scholarly journals Nasal resistance and flow resistive work of nasal breathing during exercise: effects of a nasal dilator strip

2000 ◽  
Vol 89 (3) ◽  
pp. 1114-1122 ◽  
Author(s):  
J. M. Gehring ◽  
S. R. Garlick ◽  
J. R. Wheatley ◽  
T. C. Amis
Keyword(s):  
Flow Curve ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Nasal Resistance ◽  
Flow Limitation ◽  
Nasal Airflow ◽  
Nasal Breathing ◽  
External Work ◽  
Pressure Flow ◽  
Nasal Vestibule

Using posterior rhinomanometry, we measured nasal airflow resistance (Rn) and flow-resistive work of nasal breathing (WONB), with an external nasal dilator strip (ENDS) and without (control), in 15 healthy adults (6 men, 9 women) during exclusive nasal breathing and graded (50–230 W) exercise on a cycle ergometer. ENDS decreased resting inspiratory and/or expiratory Rn (at 0.4 l/s) by >0.5 cmH2O · l−1· s in 11 subjects (“responders”). Inspired ventilation (V˙i) increased with external work rate, but tended to be greater with ENDS. Inspiratory and expiratory Rn (at 0.4 l/s) decreased asV˙i increased but, in responders, tended to remain lower with ENDS. Inspiratory (but not expiratory) Rn at peak nasal airflow (V˙n) increased as V˙i increased but, again, was lower with ENDS. At a V˙i of ∼35 l/min, ENDS decreased flow limitation and hysteresis of the inspiratory transnasal pressure-flow curve. In responders, ENDS reduced inspiratory WONB per breath and inspiratory nasal power values during exercise. We conclude that ENDS stiffens the lateral nasal vestibule walls and, in responders, may reduce the energy required for nasal ventilation during exercise.

scholarly journals The complexities of nasal airflow: theory and practice

2019 ◽  
Vol 127 (5) ◽  
pp. 1215-1223 ◽  
Author(s):  
Graham O’Neill ◽  
Neil Samuel Tolley
Keyword(s):  
Theory And Practice ◽  
Poor Correlation ◽  
Airflow Rate ◽  
Nasal Resistance ◽  
Flow Limitation ◽  
Nasal Airflow ◽  
Nasal Valve ◽  
Cross Sectional ◽  
Pressure Flow ◽  
Valve Area

The objective of this study was to investigate the effects of nasal valve area, valve stiffness, and turbinate region cross-sectional area on airflow rate, nasal resistance, flow limitation, and inspiratory “hysteresis” by the use of a mathematical model of nasal airflow. The model of O’Neill and Tolley ( Clin Otolaryngol Allied Sci 13: 273–277, 1988) describing the effects of valve area and stiffness on the nasal pressure-flow relationship was improved by the incorporation of additional terms involving 1) airflow through the turbinate region, 2) the dependence of the flow coefficients for the valve and turbinate region on the Reynolds number, and 3) effects of unsteady flow. The model was found to provide a good fit for normal values for nasal resistance and for pressure-flow curves reported in the literature for both congested and decongested states. Also, by showing the relative contribution of the nasal valve and turbinate region to nasal resistance, the model sheds light in explaining the generally poor correlation between nasal resistance measurements and the results from acoustic rhinometry. Furthermore, by proposing different flow conditions for the acceleration and deceleration phases of inspiration, the model produces an inspiratory loop (commonly referred to as hysteresis) consistent with those reported in the literature. With simulation of nasal flaring, the magnitude of the loop, the nasal resistance, and flow limitation all show change similar to that observed in the experimental results. NEW & NOTEWORTHY The present model provides considerable insight into some difficult conundrums in both clinical and technical aspects of nasal airflow. Also, the description of nasal airflow mechanics based on the Hagen–Poiseuille equation and Reynolds laminar-turbulent transition in long straight tubes, which has figured prominently in medical textbooks and journal articles for many years, is shown to be seriously in error at a fundamental level.

scholarly journals Impaired nasal breathing may prevent the beneficial effect of weight loss in the treatment of OSA

2011 ◽  
Vol 49 (5) ◽  
pp. 587-592
Author(s):  
Henry Blomster ◽  
Tatu Kemppainen ◽  
Jura Numminen ◽  
Pirkko Ruoppi ◽  
Johanna Sahlman ◽  
...  
Keyword(s):  
Weight Loss ◽  
Weight Reduction ◽  
Negative Impact ◽  
Sleep Apnoea ◽  
Nasal Resistance ◽  
Nasal Airflow ◽  
Nasal Breathing ◽  
Beneficial Effects ◽  
Obstructive Sleep ◽  
Overweight Adult

Background: Weight loss is considered an effective treatment for obstructive sleep apnoea (OSA) in overweight patients. Some patients, however, do not benefit from weight loss. It has been postulated that nasal obstruction may act as an independent risk factor for OSA. Objective: The aim of our study was to evaluate whether impaired nasal airflow might explain the missing effect of weight reduction on OSA. Methodology: Fifty-two overweight adult patients with mild OSA were recruited. After the 12-month lifestyle intervention, all patients who achieved more than 5% weight loss were divided into two groups based on whether they still had OSA or not. Change in nasal resistance measured by rhinomanometer and AHI were the main outcome variables. Results: A total of 26/52 patients achieved 5% weight reduction. Of those 26 patients, 16 were objectively cured from OSA and 10 patients did not benefit from weight loss. Nasal resistance reduced significantly more in patients who had been cured from OSA. Smoking had a negative impact on both nasal resistance and improvement of AHI. Conclusions: Impaired nasal breathing and smoking may prevent the beneficial effects of weight reduction in the treatment of OSA.

scholarly journals NEW CALCULATING METHOD OF NASAL RESISTANCE APPLICABLE TO ANY PREDETERMINED POINTS ON DIFFERENTIAL PRESSURE/FLOW CURVE

1999 ◽  
Vol 38 (4) ◽  
pp. 422-426
Author(s):  
Toshiko Mamiya ◽  
Kensei Naito ◽  
Yuka Kondo ◽  
Sho Miyata ◽  
Tatsuyoshi Okada ◽  
...  
Keyword(s):  
Flow Curve ◽  
Differential Pressure ◽  
Nasal Resistance ◽  
Pressure Flow ◽  
Calculating Method

scholarly journals Evaluation of the pressure-flow curve during nasal breathing

1994 ◽  
Vol 33 (2) ◽  
pp. 292-296
Author(s):  
Satoshi Nonaka ◽  
Mitsuhiro Tanida ◽  
Kizuku Nakajima ◽  
Hiroshi Horikawa ◽  
Tokuji Unno
Keyword(s):  
Flow Curve ◽  
Nasal Breathing ◽  
Pressure Flow

Normal Nasal Resistance

1985 ◽  
Vol 93 (6) ◽  
pp. 778-785 ◽  
Author(s):  
John F. Pallanch ◽  
Thomas V. McCaffrey ◽  
Eugene B. Kern
Keyword(s):  
Flow Curve ◽  
Nasal Resistance ◽  
Pressure Flow ◽  
Log Transformation ◽  
Nasal Symptoms ◽  
Before And After ◽  
The Mean ◽  
The Right ◽  
Normal Adults

Eighty normal adults without nasal symptoms were studied to determine normal nasal resistance values and the variation of nasal resistance in normal adults. A microprocessor-based system for collection and analysis of transnasal pressure and flow was used to obtain nasal resistance values. Unilateral and total transnasal pressure and flow values were determined before and after decongestion of the nose with 1% phenylephrine spray. The distribution of the 80 resistance values was found to be skewed to the right. Log transformation of the resistance values was the best method to normalize their distribution. The mean and variation of normal nasal resistance are reported at flows of 0.1 and 0.2 L/sec, at pressures of 0.5 and 1 cm H2O, and at radii of 1, 2, and 3 on the pressure-flow curve.

scholarly journals Confinement, partial sleep deprivation and defined physical activity–influence on cardiorespiratory regulation and capacity

2021 ◽  
Author(s):  
Jessica Koschate ◽  
Uwe Drescher ◽  
Uwe Hoffmann
Keyword(s):  
Physical Activity ◽  
Cardiorespiratory Fitness ◽  
Space Mission ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Binary Sequences ◽  
Kinetics Parameters ◽  
Slow Heart Rate ◽  
Partial Sleep Deprivation ◽  
Sleep Schedule

Abstract Introduction Adequate cardiorespiratory fitness is of utmost importance during spaceflight and should be assessable via moderate work rate intensities, e.g., using kinetics parameters. The combination of restricted sleep, and defined physical exercise during a 45-day simulated space mission is expected to slow heart rate (HR) kinetics without changes in oxygen uptake ($${\dot{\text{V}}\text{O}}_{{2}}$$ V ˙ O 2 ) kinetics. Methods Overall, 14 crew members (9 males, 5 females, 37 ± 7 yrs, 23.4 ± 3.5 kg m−2) simulated a 45-d-mission to an asteroid. During the mission, the sleep schedule included 5 nights of 5 h and 2 nights of 8 h sleep. The crew members were tested on a cycle ergometer, using pseudo-random binary sequences, changing between 30 and 80 W on day 8 before (MD-8), day 22 (MD22) and 42 (MD42) after the beginning and day 4 (MD + 4) following the end of the mission. Kinetics information was assessed using the maxima of cross-correlation functions (CCFmax). Higher CCFmax indicates faster responses. Results CCFmax(HR) was significantly (p = 0.008) slower at MD-8 (0.30 ± 0.06) compared with MD22 (0.36 ± 0.06), MD42 (0.38 ± 0.06) and MD + 4 (0.35 ± 0.06). Mean HR values during the different work rate steps were higher at MD-8 and MD + 4 compared to MD22 and MD42 (p < 0.001). Discussion The physical training during the mission accelerated HR kinetics, but had no impact on mean HR values post mission. Thus, HR kinetics seem to be sensitive to changes in cardiorespiratory fitness and may be a valuable parameter to monitor fitness. Kinetics and capacities adapt independently in response to confinement in combination with defined physical activity and sleep.

Exercise efficiency: validity of base-line subtractions

1980 ◽  
Vol 48 (3) ◽  
pp. 518-522 ◽  
Author(s):  
W. N. Stainbsy ◽  
L. B. Gladden ◽  
J. K. Barclay ◽  
B. A. Wilson
Keyword(s):  
Energy Storage ◽  
Energy Expenditure ◽  
Work Rate ◽  
Published Data ◽  
Base Line ◽  
External Work ◽  
Future Studies ◽  
Using Data ◽  
Exercise Efficiency ◽  
Adequate Analysis

In evaluating the efficiency of humans performing exercise, base-line subtractions have been used in an attempt to determine the efficiency of the muscles in performing the external work. Despite the fact that base lines have been criticized previously, they have been widely used without adequate analysis of the implications involved. Calculations of efficiencies using data available in the literature for isolated muscle preparations revealed that base-line subtractions result in unreasonably high efficiencies. This suggests strongly that the base lines are invalid. To be valid, a base line must continue unchanged under all the conditions in which it is applied. Previously published data indicate clearly that exercise base lines change with increasing work rate and are therefore invalid. The use of base lines is further complicated by elastic energy storage in some types of exercise. Although exercise efficiencies using base line subtractions may be useful, they do not indicate muscle efficiency. Perhaps future studies of exercise metabolism should be directed less at refining base lines and more toward describing and quantifying the determinants of energy expenditure.

scholarly journals Maximal Oxygen Uptake Validation in Children With Expiratory Flow Limitation

2013 ◽  
Vol 25 (1) ◽  
pp. 84-100 ◽  
Author(s):  
Katherine E. Robben ◽  
David C. Poole ◽  
Craig A. Harms
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Constant Load ◽  
Work Rate ◽  
Flow Limitation ◽  
Expiratory Flow Limitation ◽  
Test Protocol ◽  
Wide Range ◽  
Rate Relationship ◽  
Expiratory Flow

A two-test protocol (incremental/ramp (IWT) + supramaximal constant-load (CWR)) to affirm max and obviate reliance on secondary criteria has only been validated in highly fit children. In girls (n = 15) and boys (n = 12) with a wide range of VO2max (17–47 ml/kg/min), we hypothesized that this procedure would evince a VO2-WR plateau and unambiguous VO2max even in the presence of expiratory flow limitation (EFL). A plateau in the VO2-work rate relationship occurred in 75% of subjects irrespective of EFL There was a range in RER at max exercise for girls (0.97–1.14; mean 1.06 ± 0.04) and boys (0.98−1.09; mean 1.03 ± 0.03) such that 3/15 girls and 2/12 boys did not achieve the criterion RER. Moreover, in girls with RER > 1.0 it would have been possible to achieve this criterion at 78% VO2max. Boys achieved 92% VO2max at RER = 1.0. This was true also for HRmax where 8/15 girls’ and 6/12 boys’ VO2max would have been rejected based on HRmax being < 90% of age-predicted HRmax. In those who achieved the HRmax criterion, it represented a VO2 of 86% (girls) and 87% (boys) VO2max. We conclude that this two-test protocol confirms VO2max in children across a threefold range of VO2max irrespective of EFL and circumvents reliance on secondary criteria.

Lactate accumulation during incremental exercise with varied inspired oxygen fractions

1983 ◽  
Vol 55 (4) ◽  
pp. 1134-1140 ◽  
Author(s):  
M. C. Hogan ◽  
R. H. Cox ◽  
H. G. Welch
Keyword(s):  
Cycle Ergometer ◽  
Work Rate ◽  
O2 Uptake ◽  
Lactate Accumulation ◽  
Oxygen Fraction ◽  
Co2 Output ◽  
Break Points ◽  
Expired Gas ◽  
Gas Fractions ◽  
Inspired Oxygen

Six subjects pedaled a stationary cycle ergometer to exhaustion on three separate occasions while breathing gas mixtures of 17, 21, or 60% O2 in N2. Each subject rode for 3 min at work rates of 60, 90, 105 W, followed by 15-W increases every 3 min until exhaustion. Inspired and expired gas fractions, ventilation (V), heart rate, and blood lactate were measured. O2 uptake (VO2) and CO2 output (VCO2) were calculated for the last minute of each work rate; blood samples were drawn during the last 5 s. “Break points” for lactate, V, VCO2, V/VO2, and expired oxygen fraction (FEO2) were mathematically determined. VO2 was not significantly different at any work rate among the three different conditions. Nor did maximal VO2 differ significantly among the three treatments (P greater than 0.05). Lactate concentrations were significantly lower during hyperoxia and significantly higher during hypoxia compared with normoxia. Lactate values at exhaustion were not significantly different among the three treatments. Four subjects were able to work for a longer period of time during hyperoxic breathing. The variations in lactate accumulation as reported in this study cannot be explained on the basis of differences in VO2. The results of this research lend support to the hypothesis that differences in the performance of subjects breathing altered fractions of inspired oxygen may be caused by differences in lactate (or H+) accumulation.

Hypernasality and Velopharyngeal Impairment

1994 ◽  
Vol 31 (4) ◽  
pp. 257-262 ◽  
Author(s):  
Donald W. Warren ◽  
Rodger M. Dalston ◽  
Robert Mayo
Keyword(s):  
Airflow Rate ◽  
Nasal Airflow ◽  
Moderate Correlation ◽  
Interval Scale ◽  
Pressure Flow ◽  
Orifice Area ◽  
The Relationship ◽  
Nasal Resonance

Although the primary cause of hypernasality is impaired velopharyngeal (VP) function, a variety of other factors influence the outcome perceived by the listener. The purpose of the current study was to assess the relationship between oral-nasal resonance balance and (1) velopharyngeal orifice area; (2) nasal airflow rate; and (3) duration of nasal airflow. The pressure-flow technique was used to estimate VP area and measure nasal airflow rate and duration. Ratings of oral-nasal balance were made on a 6-point equal-appearing interval scale. Results Indicated a moderate correlation between hypernasality rating and VP area (0.66), nasal airflow (0.61), and nasal airflow duration (0.53). Adults tended to be perceived as more hypernasal than children for a given degree of VP impairment. Finally, when the degree of VP opening was small, perceived oral-nasal resonance balance appeared to be related to duration of the opening-closing movements.

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