Steady-state response of conscious man to small expiratory resistive loads

Hill, A. Ross; Kaiser, Donald L.; Lu, Jau-Yeong; Rochester, Dudley F.

doi:10.1016/0034-5687(85)90079-9

Cited by 10 publications

(13 citation statements)

References 21 publications

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“…Expiratory resistive loading and PLB both decreased expiratory flow (from a baseline value of 0.35 L/s to 0.29 L/s and 0.33 L/s for ERL and PLB, respectively), but ERL produced a much smaller prolongation in expiratory time (37% versus 71%) and failed to produce the changes in respiratory rate and Vt that were associated with PLB. Pursed-lip breathing caused the respiratory rate to fall from 15 to 10 and Vt to rise from 0.80 L to 1.3 L, whereas ERL produced a respiratory rate of 13 and a Vt of 0.9 L. In contrast, the changes in breathing pattern in response to ERL in people without pulmonary symptoms that were reported by Hill et al 22 and Gothe and Cherniack 23 were qualitatively similar to the changes stimulated by PLB in the work of Spahija and Grassino. 21 Spahija and Grassino found that ERL increased EELV, whereas it remained unchanged with PLB.…”

Section: Work Of Breathingcontrasting

confidence: 44%

Evidence Underlying Breathing Retraining in People With Stable Chronic Obstructive Pulmonary Disease

Dechman

Wilson

2004

Physical Therapy

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The efficacy of pursed-lip breathing (PLB) and diaphragmatic breathing (DB) in the rehabilitation of people with chronic obstructive pulmonary disease (COPD) remains unclear. This review examines the evidence regarding the usefulness of these techniques in improving the breathing of people with stable COPD. The studies included in our review of the literature used either PLB or DB in isolation, contained a clear description of the methods, and used outcomes that were measured with what we considered to be appropriate procedures. Pursed-lip breathing slows the respiratory rate, and evidence suggests that this decreases the resistive pressure drop across the airways and, therefore, decreases airway narrowing during expiration. This decrease in airway narrowing may account for the decreased dyspnea some people experience when using this technique. Diaphragmatic breathing has negative and positive effects, but the latter appear to be caused by simply slowing the respiratory rate. Evidence supports the use of PLB, but not DB, for improving the breathing of people with COPD.[Dechman G, Wilson CR. Evidence underlying breathing retraining in people with stable chronic obstructive pulmonary disease. Phys Ther.

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Section: Work Of Breathingcontrasting

confidence: 44%

Evidence Underlying Breathing Retraining in People With Stable Chronic Obstructive Pulmonary Disease

Dechman

Wilson

2004

Physical Therapy

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“…(19, 47,73,87) Applied ERL under steady-state exercise conditions tend to also reduce VE but again, the magnitude of these reductions is much less than those found for IRL. (21,60,118,136) The changes in JVE during non-steady-state maximal efforts mimic those reported during steady-state work for individually applied inspiratory (36,103,107) and expiratory resistances. (65) Specifically, there appears to be little difference in VE between unloaded and resistive load conditions under low to moderate rate exercise intensities.…”

Section: 1supporting

confidence: 55%

“…Hill el al. (6) reported substantial increases in VT (24%) with ERL during quiet breathing and both Hill et al (60) and Poon et al (116) found significant decreases in f under such conditions. Expiratory resistive loading appears to reduce ventilation at rest.…”

Section: 1mentioning

confidence: 99%

Workplace Breathing Rates: Defining Anticipated Values and Ranges for Respirator Certification Testing

Caretti¹,

Gardner²,

Coyne³

2004

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204. Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information N it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)2 SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION I AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTTest methods currently used by the National Institute for Occupational Safety and Health (NIOSH) are designed to assure that respirators meet a minimum level of efficacy when tested under standard laboratory protocols. For air-purifying respirators (APRs), the primary performance tests most affected by airflow rate are filter gas-life capacity, particulate filter efficiency, and respirator breathing resistances. Presently, NIOSH measures all three parameters using constant-rate airflow conditions. An analysis of the measured and estimated minute volumes contained in the literature indicated a range from about 8 to 162 L'min' for unencumbered ventilation and work activities that spanned from mild to exhaustive. The mean minute volume of the distribution was 38.5 ± 16.6 L'min-1, and the median was 33.6 L-minin. Based on an empirical relationship between minute volume and peak inspiratory flow (PIF), peak flows between 72 L'min-' and 183 L'min-1 would be expected for the mean minute volume for 38.5 L'min'. The anticipated range of PIF rates for the 9 5 dh percentile minute volume is between 182 L-min-' and 295 L-min-'. The results of this literature review suggest an increase in cyclic flow rates used for respirator certification testing should be considered to better represent ventilation rates found in the workplace. Blank EXECUTIVE SUMMARY Test methods currently used by the National Institute for Occupational Safety and Health (NIOSH) are designed to assure that all respirators of a given type will meet a minimum level of efficacy when tested under standard laboratory protocols. The relevance and adequacy of airflow rates used in respirator certification testing has been a longstanding debate. The concern is that the current test flow rates substantially underestimate real world values, implying that filters certified under existing standards may not provide adequate protection. For qualifying airpurifying respirators (APRs), the primar...

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“…(26) However, this same publication reports that minute volumes increase with increasing exhalation resistance, a finding that is vastly different from those reported herein and by others under steady-state exercise conditions. (12,27,28) …”

Section: Exhalation Resistances and Performancementioning

confidence: 98%

“…93.5 ± 2.2 (21) 93.4 ± 5.8 (21) 80.5 ± 6.4 (21) VO 2 (mL · kg −1 · min −1 ) 41.8 ± 1.8 (29) 44.2 ± 1.7 (27) 43.1 ± 2.0 (19) 44.2 ± 1.6 (32)…”

Section: Effects Of Increasing Inhalation Resistancementioning

confidence: 99%

Performance when Breathing Through Different Respirator Inhalation and Exhalation Resistances During Hard Work

Caretti

Coyne

Johnson

et al. 2006

Journal of Occupational and Environmental Hygiene

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Respirator inspiratory and expiratory breathing resistances impact ventilation and performance when studied independently. However, it is less clear as to how various combinations of inhalation and exhalation resistance affect user performance. The present study investigated the performance of 11 individuals during constant load, demanding work to exhaustion while wearing respirators with eight different combinations of inhalation and exhalation resistance. Exercise performance time, performance rating, minute volume, and peak inspiratory and expiratory airflow were recorded at the end of each test trial, and independent correlations with inhalation resistance and exhalation resistance were assessed. The combined impacts of respirator inhalation and exhalation resistances were quantified as the total external work of breathing (WOB(tot)) and correlations between the test variables and WOB(tot) were also examined. Significantly linear decreases in performance were found with increased inhalation resistances independent of exhalation resistance (R(2) = 0.99; p < 0.001) and with increased WOB(tot) (R(2) = 0.92; p < 0.001). Performance also decreased with increased exhalation resistance but no significant relationships were found. Minute volume decreased linearly with increased inhalation resistance independent of exhalation resistance (R(2) = 0.99; p < 0.001), but the linear decrease observed between minute volume and WOB(tot) was weak (R(2) = 0.36; p < 0.05). These findings suggest that WOB(tot) serves as a reliable estimate of the combined impacts of respirator inhalation and exhalation resistances on user performance during hard work, but that inhalation resistance alone serves as a better predictor of ventilation during respirator wear.

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Steady-state response of conscious man to small expiratory resistive loads

Cited by 10 publications

References 21 publications

Evidence Underlying Breathing Retraining in People With Stable Chronic Obstructive Pulmonary Disease

Evidence Underlying Breathing Retraining in People With Stable Chronic Obstructive Pulmonary Disease

Workplace Breathing Rates: Defining Anticipated Values and Ranges for Respirator Certification Testing

Performance when Breathing Through Different Respirator Inhalation and Exhalation Resistances During Hard Work

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