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.

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.

Effect of Body Posture on Flow-volume Loop and Upper Airway Obstruction Indices, Before and After Thyroid Surger

CHEST Journal ◽  
2003 ◽  
Vol 124 (4) ◽  
pp. 93S
Author(s):  
Marc Meysman ◽  
Jan Lamote ◽  
Bea Van Elewijck ◽  
Nancy Celis ◽  
Sonja Van Poyer ◽  
...  
Keyword(s):  
Airway Obstruction ◽  
Upper Airway ◽  
Body Posture ◽  
Upper Airway Obstruction ◽  
Flow Volume ◽  
Flow Volume Loop ◽  
Before And After

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.

Ventilatory dynamics during transient arousal from NREM sleep: implications for respiratory control stability

1996 ◽  
Vol 80 (5) ◽  
pp. 1475-1484 ◽  
Author(s):  
M. C. Khoo ◽  
S. S. Koh ◽  
J. J. Shin ◽  
P. R. Westbrook ◽  
R. B. Berry
Keyword(s):  
Respiratory Control ◽  
Upper Airway ◽  
Nrem Sleep ◽  
Before And After ◽  
Stage 2 Sleep ◽  
Repeated Administrations ◽  
Time Courses ◽  
Control Stability ◽  
Airway Dynamics ◽  
Normal Adults

The polysomnographic and ventilatory patterns of nine normal adults were measured during non-rapid-eye-movement (NREM) stage 2 sleep before and after repeated administrations of a tone (40-72 dB) lasting 5 s. The ventilatory response to arousal (VRA) was determined in data sections showing electrocortical arousal following the start of the tone. Mean inspiratory flow and tidal volume increased significantly above control levels in the first seven breaths after the start of arousal, with peak increases (64.2% > control) occurring on the second breath. Breath-to-breath occlusion pressure 100 ms after the start of inspiration showed significant increases only on the second and third postarousal breaths, whereas upper airway resistance declined immediately and remained below control for > or = 7 consecutive breaths. These results suggest that the first breath and latter portion of the VRA are determined more by upper airway dynamics than by changes in the neural drive to breathe. Computer model simulations comparing different VRA time courses show that sustained periodic apnea is more likely to occur when the fall in the postarousal increase in ventilation is more abrupt.

Computational Modeling of Upper Airway Before and After Adenotonsillectomy for Obstructive Sleep Apnea

2008 ◽  
Vol 118 (2) ◽  
pp. 360-362 ◽  
Author(s):  
Mihai Mihaescu ◽  
Shanmugam Murugappan ◽  
Ephraim Gutmark ◽  
Lane F. Donnelly ◽  
Maninder Kalra
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Computational Modeling ◽  
Upper Airway ◽  
Obstructive Sleep ◽  
Before And After

Effects of topical anesthesia on upper airway resistance during wake-sleep transitions

2005 ◽  
Vol 99 (2) ◽  
pp. 549-555 ◽  
Author(s):  
Liam S. Doherty ◽  
Philip Nolan ◽  
Walter T. McNicholas
Keyword(s):  
Sleep Onset ◽  
Upper Airway ◽  
Significant Rise ◽  
Topical Anesthesia ◽  
Reflex Response ◽  
Stage 2 Sleep ◽  
Normal Humans ◽  
Stage 1 ◽  
Sleep Transition ◽  
Stable Stage

Deformation of the upper airway (UA) by negative transmural pressure alters the activity of UA mechanoreceptors, causing a reflex increase in UA muscle activity. Topical anesthesia of the UA mucosa, which greatly reduces this reflex response, causes an increase in UA resistance during stage 2 sleep. We hypothesized that topical anesthesia of the UA mucosa would predispose to UA instability at sleep onset and, therefore, examined the effect of UA anesthesia on pharyngeal resistance (Rph) in stage 1 sleep. Eleven normal, healthy volunteers were instrumented to record standard polysomnographic variables, respiratory airflow, and UA pressure at the nasal choanae and the epiglottis. Subjects were permitted to sleep until stable stage 2 sleep was reached and were then awoken. This procedure was repeated three times to obtain reproducible wake-sleep transitions. The UA mucosa was then anesthetized with 10% lidocaine to the oropharynx and laryngopharynx, and the pharyngeal mechanics were studied during the subsequent wake-sleep transition. Three subjects were excluded because of failure to resume sleep postanesthesia. Rph was significantly higher after anesthesia during stage 1 sleep [2.88 ± 0.77 cmH2O·l−1·s (mean ± SE)] compared with control (0.95 ± 0.35 cmH2O·l−1·s; P < 0.05), but there was no difference during wakefulness. Furthermore, there was a significant rise in Rph at wake-to-sleep transitions and a significant fall in Rph at sleep-to-wake transitions after anesthesia ( P < 0.05) but not in the control condition. We conclude that sensory receptors in the UA mucosa contribute to the maintenance of UA patency at wake-sleep transition in normal humans.

scholarly journals Study of correlation between perceived sleep disturbances in depressed patients with objective changes in sleep architecture using polysomnography before and after antidepressant therapy

2020 ◽  
Vol 8 (7) ◽  
pp. 2551
Author(s):  
Ganesh Ingole ◽  
Harpreet S. Dhillon ◽  
Bhupendra Yadav
Keyword(s):  
Sleep Disturbances ◽  
Total Sleep Time ◽  
Antidepressant Treatment ◽  
Sleep Onset ◽  
Sleep Time ◽  
Sleep Efficiency ◽  
Sleep Architecture ◽  
Wake Time ◽  
Depressed Patients ◽  
Before And After

Background: A prospective cohort study to correlate perceived sleep disturbances in depressed patients with objective changes in sleep architecture using polysomnography (PSG) before and after antidepressant therapy.Methods: Patients were recruited into the study after applying strict inclusion and exclusion criterion to rule out other comorbidities which could influence sleep. A diagnosis of Depressive episode was made based on ICD-10 DCR. Psychometry, in the form of Beck Depressive inventory (BDI) and HAMD (Hamilton depression rating scale) insomnia subscale was applied on Day 1 of admission. Patients were subjected to sleep study on Day 03 of admission with Polysomnography. Patients were started on antidepressant treatment post Polysomnography. An adequate trial of antidepressants for 08 weeks was administered and BDI score ≤09 was taken as remission. Polysomnography was repeated post remission. Statistical analysis was performed using Kruskal Wallis test and Pearson correlation coefficient.Results: The results showed positive (improvement) polysomnographic findings in terms of total sleep time, sleep efficiency, wake after sleep onset, percentage wake time and these findings were statistically significant. HAM-D Insomnia subscale was found to correlate with total sleep time, sleep efficiency, wake after sleep onset, total wake time and N2 Stage percentage.Conclusions: Antidepressant treatment effectively improves sleep architecture in Depressive disorder and HAM-D Insomnia subscale correlates with objective findings of total sleep time, sleep efficiency, wake after sleep onset, total wake time and duration of N2 stage of NREM.

scholarly journals N-dihydrogalactochitosan reduces mortality in a lethal mouse model of SARS-CoV-2

2021 ◽  
Author(s):  
Christopher M Weiss ◽  
Hongwei Liu ◽  
Erin E Ball ◽  
Samuel Lam ◽  
Tomas Hode ◽  
...  
Keyword(s):  
Immune Responses ◽  
Infectious Virus ◽  
Severe Disease ◽  
Upper Airway ◽  
Innate Immune ◽  
Morbidity And Mortality ◽  
Vaccine Hesitancy ◽  
Innate Immune Responses ◽  
Before And After ◽  
Rapid Emergence

The rapid emergence and global dissemination of SARS-CoV-2 that causes COVID-19 continues to cause an unprecedented global health burden resulting in more than 4 million deaths in the 20 months since the virus was discovered. While multiple vaccine countermeasures have been approved for emergency use, additional treatments are still needed due to sluggish vaccine rollout and vaccine hesitancy. Immunoadjuvant compounds delivered intranasally can guide non-specific innate immune responses during the critical early stages of viral replication, reducing morbidity and mortality. N-dihydrogalactochitosan (GC) is a novel mucoadhesive immunostimulatory polymer of β-0-4-linked N-acetylglucosamine that is solubilized by the conjugation of galactose glycans. We tested GC as a potential countermeasure for COVID-19. GC administered intranasally before and after SARS-CoV-2 exposure diminished morbidity and mortality in humanized ACE2 receptor expressing mice by up to 75% and reduced infectious virus levels in the upper airway and lungs. Our findings demonstrate a new application for soluble immunoadjuvants like GC for preventing severe disease associated with SARS-CoV-2.

scholarly journals Toxicity associated with ingestion of a polyacrylic acid hydrogel dog pad

2018 ◽  
Vol 30 (5) ◽  
pp. 708-714 ◽  
Author(s):  
David C. Dorman ◽  
Melanie L. Foster ◽  
Brooke Olesnevich ◽  
Brad Bolon ◽  
Aude Castel ◽  
...  
Keyword(s):  
Motor Activity ◽  
Polyacrylic Acid ◽  
Muscle Tone ◽  
Clinical Signs ◽  
High Dose ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Before And After ◽  
Acute Neurotoxicity ◽  
Disposable Diapers

Superabsorbent sodium polyacrylate polymeric hydrogels that retain large amounts of liquids are used in disposable diapers, sanitary napkins, and other applications. These polymers are generally considered “nontoxic” with acute oral median lethal doses (LD50) >5 g/kg. Despite this favorable toxicity profile, we identified a novel toxic syndrome in dogs and rats following the ingestion of a commercial dog pad composed primarily of a polyacrylic acid hydrogel. Inappropriate mentation, cerebellar ataxia, vomiting, and intention tremors were observed within 24 h after the ingestion of up to 15.7 g/kg of the hydrogel by an adult, castrated male Australian Shepherd mix. These observations prompted an experimental study in rats to further characterize the toxicity of the hydrogel. Adult, female Sprague Dawley rats ( n = 9) were assessed before and after hydrogel ingestion (2.6–19.2 g/kg over 4 h) using a functional observation battery and spontaneous motor activity. Clinical signs consistent with neurotoxicity emerged in rats as early as 2 h after the end of hydrogel exposure, including decreased activity in an open field, hunched posture, gait changes, reduced reaction to handling, decreased muscle tone, and abnormal surface righting. Hydrogel-exposed rats also had reduced motor activity when compared with pre-exposure baseline data. Rats that ingested the hydrogel did not develop nervous system lesions. These findings support the conclusion that some pet pad hydrogel products can induce acute neurotoxicity in animals under high-dose exposure conditions.

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