Reflex effects and receptor responses to upper airway pressure and flow stimuli in developing puppies

1985 ◽  
Vol 58 (1) ◽  
pp. 258-264 ◽  
Author(s):  
J. T. Fisher ◽  
O. P. Mathew ◽  
F. B. Sant'Ambrogio ◽  
G. Sant'Ambrogio
Keyword(s):  
Negative Pressure ◽  
Breathing Pattern ◽  
Discharge Rate ◽  
Age Groups ◽  
Upper Airway ◽  
Positive Pressure ◽  
Laryngeal Nerves ◽  
Significant Prolongation ◽  
The Central Nervous System ◽  
Negative Pressures

We studied the changes in breathing pattern due to pressure and airflow stimuli applied to isolated upper airway in nine 1- to 14-day-old and six 29- to 35-day-old anesthetized puppies breathing through a tracheostomy. Negative-pressure and flow, both inspiratory and expiratory, altered the breathing pattern only in the 1- to 14-day-old puppies, whereas positive pressure was ineffective in both age groups. Negative pressure caused apnea in 12% of the trials, expiratory flow in 18%, and inspiratory flow in 21%. When apnea did not occur there was a significant prolongation of inspiratory and expiratory time and a decrease of tidal volume of the first breath following the application of negative pressures. Section of the superior laryngeal nerves abolished the responses to pressure and flow. In nine 1- to 14-day-old and four 29- to 35-day-old puppies we recorded the activity of single units of the superior laryngeal nerves. We identified specialized receptors responding to pressure (68.5%), flow (2.7%), and contraction of upper airway muscles (drive, 28.8%). All types of receptors had a prevalent inspiratory-related activity. In the younger age group the discharge rate of pressure receptors at comparable negative pressures was lower than in older puppies. The strong inhibitory influences originating from the upper airway in the early stages of development presumably reflect different integrative properties of the central nervous system.

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.

scholarly journals Modulation of laryngeal and respiratory pump muscle activities with upper airway pressure and flow

2001 ◽  
Vol 91 (2) ◽  
pp. 897-904 ◽  
Author(s):  
M. H. Stella ◽  
S. J. England
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Upper Airway ◽  
Abdominal Muscle ◽  
Positive Pressure ◽  
Emg Activity ◽  
Posterior Cricoarytenoid ◽  
Spontaneously Breathing ◽  
Respiratory Muscle Activity ◽  
Stimulation Of

The hypothesis that upper airway (UA) pressure and flow modulate respiratory muscle activity in a respiratory phase-specific fashion was assessed in anesthetized, tracheotomized, spontaneously breathing piglets. We generated negative pressure and inspiratory flow in phase with tracheal inspiration or positive pressure and expiratory flow in phase with tracheal expiration in the isolated UA. Stimulation of UA negative pressure receptors with body temperature air resulted in a 10–15% enhancement of phasic moving-time-averaged posterior cricoarytenoid electromyographic (EMG) activity above tonic levels obtained without pressure and flow in the UA (baseline). Stimulation of UA positive pressure receptors increased phasic moving-time-averaged thyroarytenoid EMG activity above tonic levels by 45% from baseline. The same enhancement of posterior cricoarytenoid or thyroarytenoid EMG activity was observed with the addition of flow receptor stimulation with room temperature air. Tidal volume and diaphragmatic and abdominal muscle activity were unaffected by UA flow and/or pressure, whereas respiratory timing was minimally affected. We conclude that laryngeal afferents, mainly from pressure receptors, are important in modulating the respiratory activity of laryngeal muscles.

scholarly journals Negative pressure ventilation enhances acinar perfusion in isolated rat lungs

2017 ◽  
Vol 8 (1) ◽  
pp. 204589321775359 ◽  
Author(s):  
Kal E. Watson ◽  
Gilad S. Segal ◽  
Robert L. Conhaim
Keyword(s):  
Negative Pressure ◽  
Pulmonary Circulation ◽  
Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Latex Particles ◽  
Negative Pressure Ventilation ◽  
Rat Lungs ◽  
Confocal Images ◽  
Negative Pressures ◽  
Isolated Rat

We compared acinar perfusion in isolated rat lungs ventilated using positive or negative pressures. The lungs were ventilated with air at transpulmomary pressures of 15/5 cm H2O, at 25 breaths/min, and perfused with a hetastarch solution at Ppulm art/PLA pressures of 10/0 cm H2O. We evaluated overall perfusability from perfusate flows, and from the venous concentrations of 4-µm diameter fluorescent latex particles infused into the pulmonary circulation during perfusion. We measured perfusion distribution from the trapping patterns of those particles within the lung. We infused approximately 9 million red fluorescent particles into each lung, followed 20 min later by an infusion of an equal number of green particles. In positive pressure lungs, 94.7 ± 2.4% of the infused particles remained trapped within the lungs, compared to 86.8 ± 5.6% in negative pressure lungs ( P ≤ 0.05). Perfusate flows averaged 2.5 ± 0.1 mL/min in lungs ventilated with positive pressures, compared to 5.6 ± 01 mL/min in lungs ventilated with negative pressures ( P ≤ 0.05). Particle infusions had little effect on perfusate flows. In confocal images of dried sections of each lung, red and green particles were co-localized in clusters in positive pressure lungs, suggesting that acinar vessels that lacked particles were collapsed by these pressures thereby preventing perfusion through them. Particles were more broadly and uniformly distributed in negative pressure lungs, suggesting that perfusion in these lungs was also more uniformly distributed. Our results suggest that the acinar circulation is organized as a web, and further suggest that portions of this web are collapsed by positive pressure ventilation.

Laryngeal influences on breathing pattern and posterior cricoarytenoid muscle activity

1985 ◽  
Vol 58 (4) ◽  
pp. 1298-1304 ◽  
Author(s):  
F. B. Sant'Ambrogio ◽  
O. P. Mathew ◽  
W. D. Clark ◽  
G. Sant'Ambrogio
Keyword(s):  
Breathing Pattern ◽  
Upper Airway ◽  
Airway Patency ◽  
Airway Occlusion ◽  
Laryngeal Nerves ◽  
Relative Contribution ◽  
Posterior Cricoarytenoid Muscle ◽  
Regulation Of Breathing ◽  
Anesthetized Dogs ◽  
Posterior Cricoarytenoid

Receptors responding to transmural pressure, airflow, and contraction of laryngeal muscles have been previously identified in the larynx. To assess the relative contribution of these three types of receptors to the reflex changes in breathing pattern and upper airway patency, we studied diaphragmatic (DIA) and posterior cricoarytenoid muscle (PCA) activity in anesthetized dogs during spontaneous breathing and occluded efforts with and without bypassing the larynx. Inspiratory duration (TI) was longer, mean inspiratory slope (peak DIA/TI) was lower, and PCA activity was greater with upper airway occlusion than with tracheal occlusion (larynx bypassed). Bilateral section of the superior laryngeal nerves eliminated these differences. When respiratory airflow was diverted from the tracheostomy to the upper airway the only change attributable to laryngeal afferents was an increase in PCA activity. These results confirm the importance of the superior laryngeal nerves in the regulation of breathing pattern and upper airway patency and suggest a prevalent role for laryngeal negative pressure receptors.

scholarly journals Negative Pressure Pulmonary Edema as a Cause of Diffuse Alveolar Hemorrhage in the Newborn

2020 ◽  
Vol 10 (01) ◽  
pp. e212-e214
Author(s):  
Alejandro Donoso ◽  
Gianfranco Tomarelli ◽  
Daniela Arriagada
Keyword(s):  
Pulmonary Edema ◽  
Negative Pressure ◽  
Age Groups ◽  
Upper Airway ◽  
Diffuse Alveolar Hemorrhage ◽  
Alveolar Hemorrhage ◽  
Negative Pressure Pulmonary Edema ◽  
Refractory Hypoxemia ◽  
Life Threatening ◽  
Nitric Oxide Therapy

AbstractNegative pressure pulmonary edema (NPPE) is a rare entity that can become life threatening. Its development in neonates is very rare, and its presentation as alveolar hemorrhage is uncommon. We report a case of a newborn 23 days old, previously healthy, who presented an episode of choking during breastfeeding. This progressed to acute respiratory failure due to diffuse alveolar hemorrhage. A few hours after admission, the newborn developed refractory hypoxemia, requiring high-frequency oscillatory ventilation and nitric oxide therapy for 24 hours. NPPE was postulated as a diagnosis of exclusion. The newborn recovered completely. NPPE should always be considered in a case with recent obstruction of the upper airway, even in unusual age groups. Sometimes it can manifest as alveolar hemorrhage.

Laryngeal-receptor responses to phasic CO2 in anesthetized cats

1998 ◽  
Vol 85 (3) ◽  
pp. 1135-1141 ◽  
Author(s):  
A. Bradford ◽  
D. McKeogh ◽  
R. G. O’Regan
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Upper Airway ◽  
Respiratory Cycle ◽  
Positive Pressure ◽  
Receptor Stimulation ◽  
Airway Patency ◽  
Cold Receptors ◽  
Regulation Of Breathing ◽  
Spontaneously Breathing

We compared the effects of CO2 applied continuously and during expiration on laryngeal-receptor activity in paralyzed, artificially ventilated and nonparalyzed, spontaneously breathing cats by using an isolated larynx, artificially ventilated to approximate a normal respiratory cycle. The majority of quiescent negative-pressure and all cold receptors were excited by 5 and 9% CO2 applied both continuously and during expiration. In general, quiescent positive-pressure, tonic negative-pressure, and tonic positive-pressure receptors were inhibited by 5 and 9% CO2 applied continuously and during expiration. There were no significant differences between responses to 5 and 9% CO2 or to continuous and expired CO2 or between paralyzed and nonparalyzed preparations. In conclusion, laryngeal receptors respond to changes in CO2 concentration occurring during a normal respiratory cycle. Because laryngeal-receptor stimulation exerts reflex effects on ventilation and upper airway muscle activity, these results suggest that airway CO2 plays a role in reflex regulation of breathing and upper airway patency.

scholarly journals 1863 THE EFFECT OF UPPER AIRWAY NEGATIVE PRESSURE IN INSPIRATION (EARLY VS LATE) ON THE BREATHING PATTERN

1985 ◽  
Vol 19 (4) ◽  
pp. 421A-421A
Author(s):  
Diane L Woodall ◽  
Mark L Clark ◽  
Oommen P Mathew
Keyword(s):  
Negative Pressure ◽  
Breathing Pattern ◽  
Upper Airway

Responses to negative pressure surrounding the neck in anesthetized animals

1990 ◽  
Vol 68 (1) ◽  
pp. 154-160 ◽  
Author(s):  
A. D. Wolin ◽  
K. P. Strohl ◽  
B. N. Acree ◽  
J. M. Fouke
Keyword(s):  
Negative Pressure ◽  
Airway Resistance ◽  
Upper Airway ◽  
Transmural Pressure ◽  
Positive Pressure ◽  
Respiratory Drive ◽  
Airway Wall ◽  
Airway Patency ◽  
Upper Airway Resistance ◽  
Continuous Positive Pressure

Continuous positive pressure applied at the nose has been shown to cause a decrease in upper airway resistance. The present study was designed to determine whether a similar positive transmural pressure gradient, generated by applying a negative pressure at the body surface around the neck, altered upper airway patency. Studies were performed in nine spontaneously breathing anesthetized supine dogs. Airflow was measured with a pneumotachograph mounted on an airtight muzzle placed over the nose and mouth of each animal. Upper airway pressure was measured as the differential pressure between the extrathoracic trachea and the inside of the muzzle. Upper airway resistance was monitored as an index of airway patency. Negative pressure (-2 to -20 cmH2O) was applied around the neck by using a cuirass extending from the jaw to the thorax. In each animal, increasingly negative pressures were transmitted to the airway wall in a progressive, although not linear, fashion. Decreasing the pressure produced a progressive fall in upper airway resistance, without causing a significant change in respiratory drive or respiratory timing. At -5 cmH2O pressure, there occurred a significant fall in upper airway resistance, comparable with the response of a single, intravenous injection of sodium cyanide (0.5-3.0 mg), a respiratory stimulant that produces substantial increases in respiratory drive. We conclude that upper airway resistance is influenced by the transmural pressure across the airway wall and that such a gradient can be accomplished by making the extraluminal pressure more negative.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Superior laryngeal nerve section alters responses to upper airway distortion in sleeping dogs

1997 ◽  
Vol 83 (3) ◽  
pp. 768-775 ◽  
Author(s):  
Aidan K. Curran ◽  
Peter R. Eastwood ◽  
Craig A. Harms ◽  
Curtis A. Smith ◽  
Jerome A. Dempsey
Keyword(s):  
Negative Pressure ◽  
Minute Ventilation ◽  
Superior Laryngeal Nerve ◽  
Upper Airway ◽  
Inspiratory Effort ◽  
Laryngeal Nerve ◽  
Respiratory Frequency ◽  
Nerve Section ◽  
Expiratory Time ◽  
Negative Pressures

Curran, Aidan K., Peter R. Eastwood, Craig A. Harms, Curtis A. Smith, and Jerome A. Dempsey. Superior laryngeal nerve section alters responses to upper airway distortion in sleeping dogs. J. Appl. Physiol. 83(3): 768–775, 1997.—We investigated the effect of superior laryngeal nerve (SLN) section on expiratory time (Te) and genioglossus electromyogram (EMGgg) responses to upper airway (UA) negative pressure (UANP) in sleeping dogs. The same dogs used in a similar intact study (C. A. Harms, C. A., Y.-J. Zeng, C. A. Smith, E. H. Vidruk, and J. A. Dempsey. J. Appl. Physiol. 80: 1528–1539, 1996) were bilaterally SLN sectioned. After recovery, the UA was isolated while the animal breathed through a tracheostomy. Square waves of negative pressure were applied to the UA from below the larynx or from the mask (nares) at end expiration and held until the next inspiratory effort. Section of the SLN increased eupneic respiratory frequency and minute ventilation. Relative to the same dogs before SLN section, sublaryngeal UANP caused less Te prolongation while activation of the genioglossus required less negative pressures. Mask UANP had no effect on Te or EMGgg activity. We conclude that the SLN 1) is not obligatory for the reflex prolongation of Te and activation of EMGgg activity produced by UANP and 2) plays an important role in the maintenance of UA stability and the pattern of breathing in sleeping dogs.

Influence of negative pressure applied to the upper airway on the breathing pattern in unanesthetized awake dogs

1986 ◽  
Vol 65 (3) ◽  
pp. 315-329 ◽  
Author(s):  
Stephen G. McNamara ◽  
Faiq G. Issa ◽  
Edwin Szeto ◽  
Colin E. Sullivan
Keyword(s):  
Negative Pressure ◽  
Breathing Pattern ◽  
Upper Airway
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