Effect of upper airway pressure pulses on breathing pattern

1986 ◽  
Vol 66 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Diane L. Woodall ◽  
Oommen P. Mathew
Keyword(s):  
Airway Pressure ◽  
Breathing Pattern ◽  
Upper Airway ◽  
Pressure Pulses

Interaction between upper airway negative pressure pulses and CO2 on breathing pattern

1988 ◽  
Vol 65 (1) ◽  
pp. 205-209 ◽  
Author(s):  
D. L. Woodall ◽  
O. P. Mathew
Keyword(s):  
Closed System ◽  
Negative Pressure ◽  
Breathing Pattern ◽  
Upper Airway ◽  
System A ◽  
Pressure Pulses ◽  
Inspiratory Activity ◽  
Resultant Increase ◽  
Breathing Room ◽  
Spontaneously Breathing

The interaction between CO2 and negative pressure pulses on breathing pattern was investigated in 10 anesthetized, spontaneously breathing rabbits. The upper airway was functionally isolated into a closed system. A servo-respirator triggered by the inspiratory activity of the diaphragm was used to apply pressure pulses of -15 cmH2O to the isolated upper airway in early inspiration while the animal was breathing room air, 100% O2, 6% CO2 in O2, or 9% CO2 in O2. The negative pressure pulses produced a reversible inhibition of inspiration in most trials with resultant increase in inspiratory duration (TI); no change was observed in peak diaphragmatic electromyogram (Dia EMG) or expiratory duration, whereas a decrease was seen in mean inspiratory drive (peak Dia EMG/TI). This prolongation of inspiratory duration and decrease in mean inspiratory drive with negative pressure pulses persisted at higher levels of CO2; the slopes of the test breaths were not significantly different from that of control breaths. These results suggest that upper airway negative pressure pulses are equally effective in altering the breathing pattern at all levels of CO2.

Tracheal smooth muscle responses to upper airway pressure in conscious dogs

1990 ◽  
Vol 68 (4) ◽  
pp. 1555-1561 ◽  
Author(s):  
L. Plowman ◽  
P. H. Edwards ◽  
D. C. Lauff ◽  
M. Berthon-Jones ◽  
C. E. Sullivan
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Airway Pressure ◽  
Breathing Pattern ◽  
Muscle Tone ◽  
Upper Airway ◽  
Tracheal Smooth Muscle ◽  
Smooth Muscle Tone ◽  
Pressure Stimulus ◽  
Tracheal Stoma

We studied the influence of changes in pressure applied to the isolated upper airway of four conscious dogs on tracheal smooth muscle tone and breathing pattern. The dogs were prepared with a permanent side-hole tracheal stoma and were trained to sleep with a snout mask hermetically sealed in place while breathing through a cuffed endotracheal tube inserted distally into the tracheal stoma. Changes in tracheal smooth muscle tone were continuously monitored by measuring the pressure in the water-filled cuff that distended the tracheal airway while pressure changes were introduced in the upper airway independently of breathing. Increases or decreases of upper airway pressure (+/- 10 cmH2O) had little effect on tracheal airway smooth muscle tone. In contrast, an oscillating pressure wave at 30 Hz and +/- 3 cmH2O amplitude (or -3 to -7 cmH2O amplitude) caused a marked increase in tracheal airway smooth muscle tone. An elevated tracheal airway tone could be maintained over many minutes when the oscillating pressure stimulus was pulsed so that there was a cycle of 0.5 s on, 0.5 s off. This stimulus did not change the functional residual capacity but resulted in coughing, swallowing, or sighing in 54% of the tests. In the remaining tests, the pressure stimulus produced a rapid, shallow, and erratic breathing pattern. The tracheal airway constrictor response (but not the ventilatory response) was completely abolished by intravenous atropine. We suggest that upper airway vibration is a potentially powerful mechanism of reflex airway smooth muscle constriction.

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.

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

scholarly journals Geniohyoid muscle function in awake canines

2003 ◽  
Vol 95 (2) ◽  
pp. 810-817 ◽  
Author(s):  
M. Yokoba ◽  
H. G. Hawes ◽  
P. A. Easton
Keyword(s):  
Muscle Function ◽  
Breathing Pattern ◽  
Muscle Length ◽  
Upper Airway ◽  
Mechanical Action ◽  
Emg Activity ◽  
Airway Occlusion ◽  
Lateral Decubitus ◽  
The Right ◽  
Emg Electrodes

The geniohyoid (Genio) upper airway muscle shows phasic, inspiratory electrical activity in awake humans but no activity and lengthening in anesthetized cats. There is no information about the mechanical action of the Genio, including length and shortening, in any awake, nonanesthetized mammal during respiration (or swallowing). Therefore, we studied four canines, mean weight 28.8 kg, 1.5 days after Genio implantation with sonomicrometry transducers and bipolar electromyogram (EMG) electrodes. Awake recordings of breathing pattern, muscle length and shortening, and EMG activity were made with the animal in the right lateral decubitus position during quiet resting, CO2-stimulated breathing, inspiratory-resisted breathing (80 cmH2O · l-1 · s), and airway occlusion. Genio length and activity were also measured during swallowing, when it shortened, showing a 9.31% change from resting length, and its EMG activity increased 6.44 V. During resting breathing, there was no phasic Genio EMG activity at all, and Genio showed virtually no movement during inspiration. During CO2-stimulated breathing, Genio showed minimal lengthening of only 0.07% change from resting length, whereas phasic EMG activity was still absent. During inspiratory-resisted breathing and airway occlusion, Genio showed phasic EMG activity but still lengthened. We conclude that the Genio in awake, nonanesthetized canines shows active contraction and EMG activity only during swallowing. During quiet or stimulated breathing, Genio is electrically inactive with passive lengthening. Even against resistance, Genio is electrically active but still lengthens during inspiration.

scholarly journals 1244 A Curious Case of ASV Failure

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A474-A474
Author(s):  
Nishant Chaudhary ◽  
Mirna Ayache ◽  
John Carter
Keyword(s):  
Sleep Apnea ◽  
Airway Obstruction ◽  
Airway Pressure ◽  
Positive Airway Pressure ◽  
Central Sleep Apnea ◽  
Upper Airway ◽  
Upper Airway Obstruction ◽  
Neck Extension ◽  
Sleep Study ◽  
Obstructive Sleep

Abstract Introduction Positive airway pressure-induced upper airway obstruction has been reported with the treatment of obstructive sleep apnea (OSA) using continuous positive airway pressure (CPAP) along with an oronasal interface. Here we describe a case of persistent treatment emergent central sleep apnea (TECSA) inadequately treated with adaptive servo ventilation (ASV), with an airflow pattern suggestive of ASV-induced upper airway obstruction. Report of Case A 32-year-old male, with severe OSA (apnea hypopnea index: 52.4) and no other significant past medical history, was treated with CPAP and required higher pressures during titration sleep studies to alleviate obstructive events, despite a Mallampati Class II airway and a normal body mass index. Drug-Induced Sleep Endoscopy (DISE) showed a complete velopharynx and oropharynx anterior posterior (AP) collapse, long soft palate, which improved with neck extension. CPAP therapy, however, did not result in any symptomatic benefit and compliance reports revealed high residual AHI and persistent TECSA. He underwent an ASV titration sleep study up to a final setting of expiratory positive airway pressure 9 cm H2O, pressure support 6-15 cm H2O (auto-rate), with a full-face mask due to high oral leak associated with the nasal interface. The ASV device detected central apneas and provided mandatory breaths, but did not capture the thorax or abdomen, despite normal mask pressure tracings. Several such apneas occurred, with significant oxyhemoglobin desaturation. Conclusion We postulate that the ASV failure to correct central sleep apnea as evidenced by the absence of thoracoabdominal inspiratory effort, occurred due to ASV-induced upper airway obstruction. Further treatment options for this ASV phenomenon are to pursue an ASV-assisted DISE and determine the effectiveness of adjunctive therapy including neck extension, nasal mask with a mouth closing device and a mandibular assist device.

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