽  
J. Couture ◽  
M. Desmeules
Keyword(s):  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Upper Airway ◽  
Normal Subjects ◽  
Base Line ◽  
Upper Airways ◽  
Airway Patency ◽  
Lung Inflation ◽  
Bias Flow ◽  
Expiratory Positive Airway Pressure

The influence of pulmonary inflation and positive airway pressure on nasal and pharyngeal resistance were studied in 10 normal subjects lying in an iron lung. Upper airway pressures were measured with two low-bias flow catheters while the subjects breathed by the nose through a Fleish no. 3 pneumotachograph into a spirometer. Resistances were calculated at isoflow rates in four different conditions: exclusive pulmonary inflation, achieved by applying a negative extra-thoracic pressure (NEP); expiratory positive airway pressure (EPAP), which was created by immersion of the expiratory line; continuous positive airway pressure (CPAP), realized by loading the bell of the spirometer; and CPAP without pulmonary inflation by simultaneously applying the same positive extrathoracic pressure (CPAP + PEP). Resistance measurements were obtained at 5- and 10-cmH2O pressure levels. Pharyngeal resistance (Rph) significantly decreased during each measurement; the decreases in nasal resistance were only significant with CPAP and CPAP + PEP; the deepest fall in Rph occurred with CPAP. It reached 70.8 +/- 5.5 and 54.8 +/- 6.5% (SE) of base-line values at 5 and 10 cmH2O, respectively. The changes in lung volume recorded with CPAP + PEP ranged from -180 to 120 ml at 5 cmH2O and from -240 to 120 ml at 10 cmH2O. Resistances tended to increase with CPAP + PEP compared with CPAP values, but these changes were not significant (Rph = 75.9 +/- 6.1 and 59.9 +/- 6.6% at 5 and 10 cmH2O of CPAP + PEP). We conclude that 1) the upper airway patency increases during pulmonary inflation, 2) the main effect of CPAP is related to pneumatic splinting, and 3) pulmonary inflation contributes little to the decrease in upper airways resistance observed with CPAP.

Waking and genioglossus muscle responses to upper airway pressure oscillation in sleeping dogs

1990 ◽  
Vol 68 (6) ◽  
pp. 2564-2573 ◽  
Author(s):  
L. Plowman ◽  
D. C. Lauff ◽  
M. Berthon-Jones ◽  
C. E. Sullivan
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Upper Airway ◽  
Pressure Oscillation ◽  
Pressure Waves ◽  
Sleep State ◽  
Upper Airways ◽  
Airway Patency ◽  
Obstructive Sleep ◽  
Oscillatory Pressure

We studied waking and genioglossus electromyographic (EMGgg) responses to oscillating pressure waves applied to the upper airways of three sleeping dogs. The dogs were previously prepared with a permanent side-hole tracheal stoma and were trained to sleep with a tight-fitting snout mask, hermetically sealed in place, while breathing through a cuffed endotracheal tube inserted through the tracheostomy. Sleep state was determined by behavioral, electroencephalographic, and electromyographic criteria, and EMGgg activity was measured using fine bipolar electrodes inserted directly into the muscle. Oscillatory pressure waves of 30 Hz and +/- 3 cmH2O (tested at atmospheric and subatmospheric upper airway pressures) were applied at the dog's nostrils or larynx, either constantly for a period of 1 min or in 0.5-s bursts. We found that the pressure stimulus had two major effects. First, it was a potentially powerful arousal-promoting stimulus. Arousal occurred in 78% of tests in slow-wave sleep (SWS) and 55% of tests in rapid-eye-movement (REM) sleep, with swallowing and sighing accompanying many of the arousals. Second, it produced an immediate and sustained augmentation of EMGgg, in wakefulness, SWS, and REM sleep. We conclude that oscillatory pressure waves in the upper airway, as found in snoring, produce reflex responses that help maintain upper airway patency during sleep. Loss of this type of reflex might contribute to the onset of obstructive sleep apnea in chronic snorers.

scholarly journals Developmental features and predicting airway failure risk in critically ill children with mandibular hypoplasia using 3D computational tomographic analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Doo-Hwan Kim ◽  
Eunseo Gwon ◽  
Junheok Ock ◽  
Jong-Woo Choi ◽  
Jee Ho Lee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Difficult Airway ◽  
Hyoid Bone ◽  
Three Dimensional ◽  
Upper Airway ◽  
Critically Ill Children ◽  
Healthy Controls ◽  
Mandibular Hypoplasia ◽  
Tongue Position ◽  
Developmental Features

AbstractIn children with mandibular hypoplasia, airway management is challenging. However, detailed cephalometric assessment data for this population are sparse. The aim of this study was to find risk factors for predicting difficult airways in children with mandibular hypoplasia, and compare upper airway anatomical differences using three-dimensional computed tomography (3D CT) between children with mandibular hypoplasia and demographically matched healthy controls. There were significant discrepancies in relative tongue position (P < 0.01) and anterior distance of the hyoid bone (P < 0.01) between patients with mandibular hypoplasia and healthy controls. All mandibular measures were significantly different between the two groups, except for the height of the ramus of the mandible. After adjusting for age and sex, the anterior distance of hyoid bone and inferior pogonial angle were significantly associated with a difficult airway (P = 0.01 and P = 0.02). Quantitative analysis of upper airway structures revealed significant discrepancies, including relative tongue position, hyoid distance, and mandible measures between patients with mandibular hypoplasia and healthy controls. The anterior distance of the hyoid bone and inferior pogonial angle may be risk factors for a difficult airway in patients with mandibular hypoplasia.

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 &lt; 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 &lt; 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.

Does Presurgical Nasoalveolar Molding Have a Long-Term Effect on Nasal and Upper Airway Dimensions?

2020 ◽  
pp. 105566562098023
Author(s):  
Ashwina S. Banari ◽  
Sanjeev Datana ◽  
Shiv Shankar Agarwal ◽  
Sujit Kumar Bhandari
Keyword(s):  
Upper Airway ◽  
P Value ◽  
Airway Patency ◽  
The Mean ◽  
Group 2 ◽  
Acoustic Pharyngometry ◽  
Nasoalveolar Molding ◽  
Area And Volume ◽  
Group 1

Objectives: To compare nasal and upper airway dimensions in patients with cleft lip and palate (CLP) who underwent nasoalveolar molding (NAM) with those without NAM during infancy using acoustic pharyngometry and rhinometry. Materials and Methods: Eccovision acoustic pharyngometry and rhinometry (Sleep Group Solutions) was used for assessment of mean area and volume of nasal and upper airway in patients with complete unilateral CLP (age range 16-21 years) treated with NAM (group 1, n = 19) versus without NAM (group 2, n = 22). Results: The mean nasal cross-sectional areas and volume were higher in group 1 compared to group 2 on both cleft ( P value <.001) and noncleft side ( P value >.05). The mean area and volume of upper airway were also significantly higher in group 1 compared to group 2 ( P value <.05). Conclusions: Nasoalveolar molding being one of the first interventions in chronology of treatment of patients with CLP, its long-term outcome on nasal and upper airway patency needs to be ascertained. The results of the present study show that the patients with CLP who have undergone NAM during infancy have better improvement in nasal and upper airway patency compared with those who had not undergone NAM procedure. The basic advantages of being noninvasive, nonionizing and providing dynamic assessment of nasal and upper airway patency make acoustic pharyngometry and rhinometry a diagnostic tool of choice to be used in patients with CLP.

Motor responses to positive-pressure breathing in the developing opossum

1985 ◽  
Vol 58 (5) ◽  
pp. 1489-1495 ◽  
Author(s):  
J. P. Farber
Keyword(s):  
Airway Resistance ◽  
Upper Airway ◽  
Abdominal Muscle ◽  
Positive Pressure ◽  
Postnatal Life ◽  
Abdominal Muscles ◽  
Upper Airways ◽  
Motor Responses ◽  
Upper Airway Resistance ◽  
Upper Airway Muscles

The suckling opossum exhibits an expiration-phased discharge in abdominal muscles during positive-pressure breathing (PPB); the response becomes apparent, however, only after the 3rd-5th wk of postnatal life. The purpose of this study was to determine whether the early lack of activation represented a deficiency of segmental outflow to abdominal muscles or whether comparable effects were observed in cranial outflows to muscles of the upper airways due to immaturity of afferent and/or supraspinal pathways. Anesthetized suckling opossums between 15 and 50 days of age were exposed to PPB; electromyogram (EMG) responses in diaphragm and abdominal muscles were measured, along with EMG of larynx dilator muscles and/or upper airway resistance. In animals older than approximately 30 days of age, the onset of PPB was associated with a prolonged expiration-phased EMG activation of larynx dilator muscles and/or decreased upper airway resistance, along with expiratory recruitment of the abdominal muscle EMG. These effects persisted as long as the load was maintained. Younger animals showed only those responses related to the upper airway; in fact, activation of upper airway muscles during PPB could be associated with suppression of the abdominal motor outflow. After unilateral vagotomy, abdominal and upper airway motor responses to PPB were reduced. The balance between PPB-induced excitatory and inhibitory or disfacilitory influences from the supraspinal level on abdominal motoneurons and/or spinal processing of information from higher centers may shift toward net excitation as the opossum matures.

Jaw thrust can deteriorate upper airway patency

2005 ◽  
Vol 49 (4) ◽  
pp. 583-585 ◽  
Author(s):  
B. S. Von Ungern-Sternberg ◽  
T. O. Erb ◽  
F. J. Frei
Keyword(s):  
Upper Airway ◽  
Airway Patency
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