Decreased Surface Tension of Upper Airway Mucosal Lining Liquid Increases Upper Airway Patency in Anaesthetised Rabbits

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.

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Surface Tension of Upper Airway Mucosal Lining Liquid in Obstructive Sleep Apnea/Hypopnea Syndrome

SLEEP ◽

10.1093/sleep/28.4.457 ◽

2005 ◽

Vol 28 (4) ◽

pp. 457-463 ◽

Cited By ~ 29

Author(s):

Jason P. Kirkness ◽

Melanie Madronio ◽

Rosie Stavrinou ◽

John R. Wheatley ◽

Terence C. Amis

Keyword(s):

Surface Tension ◽

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Upper Airway ◽

Obstructive Sleep ◽

Mucosal Lining ◽

Hypopnea Syndrome

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Application of the ‘pull-off’ force method for measurement of surface tension of upper airway mucosal lining liquid

Physiological Measurement ◽

10.1088/0967-3334/26/5/009 ◽

2005 ◽

Vol 26 (5) ◽

pp. 677-688 ◽

Cited By ~ 15

Author(s):

Jason P Kirkness ◽

Hugo K Christenson ◽

John R Wheatley ◽

Terence C Amis

Keyword(s):

Surface Tension ◽

Upper Airway ◽

Force Method ◽

Mucosal Lining

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Effect of Head Elevation on Passive Upper Airway Collapsibility in Normal Subjects during Propofol Anesthesia

Anesthesiology ◽

10.1097/aln.0b013e318223ba6d ◽

2011 ◽

Vol 115 (2) ◽

pp. 273-281 ◽

Cited By ~ 16

Author(s):

Masato Kobayashi ◽

Takao Ayuse ◽

Yuko Hoshino ◽

Shinji Kurata ◽

Shunji Moromugi ◽

...

Keyword(s):

Upper Airway ◽

Normal Subjects ◽

Target Concentration ◽

Airway Patency ◽

Head Elevation ◽

Jaw Opening ◽

Airway Collapsibility ◽

Upper Airway Collapsibility ◽

Head Flexion ◽

Male Subjects

Background Head elevation can restore airway patency during anesthesia, although its effect may be offset by concomitant bite opening or accidental neck flexion. The aim of this study is to examine the effect of head elevation on the passive upper airway collapsibility during propofol anesthesia. Method Twenty male subjects were studied, randomized to one of two experimental groups: fixed-jaw or free-jaw. Propofol infusion was used for induction and to maintain blood at a constant target concentration between 1.5 and 2.0 μg/ml. Nasal mask pressure (PN) was intermittently reduced to evaluate the upper airway collapsibility (passive PCRIT) and upstream resistance (RUS) at each level of head elevation (0, 3, 6, and 9 cm). The authors measured the Frankfort plane (head flexion) and the mandible plane (jaw opening) angles at each level of head elevation. Analysis of variance was used to determine the effect of head elevation on PCRIT, head flexion, and jaw opening within each group. Results In both groups the Frankfort plane and mandible plane angles increased with head elevation (P < 0.05), although the mandible plane angle was smaller in the free-jaw group (i.e., increased jaw opening). In the fixed-jaw group, head elevation decreased upper airway collapsibility (PCRIT ~ -7 cm H₂O at greater than 6 cm elevation) compared with the baseline position (PCRIT ~ -3 cm H₂O at 0 cm elevation; P < 0.05). Conclusion : Elevating the head position by 6 cm while ensuring mouth closure (centric occlusion) produces substantial decreases in upper airway collapsibility and maintains upper airway patency during anesthesia.

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Does Presurgical Nasoalveolar Molding Have a Long-Term Effect on Nasal and Upper Airway Dimensions?

The Cleft Palate-Craniofacial Journal ◽

10.1177/1055665620980234 ◽

2020 ◽

pp. 105566562098023

Author(s):

Ashwina S. Banari ◽

Sanjeev Datana ◽

Shiv Shankar Agarwal ◽

Sujit Kumar Bhandari

Keyword(s):

Upper Airway ◽

P Value ◽

Airway Patency ◽

The Mean ◽

Group 2 ◽

Acoustic Pharyngometry ◽

Nasoalveolar Molding ◽

Area And Volume ◽

Group 1

Objectives: To compare nasal and upper airway dimensions in patients with cleft lip and palate (CLP) who underwent nasoalveolar molding (NAM) with those without NAM during infancy using acoustic pharyngometry and rhinometry. Materials and Methods: Eccovision acoustic pharyngometry and rhinometry (Sleep Group Solutions) was used for assessment of mean area and volume of nasal and upper airway in patients with complete unilateral CLP (age range 16-21 years) treated with NAM (group 1, n = 19) versus without NAM (group 2, n = 22). Results: The mean nasal cross-sectional areas and volume were higher in group 1 compared to group 2 on both cleft ( P value <.001) and noncleft side ( P value >.05). The mean area and volume of upper airway were also significantly higher in group 1 compared to group 2 ( P value <.05). Conclusions: Nasoalveolar molding being one of the first interventions in chronology of treatment of patients with CLP, its long-term outcome on nasal and upper airway patency needs to be ascertained. The results of the present study show that the patients with CLP who have undergone NAM during infancy have better improvement in nasal and upper airway patency compared with those who had not undergone NAM procedure. The basic advantages of being noninvasive, nonionizing and providing dynamic assessment of nasal and upper airway patency make acoustic pharyngometry and rhinometry a diagnostic tool of choice to be used in patients with CLP.

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Jaw thrust can deteriorate upper airway patency

Acta Anaesthesiologica Scandinavica ◽

10.1111/j.1399-6576.2005.00637.x ◽

2005 ◽

Vol 49 (4) ◽

pp. 583-585 ◽

Cited By ~ 10

Author(s):

B. S. Von Ungern-Sternberg ◽

T. O. Erb ◽

F. J. Frei

Keyword(s):

Upper Airway ◽

Airway Patency

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Mechanical effects of pharyngeal constrictor activation on pharyngeal airway function

Journal of Applied Physiology ◽

10.1152/jappl.1999.86.1.411 ◽

1999 ◽

Vol 86 (1) ◽

pp. 411-417 ◽

Cited By ~ 37

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.

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Inspiratory coactivation of the genioglossus enlarges retroglossal space in laryngectomized humans

Journal of Applied Physiology ◽

10.1152/jappl.1996.80.5.1595 ◽

1996 ◽

Vol 80 (5) ◽

pp. 1595-1604 ◽

Cited By ~ 55

Author(s):

I. Kobayashi ◽

A. Perry ◽

J. Rhymer ◽

B. Wuyam ◽

P. Hughes ◽

...

Keyword(s):

Upper Airway ◽

Dependent Manner ◽

Tongue Movement ◽

Forward Movement ◽

Upper Airways ◽

Posterior Aspect ◽

Airway Patency ◽

Significant Movement ◽

Tongue Position ◽

Tracheal Stoma

To investigate the relationship between the electrical activity of the genioglossus (GG-EMG) and associated tongue movement, seven laryngectomized subjects breathing through a tracheal stoma (without pressure or flow change in the upper airway) were studied in the supine position. Tongue movement, with the use of lateral fluoroscopy, and GG-EMG expressed as a percentage of maximum voluntary genioglossal activation were monitored simultaneously during 1) spontaneous inspiration (SI), 2) resistive loaded inspiration (LI), and 3) rapid inspiration (RI). Tongue position during each maneuver was compared with its position during spontaneous expiration. Peak GG-EMG during the three maneuvers was significantly different from each other (SI: 5.4 +/- 1.6, LI: 11.9 +/- 1.8, and RI: 51.6 +/- 9.4 (SE) %, respectively). Associated forward movement of the posterior aspect of the tongue was minimum during SI; however, significant movement was observed during LI, and this was increased during RI. Significant covariance existed between peak GG-EMG and this movement. Genioglossal coactivation with inspiration enlarges the glossopharyngeal airway, particularly in its caudal part. In subjects with intact upper airways, this activation may protect or enhance upper airway patency in an effort-dependent manner.

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Comparison of upper airway patency in patients with mild obstructive sleep apnea during dexmedetomidine or propofol sedation: a prospective, randomized, controlled trial

BMC Anesthesiology ◽

10.1186/s12871-018-0586-5 ◽

2018 ◽

Vol 18 (1) ◽

Cited By ~ 3

Author(s):

Hyun-Jung Shin ◽

Eun-Young Kim ◽

Jung-Won Hwang ◽

Sang-Hwan Do ◽

Hyo-Seok Na

Keyword(s):

Randomized Controlled Trial ◽

Obstructive Sleep Apnea ◽

Sleep Apnea ◽

Controlled Trial ◽

Upper Airway ◽

Airway Patency ◽

Randomized Controlled ◽

Obstructive Sleep ◽

Prospective Randomized Controlled Trial ◽

Mild Obstructive Sleep Apnea

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Ketamine Activates Breathing and Abolishes the Coupling between Loss of Consciousness and Upper Airway Dilator Muscle Dysfunction

Anesthesiology ◽

10.1097/aln.0b013e31823d010a ◽

2012 ◽

Vol 116 (1) ◽

pp. 35-46 ◽

Cited By ~ 61

Author(s):

Matthias Eikermann ◽

Martina Grosse-Sundrup ◽

Sebastian Zaremba ◽

Mark E. Henry ◽

Edward A. Bittner ◽

...

Keyword(s):

Power Spectrum ◽

Eye Movement ◽

Upper Airway ◽

Muscle Dysfunction ◽

High Dose ◽

Loss Of Consciousness ◽

Respiratory Drive ◽

Airway Patency ◽

Dilator Muscle ◽

Ketamine Anesthesia

Background Procedural sedation is frequently performed in spontaneously breathing patients, but hypnotics and opioids decrease respiratory drive and place the upper airway at risk for collapse. Methods In a randomized, controlled, cross-over, pharmaco-physiologic study in 12 rats, we conducted acute experiments to compare breathing and genioglossus electromyogram activity at equianesthetic concentrations of ketamine, a noncompetitive N-methyl-D-aspartate receptor antagonist that combines potent analgesic with hypnotic action effects, versus propofol. In 10 chronically instrumented rats resting in a plethysmograph, we measured these variables as well as electroencephalography during five conditions: quiet wakefulness, nonrapid-eye-movement sleep, rapid eye movement sleep, and low-dose (60 mg/kg intraperitoneally) and high-dose ketamine anesthesia (125 mg/kg intraperitoneally). Results Ketamine anesthesia was associated with markedly increased genioglossus activity (1.5 to fivefold higher values of genioglossus electromyogram) compared with sleep- and propofol-induced unconsciousness. Plethysmography revealed a respiratory stimulating effect: higher values of flow rate, respiratory rate, and duty-cycle (effective inspiratory time, 1.5-to-2-fold higher values). During wakefulness and normal sleep, the δ (f = 6.51, P = 0.04) electroencephalogram power spectrum was an independent predictor of genioglossus activity, indicating an association between electroencephalographic determinants of consciousness and genioglossus activity. Following ketamine administration, electroencephalogram power spectrum and genioglossus electroencephalogram was dissociated (P = 0.9 for the relationship between δ/θ power spectrum and genioglossus electromyogram). Conclusions Ketamine is a respiratory stimulant that abolishes the coupling between loss-of-consciousness and upper airway dilator muscle dysfunction in a wide dose-range. Ketamine compared with propofol might help stabilize airway patency during sedation and anesthesia.

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