scholarly journals APNEA INDUCED BY UPPER AIRWAY PRESSURE CHANGES DECREASES WITH MATURATION IN PUPPIES

1984 ◽  
Vol 18 ◽  
pp. 397A-397A
Author(s):  
Oommen P Mathew ◽  
John T Fisher ◽  
Franca B Sant'Ambrogio ◽  
Giuseppe Sant'Ambrogio
Keyword(s):  
Airway Pressure ◽  
Upper Airway ◽  
Pressure Changes

Influence of upper airway pressure changes on respiratory frequency

1982 ◽  
Vol 49 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Oommen P. Mathew ◽  
Yousef K. Abu-Osba ◽  
Bradley T. Thach
Keyword(s):  
Airway Pressure ◽  
Upper Airway ◽  
Respiratory Frequency ◽  
Pressure Changes

Upper airway dilating forces during wakefulness and sleep in dogs

1986 ◽  
Vol 61 (6) ◽  
pp. 2148-2155 ◽  
Author(s):  
A. S. Goh ◽  
F. G. Issa ◽  
C. E. Sullivan
Keyword(s):  
Rem Sleep ◽  
Airway Pressure ◽  
Slow Wave Sleep ◽  
Upper Airway ◽  
Base Line ◽  
Phasic Change ◽  
Isolated Segment ◽  
The Mean ◽  
Line Level ◽  
Pressure Changes

We measured the pressure within an isolated segment of the upper airway in three dogs during wakefulness (W), slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. Measurements were taken from a segment of the upper airway between the nares and midtrachea while the dog breathed through a tracheostoma. These pressure changes represented the sum of respiratory-related forces generated by all muscles of the upper airway. The mean base-line level of upper airway pressure (Pua) was -0.5 +/- 0.03 cmH2O during W, increased by a mean of 2.1 +/- 0.2 cmH2O during SWS, and was variable during REM sleep. The mean inspiratory-related phasic change in Pua was -1.2 +/- 0.1 cmH2O during wakefulness. During SWS, this phasic change in Pua decreased significantly to a mean of -0.9 +/- 0.1 cmH2O (P less than 0.05). During REM sleep, the phasic activity was extremely variable with periods in which there were no fluctuations in Pua and others with high swings in Pua. These data indicate that in dogs the sum of forces which dilate the upper airway during W decreases during SWS and REM sleep. The consistent coupling between inspiratory drive and upper airway dilatation during wakefulness persists in SWS, but is frequently uncoupled during REM sleep.

Influence of upper airway pressure changes on genioglossus muscle respiratory activity

1982 ◽  
Vol 52 (2) ◽  
pp. 438-444 ◽  
Author(s):  
O. P. Mathew ◽  
Y. K. Abu-Osba ◽  
B. T. Thach
Keyword(s):  
Airway Pressure ◽  
Upper Airway ◽  
Positive Pressure ◽  
Emg Activity ◽  
Airway Patency ◽  
Pharyngeal Airway ◽  
Reflex Pathways ◽  
Inspiratory Activity ◽  
Pressure Changes ◽  
Reflex System

The effects of change in pharyngeal airway pressure on electromyographic (EMG) activity of a pharyngeal dilating muscle (genioglossus) were investigated in 20 anesthetized rabbits. In vagotomized animals, upper airway loading maneuvers (nasal occlusion) increased the peak inspiratory activity of the genioglossus (GG) muscle on the first occluded breath. In contrast, “unloading” maneuvers (switching from nose to tracheostomy breathing) decreased GG activity. To further characterize the GG response, sustained pressure changes were produced within the isolated upper airway. Negative pressure increased GG activity; positive pressure decreased it. A poststimulus effect consisting of increased GG activity compared with control was seen following both negative- and positive-pressure stimuli. Cyclical pressure changes applied to the isolated upper airway increased the GG activity. These observations indicate the presence of reflex pathways that regulate GG muscle activity in response to upper airway pressure loads. This reflex system appears to play a role in regulating GG activity during tidal breathing and could be important in ensuring pharyngeal airway patency.

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.

Genioglossus muscle responses to upper airway pressure changes: afferent pathways

1982 ◽  
Vol 52 (2) ◽  
pp. 445-450 ◽  
Author(s):  
O. P. Mathew ◽  
Y. K. Abu-Osba ◽  
B. T. Thach
Keyword(s):  
Airway Pressure ◽  
Upper Airway ◽  
Topical Anesthesia ◽  
Emg Activity ◽  
Afferent Pathway ◽  
Nerve Section ◽  
Primary Afferent ◽  
Genioglossus Muscle ◽  
Airway Reflex ◽  
Pressure Changes

The afferent pathway of an upper airway reflex in which genioglossus muscle electromyographic (GG EMG) activity is influenced by pharyngeal pressure changes was investigated in 20 anesthetized rabbits. We took advantage of the fact that the upper airway was separated into two compartments by pharyngeal closure occurring when the animals breathe through a tracheostomy. This allowed pressure to be delivered selectively either to the nose and nasopharynx or to the larynx and hypopharynx. Midcervical vagotomy did not eliminate the GG EMG response to pressure stimuli. On the other hand high cervical vagotomy or superior laryngeal nerve section eliminated the response in the laryngeal compartment, but not in the nasopharyngeal compartment. Topical anesthesia of the mucosa of the nose, pharynx, and larynx abolished the response in both compartments. Therefore we conclude that more than one afferent pathway exists for this upper airway pressure reflex; the primary afferent pathway from the laryngeal compartment is the superior laryngeal branch of the vagus nerve, whereas the primary afferent pathway for the nasopharynx is nonvagal. Trigeminal nerve, glossopharyngeal nerve, and/or nervus intermedius carry nonvagal afferents from the nasopharynx and nose. The topical anesthetic and nerve section studies suggest that superficial receptors mediate this response. The occurrence of swallowing in response to upper airway pressure changes and its elimination by topical anesthesia or superior mechanoreceptors may mediate both genioglossus respiratory responses and swallowing responses.

Mechanical effects of pharyngeal constrictor activation on pharyngeal airway function

1999 ◽  
Vol 86 (1) ◽  
pp. 411-417 ◽  
Author(s):  
Samuel T. Kuna ◽  
Christi R. Vanoye
Keyword(s):  
Axial Force ◽  
Airway Pressure ◽  
Muscle Activation ◽  
Upper Airway ◽  
Stimulation Frequency ◽  
Airway Patency ◽  
Pharyngeal Airway ◽  
Mechanical Effects ◽  
Airway Function ◽  
Pharyngeal Branch

The mechanical effects of pharyngeal constrictor (PC) muscle activation on pharyngeal airway function were determined in 20 decerebrate, tracheotomized cats. In 10 cats, a high-compliance balloon attached to a pressure transducer was partially inflated to just occlude the pharyngeal airway. During progressive hyperoxic hypercapnia, changes in pharyngeal balloon pressure were directly related to phasic expiratory hyopharyngeus (middle PC) activity. In two separate protocols in 10 additional cats, the following measurements were obtained with and without bilateral electrical stimulation (0.2-ms duration, threshold voltage) of the distal cut end of the vagus nerve’s pharyngeal branch supplying PC motor output: 1) pressure-volume relationships in an isolated, sealed upper airway at a stimulation frequency of 30 Hz and 2) rostrally directed axial force over a stimulation frequency range of 0–40 Hz. Airway compliance determined from the pressure-volume relationships decreased with PC stimulation at and below resting airway volume. Compared with the unstimulated condition, PC stimulation increased airway pressure at airway volumes at and above resting volume. This constrictor effect progressively diminished as airway volume was brought below resting volume. At relatively low airway volumes below resting volume, PC stimulation decreased airway pressure compared with that without stimulation. PC stimulation generated a rostrally directed axial force that was directly related to stimulation frequency. The results indicate that PC activation stiffens the pharyngeal airway, exerting both radial and axial effects. The radial effects are dependent on airway volume: constriction of the airway at relatively high airway volumes, and dilation of the airway at relatively low airway volumes. The results imply that, under certain conditions, PC muscle activation may promote pharyngeal airway patency.

Influence of lung volume dependence of upper airway resistance during continuous negative airway pressure

1994 ◽  
Vol 77 (2) ◽  
pp. 840-844 ◽  
Author(s):  
F. Series ◽  
I. Marc
Keyword(s):  
Lung Volume ◽  
Airway Pressure ◽  
Airway Resistance ◽  
Upper Airway ◽  
Random Order ◽  
Pressure Increase ◽  
Nasal Mask ◽  
Upper Airway Resistance ◽  
Volume Dependence ◽  
Negative Airway Pressure

To quantify the contribution of lung volume dependence of upper airway (UA) on continuous negative airway pressure (CNAP)-induced increase in upper airway resistance, we compared the changes in supralaryngeal resistance during an isolated decrease in lung volume and during CNAP in eight normal awake subjects. Inspiratory supralaryngeal resistance was measured at isoflow during four trials, during two CNAP trials where the pressure in a nasal mask was progressively decreased in 3- to 5-cmH2O steps and during two continuous positive extrathoracic pressure (CPEP) trials where the pressure around the chest (in an iron lung) was increased in similar steps. The CNAP and CPEP trials were done in random order. During the CPEP trial, the neck was covered by a rigid collar to prevent compression by the cervical seal of the iron lung. In each subject, resistance progressively increased during the experiments. The increase was linearily correlated with the pressure increase in the iron lung and with the square of the mask pressure during CNAP. There was a highly significant correlation between the rate of rise in resistance between CNAP and CPEP: the steeper the increase in resistance with decreasing lung volume, the steeper the increase in resistance with decreasing airway pressure. Lung volume dependence in UA resistance can account for 61% of the CNAP-induced increase in resistance. We conclude that in normal awake subjects the changes in supralaryngeal resistance induced by CNAP can partly be explained by the lung volume dependence of this resistance.

scholarly journals A Detection and Therapeutic Device to Overcome Sleep Apnea in Infants

2020 ◽  
Vol 2 (1) ◽  
pp. 35
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Airway Pressure ◽  
Upper Airway ◽  
Periodic Breathing ◽  
Breathing Patterns ◽  
Efficient System ◽  
Pressure Therapy ◽  
Obstructive Sleep ◽  
Upper Airway Structure

Among the various sleep-disordered breathing patterns infant’s experience, like periodic breathing, premature apnea, obstructive sleep apnea, has been considered a major cause of concern. Upper airway structure, mechanics of the pulmonary system, etc., are a few reasons why the infants are vulnerable to obstructive sleep-disordered. An imbalance in the viscoelastic properties of the pharynx, dilators, and pressure can lead to airway collapse. A low level of oxygen in blood or hypoxemia is considered a characteristic in infants with severe OSA. Invasive treatments like nasopharyngeal tubes, continuous positive airway pressure (CPAP), or tracheostomy are found to be helpful in most cases where infants experience sleep apnea. This paper proposes an efficient system for monitoring obstructive sleep apnea in infants on a long-term basis, and if any anomaly is detected, the device provides Continuous Airway Pressure therapy until the abnormality is normalized.

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