The switching point from nasal to oronasal breathing

Niinimaa, V.; Cole, Philip; Mintz, Sheldon; Shephard, Roy J.

doi:10.1016/0034-5687(80)90104-8

Cited by 207 publications

(110 citation statements)

References 9 publications

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“…All subjects gave written informed consent before the study, as laid down by the Institutional Review Board for Human Investigation, University Hospitals of Cleveland. The asthmatic subjects had a previous diagnosis of asthma and a history ofepisodic wheezing or post-exertional wheezing (or both).5 They were in a stable condition and could refrain from taking their medications for at least six and usually (11 Nasal response to exercise and exercise induced bronchoconstriction in normal and asthmatic subjects Specific airway resistance was measured by body plethysmography, while the subject was seated, breathing through the mouth and wearing noseclips. The product of thoracic gas volume and specific airway resistance (specific resistance: sRaw) was computed.…”

Section: Subjectsmentioning

confidence: 99%

The nasal response to exercise and exercise induced bronchoconstriction in normal and asthmatic subjects.

Decker

Olson

Flak

et al. 1988

Thorax

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Two studies were carried out to test the hypothesis that the fall and recovery of nasal resistance after exercise in asthmatic and non-asthmatic subjects are related to the development of bronchoconstriction after exercise. In study 1 nasal resistance (posterior rhinomanometry) and specific airway resistance (sRaw) were measured before challenge and one, five, 10 and 30 minutes after four minutes of exhausting legwork exercise in nine asthmatic subjects and nine age matched healthy subjects. One minute after exercise there was a reduction in nasal resistance of49% (SD 15%) from baseline in the healthy subjects and of 66% (17%) in the asthmatic subjects. This response and the subsequent return ofnasal resistance to baseline values did not differ significantly between the two groups despite a substantial difference in the change in sRaw, an increase of 74% (45%) in the asthmatic subjects 10 minutes after exercise, and no change in the non-asthmatic subjects. In study 2, nasal and specific airway resistances were monitored according to the same measurement protocol in six subjects with increased airway reactivity. Subjects exercised on two occasions, wearing a noseclip, once while breathing cold, dry air and once while breathing warm, humid air. The fall in nasal resistance was similar under both conditions (to 47% and 39% of baseline), though sRaw rose only after cold air inhalation (to 172% of baseline). The results indicate that the nasal response to exercise is not related to bronchial obstruction in asthmatic subjects after exercise or to the temperature or humidity of the air inspired through the mouth during exercise.

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Section: Subjectsmentioning

confidence: 99%

The nasal response to exercise and exercise induced bronchoconstriction in normal and asthmatic subjects.

Decker

Olson

Flak

et al. 1988

Thorax

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“…On a subsequent study day, the relative contributions of oral vs. nasal breathing were measured at rest and during incrementally graded submaximal exercise on the cycle ergometer (10% increments from 0-60% PWC max for each subject) (21,22). The subject was fitted with a nasal mask (Respironics, Murrysville, PA) (approximate dead space of 60 ml) that was similar to that used in pulmonary sleep laboratories and modified to allow insertion of a mass flowmeter (Korr Medical Technologies, Salt Lake City, UT) to detect nasal airflow (21,22).…”

Section: Methodsmentioning

confidence: 99%

“…The subject was fitted with a nasal mask (Respironics, Murrysville, PA) (approximate dead space of 60 ml) that was similar to that used in pulmonary sleep laboratories and modified to allow insertion of a mass flowmeter (Korr Medical Technologies, Salt Lake City, UT) to detect nasal airflow (21,22). Total ventilation (V E) was determined by respiratory inductance plethysmography (Respitrace) (calibrated by spirometry) (4,7,30).…”

Section: Methodsmentioning

confidence: 99%

“…The capability of the nose to filter or condition inspired air is diminished as airflow is diverted from nasal to mouth breathing during exercise. The level of ventilation at which this switch from nasal to oronasal breathing occurs has been previously referred to as the "oronasal switching point" (21). A number of studies, however, have shown that oronasal breathing occurs at resting ventilation in some individuals (3,7,14).…”

mentioning

confidence: 99%

“…The level of exercise at which the oronasal switching point occurs and the relative contributions of oral vs. nasal breathing at rest and during exercise have been studied by a number of investigators (3,7,14,21,22,25,27,31). The physiological determinants of the relative contributions to nasal and oral breathing during exercise are still not well understood.…”

mentioning

confidence: 99%

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Nasal contribution to breathing with exercise: effect of race and gender

Bennett

Zeman²,

Jarabek³

2003

Journal of Applied Physiology

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Because the nose acts as a filter to prevent penetration of toxic particles and gases to the lower respiratory tract, the route of breathing, oral vs. nasal, may be an important determinant of toxicant dose to the lungs. Using respiratory inductance plethysmography and a nasal mask fitted with flowmeter, we measured the nasal contribution to breathing at rest and during exercise (to 60% maximum workload) in healthy young adults (men/women = 11/11 and Caucasian/African-American = 11/11). We found that the nasal contribution to breathing is less during submaximal exercise in the Caucasians vs. African-Americans (e.g., at 60% maximum workload, mean nasal-to-total ventilation ratio = 0.40 ± 0.21 and 0.65 ± 0.24, respectively, P < 0.05). This difference is likely due to the African-Americans' ability to achieve higher maximal inspiratory flows through their nose than the Caucasians. Men also had a lesser nasal contribution to breathing during exercise compared with women. This is likely due to greater minute ventilations at any given percentage of maximum workload in men vs. women.

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Study of respirator effect on nasal-oral flow partition

1997

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Factors affecting worker tolerance of respiratory personal protective devices are inadequately understood. This study evaluates whether respirator‐type loads affected the switch from nasal to oral breathing. Eleven healthy subjects were studied under progressive exercise conditions, using a respirator full‐face mask with inspiratory resistance (I), pressure breathing (P) (10 cm H2O end‐expiratory pressure), or no load (N). A rapid‐response thermistor was used to determine whether flow was predominantly oral or nasal. Both P and I increased the percentage of time that breathing was predominantly oral. The effect was most pronounced at higher exercise levels. The percentage of mouth breathing appeared to be closely related to the expiratory time. This study suggests that nasal‐oral flow partitioning should be considered as a possible determinant of respirator tolerance. Am. J. Ind. Med. 32:408–412, 1997. © 1997 Wiley‐Liss, Inc.

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The switching point from nasal to oronasal breathing

Cited by 207 publications

References 9 publications

The nasal response to exercise and exercise induced bronchoconstriction in normal and asthmatic subjects.

The nasal response to exercise and exercise induced bronchoconstriction in normal and asthmatic subjects.

Nasal contribution to breathing with exercise: effect of race and gender

Study of respirator effect on nasal-oral flow partition

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