Effects of pharyngeal lubrication on the opening of obstructed upper airway

1992 ◽  
Vol 72 (6) ◽  
pp. 2311-2316 ◽  
Author(s):  
H. Miki ◽  
W. Hida ◽  
Y. Kikuchi ◽  
T. Chonan ◽  
M. Satoh ◽  
...  
Keyword(s):  
Hypoglossal Nerve ◽  
Muscle Tone ◽  
Upper Airway ◽  
Intraluminal Pressure ◽  
Lower Airway ◽  
Before And After ◽  
Airway Opening ◽  
Cervical Trachea ◽  
Artificial Surfactant ◽  
Stimulation Of

We examined the effect of electrical stimulation of the hypoglossal nerve and pharyngeal lubrication with artificial surfactant (Surfactant T-A) on the opening of obstructed upper airway in nine anesthetized supine dogs. The upper airway was isolated from the lower airway by transecting the cervical trachea. Upper airway obstruction was induced by applying constant negative pressures (5, 10, 20, and 30 cmH2O) on the rostral cut end of the trachea. Peripheral cut ends of the hypoglossal nerves were electrically stimulated by square-wave pulses at various frequencies from 10 to 30 Hz (0.2-ms duration, 5–7 V), and the critical stimulating frequency necessary for opening the obstructed upper airway was measured at each driving pressure before and after pharyngeal lubrication with artificial surfactant. The critical stimulation frequency for upper airway opening significantly increased as upper airway pressure became more negative and significantly decreased with lubrication of the upper airway. These findings suggest that greater muscle tone of the genioglossus is needed to open the occluded upper airway with larger negative intraluminal pressure and that lubrication of the pharyngeal mucosa with artificial surfactant facilitates reopening of the upper airway.

Reflex control of the tracheal vasculature of sheep

1993 ◽  
Vol 75 (5) ◽  
pp. 2173-2179 ◽  
Author(s):  
S. E. Webber ◽  
J. G. Widdicombe
Keyword(s):  
Carotid Body ◽  
Muscle Tone ◽  
Intravenous Injections ◽  
Stretch Receptors ◽  
Pulmonary Stretch Receptors ◽  
Before And After ◽  
Cervical Trachea ◽  
Carotid Body Chemoreceptors ◽  
Reflex Stimulation ◽  
Stimulation Of

Arteries to the cervical trachea were perfused at constant flow in anesthetized sheep. Perfusion pressures (PP), blood pressure (BP), and changes in tracheal smooth muscle tone (Ptr) were measured. Stimulation of pulmonary C-fiber receptors decreased PP (-6.5%) and BP (-16.8%) and increased Ptr (+61.5%), changes prevented by vagotomy and therefore reflex. Stimulation of cardiac receptors and slowly adapting pulmonary stretch receptors decreased PP (-7.9%) and BP (-21.0) and increased Ptr (+19.0%), changes reversed by vagotomy and therefore reflex. Stimulation and inhibition of slowly adapting pulmonary stretch receptors had no vagal-dependent effect on PP and BP, but inflation decreased (-20.3%) and deflation increased Ptr (+35.2%), effects abolished by vagotomy and therefore reflex. Systemic hypoxia increased PP and BP before and after vagotomy (+12.2 and +40.3%), effects greatly reduced by cutting the carotid body nerves; it increased Ptr (+29.8%), an effect abolished by vagotomy and cutting the carotid body nerves. Systemic hypercapnia increased PP (+16.9%), BP (+20.5%), and Ptr (+36.2%), the first two responses being unaffected by vagotomy and the last almost abolished. Stimulation of carotid body chemoreceptors by KCN increased PP (+22.5%), BP (+104.7%), and Ptr (+8.5%), all responses prevented by cutting the carotid body nerves. Responses to intravenous injections of KCN were similar.

Functional anatomy of the vagal innervation of the cervical trachea of the dog

2000 ◽  
Vol 89 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Robert L. Coon ◽  
Patrick J. Mueller ◽  
Philip S. Clifford
Keyword(s):  
Smooth Muscle ◽  
Vagus Nerve ◽  
Neural Control ◽  
Muscle Tone ◽  
Cuff Pressure ◽  
Vagal Innervation ◽  
Cervical Trachea ◽  
The Right ◽  
Left Vagus ◽  
Stimulation Of

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea. After establishment of tracheal tone, as indicated by increased cuff pressure, either the right or left vagus nerve was sectioned followed by section of the contralateral vagus. Sectioning the right vagus first resulted in total loss of tone in the cervical trachea, whereas sectioning the left vagus first produced either a partial or no decrease in tracheal tone. After bilateral section of the vagi, cuff pressure was recorded during electrical stimulation of the rostral end of the right or left vagus. At the maximum current strength used, stimulation of the left vagus produced tracheal constriction that averaged 28.5% of the response to stimulation of the right vagus (9.0 ± 1.8 and 31.6 ± 2.5 mmHg, respectively). In conclusion, the musculature of cervical trachea in the dog appears to be predominantly controlled by vagal efferents in the right vagus nerve.

Effect of upper airway negative pressure on proprioceptive afferents from the tongue

1999 ◽  
Vol 86 (4) ◽  
pp. 1396-1401 ◽  
Author(s):  
A. Brancatisano ◽  
P. Davis ◽  
T. van der Touw ◽  
J. R. Wheatley
Keyword(s):  
Hypoglossal Nerve ◽  
Upper Airway ◽  
Rapid Onset ◽  
Firing Frequency ◽  
Tongue Muscle ◽  
Airway Mucosa ◽  
Afferent Fibers ◽  
Before And After ◽  
Proprioceptive Afferents ◽  
Passive Stretch

We examined whether receptors in the tongue muscle respond to negative upper airway pressure (NUAP). In six cats, one hypoglossal nerve was cut and its distal end was prepared for single-fiber recording. Twelve afferent fibers were selected for study on the basis of their sensitivity to passive stretch (PS) of the tongue. Fiber discharge frequency was measured during PS of the tongue and after the rapid onset of constant NUAP. During PS of 1–3 cm, firing frequency increased from 17 ± 7 to 40 ± 11 (SE) Hz ( P < 0.01). In addition, 8 of the 12 fibers responded to NUAP (−10 to −30 cmH2O), with firing frequency increasing from 23 ± 9 to 41 ± 9 Hz ( P < 0.001). In two fibers tested, the increase in firing frequency in response to NUAP was not altered by topical anesthesia (10% lignocaine) applied liberally to the entire upper airway mucosa. Our results demonstrate that afferent discharges from the hypoglossal nerve are elicited by 1) stretching of the tongue and 2) NUAP before and after upper airway anesthesia. We speculate that activation of proprioceptive mechanoreceptors in the cat’s tongue provides an additional pathway for the reflex activation of upper airway dilator muscles in response to NUAP, independent of superficially located mucosal mechanoreceptors.

Active upper airway closure during induced central apneas in lambs is complete at the laryngeal level only

2003 ◽  
Vol 95 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Pierre-Hugues Fortier ◽  
Philippe Reix ◽  
Julie Arsenault ◽  
Dominique Dorion ◽  
Jean-Paul Praud
Keyword(s):  
Upper Airway ◽  
Emg Activity ◽  
Airway Closure ◽  
Internal Branch ◽  
Laryngeal Nerves ◽  
Before And After ◽  
Subglottal Pressure ◽  
Central Apneas ◽  
Afferent Innervation ◽  
Stimulation Of

We tested the hypotheses that active upper airway closure during induced central apneas in nonsedated lambs 1) is complete and occurs at the laryngeal level and 2) is not due to stimulation of the superior laryngeal nerves (SLN). Five newborn lambs were surgically instrumented to record thyroarytenoid (TA) muscle (glottal constrictor) electromyographic (EMG) activity with supra- and subglottal pressures. Hypocapnic and nonhypocapnic central apneas were induced before and after SLN sectioning in the five lambs. A total of 174 apneas were induced, 116 before and 58 after sectioning of the internal branch of the SLN (iSLN). Continuous TA EMG activity was observed in 88% of apneas before iSLN section and in 87% of apneas after iSLN section. A transglottal pressure different from zero was observed in all apneas with TA EMG activity, with a mean subglottal pressure of 4.3 ± 0.8 cmH2O before and 4.7 ± 0.7 cmH2O after iSLN section. Supraglottal pressure was consistently atmospheric. Sectioning of both iSLNs had no effects on the results. We conclude that upper airway closure during induced central apneas in lambs is active, complete, and occurs at the glottal level only. Consequently, a positive subglottal pressure is maintained throughout the apnea. Finally, this complete active glottal closure is independent from laryngeal afferent innervation.

Effect of surface tension of mucosal lining liquid on upper airway mechanics in anesthetized humans

2003 ◽  
Vol 95 (1) ◽  
pp. 357-363 ◽  
Author(s):  
Jason P. Kirkness ◽  
Peter R. Eastwood ◽  
Irene Szollosi ◽  
Peter R. Platt ◽  
John R. Wheatley ◽  
...  
Keyword(s):  
Surface Tension ◽  
Human Subjects ◽  
Upper Airway ◽  
Exogenous Surfactant ◽  
Airway Mechanics ◽  
Before And After ◽  
Airway Opening ◽  
Mucosal Lining ◽  
Effect Of Surface

Upper airway (UA) patency may be influenced by surface tension (γ) operating within the (UAL). We examined the role of γ of UAL in the maintenance of UA patency in eight isoflurane-anesthetized supine human subjects breathing via a nasal mask connected to a pneumotachograph attached to a pressure delivery system. We evaluated 1) mask pressure at which the UA closed (Pcrit), 2) UA resistance upstream from the site of UA collapse (RUS), and 3) mask pressure at which the UA reopened (Po). A multiple pressure-transducer catheter was used to identify the site of airway closure (velopharyngeal in all subjects). UAL samples (0.2 μl) were collected, and the γ of UAL was determined by using the “pull-off force” technique. Studies were performed before and after the intrapharyngeal instillation of 5 ml of exogenous surfactant (Exosurf, Glaxo Smith Kline). The γ of UAL decreased from 61.9 ± 4.1 (control) to 50.3 ± 5.0 mN/m (surfactant; P < 0.02). Changes in Po, RUS, and Po - Pcrit (change = control - surfactant) were positively correlated with changes in γ ( r2 > 0.6; P < 0.02) but not with changes in Pcrit ( r2 = 0.4; P > 0.9). In addition, mean peak inspiratory airflow (no flow limitation) significantly increased ( P < 0.04) from 0.31 ± 0.06 (control) to 0.36 ± 0.06 l/s (surfactant). These findings suggest that γ of UAL exerts a force on the UA wall that hinders airway opening. Instillation of exogenous surfactant into the UA lowers the γ of UAL, thus increasing UA patency and augmenting reopening of the collapsed airway.

Hypoglossal nerve stimulation [HGNS] for Obstructive Sleep Apnea [OSA] treatment – a review

2017 ◽  
Vol 6 (3) ◽  
pp. 66-71
Author(s):  
Małgorzata Bilińska ◽  
Kazimierz Niemczyk
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Hypoglossal Nerve ◽  
Muscle Tone ◽  
Upper Airway ◽  
Western Society ◽  
Obstructive Sleep ◽  
Increased Risk ◽  
Osa Treatment ◽  
Oncologic Diseases

Obstructive sleep apnea (OSA) is characterized by recurrent periods of upper airway obstruction (hypopneas and apneas) during sleep. It leads to repeated oxyhemoglobin desaturations, nocturnal hypercapnia, and arousals. Common symptoms include loud snoring with breathing interruptions. Excessive daytime sleepiness and cognitive impairment occur. Obstructive sleep apnea is a major cause of morbidity and mortality in Western society. Its association with an increased risk of development and progression of neurocognitive, metabolic, cardiovascular and oncologic diseases and complications is well described. The significant factor in OSA pathogenesis is reduced muscle tone in the tongue and upper airway. In the recent years, devices providing neurostimulation of the hypoglossal nerve (HGNS) were developed as an alternative for noncompliant CPAP (continuous positive airway pressure) patients. Clinical trials suggest that electrical stimulation of the hypoglossal nerve is effective. This is considered to be one of the targets of neurostimulation in the treatment of obstructive sleep apnea (OSA).

Electrical stimulation of the lingual musculature in obstructive sleep apnea

1996 ◽  
Vol 81 (2) ◽  
pp. 643-652 ◽  
Author(s):  
A. R. Schwartz ◽  
D. W. Eisele ◽  
A. Hari ◽  
R. Testerman ◽  
D. Erickson ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Upper Airway ◽  
Airflow Limitation ◽  
Fine Wire ◽  
Obstructive Sleep ◽  
Before And After ◽  
Inspiratory Airflow Limitation ◽  
Nasal Pressure ◽  
Stimulation Of

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.

scholarly journals Electrical stimulation of the hypoglossal nerve: a potential therapy

2014 ◽  
Vol 116 (3) ◽  
pp. 337-344 ◽  
Author(s):  
Alan R. Schwartz ◽  
Philip L. Smith ◽  
Arie Oliven
Keyword(s):  
Obstructive Sleep Apnea ◽  
Electrical Stimulation ◽  
Sleep Apnea ◽  
Hypoglossal Nerve ◽  
Therapeutic Potential ◽  
Muscle Tone ◽  
Feasibility Trial ◽  
Airway Patency ◽  
Obstructive Sleep ◽  
Stimulation Of

Obstructive sleep apnea is characterized by recurrent episodes of pharyngeal collapse, which result from a decrease in pharyngeal dilator muscle tone. The genioglossus is a major pharyngeal dilator that maintains airway patency during sleep. Early studies in animal and humans have demonstrated that electrical stimulation of this muscle reduces pharyngeal collapsibility, increases airflow, and mitigates obstructive sleep apnea. These findings impelled the development of fully implantable hypoglossal nerve stimulating systems (HGNS), for which feasibility trial results are now available. These pilot studies have confirmed that hypoglossal nerve stimulation can prevent pharyngeal collapse without arousing patients from sleep. Potentially, a substantial segment of the patient population with obstructive sleep apnea can be treated with this novel approach. Furthermore, the feasibility trial findings suggest that the therapeutic potential of HGNS can be optimized by selecting patients judiciously, titrating the stimulus intensity optimally, and characterizing the underlying function and anatomy of the pharynx. These strategies are currently being examined in ongoing pivotal trials of HGNS.

Effects of upper airway anesthesia on pharyngeal patency during sleep

1988 ◽  
Vol 64 (4) ◽  
pp. 1346-1353 ◽  
Author(s):  
E. L. DeWeese ◽  
T. Y. Sullivan
Keyword(s):  
Sensory Feedback ◽  
Breathing Pattern ◽  
Muscle Tone ◽  
Sleep Onset ◽  
Upper Airway ◽  
Flow Volume ◽  
Pharyngeal Muscle ◽  
Peak Inspiratory Flow ◽  
Topical Lidocaine ◽  
Before And After

Pharyngeal patency depends, in part, on the tone and inspiratory activation of pharyngeal dilator muscles. To evaluate the influence of upper airway sensory feedback on pharyngeal muscle tone and thus pharyngeal patency, we measured pharyngeal airflow resistance and breathing pattern in 15 normal, supine subjects before and after topical lidocaine anesthesia of the pharynx and glottis. Studies were conducted during sleep and during quiet, relaxed wakefulness before sleep onset. Maximal flow-volume loops were also measured before and after anesthesia. During sleep, pharyngeal resistance at peak inspiratory flow increased by 63% after topical anesthesia (P less than 0.01). Resistance during expiration increased by 40% (P less than 0.01). Similar changes were observed during quiet wakefulness. However, upper airway anesthesia did not affect breathing pattern during sleep and did not alter awake flow-volume loops. These results indicate that pharyngeal patency during sleep is compromised when the upper airway is anesthetized and suggest that upper airway reflexes, which promote pharyngeal patency, exist in humans.

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