Neural drive to nasal dilator muscles: influence of exercise intensity and oronasal flow partitioning

1995 ◽  
Vol 79 (4) ◽  
pp. 1330-1337 ◽  
Author(s):  
R. F. Fregosi ◽  
R. W. Lansing
Keyword(s):  
Exercise Intensity ◽  
Respiratory Drive ◽  
Nasal Airway ◽  
Nasal Airflow ◽  
Neural Drive ◽  
Dilator Muscle ◽  
Turbulent Airflow ◽  
Flow Turbulence ◽  
Highly Correlated ◽  
Ventilation Rates

Our aim was to test the following hypotheses: 1) neural drive to the muscles of the alae nasi (AN) is proportional to nasal airflow and is independent of the overall level of central respiratory drive, and 2) the switch from nasal to oronasal breathing corresponds to the onset of marked flow turbulence in the nasal airway. Total and nasal inspired ventilation rates (VI) and the electromyogram (EMG) of the AN muscles were measured in seven subjects during progressive-intensity bicycling exercise. In separate experiments in six subjects the nasal VI corresponding to the transition from laminar to turbulent airflow was determined by measuring the pressure-flow relationship of the nasal airway with anterior rhinomanometry. Nasal VI accounted for 70 +/- 11% of total VI at rest and 27 +/- 8% (SE) at 90% of the maximal attainable power (max). Nasal VI and integrated AN EMG activities increased linearly with exercise intensity up to 60% of the max power, but both variables plateaued at this level even though total VI (and central respiratory drive) began to increase exponentially as exercise intensity increased to 90% max. The onset of the exponential rise in total VI was associated with a sharp increase in oral VI and with the onset of marked flow turbulence in the nasal airway. The results suggest that during incremental exercise 1) changes in AN EMG activities are highly correlated with changes in nasal VI, 2) turbulent flow in the nose may be the stimulus for the switch to oronasal breathing so that total pulmonary resistance is minimized, and 3) the correlation between nasal airflow and neural drive to the AN muscles is probably mediated by mechanisms that monitor airway resistance. Although these mechanisms were not identified, the most likely possibilities are receptors in the upper and/or lower airways that are sensitive to negative transmural pressure, or to effort sensations leading to greater corollary motor discharge to nasal dilator muscle motoneurons.

Influence of nasal airflow and resistance on nasal dilator muscle activities during exercise

1993 ◽  
Vol 74 (5) ◽  
pp. 2529-2536 ◽  
Author(s):  
D. C. Connel ◽  
R. F. Fregosi
Keyword(s):  
Airway Resistance ◽  
Minute Ventilation ◽  
Nasal Airway ◽  
Nasal Airflow ◽  
Nasal Breathing ◽  
Airway Patency ◽  
Dilator Muscle ◽  
The Face ◽  
Flow Turbulence ◽  
Nasal Flow

Our purpose was to assess the separate effects of nasal airflow and resistance on the activity of the nasal dilator [alae nasi (AN)] muscles. Nasal airflow and the AN electromyogram were recorded at rest and during progressive-intensity exercise at 60, 120, and 150–180 W in 10 healthy subjects who breathed nasally under all conditions. The activity of the AN muscles increased linearly as a function of the increase in nasal minute ventilation evoked by progressive-intensity exercise (r = 0.99, P < 0.002). Reciprocal changes in nasal airflow and resistance were produced by surreptitious substitution of 12–15 breaths of 79% He-21% O2 for air at rest and during exercise. The switch to He-O2 decreased airway resistance (anterior rhinomanometry) by approximately 30% at rest and 40–60% during exercise. He-O2 did not change nasal flow or AN activities significantly under resting conditions. In contrast, He-O2 increased nasal flow and decreased the AN electromyogram by 25–50% during exercise (P < 0.05). The results suggest that AN muscle activities during nasal breathing are regulated by mechanisms that track airway resistance or the level of flow turbulence. The increase in AN activities during exercise probably helps ensure nasal airway patency in the face of the considerable collapsing pressures that prevail under these conditions.

Control of nasal dilator muscle activities during exercise: role of nasopharyngeal afferents

1996 ◽  
Vol 80 (5) ◽  
pp. 1520-1527 ◽  
Author(s):  
J. Sullivan ◽  
D. Fuller ◽  
R. F. Fregosi
Keyword(s):  
Exercise Intensity ◽  
Airway Resistance ◽  
Upper Airway ◽  
Receptor Activity ◽  
Emg Activity ◽  
Nasal Airway ◽  
Bicycle Exercise ◽  
Dilator Muscle ◽  
Response To Exercise

Our primary aim was to determine whether reducing the activity of nasal airway receptors would influence drive to the nasal dilator muscles (NDMs) during exercise. We used lidocaine (2%) or nasal splints to diminish afferent airway receptor activity and measured the electromyogram (EMG) activity of the NDMs during incremental bicycle exercise in subjects who breathed nasally. NDM EMG activities increased as a function of exercise intensity but were not changed by lidocaine and were only slightly reduced by splinting. Similarly, neither intervention altered the normal decrease in NDM EMG activity associated with reductions in airway resistance evoked by He-O2 breathing. We also compared the NDM EMG response to exercise with that evoked by CO2 rebreathing at rest to determine whether the nature of the ventilatory stimulus influences drive to the NDMs; comparisons were made at constant levels of nasal inspired ventilation and, therefore, constant total ventilatory output. The increase in EMG activity was much higher during exercise compared with hyperoxic hypercapnia. In conclusion, 1) desensitizing the nasal airway does not alter NDM activity significantly during exercise and 2) exercise results in much greater increases in NDM activity compared with hypercapnia, indicating that different ventilatory stimuli can evoke more or less activation of upper airway motoneurons, even when comparisons are made at constant levels of total ventilatory output.

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.

scholarly journals Validity of Reporting Oxygen Uptake Efficiency Slope from Submaximal Exercise Using Respiratory Exchange Ratio as Secondary Criterion

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Wilby Williamson ◽  
Jonathan Fuld ◽  
Kate Westgate ◽  
Karl Sylvester ◽  
Ulf Ekelund ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Test Data ◽  
Exercise Intensity ◽  
Respiratory Exchange Ratio ◽  
Fold Increase ◽  
Moderate Intensity ◽  
Uptake Efficiency ◽  
Highly Correlated ◽  
Oxygen Uptake Efficiency Slope ◽  
Treadmill Protocol

Background. Oxygen uptake efficiency slope (OUES) is a reproducible, objective marker of cardiopulmonary function. OUES is reported as being relatively independent of exercise intensity. Practical guidance and criteria for reporting OUES from submaximal tests has not been established.Objective. Evaluate the use of respiratory exchange ratio (RER) as a secondary criterion for reporting OUES.Design. 100 healthy volunteers (53 women) completed a ramped treadmill protocol to exhaustive exercise. OUES was calculated from data truncated to RER levels from 0.85 to 1.2 and compared to values generated from full test data. Results. Mean (sd) OUES from full test data and data truncated to RER 1.0 and RER 0.9 was 2814 (718), 2895 (730), and 2810 (789) mL/min per 10-fold increase in VE, respectively. Full test OUES was highly correlated with OUES from RER 1.0 (r=0.9) and moderately correlated with OUES from RER 0.9 (r=0.79).Conclusion. OUES values peaked in association with an RER level of 1.0. Sub-maximal OUES values are not independent of exercise intensity. There is a significant increase in OUES value as exercise moves from low to moderate intensity. RER can be used as a secondary criterion to define this transition.

scholarly journals Numerical Simulations of Heat Transfer Phenomena through a Baffled Rectangular Channel

2021 ◽  
Vol 6 (5) ◽  
pp. 1230-1241
Author(s):  
Sandip Saha ◽  
Pankaj Biswas ◽  
Apurba Narayan Das
Keyword(s):  
Rectangular Channel ◽  
Simple Algorithm ◽  
Convective Heat Exchange ◽  
Thermal Exchange ◽  
Thermal Enhancement ◽  
Turbulent Airflow ◽  
Fluent Software ◽  
Flow Turbulence ◽  
Volume Method ◽  
Velocity Turbulence

In presence of baffle, the turbulent airflow phenomena as well as forced convective heat exchange characteristics in two-dimensional rectangular channel have been analyzed in this work. For variations in Reynolds number (Re), we have studied the variations in characteristics of thermal behavior due to the change in the shape of baffle. Computations have been done using finite volume method (FVM) and FLUENT software and the SIMPLE algorithm has been employed for solving the governing equations. Finally, the flow and thermal exchange characteristics viz., streamline flow, turbulence intensity (TE), axial velocity, turbulence kinetic energy (TKE), normalized friction factor (F), normalized average Nusselt number (Nuavg) and thermal enhancement factor (TEF) have been studied in details from numerical standpoint. It has been found that the triangular shaped baffle provides highest value of F at Re = 30,000 and at Re = 46, 000, the maximum value of the TEF is found for the same baffle implying that triangular shaped baffle is more suitable for overall purposes.

scholarly journals Assessment of Nasal Airflow and Pain, Safety and Cost of an Improvised Nasal Airway (Nasogastric) Tube After Endoscopic Sinus Surgery

2020 ◽  
Vol 35 (2) ◽  
pp. 22
Author(s):  
Josephine Grace Rojo ◽  
Rachel Zita Ramos
Keyword(s):  
Pain Score ◽  
Postoperative Period ◽  
Nasogastric Tube ◽  
Endoscopic Sinus Surgery ◽  
Nasal Packing ◽  
Sinus Surgery ◽  
Nasal Airway ◽  
Nasal Airflow ◽  
Significant Difference ◽  
Group A

ABSTRACT Objective: To compare subjective nasal airflow and overall pain score (as well as safety and added cost of) using an improvised nasal airway tube (nasogastric tube) versus nasal packing after endoscopic sinus surgery (ESS) for chronic rhinosinusitis with nasal polyposis (CRSwNP). Methods:Design: Quasi - Experimental Prospective Cohort StudySetting: Tertiary Government Training HospitalParticipants: Twenty-six (26) consecutive patients aged 18 to 77 years old diagnosed with CRSwNP who underwent ESS were alternately assigned to an experimental group (A) of 13, where an improvised nasal airway (nasogastric) tube was placed in addition to the nasal pack or a control group (B) of 13 with nasal packing alone. Results: There was a significant difference in subjective nasal airflow between experimental (A) and control (B) groups during the immediate postoperative period where the mean subjective airflow was 8.07 and 0.00 over 10.00, respectively. No significant difference was noted between the groups in terms of age, gender, severity of polyposis and overall pain score. No complications such as bleeding, Toxic Shock Syndrome, vestibular or alar injury and septal necrosis were noted immediately post-op and after one week follow-up in both groups. An approximate cost of PhP 25 was added to group A. Conclusion: An improvised nasal airway using a nasogastric tube provides adequate airflow without additional pain in the immediate postoperative period. It is safe to use and an affordable option for patients in need of nasal airway stents residing in areas where a preformed nasal packing with incorporated tube stent is not available.

scholarly journals The Nature of Nasal Fricatives: Articulatory-Perceptual Characteristics and Etiologic Considerations

2015 ◽  
Vol 25 (1) ◽  
pp. 17-28 ◽  
Author(s):  
David J. Zajac
Keyword(s):  
Oral Cavity ◽  
Cleft Palate ◽  
Theoretical Framework ◽  
Nasal Airflow ◽  
Turbulent Airflow ◽  
Perceptual Characteristics

Nasal fricatives (NFs) are unusual, maladaptive articulations used by children both with and without palatal anomalies to replace oral fricatives. Nasal fricatives vary in articulatory, aerodynamic, and acoustic-perceptual characteristics with two generally distinct types recognized. One type is produced with velopharyngeal (VP) constriction that results in turbulent nasal airflow and, frequently, tissue vibration (flutter) at the VP port. Trost (1981) described these as posterior NFs that have a distinctive snorting quality. A second type of NF is produced without significant VP constriction resulting in turbulent airflow generated at the anterior liminal valve of the nose. Of importance, both types are “active” alternative articulations in that the speaker occludes the oral cavity to direct all airflow through the nose (Harding & Grunwell, 1998). It is this oral gesture that differentiates NFs from obligatory (or passive) nasal air escape that may sound similar due to incomplete VP closure. The purpose of this article is to (1) describe the articulatory, aerodynamic, and acoustic-perceptual nature of NFs, and (2) propose a theoretical framework for the acquisition of NFs by children both with and without cleft palate.

Comparison of Nasal Airway Patency Changes after Treatment with Oxymetazoline and Pseudoephedrine

1987 ◽  
Vol 1 (2) ◽  
pp. 87-94 ◽  
Author(s):  
John T. Connell ◽  
M. Ines Linzmayer
Keyword(s):  
Nasal Congestion ◽  
Rapid Onset ◽  
Nasal Airway ◽  
Nasal Airflow ◽  
Night Time ◽  
Duration Of Action ◽  
Airway Patency ◽  
Drug Of Choice

Oxymetazoline (Afrin) and pseudoephedrine (Sudafed) were compared by rhinomanometric measurements using nasal airflow, a parameter of nasal airway patency, and therefore airway congestion. Oxymetazoline had a more rapid onset and duration of action, greater improvement in airway patency, and longer action than pseudoephedrine, the best of the oral decongestants. The decongestive effect was more reliable for oxymetazoline with 28 of 29 subjects experiencing some degree of decongestion compared to 21 of 30 for pseudoephedrine. Utilizing a combination of oral and topical decongestants may result in the most logical regimen for treatment of nasal congestion. Oxymetazoline is the drug of choice for night time decongestion.

scholarly journals Muscle metabolic and neuromuscular determinants of fatigue during cycling in different exercise intensity domains

2017 ◽  
Vol 122 (3) ◽  
pp. 446-459 ◽  
Author(s):  
Matthew I. Black ◽  
Andrew M. Jones ◽  
Jamie R. Blackwell ◽  
Stephen J. Bailey ◽  
Lee J. Wylie ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Exercise Intensity ◽  
Wave Amplitude ◽  
Critical Power ◽  
Moderate Intensity ◽  
Neural Drive ◽  
M Wave ◽  
Fatigue Development ◽  
Neuromuscular Responses ◽  
Gas Exchange Threshold

Lactate or gas exchange threshold (GET) and critical power (CP) are closely associated with human exercise performance. We tested the hypothesis that the limit of tolerance (Tlim) during cycle exercise performed within the exercise intensity domains demarcated by GET and CP is linked to discrete muscle metabolic and neuromuscular responses. Eleven men performed a ramp incremental exercise test, 4–5 severe-intensity (SEV; >CP) constant-work-rate (CWR) tests until Tlim, a heavy-intensity (HVY; <CP but >GET) CWR test until Tlim, and a moderate-intensity (MOD; <GET) CWR test until Tlim. Muscle biopsies revealed that a similar ( P > 0.05) muscle metabolic milieu (i.e., low pH and [PCr] and high [lactate]) was attained at Tlim (approximately 2–14 min) for all SEV exercise bouts. The muscle metabolic perturbation was greater at Tlim following SEV compared with HVY, and also following SEV and HVY compared with MOD (all P < 0.05). The normalized M-wave amplitude for the vastus lateralis (VL) muscle decreased to a similar extent following SEV (−38 ± 15%), HVY (−68 ± 24%), and MOD (−53 ± 29%), ( P > 0.05). Neural drive to the VL increased during SEV (4 ± 4%; P < 0.05) but did not change during HVY or MOD ( P > 0.05). During SEV and HVY, but not MOD, the rates of change in M-wave amplitude and neural drive were correlated with changes in muscle metabolic ([PCr], [lactate]) and blood ionic/acid-base status ([lactate], [K+]) ( P < 0.05). The results of this study indicate that the metabolic and neuromuscular determinants of fatigue development differ according to the intensity domain in which the exercise is performed. NEW & NOTEWORTHY The gas exchange threshold and the critical power demarcate discrete exercise intensity domains. For the first time, we show that the limit of tolerance during whole-body exercise within these domains is characterized by distinct metabolic and neuromuscular responses. Fatigue development during exercise greater than critical power is associated with the attainment of consistent “limiting” values of muscle metabolites, whereas substrate availability and limitations to muscle activation may constrain performance at lower intensities.

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.

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