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Dirkjan Slebos - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of Multiple Diagnostic Tests to Measure Dynamic Hyperinflation in Patients with Severe Emphysema Treated with Endobronchial Coils
    Lung, 2021
    Co-Authors: Marlies Van Dijk, Karin Klooster, Jorine E Hartman, Sonja W. S. Augustijn, Nick H. T. Ten Hacken, Dirkjan Slebos
    Abstract:

    Purpose For this study, we aimed to compare dynamic Hyperinflation measured by cardiopulmonary exercise testing (CPET), a six-minute walking test (6-MWT), and a manually paced tachypnea test (MPT) in patients with severe emphysema who were treated with endobronchial coils. Additionally, we investigated whether dynamic Hyperinflation changed after treatment with endobronchial coils. Methods Dynamic Hyperinflation was measured with CPET, 6-MWT, and an MPT in 29 patients before and after coil treatment. Results There was no significant change in dynamic Hyperinflation after treatment with coils. Comparison of CPET and MPT showed a strong association (rho 0.660, p 

  • change in dynamic Hyperinflation after bronchoscopic lung volume reduction in patients with emphysema
    Lung, 2020
    Co-Authors: Marlies Van Dijk, Karin Klooster, Jorine E Hartman, Nick Ten H T Hacken, Dirkjan Slebos
    Abstract:

    In patients with severe emphysema, dynamic Hyperinflation is superimposed on top of already existing static Hyperinflation. Static Hyperinflation reduces significantly after bronchoscopic lung volume reduction (BLVR). In this study, we investigated the effect of BLVR compared to standard of care (SoC) on dynamic Hyperinflation. Dynamic Hyperinflation was induced by a manually paced tachypnea test (MPT) and was defined by change in inspiratory capacity (IC) measured before and after MPT. Static and dynamic Hyperinflation measurements were performed both at baseline and 6 months after BLVR with endobronchial valves or coils (treatment group) or SoC (control group). Eighteen patients underwent BLVR (78% female, 57 (43–67) years, FEV1 25(18–37) %predicted, residual volume 231 (182–376) %predicted). Thirteen patients received SoC (100% female, 59 (44–74) years, FEV1 25 (19–37) %predicted, residual volume 225 (152–279) %predicted. The 6 months median change in dynamic Hyperinflation in the treatment group was: + 225 ml (range − 113 to + 803) (p < 0.01) vs 0 ml (− 1067 to + 500) in the control group (p = 0.422). An increase in dynamic Hyperinflation was significantly associated with a decrease in residual volume (r = − 0.439, p < 0.01). Bronchoscopic lung volume reduction increases the ability for dynamic Hyperinflation in patients with severe emphysema. We propose this is a consequence of improved static Hyperinflation.

  • Change in Dynamic Hyperinflation After Bronchoscopic Lung Volume Reduction in Patients with Emphysema
    Lung, 2020
    Co-Authors: Marlies Van Dijk, Karin Klooster, Jorine E Hartman, Nick Ten H T Hacken, Dirkjan Slebos
    Abstract:

    Background and Purpose In patients with severe emphysema, dynamic Hyperinflation is superimposed on top of already existing static Hyperinflation. Static Hyperinflation reduces significantly after bronchoscopic lung volume reduction (BLVR). In this study, we investigated the effect of BLVR compared to standard of care (SoC) on dynamic Hyperinflation. Methods Dynamic Hyperinflation was induced by a manually paced tachypnea test (MPT) and was defined by change in inspiratory capacity (IC) measured before and after MPT. Static and dynamic Hyperinflation measurements were performed both at baseline and 6 months after BLVR with endobronchial valves or coils (treatment group) or SoC (control group). Results Eighteen patients underwent BLVR (78% female, 57 (43–67) years, FEV_1 25(18–37) %predicted, residual volume 231 (182–376) %predicted). Thirteen patients received SoC (100% female, 59 (44–74) years, FEV_1 25 (19–37) %predicted, residual volume 225 (152–279) %predicted. The 6 months median change in dynamic Hyperinflation in the treatment group was: + 225 ml (range − 113 to + 803) ( p  

  • determining the role of dynamic Hyperinflation in patients with severe chronic obstructive pulmonary disease
    Respiration, 2015
    Co-Authors: Karin Klooster, Jorine E Hartman, Nick Ten H T Hacken, Frank C Sciurba, Huib A M Kerstjens, Dirkjan Slebos
    Abstract:

    Background: Dynamic Hyperinflation due to increased respiratory frequency during exercise is associated with limitations in exercise capacity in patients with moderately severe chronic obstructive pulmonary disease (COPD). Objectives: The present study assessed whether the manually paced tachypnea (MPT) test, sitting at rest, induces dynamic Hyperinflation correlating with exercise capacity in patients with very severe COPD. Methods: Dynamic Hyperinflation was induced by the MPT test, using a breathing frequency of 40/min for 1 min. Dynamic Hyperinflation was defined as a ‘change' in inspiratory capacity (IC) before and directly after the MPT test. At baseline, static Hyperinflation by body plethysmography was measured, as well as the 6-min walking test and spirometry. Results: We studied 74 patients with severe COPD (age 59 ± 9 years, FEV1 28 ± 10% predicted). All patients tolerated the MPT test well. It induced a significant decrease in IC: -0.65 ± 0.33 liters, p Conclusions: In patients with very severe COPD, dynamic Hyperinflation measurement by the MPT test is feasible and contributes less importantly to exercise performance than static Hyperinflation.

Franco Laghi - One of the best experts on this subject based on the ideXlab platform.

  • The Effect of Breathing Retraining Using Metronome-Based Acoustic Feedback on Exercise Endurance in COPD: A Randomized Trial
    Lung, 2019
    Co-Authors: Eileen G. Collins, Christine Jelinek, Susan O’connell, Jolene Butler, Domenic Reda, Franco Laghi
    Abstract:

    Background During exercise-training patients with chronic obstructive pulmonary disease (COPD) can entrain their breathing pattern to visual-feedback cues as to achieve a slower respiratory rate and prolong exhalation. The result is an improvement in exercise tolerance and a reduction in dynamic Hyperinflation. Acoustic stimuli, including metronome-generated acoustic stimuli, can entrain human movements. Accordingly, we hypothesized that exercise duration and dynamic Hyperinflation would be less after exercise-training plus breathing-retraining using a metronome-based acoustic-feedback system than after exercise-training alone. Methods Of 205 patients with COPD [FEV_1 = 44 ± 16% predicted (± SD)] recruited, 119 were randomly assigned to exercise-training plus breathing-retraining using acoustic feedback ( n  = 58) or exercise-training alone ( n  = 61). Patients exercised on a treadmill thrice-weekly for 12 weeks. Before and at completion of training, patients underwent constant-load treadmill testing with inspiratory capacity measures every 2 min. Results At completion of training, improvements in exercise duration in the breathing-retraining plus exercise-training and exercise-training alone groups were similar ( p  = 0.35). At isotime, inspiratory capacity increased (less exercise-induced dynamic Hyperinflation) by 3% ( p  = 0.001) in the breathing-retraining plus exercise-training group and remained unchanged in the exercise-alone group. The between-group change in inspiratory capacity, however, was not significant ( p  = 0.08). Conclusions In patients with COPD, breathing-retraining using a metronome-based acoustic feedback did not result in improved exercise endurance or decreased dynamic Hyperinflation when compared to exercise-training alone. Trial registry : ClinicalTrials.gov; No.: NCT NCT01009099; URL: http://www.clinicaltrials.gov

  • the effect of breathing retraining using metronome based acoustic feedback on exercise endurance in copd a randomized trial
    Lung, 2019
    Co-Authors: Eileen G. Collins, Christine Jelinek, Jolene Butler, Franco Laghi, Susan Oconnell, Domenic J Reda
    Abstract:

    During exercise-training patients with chronic obstructive pulmonary disease (COPD) can entrain their breathing pattern to visual-feedback cues as to achieve a slower respiratory rate and prolong exhalation. The result is an improvement in exercise tolerance and a reduction in dynamic Hyperinflation. Acoustic stimuli, including metronome-generated acoustic stimuli, can entrain human movements. Accordingly, we hypothesized that exercise duration and dynamic Hyperinflation would be less after exercise-training plus breathing-retraining using a metronome-based acoustic-feedback system than after exercise-training alone. Of 205 patients with COPD [FEV1 = 44 ± 16% predicted (± SD)] recruited, 119 were randomly assigned to exercise-training plus breathing-retraining using acoustic feedback (n = 58) or exercise-training alone (n = 61). Patients exercised on a treadmill thrice-weekly for 12 weeks. Before and at completion of training, patients underwent constant-load treadmill testing with inspiratory capacity measures every 2 min. At completion of training, improvements in exercise duration in the breathing-retraining plus exercise-training and exercise-training alone groups were similar (p = 0.35). At isotime, inspiratory capacity increased (less exercise-induced dynamic Hyperinflation) by 3% (p = 0.001) in the breathing-retraining plus exercise-training group and remained unchanged in the exercise-alone group. The between-group change in inspiratory capacity, however, was not significant (p = 0.08). In patients with COPD, breathing-retraining using a metronome-based acoustic feedback did not result in improved exercise endurance or decreased dynamic Hyperinflation when compared to exercise-training alone. Trial registry: ClinicalTrials.gov; No.: NCT NCT01009099; URL: http://www.clinicaltrials.gov

Chikako Saiki - One of the best experts on this subject based on the ideXlab platform.

  • the inhibitory effect of ouabain on the response of slowly adapting pulmonary stretch receptors to Hyperinflation in the rabbit
    Life Sciences, 2005
    Co-Authors: Shigeji Matsumoto, Chikako Saiki, Mizuho Ikeda, Toshimi Nishikawa, Shinki Yoshida, Yoshinobu Fujimi, Takeshi Tanimoto, Yasuo Itoh, Mamoru Takeda
    Abstract:

    Abstract The combined effects of ouabain (Na + –K + ATPase inhibitor) and Hyperinflation (inflation volume = three tidal volumes) on slowly adapting pulmonary stretch receptors (SARs) were studied before and after administration of nifedipine (an L-type Ca 2+ channel blocker) and KB-R7943 (a reverse-mode Na + –Ca 2+ exchanger blocker) in anesthetized, artificially ventilated rabbits after bilateral vagotomy. Before ouabain administration, Hyperinflation stimulated SAR activity. After 20 min of ouabain administration (30 μg/kg) the SARs increased discharge rates in normal inflation. Under these conditions, Hyperinflation initially stimulated SAR activity but subsequently inhibited the activity at peak inflation. Additional administration of 60 μg/kg ouabain (total dose = 90 μg/kg) caused a further stimulation of SAR activity, but 20 min later both normal inflation and Hyperinflation resulted in a greater inhibition of the receptor activity. The Hyperinflation-induced SAR inhibition in the presence of ouabain (30 μg/kg) was not significantly altered by administration of either nifedipine (2 and 4 mg/kg) or KB-R7943 (1 and 3 mg/kg). In another series of experiments, we further examined the combined effects of ouabain and Hyperinflation in veratridine (a Na + channel opener, 40 μg/kg)-treated animals. After recovery from the veratridine effect on SAR activity, which vigorously stimulated the receptor activity, ouabain treatment (30 μg/kg) that silenced the receptor activity at peak inflation greatly inhibited Hyperinflation-induced SAR stimulation. These results suggest that Hyperinflation-induced SAR inhibition in the presence of ouabain may be related to a Na + overload, but not to a Ca 2+ influx via activation of L-type Ca 2+ channels, in the SAR endings.

  • effects of potassium channel and na ca2 exchange blockers on the responses of slowly adapting pulmonary stretch receptors to Hyperinflation in flecainide treated rats
    British Journal of Pharmacology, 2001
    Co-Authors: Shigeji Matsumoto, Chikako Saiki, Mizuho Ikeda, Toshimi Nishikawa, Shinki Yoshida, Takeshi Tanimoto, Mamoru Takeda
    Abstract:

    The effects of K+ channel blockers, such as 4-aminopyridine (4-AP) and tetraethylammonium (TEA), and a reverse-mode Na+ – Ca2+ exchange blocker, 2-[2-[4-(4-nitrobenzyloxyl) phenyl] ethyl] isothiourea methanesulphonate (KB-R7943), on the responses of slowly adapting pulmonary stretch receptor activity to Hyperinflation (inflation volume=3 tidal volumes) were investigated in anaesthetized, artificially ventilated, unilaterally vagotomized rats after pretreatment with a Na+ channel blocker flecainide. The administration of flecainide (9 mg kg−1) at a dose greater than that which abolished 50 μg kg−1 veratridine-induced SAR stimulation also inhibited Hyperinflation-induced stimulation of SARs. In flecainide-treated animals, administration of 4-AP (0.7 and 2 mg kg−1) stimulated SAR activity during normal inflation and also caused a partial blockade of Hyperinflation-induced SAR inhibition. The discharges of SARs during normal inflation in flecainide-treated animals were not significantly altered by administration of either TEA (2 and 7 mg kg−1) or KB-R7943 (1 and 3 mg kg−1), but both K+ channel and Na+-Ca2+ exchange blockers partially attenuated Hyperinflation-induced SAR inhibition. These results suggest that Hyperinflation-induced SAR inhibition in the presence of flecainide (9 mg kg−1) involves the activation of several K+ conductance pathways. British Journal of Pharmacology (2001) 134, 682–690; doi:10.1038/sj.bjp.0704277

  • inhibitory mechanism of slowly adapting pulmonary stretch receptors after release from Hyperinflation in anesthetized rabbits
    Life Sciences, 2000
    Co-Authors: Shigeji Matsumoto, Mizuho Ikeda, Toshimi Nishikawa, Shinki Yoshida, Takeshi Tanimoto, Chikako Saiki
    Abstract:

    Abstract In anesthetized, artificially ventilated rabbits with vagus nerve section, release from 10 consecutive Hyperinflations (inflation volume = 3 tidal volume) caused an inhibition of the slowly adapting pulmonary stretch receptor (SAR) activity for 16–22 sec. Intravenous administration of tetraethylammonium (TEA, 10 and 20 mg/kg), a K+ channel blocker, did not significantly alter either basal SAR discharge or tracheal pressure (PT). Although TEA treatment at 10.0 mg/kg had no significant effect on the magnitude and duration of inhibited SAR activity seen after release from Hyperinflation, the increasing dose of this K+ channel blocker up to 20 mg/kg inhibited these effects of the receptor activity but this inhibition was small. The Na+-K+ ATPase inhibitor ouabain (5 and 10 μg/kg) that had no significant effect on SAR activity and PT in the control abolished or attenuated the inhibitory action of SARs in a dose-dependent manner. Furthermore, the changes in dynamic lung compliance (Cdyn) and PT in response to post-Hyperinflation were not significantly influenced by pretreatment with either TEA or ouabain. These results suggest that the inhibitory action of receptors seen during post-Hyperinflation corresponded with the induction of slow afterhyperpolarization (sAHP), and that the mechanism of generating the sAHP of SARs is mainly mediated by the activation of Na+-K+ pump activity.

Shigeji Matsumoto - One of the best experts on this subject based on the ideXlab platform.

  • the inhibitory effect of ouabain on the response of slowly adapting pulmonary stretch receptors to Hyperinflation in the rabbit
    Life Sciences, 2005
    Co-Authors: Shigeji Matsumoto, Chikako Saiki, Mizuho Ikeda, Toshimi Nishikawa, Shinki Yoshida, Yoshinobu Fujimi, Takeshi Tanimoto, Yasuo Itoh, Mamoru Takeda
    Abstract:

    Abstract The combined effects of ouabain (Na + –K + ATPase inhibitor) and Hyperinflation (inflation volume = three tidal volumes) on slowly adapting pulmonary stretch receptors (SARs) were studied before and after administration of nifedipine (an L-type Ca 2+ channel blocker) and KB-R7943 (a reverse-mode Na + –Ca 2+ exchanger blocker) in anesthetized, artificially ventilated rabbits after bilateral vagotomy. Before ouabain administration, Hyperinflation stimulated SAR activity. After 20 min of ouabain administration (30 μg/kg) the SARs increased discharge rates in normal inflation. Under these conditions, Hyperinflation initially stimulated SAR activity but subsequently inhibited the activity at peak inflation. Additional administration of 60 μg/kg ouabain (total dose = 90 μg/kg) caused a further stimulation of SAR activity, but 20 min later both normal inflation and Hyperinflation resulted in a greater inhibition of the receptor activity. The Hyperinflation-induced SAR inhibition in the presence of ouabain (30 μg/kg) was not significantly altered by administration of either nifedipine (2 and 4 mg/kg) or KB-R7943 (1 and 3 mg/kg). In another series of experiments, we further examined the combined effects of ouabain and Hyperinflation in veratridine (a Na + channel opener, 40 μg/kg)-treated animals. After recovery from the veratridine effect on SAR activity, which vigorously stimulated the receptor activity, ouabain treatment (30 μg/kg) that silenced the receptor activity at peak inflation greatly inhibited Hyperinflation-induced SAR stimulation. These results suggest that Hyperinflation-induced SAR inhibition in the presence of ouabain may be related to a Na + overload, but not to a Ca 2+ influx via activation of L-type Ca 2+ channels, in the SAR endings.

  • effects of potassium channel and na ca2 exchange blockers on the responses of slowly adapting pulmonary stretch receptors to Hyperinflation in flecainide treated rats
    British Journal of Pharmacology, 2001
    Co-Authors: Shigeji Matsumoto, Chikako Saiki, Mizuho Ikeda, Toshimi Nishikawa, Shinki Yoshida, Takeshi Tanimoto, Mamoru Takeda
    Abstract:

    The effects of K+ channel blockers, such as 4-aminopyridine (4-AP) and tetraethylammonium (TEA), and a reverse-mode Na+ – Ca2+ exchange blocker, 2-[2-[4-(4-nitrobenzyloxyl) phenyl] ethyl] isothiourea methanesulphonate (KB-R7943), on the responses of slowly adapting pulmonary stretch receptor activity to Hyperinflation (inflation volume=3 tidal volumes) were investigated in anaesthetized, artificially ventilated, unilaterally vagotomized rats after pretreatment with a Na+ channel blocker flecainide. The administration of flecainide (9 mg kg−1) at a dose greater than that which abolished 50 μg kg−1 veratridine-induced SAR stimulation also inhibited Hyperinflation-induced stimulation of SARs. In flecainide-treated animals, administration of 4-AP (0.7 and 2 mg kg−1) stimulated SAR activity during normal inflation and also caused a partial blockade of Hyperinflation-induced SAR inhibition. The discharges of SARs during normal inflation in flecainide-treated animals were not significantly altered by administration of either TEA (2 and 7 mg kg−1) or KB-R7943 (1 and 3 mg kg−1), but both K+ channel and Na+-Ca2+ exchange blockers partially attenuated Hyperinflation-induced SAR inhibition. These results suggest that Hyperinflation-induced SAR inhibition in the presence of flecainide (9 mg kg−1) involves the activation of several K+ conductance pathways. British Journal of Pharmacology (2001) 134, 682–690; doi:10.1038/sj.bjp.0704277

  • inhibitory mechanism of slowly adapting pulmonary stretch receptors after release from Hyperinflation in anesthetized rabbits
    Life Sciences, 2000
    Co-Authors: Shigeji Matsumoto, Mizuho Ikeda, Toshimi Nishikawa, Shinki Yoshida, Takeshi Tanimoto, Chikako Saiki
    Abstract:

    Abstract In anesthetized, artificially ventilated rabbits with vagus nerve section, release from 10 consecutive Hyperinflations (inflation volume = 3 tidal volume) caused an inhibition of the slowly adapting pulmonary stretch receptor (SAR) activity for 16–22 sec. Intravenous administration of tetraethylammonium (TEA, 10 and 20 mg/kg), a K+ channel blocker, did not significantly alter either basal SAR discharge or tracheal pressure (PT). Although TEA treatment at 10.0 mg/kg had no significant effect on the magnitude and duration of inhibited SAR activity seen after release from Hyperinflation, the increasing dose of this K+ channel blocker up to 20 mg/kg inhibited these effects of the receptor activity but this inhibition was small. The Na+-K+ ATPase inhibitor ouabain (5 and 10 μg/kg) that had no significant effect on SAR activity and PT in the control abolished or attenuated the inhibitory action of SARs in a dose-dependent manner. Furthermore, the changes in dynamic lung compliance (Cdyn) and PT in response to post-Hyperinflation were not significantly influenced by pretreatment with either TEA or ouabain. These results suggest that the inhibitory action of receptors seen during post-Hyperinflation corresponded with the induction of slow afterhyperpolarization (sAHP), and that the mechanism of generating the sAHP of SARs is mainly mediated by the activation of Na+-K+ pump activity.

Huib A M Kerstjens - One of the best experts on this subject based on the ideXlab platform.

  • Identifying a nasal gene expression signature associated with Hyperinflation and treatment response in severe COPD
    Scientific reports, 2020
    Co-Authors: Alen Faiz, Huib A M Kerstjens, Kai Imkamp, Erica Van Der Wiel, Ilse M. Boudewijn, Gerard H. Koppelman, Corry-anke Brandsma, Wim Timens, Sebastiaan J. Vroegop, Henk R. Pasma
    Abstract:

    Hyperinflation contributes to dyspnea intensity in COPD. Little is known about the molecular mechanisms underlying Hyperinflation and how inhaled corticosteroids (ICS) affect this important aspect of COPD pathophysiology. To investigate the effect of ICS/long-acting β2-agonist (LABA) treatment on both lung function measures of Hyperinflation, and the nasal epithelial gene-expression profile in severe COPD. 117 patients were screened and 60 COPD patients entered a 1-month run-in period on low-dose ICS/LABA budesonide/formoterol (BUD/F) 200/6 one inhalation b.i.d. Patients were then randomly assigned to 3-month treatment with either a high dose BDP/F 100/6 two inhalations b.i.d. (n = 31) or BUD/F 200/6 two inhalations b.i.d. (n = 29). Lung function measurements and nasal epithelial gene-expression were assessed before and after 3-month treatment and validated in independent datasets. After 3-month ICS/LABA treatment, residual volume (RV)/total lung capacity (TLC)% predicted was reduced compared to baseline (p 

  • static and dynamic Hyperinflation during severe acute exacerbations of chronic obstructive pulmonary disease
    International Journal of Chronic Obstructive Pulmonary Disease, 2018
    Co-Authors: Wouter H Van Geffen, Huib A M Kerstjens
    Abstract:

    Background: Static Hyperinflation is known to be increased during moderate acute exacerbations of chronic obstructive pulmonary disease (COPD) (AECOPD), but few data exist in patients with severe exacerbations of COPD. The role of dynamic Hyperinflation during exacerbations is unclear. Methods: In a prospective, observational cohort study, we recruited patients admitted to hospital for AECOPD. The following measurements were performed upon admission and again after resolution (stable state) at least 42 days later: inspiratory capacity (IC), body plethysmography, dynamic Hyperinflation by metronome-paced IC measurement, health-related quality of life and dyspnea. Results: Forty COPD patients were included of whom 28 attended follow-up. The IC was low at admission (2.05 +/- 0.11 L) and increased again during resolution by 15.6%+/- 23.1% or 0.28 +/- 0.08 L (mean +/- standard error of the mean, p Conclusion: Static Hyperinflation is increased during severe AECOPD requiring hospitalization compared with stable state. We could measure metronome-paced dynamic Hyperinflation during severe AECOPD but found no increase.

  • static and dynamic Hyperinflation during severe acute exacerbations of chronic obstructive pulmonary disease
    European Respiratory Journal, 2017
    Co-Authors: Wouter H Van Geffen, Huib A M Kerstjens
    Abstract:

    Background: Static Hyperinflation is known to be increased during moderate exacerbations of COPD (AECOPD), but few data exist in patients with severe COPD or with severe exacerbations of COPD. As far as we are aware, no data have been presented of attempts at measuring dynamic Hyperinflation during exacerbations. We were interested in these parameters and their relation to dyspnoea during exacerbations. Methods: In a single center registered trial, we recruited patients admitted to hospital for an AECOPD. The following measurements were performed upon admission, and again after resolution (stable state) at least 42 days later: inspiratory capacity (IC), bodyplethysmography, dynamic Hyperinflation by metronome-paced IC measurement, health-related quality of life and dyspnea. Results: Forty COPD patients were included of whom 28 attended follow-up. From exacerbation to stable state, the IC was decreased at admission (2.05±0.11L) and increased again during resolution by 0.28±0.08 L (mean±SEM, p Conclusions: Static Hyperinflation is increased during severe AECOPD. We could not demonstrate an increase in metronome paced dynamic Hyperinflation during severe AECOPD, possibly due to lack of room for further increase in Hyperinflation

  • determining the role of dynamic Hyperinflation in patients with severe chronic obstructive pulmonary disease
    Respiration, 2015
    Co-Authors: Karin Klooster, Jorine E Hartman, Nick Ten H T Hacken, Frank C Sciurba, Huib A M Kerstjens, Dirkjan Slebos
    Abstract:

    Background: Dynamic Hyperinflation due to increased respiratory frequency during exercise is associated with limitations in exercise capacity in patients with moderately severe chronic obstructive pulmonary disease (COPD). Objectives: The present study assessed whether the manually paced tachypnea (MPT) test, sitting at rest, induces dynamic Hyperinflation correlating with exercise capacity in patients with very severe COPD. Methods: Dynamic Hyperinflation was induced by the MPT test, using a breathing frequency of 40/min for 1 min. Dynamic Hyperinflation was defined as a ‘change' in inspiratory capacity (IC) before and directly after the MPT test. At baseline, static Hyperinflation by body plethysmography was measured, as well as the 6-min walking test and spirometry. Results: We studied 74 patients with severe COPD (age 59 ± 9 years, FEV1 28 ± 10% predicted). All patients tolerated the MPT test well. It induced a significant decrease in IC: -0.65 ± 0.33 liters, p Conclusions: In patients with very severe COPD, dynamic Hyperinflation measurement by the MPT test is feasible and contributes less importantly to exercise performance than static Hyperinflation.