Dependence of pharyngeal resistance on genioglossal EMG activity, nasal resistance, and airflow

1992 ◽  
Vol 73 (2) ◽  
pp. 584-590 ◽  
Author(s):  
J. C. Leiter ◽  
S. L. Knuth ◽  
D. Bartlett
Keyword(s):  
Upper Airway ◽  
Face Mask ◽  
Head Position ◽  
Emg Activity ◽  
Nasal Resistance ◽  
Pharyngeal Airway ◽  
Nasal Pressure ◽  
The Stability ◽  
Normal Men ◽  
Pressure Catheter

We investigated the quantitative relationships among pharyngeal resistance (Rph), genioglossal electromyographic (EMGge) activity, nasal resistance (Rna), and airflow in 11 normal men aged 19–50 while they were awake. We made measurements with subjects seated with the head erect, seated with the head flexed forward approximately 40 degrees, and supine. Each subject wore a face mask connected to a pneumotachograph to measure airflow. After topical anesthesia of the nose, two catheters for measuring nasal and pharyngeal airway pressures were passed through one nostril: the nasal pressure catheter was positioned at the nasal choanae, and the pharyngeal pressure catheter was positioned just above the epiglottis. We measured EMGge activity with an intraoral surface electrode. The subjects breathed exclusively through the nose while inhaling room air or rebreathing CO2. We measured Rph, Rna, airflow, and EMGge activity at approximately 90-ms intervals throughout each inspiration. Rph was invariant as head position was changed. At any given head position, EMGge activity rose as airflow increased, and Rph remained constant. In contrast, Rna increased as airflow increased. Because Rph was constant, EMGge activity was not correlated with Rph, but EMGge was positively correlated with Rna and airflow. On the basis of the stability of Rph in the face of marked changes in collapsing forces, we conclude that the dynamic interplay of posture, head and jaw position, and upper airway muscle activity quite effectively maintains pharyngeal patency, and interactions among these factors are subtle and complex.

scholarly journals Test of the Starling resistor model in the human upper airway during sleep

2014 ◽  
Vol 117 (12) ◽  
pp. 1478-1485 ◽  
Author(s):  
Andrew Wellman ◽  
Pedro R. Genta ◽  
Robert L. Owens ◽  
Bradley A. Edwards ◽  
Scott A. Sands ◽  
...  
Keyword(s):  
Sleep Apnea ◽  
Upper Airway ◽  
Strongly Correlated ◽  
Flow Limitation ◽  
Single Model ◽  
Multiple Sensors ◽  
Pharyngeal Airway ◽  
Wide Range ◽  
Before And After ◽  
Pressure Catheter

The human pharyngeal airway during sleep is conventionally modeled as a Starling resistor. However, inspiratory flow often decreases with increasing effort (negative effort dependence, NED) rather than remaining fixed as predicted by the Starling resistor model. In this study, we tested a major prediction of the Starling resistor model—that the resistance of the airway upstream from the site of collapse remains fixed during flow limitation. During flow limitation in 24 patients with sleep apnea, resistance at several points along the pharyngeal airway was measured using a pressure catheter with multiple sensors. Resistance between the nose and the site of collapse (the upstream segment) was measured before and after the onset of flow limitation to determine whether the upstream dimensions remained fixed (as predicted by the Starling resistor model) or narrowed (a violation of the Starling resistor model). The upstream resistance from early to mid inspiration increased considerably during flow limitation (by 35 ± 41 cmH2O·liter−1·s−1, P < 0.001). However, there was a wide range of variability between patients, and the increase in upstream resistance was strongly correlated with the amount of NED ( r = 0.75, P < 0.001). Therefore, patients with little NED exhibited little upstream narrowing (consistent with the Starling model), and patients with large NED exhibited large upstream narrowing (inconsistent with the Starling model). These findings support the idea that there is not a single model of pharyngeal collapse, but rather that different mechanisms may dominate in different patients. These differences could potentially be exploited for treatment selection.

Control of respiratory activity of the genioglossus muscle in micrognathic infants

1986 ◽  
Vol 61 (4) ◽  
pp. 1523-1533 ◽  
Author(s):  
J. L. Roberts ◽  
W. R. Reed ◽  
O. P. Mathew ◽  
B. T. Thach
Keyword(s):  
Upper Airway ◽  
Esophageal Pressure ◽  
Progressive Increase ◽  
Emg Activity ◽  
Nasal Breathing ◽  
Airway Patency ◽  
Tongue Muscle ◽  
Airway Occlusion ◽  
Pharyngeal Airway ◽  
Obstructive Sleep

The genioglossus (GG) muscle activity of four infants with micrognathia and obstructive sleep apnea was recorded to assess the role of this tongue muscle in upper airway maintenance. Respiratory air flow, esophageal pressure, and intramuscular GG electromyograms (EMG) were recorded during wakefulness and sleep. Both tonic and phasic inspiratory GG-EMG activity was recorded in each of the infants. On occasion, no phasic GG activity could be recorded; these silent periods were unassociated with respiratory embarrassment. GG activity increased during sigh breaths. GG activity also increased when the infants spontaneously changed from oral to nasal breathing and, in two infants, with neck flexion associated with complete upper airway obstruction, suggesting that GG-EMG activity is influenced by sudden changes in upper airway resistance. During sleep, the GG-EMG activity significantly increased with 5% CO2 breathing (P less than or equal to 0.001). With nasal airway occlusion during sleep, the GG-EMG activity increased with the first occluded breath and progressively increased during the subsequent occluded breaths, indicating mechanoreceptor and suggesting chemoreceptor modulation. During nasal occlusion trials, there was a progressive increase in phasic inspiratory activity of the GG-EMG that was greater than that of the diaphragm activity (as reflected by esophageal pressure excursions). When pharyngeal airway closure occurred during a nasal occlusion trial, the negative pressure at which the pharyngeal airway closed (upper airway closing pressure) correlated with the GG-EMG activity at the time of closure, suggesting that the GG muscle contributes to maintaining pharyngeal airway patency in the micrognathic infant.

Alae nasi activation and nasal resistance in healthy subjects

1982 ◽  
Vol 52 (6) ◽  
pp. 1432-1437 ◽  
Author(s):  
K. P. Strohl ◽  
C. F. O'Cain ◽  
A. S. Slutsky
Keyword(s):  
Healthy Subjects ◽  
Airway Resistance ◽  
Upper Airway ◽  
Emg Activity ◽  
Nasal Resistance ◽  
Body Plethysmography ◽  
Surface Electrodes ◽  
Upper Airway Resistance

To investigate the effect of alae nasi (AN) activation on nasal resistance, we monitored AN electromyographic (EMG) activity in 17 healthy subjects using surface electrodes placed on either side of the external nares and measured inspiratory nasal resistance utilizing the method of posterior rhinometry. With CO2 inhalation (6 subj), AN EMG activity increased as nasal resistance fell 23 +/- 5% (P less than 0.01). In the same subjects, voluntary flaring of the external nares also increased AN EMG and decreased nasal resistance by 29 +/- 5% (P less than 0.01). Nasal resistance was altered by nasal flaring and CO2 inhalation even after administration of a topical nasal vasoconstrictive spray (8 subj). In six subjects, voluntary nasal flaring or inhibition with the mouth closed produced a 21 +/- 12% change (P less than 0.01) in total airway resistance as measured by body plethysmography. We conclude that activation of the alae nasi will decrease nasal and total airway resistance during voluntary nasal flaring and during CO2 inhalation and thus should be considered in any studies of upper airway resistance.

Influence of sleep on alae nasi EMG and nasal resistance in normal men

1993 ◽  
Vol 75 (2) ◽  
pp. 626-632 ◽  
Author(s):  
J. R. Wheatley ◽  
D. J. Tangel ◽  
W. S. Mezzanotte ◽  
D. P. White
Keyword(s):  
Eye Movement ◽  
Sleep Onset ◽  
Upper Airway ◽  
Nrem Sleep ◽  
Nasal Airway ◽  
Nasal Resistance ◽  
Rapid Eye Movement ◽  
Dilator Muscle ◽  
Stage 2 Sleep ◽  
Normal Men

The influence of sleep on the upper airway musculature varies considerably, with some muscles maintaining their activity at waking levels and others falling substantially. The influence of sleep on the alae nasi (AN), a dilator muscle of the nasal airway, has been minimally studied to date. Thus we determined the effect of non-rapid-eye-movement (NREM) sleep on the AN electromyogram and its relationship to nasal resistance (Rn) in nine normal supine males. Phasic inspiratory AN activity decreased from 20 +/- 6 arbitrary units during wakefulness to 5 +/- 1 arbitrary units (P < 0.001) at the onset of stage 2 NREM sleep and remained unchanged for two subsequent hours of NREM sleep. However, the Rn at the onset of NREM sleep remained similar to awake values (5.7 +/- 0.9 cmH2O.l-1 x s) and increased only after 1 h of NREM sleep (8.6 +/- 1.7 cmH2O.l-1 x s, P < 0.05), thus demonstrating little relationship to AN activity. We conclude that Rn increases slightly after 1 h of sleep, whereas AN activity decreases at stage 2 sleep onset. Thus AN activity has little influence on Rn during sleep.

Changes in upper airway resistance during progressive normocapnic hypoxia in normal men

1991 ◽  
Vol 70 (2) ◽  
pp. 548-553 ◽  
Author(s):  
F. Maltais ◽  
L. Dinh ◽  
Y. Cormier ◽  
F. Series
Keyword(s):  
Functional Residual Capacity ◽  
Minute Ventilation ◽  
Upper Airway ◽  
Baseline Period ◽  
Respiratory Drive ◽  
Nasal Resistance ◽  
Bias Flow ◽  
Residual Capacity ◽  
Mouth Occlusion Pressure ◽  
Normal Men

The effects of normocapnic progressive hypoxia on nasal and pharyngeal resistances were evaluated in nine normal men. To calculate resistances, upper airway pressures were measured with two low-bias flow catheters; one was placed at the tip of the epiglottis and the other in the posterior nasopharynx, and we measured flow with a Fleish no. 3 pneumotachograph connected to a tightly fitting mask. Both resistances were obtained during a baseline period and during progressive normocapnic hypoxia achieved by a rebreathing method. We collected the breath-by-breath values of upper airway resistances, minute ventilation, O2 and CO2 fractions, arterial O2 saturation (SaO2), and changes in functional residual capacity (inductance vest). The central respiratory drive was evaluated by the mouth occlusion pressure 0.1 s after the onset of inspiration (P0.1), and breath-by-breath P0.1 values were estimated by intrapolation from the linear relationship between P0.1 and SaO2. In each subject both resistances decreased during the hypoxic test. The slope of the decrease in resistance with decreasing SaO2 (%baseline/%SaO2) was steeper for pharyngeal resistance than for nasal resistance [2.67 +/- 0.29 and 1.61 +/- 0.25 (SE), respectively; P less than 0.05]. The slope of the decrease in resistance with increasing P0.1 (%baseline/cmH2O) was -0.24 +/- 0.05 for nasal resistance and -0.39 +/- 0.07 for pharyngeal resistance (P less than 0.05). Functional residual capacity progressively increased during the test, but the decrease in resistance was greater than expected from an isolated increase in lung volume. We conclude that nasal and pharyngeal resistances decrease during progressive normocapnic hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of head and jaw position on respiratory-related motion of the genioglossus

2016 ◽  
Vol 120 (7) ◽  
pp. 758-765 ◽  
Author(s):  
Mingshu Cai ◽  
Elizabeth C. Brown ◽  
Alice Hatt ◽  
Shaokoon Cheng ◽  
Lynne E. Bilston
Keyword(s):  
Mouth Opening ◽  
Upper Airway ◽  
Head Position ◽  
Spatial Modulation ◽  
Mandibular Advancement ◽  
Emg Activity ◽  
Quiet Breathing ◽  
Airway Patency ◽  
Head Flexion ◽  
Jaw Position

Head and jaw position influence upper airway patency and electromyographic (EMG) activity of the main upper airway dilator muscle, the genioglossus. However, it is not known whether changes in genioglossus EMG activity translate into altered muscle movement during respiration. The aim of this study was to determine the influence of head and jaw position on dilatory motion of the genioglossus in healthy adult men during quiet breathing by measuring the displacement of the posterior tongue in six positions—neutral, head extension, head rotation, head flexion, mouth opening, and mandibular advancement. Respiratory-related motion of the genioglossus was imaged with spatial modulation of magnetization (SPAMM) in 12 awake male participants. Tissue displacement was quantified with harmonic phase (HARP) analysis. The genioglossus moved anteriorly beginning immediately before or during inspiration, and there was greater movement in the oropharynx than in the velopharynx in all positions. Anterior displacements of the oropharyngeal tongue varied between neutral head position (0.81 ± 0.41 mm), head flexion (0.62 ± 0.45 mm), extension (0.39 ± 0.19 mm), axial rotation (0.39 ± 0.2 mm), mouth open (1.24 ± 0.72 mm), and mandibular advancement (1.08 ± 0.65 mm). Anteroposterior displacement increased in the mouth-open position and decreased in the rotated position relative to cross-sectional area (CSA) ( P = 0.002 and 0.02, respectively), but CSA did not independently predict anteroposterior movement overall ( P = 0.057). The findings of this study suggest that head position influences airway dilation during inspiration and may contribute to variation in airway patency in different head positions.

Alae Nasi Activation (Nasal Flaring) Decreases Nasal Resistance in Preterm Infants

PEDIATRICS ◽  
1983 ◽  
Vol 72 (3) ◽  
pp. 338-343 ◽  
Author(s):  
Waldemar A. Carlo ◽  
Richard J. Martin ◽  
Eugene N. Bruce ◽  
Kingman P. Strohl ◽  
Avroy A. Fanaroff
Keyword(s):  
Pressure Drop ◽  
Preterm Infants ◽  
Upper Airway ◽  
Skin Surface ◽  
Nasal Resistance ◽  
Active Sleep ◽  
Quiet Sleep ◽  
Surface Electrodes ◽  
Pharyngeal Pressure ◽  
Nasal Pressure

The effect of alae nasi activation on nasal resistance in a group of healthy preterm infants was measured. Alae nasi activity was determined via the alae nasi electromyogram obtained from skin surface electrodes during both active and quiet sleep. Nasal resistance was calculated from airflow measured with a mask pneumotachograph and transnasal pressure drop obtained by simultaneous measurement of nasal pressure via a catheter inserted in one nostril and mask pressure. The percentage of breaths accompanied by phasic alae nasi activity was higher during active sleep than during quiet sleep (43% ± 10% v 14% ± 6%; P &lt; .005), and hypercapnic stimulation (4% CO2 inhalation) significantly increased the incidence of phasic alae nasi activity to comparable levels in both sleep states (82% ± 8% in active sleep and 82% ± 9% in quiet sleep). Elevation of tonic alae nasi activity also occurred more frequently during active sleep (P &lt; .05). The presence of either phasic or elevated tonic alae nasi activity decreased nasal resistance by 23% ± 4% during active sleep and 21% ± 3% during quiet sleep. This reduction in nasal resistance resulted in either a lower transnasal pressure during inspiration, a higher peak inspiratory airflow, or a combination of the two. Alae nasi activity may be an important mechanism that facilitates ventilation by reducing nasal resistance, and it may help stabilize the upper airway by preventing the development of large negative pharyngeal pressure during inspiration.

Influence of nasal airflow temperature and pressure on alae nasi electrical activity

1991 ◽  
Vol 71 (6) ◽  
pp. 2283-2291 ◽  
Author(s):  
J. R. Wheatley ◽  
T. C. Amis ◽  
L. A. Engel
Keyword(s):  
Upper Airway ◽  
Normal Subjects ◽  
Face Mask ◽  
Emg Activity ◽  
Nasal Airflow ◽  
Nasal Breathing ◽  
Oral Breathing ◽  
The Subject ◽  
Temperature And Pressure ◽  
Nasal Flow

The influence of nasal airflow, temperature, and pressure on upper airway muscle electromyogram (EMG) was studied during steady-state exercise in five normal subjects. Alae nasi (AN) and genioglossus EMG activity was recorded together with nasal and oral airflows and pressures measured simultaneously by use of a partitioned face mask. At constant ventilations between 30 and 50 l/min, peak inspiratory AN activity during nasal breathing (7.2 +/- 1.4 arbitrary units) was greater than that during oral breathing (1.0 +/- 0.3 arbitrary units; P less than 0.005). In addition, the onset of AN EMG activity preceded inspiratory flow by 0.38 +/- 0.03 s during nasal breathing but by only 0.17 +/- 0.04 s during oral breathing (P less than 0.04). When the subject changed from nasal to oral breathing, both these differences were apparent on the first breath. However, peak AN activity during nasal breathing was uninfluenced by inspiration of hot saturated air (greater than 40 degrees C), by external inspiratory nasal resistance, or by changes in the expiratory route. The genioglossus activity did not differ between nasal and oral breathing (n = 2). Our findings do not support reflex control of AN activity sensitive to nasal flow, temperature, or surface pressure. We propose a centrally controlled feedforward modulation of phasic inspiratory AN activity linked with the tonic drive to the muscles determining upper airway breathing route.

Geniohyoid muscle activity in normal men during wakefulness and sleep

1990 ◽  
Vol 69 (4) ◽  
pp. 1262-1269 ◽  
Author(s):  
D. A. Wiegand ◽  
B. Latz ◽  
C. W. Zwillich ◽  
L. Wiegand
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Muscle Activity ◽  
Sleep Stage ◽  
Upper Airway ◽  
Rapid Eye Movement ◽  
Nasal Breathing ◽  
Sleep Study ◽  
Pharyngeal Airway ◽  
Normal Men

Reduction in the activity of upper airway "dilator" muscles during sleep may allow the pharyngeal airway to collapse in some individuals. However, quantitative studies concerning the effect of sleep on specific upper airway muscles that may influence pharyngeal patency are sparse and inconclusive. We studied seven normal men (mean age 27, range 22-37 yr) during a single nocturnal sleep study and recorded sleep staging parameters, ventilation, and geniohyoid muscle electromyogram (EMGgh) during nasal breathing throughout the night. Anatomic landmarks for placement of intramuscular geniohyoid recording electrodes were determined from a cadaver study. These landmarks were used in percutaneous placement of wire electrodes, and raw and moving-time-averaged EMGgh activities were recorded. Sleep stage was determined using standard criteria. Stable periods of wakefulness and non-rapid-eye-movement (NREM) and rapid-eye-movement (REM) sleep were selected for analysis. The EMGgh exhibited phasic inspiratory activity during wakefulness and sleep in all subjects. In six of seven subjects, mean and peak inspiratory EMGgh activities were significant (P less than 0.05) reduced during stages 2 and 3/4 NREM sleep and REM sleep compared with wakefulness. This reduction of EMGgh activity was shown to result from a sleep-related decline in the level of tonic muscle activity. Phasic inspiratory EMGgh activity during all stages of sleep was not significantly different from that during wakefulness. Of interest, tonic, phasic, and peak EMGgh activities were not significantly reduced during REM sleep compared with any other sleep stage in any subject. In addition, the slope of onset of phasic EMGgh activity was not different during stage 2 NREM and REM sleep compared with wakefulness in these subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenylephrine-induced hypertension acutely decreases genioglossus EMG activity in awake humans

1992 ◽  
Vol 72 (1) ◽  
pp. 110-115 ◽  
Author(s):  
E. Garpestad ◽  
R. C. Basner ◽  
J. Ringler ◽  
J. Lilly ◽  
R. Schwartzstein ◽  
...  
Keyword(s):  
Minute Ventilation ◽  
Upper Airway ◽  
Face Mask ◽  
Systemic Blood Pressure ◽  
Emg Activity ◽  
Healthy Humans ◽  
Baseline Activity ◽  
Acute Changes ◽  
End Tidal ◽  
Airway Tone

To investigate the relationship between systemic blood pressure (BP) and upper airway dilator muscle activity, we recorded genioglossus electromyograms (EMGgg) during pharmacologically induced acute increases in BP in five healthy humans (ages 27–40 yr). EMGgg was measured with perorally placed fine-wire electrodes; phasic EMGgg was expressed as percentage of baseline activity. Subjects were studied supine, awake, and breathing through a face mask with their mouths taped. End-tidal PCO2 was monitored with a mass spectrometer; minute ventilation was measured with a pneumotachograph. Digital BP was monitored continuously with the Penaz method (Finapres, Ohmeda). Mean arterial pressure (MAP) at baseline was 89 +/- 6 (SD) mmHg. Phenylephrine was infused until MAP reached 15–25 mmHg above baseline (107 +/- 7 mmHg). Recording was continued until MAP returned to baseline (90 +/- 7 mmHg). Elevated BP was associated with a significantly decreased phasic EMGgg (P less than 0.005). With return of MAP to baseline, phasic EMGgg returned toward normal (P less than 0.01). Minute ventilation and end-tidal PCO2 did not differ among conditions. Genioglossus activity appears to be influenced by acute changes in systemic BP. We speculate that BP elevations accompanying obstructive apneas during sleep may decrease upper airway tone and facilitate subsequent apneas.

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