Jaw thrust can deteriorate upper airway patency

2005 ◽  
Vol 49 (4) ◽  
pp. 583-585 ◽  
Author(s):  
B. S. Von Ungern-Sternberg ◽  
T. O. Erb ◽  
F. J. Frei
Keyword(s):  
Upper Airway ◽  
Airway Patency

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

2011 ◽  
Vol 115 (2) ◽  
pp. 273-281 ◽  
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.

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

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.

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.

Inspiratory coactivation of the genioglossus enlarges retroglossal space in laryngectomized humans

1996 ◽  
Vol 80 (5) ◽  
pp. 1595-1604 ◽  
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.

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

2012 ◽  
Vol 116 (1) ◽  
pp. 35-46 ◽  
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.

Mass loading of the upper airway extraluminal tissue space in rabbits: effects on tissue pressure and pharyngeal airway lumen geometry

2009 ◽  
Vol 106 (3) ◽  
pp. 887-892 ◽  
Author(s):  
Kristina Kairaitis ◽  
Lauren Howitt ◽  
John R. Wheatley ◽  
Terence C. Amis
Keyword(s):  
Pressure Transducer ◽  
Tissue Expander ◽  
Upper Airway ◽  
Fat Pad ◽  
Pharyngeal Wall ◽  
Airway Patency ◽  
Pharyngeal Airway ◽  
Obstructive Sleep ◽  
Tracheal Pressure ◽  
Tissue Space

Lateral pharyngeal fat pad compression of the upper airway (UA) wall is thought to influence UA size in patients with obstructive sleep apnea. We examined interactions between acute mass/volume loading of the UA extra-luminal tissue space and UA patency. We studied 12 supine, anesthetized, spontaneously breathing, head position-controlled (50°), New Zealand White rabbits. Submucosal extraluminal tissue pressures (ETP) in the anterolateral (ETPlat) and anterior (ETPant) pharyngeal wall were monitored with surgically inserted pressure transducer-tipped catheters (Millar). Tracheal pressure (Ptr) and airflow (V̇) were measured via a pneumotachograph and pressure transducer inserted in series into the intact trachea, with hypopharyngeal cross-sectional area (CSA) measured via computed tomography, while graded saline inflation (0–1.5ml) of a compliant tissue expander balloon in the anterolateral subcutaneous tissue was performed. Inspiratory UA resistance (Rua) at 20 ml/s was calculated from a power function fitted to Ptr vs. V̇ data. Graded expansion of the anterolateral balloon increased ETPlat from 2.3 ± 0.5 cmH2O ( n = 11, mean ± SEM) to 5.0 ± 1.1 cmH2O at 1.5-ml inflation ( P < 0.05; ANOVA). However, ETPant was unchanged from 0.5 ± 0.5 cmH2O ( n = 9; P = 0.17). Concurrently, Rua increased to 119 ± 4.2% of baseline value ( n = 12; P < 0.001) associated with a significant reduction in CSA between 10 and 70% of airway length to a minimum of 82.2 ± 4.4% of baseline CSA at 40% of airway length ( P < 0.05). We conclude that anterolateral loading of the upper airway extraluminal tissue space decreases upper airway patency via an increase in ETPlat, but not ETPant. Lateral pharyngeal fat pad size may influence UA patency via increased tissue volume and pressure causing UA wall compression.

Effect of sternothyrohyoid myectomy on upper airway mechanics in normal horses

1994 ◽  
Vol 77 (6) ◽  
pp. 2812-2816 ◽  
Author(s):  
S. J. Holcombe ◽  
W. L. Beard ◽  
K. W. Hinchcliff ◽  
J. T. Robertson
Keyword(s):  
Upper Airway ◽  
Face Mask ◽  
Differential Pressure ◽  
Inspiratory Pressure ◽  
O2 Consumption ◽  
Airway Patency ◽  
Pressure Transducers ◽  
Significant Difference ◽  
Airway Mechanics ◽  
Inspiratory Resistance

The effect of transection of the sternothyroideus and sternohyoideus muscles on upper airway mechanics was investigated in exercising horses. Upper airway mechanics of six Standardbred horses were measured at rest and during exercise before and 24 h and 2 wk after sternothyrohyoid myectomy. Transnasal tracheal and pharyngeal catheters connected to differential pressure transducers were used to measure tracheal and pharyngeal pressures. A pneumotachograph mounted on the rostral end of an airtight face mask was used to measure airflow. Horses ran at 50, 75, and 100% of maximal O2 consumption on a treadmill. Twenty-four hours after sternothyrohyoid myectomy, no significant difference was detected in tracheal, pharyngeal, or translaryngeal inspiratory and expiratory pressures and impedances, inspiratory and expiratory flows, and respiratory frequency. Two weeks after sternothyrohyoid myectomy, there was a statistically significant increase in translaryngeal inspiratory pressure (P = 0.035) and tracheal inspiratory pressure (P = 0.032) compared with preoperative measurements. Two weeks after sternothyrohyoid myectomy, there was a statistically significant increase in translaryngeal inspiratory resistance (P = 0.017) and tracheal inspiratory resistance (P = 0.023) compared with preoperative values. Increased translaryngeal and tracheal inspiratory pressures and resistances after sternothyrohyoid myectomy suggest that the sternothyroideus and sternohyoideus muscles act to increase or maintain upper airway patency and stability in normal horses.

scholarly journals Reciprocal connectivity of the periaqueductal gray with the ponto-medullary respiratory network in rat

2020 ◽  
Author(s):  
Pedro Trevizan-Baú ◽  
Werner I. Furuya ◽  
Stuart B. Mazzone ◽  
Davor Stanić ◽  
Rishi R. Dhingra ◽  
...  
Keyword(s):  
Respiratory Rhythm ◽  
Upper Airway ◽  
Periaqueductal Gray ◽  
List Type ◽  
Airway Patency ◽  
Respiratory Network ◽  
Cholera Toxin Subunit B ◽  
Motor Activities ◽  
Descending Projections ◽  
Subunit B

AbstractSynaptic activities of the periaqueductal gray (PAG) can modulate or appropriate the respiratory motor activities in the context of behavior and emotion via descending projections to nucleus retroambiguus. However, alternative anatomical pathways for the mediation of PAG-evoked respiratory modulation via core nuclei of the brainstem respiratory network remains only partially described. We injected the retrograde tracer Cholera toxin subunit B (CT-B) in the pontine Kölliker-Fuse nucleus (KFn, n=5), medullary Bötzinger (BötC, n=3) and pre-Bötzinger complexes (pre-BötC; n=3), and the caudal raphé nuclei (n=3), and quantified the ascending and descending connectivity of the PAG. CT-B injections in the KFn, pre-BötC, and caudal raphé, but not in the BötC, resulted in CT-B-labeled neurons that were predominantly located in the lateral and ventrolateral PAG columns. In turn, CT-B injections into the lateral and ventrolateral PAG columns (n=4) yield the highest numbers of CT-B-labeled neurons in the KFn and far fewer numbers of labeled neurons in the pre-BötC and caudal raphé. Analysis of the relative projection strength revealed that the KFn shares the densest reciprocal connectivity with the PAG (ventrolateral and lateral columns, in particular). Overall, our data imply that the PAG may engage a distributed respiratory rhythm and pattern generating network beyond the nucleus retroambiguus to mediate downstream modulation of breathing. However, the reciprocal connectivity of the KFn and PAG suggests specific roles for synaptic interaction between these two nuclei that are most likely related to the regulation of upper airway patency during vocalization or other volitional orofacial behaviors.HighlightsThe lateral and ventrolateral PAG project to the primary respiratory network.The Kölliker-Fuse nucleus shares the densest reciprocal connectivity with the PAG.The Bötzinger complex appears to have very little connectivity with the PAG.

The Pediatric Airway

2018 ◽  
pp. 34-40
Author(s):  
Lowell Clark ◽  
Stephen Tomek
Keyword(s):  
Soft Tissue ◽  
Clinical Application ◽  
Deep Sedation ◽  
Upper Airway ◽  
Procedural Sedation ◽  
Pediatric Airway ◽  
Airway Patency ◽  
Anatomy And Physiology ◽  
Airway Function ◽  
Specific Responsibility

The practice of procedural sedation involves the use of medications that alter upper airway function and patency because of myoneural suppression of anatomic airway elements. It is the specific responsibility of the sedationist to ensure upper airway patency during conditions induced by pharmaceuticals in which the airway is almost certain to be threatened, if not totally obstructed. Soft tissue collapse during inspiration is modeled by the Starling resistor. Airway protective reflexes may be profoundly disturbed during deep sedation. The sedationist’s knowledge of the anatomy and physiology of the upper airway and proficiency in clinical application of airway supportive principles are essential.

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