scholarly journals Effect of Inspiratory Load on Thoracic Volume

2017 ◽  
Vol 32 (5) ◽  
pp. 669-674
Author(s):  
Akira SHŌBO ◽  
Fujiyasu KAKIZAKI
Keyword(s):  
Author(s):  
I. Van Diest ◽  
P. Davenport ◽  
O. Van den Bergh ◽  
E. Robertson ◽  
S. Miller

1990 ◽  
Vol 78 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Rachel C. Wilson ◽  
P. W. Jones

1. The intensity of breathlessness was measured during exercise in nine normal subjects using a modified Borg scale to examine the effect of prior experience of breathlessness on subsequent estimates of breathlessness. 2. Each subject performed four exercise tests, each of which consisted of two identical runs of workload incrementation (run 1 and run 2). An inspiratory resistive load of 3.8 cmH2O s−1 l−1 was applied during the appropriate run of the exercise test to examine the effect of (a) prior experience of ‘loaded’ breathing on breathlessness estimation during ‘unloaded’ breathing, and (b) prior experience of ‘unloaded’ breathing on breathlessness estimation during ‘loaded’ breathing. Run 1 was the conditioning run; run 2 was the run in which the effect of conditioning was measured. 3. There was a good correlation between breathlessness and minute ventilation during both unloaded’ breathing (median r = 0.93) and ‘loaded’ breathing (median r = 0.95). 4. The slope of the Borg score/minute ventilation relationship was greater during ‘loaded’ breathing than during ‘unloaded’ breathing (P < 0.01). There was no difference in mean Borg score between ‘unloaded’ and ‘loaded’ breathing. 5. After a period of ‘loaded’ breathing during run 1, estimated breathlessness was significantly reduced during ensuing ‘unloaded’ breathing in run 2 (P < 0.01) compared with the exercise test in which ‘unloaded’ breathing was experienced throughout both run 1 and run 2. 6. After a period of ‘unloaded’ breathing in run 1, estimated breathlessness was significantly increased during ensuing ‘loaded’ breathing in run 2 (P < 0.01) compared with the exercise test in which the inspiratory load had already been experienced in run 1. 7. Changes in the pattern of breathing (inspiratory time, expiratory time, total breath duration, inspiration time/total breath duration ratio and tidal volume) were not consistent with the changes in breathlessness. 8. We suggest that perception of breathlessness may be influenced by a subject's immediate prior experience of an altered relationship between breathlessness and ventilation.


2015 ◽  
pp. 673-682 ◽  
Author(s):  
C. U. JONES ◽  
B. SANGTHONG ◽  
O. PACHIRAT ◽  
D. A. JONES

Slow breathing training reduces resting blood pressure, probably by modifying central autonomic control, but evidence for this is lacking. The pressor response to static handgrip exercise is a measure of autonomic control and the aim of this study was to determine whether slow breathing training modulates the pressor responses to exercise of untrained muscles. Twenty hypertensive patients trained for 8 weeks, 10 with unloaded slow breathing (Unloaded) and 10 breathing against an inspiratory load of 20 cm H2O (Loaded). Ten subjects were untrained controls. Subjects performed a 2 min handgrip pressor test (30 % MVC) pre- and post-training, and blood pressure and heart rate (HR) were measured before the contraction, at the end and following 2 min recovery. Resting systolic (sBP) and HR were reduced as a result of training, as reported previously. After training there was both a smaller pressor response to hand grip exercise and a more rapid recovery of sBP and HR compared to pre-training. There were no changes in the Controls and no differences between the Unloaded and Loaded groups. Combining the two training groups, the sBP response to handgrip exercise after training was reduced by 10 mm Hg (95 % CI: −7, −13) and HR by 5 bpm (95 % CI: −4, −6), all p<0.05. These results are consistent with slow breathing training modifying central mechanisms regulating cardiovascular function.


SLEEP ◽  
2021 ◽  
Author(s):  
Willy-Paul Westphal ◽  
Christophe Rault ◽  
René Robert ◽  
Stéphanie Ragot ◽  
Jean-Philippe Neau ◽  
...  

Abstract Study Objectives Sleep deprivation alters inspiratory endurance by reducing inspiratory motor output. Vagal tone is involved in exercise endurance. This study aimed to investigate the effect of sleep deprivation on vagal tone adaptation in healthy subjects performing an inspiratory effort. Methods Vagal tone was assessed using Heart Rate Variability normalized units of frequency domain component HF (high frequency) before, at the start, and the end of an inspiratory loading trial performed until exhaustion by 16 volunteers after one night of sleep deprivation and one night of normal sleep, where sleep deprivation reduced the inspiratory endurance by half compared to the normal sleep condition (30min vs 60 min). Results At rest, heart rate was similar in sleep deprivation and normal sleep conditions. In normal sleep condition, heart rate increased during inspiratory loading task; this increase was greater in sleep deprivation condition. In normal sleep condition, vagal tone increased at the beginning of the trial. This vagal tone increase was absent in sleep deprivation condition. Conclusions Sleep deprivation abolished vagal tone response to inspiratory load, possibly contributing to a higher heart rate during the trial and to a reduced inspiratory endurance.


2020 ◽  
Vol 65 (9) ◽  
pp. 1285-1294
Author(s):  
Jéssica Danielle Medeiros da Fonsêca ◽  
Vanessa Regiane Resqueti ◽  
Kadja Benício ◽  
Valéria Soraya de Farias Sales ◽  
Luciana Fontes Silva da Cunha Lima ◽  
...  

2015 ◽  
Vol 114 (5) ◽  
pp. 2883-2892 ◽  
Author(s):  
Michael J. Woods ◽  
Christian L. Nicholas ◽  
John G. Semmler ◽  
Julia K. M. Chan ◽  
Amy S. Jordan ◽  
...  

Common drive is thought to constitute a central mechanism by which the efficiency of a motor neuron pool is increased. This study tested the hypothesis that common drive to the upper airway muscle genioglossus (GG) would increase with increased respiratory drive in response to an inspiratory load. Respiration, GG electromyographic (EMG) activity, single-motor unit activity, and coherence in the 0–5 Hz range between pairs of GG motor units were assessed for the 30 s before an inspiratory load, the first and second 30 s of the load, and the 30 s after the load. Twelve of twenty young, healthy male subjects provided usable data, yielding 77 pairs of motor units: 2 Inspiratory Phasic, 39 Inspiratory Tonic, 15 Expiratory Tonic, and 21 Tonic. Respiratory and GG inspiratory activity significantly increased during the loads and returned to preload levels during the postload periods (all showed significant quadratic functions over load trials, P < 0.05). As hypothesized, common drive increased during the load in inspiratory modulated motor units to a greater extent than in expiratory/tonic motor units (significant load × discharge pattern interaction, P < 0.05). Furthermore, this effect persisted during the postload period. In conclusion, common drive to inspiratory modulated motor units was elevated in response to increased respiratory drive. The postload elevation in common drive was suggestive of a poststimulus activation effect.


Author(s):  
Eliete Colaço ◽  
Lucien Peroni Gualdi ◽  
Alana E.F. Da Gama ◽  
Carine Wiesiolek ◽  
Daniella C. Brandão ◽  
...  

2019 ◽  
Vol 32 ◽  
Author(s):  
Maura Rigoldi Simões da Rocha ◽  
Daniela Faleiros Bertelli Merino ◽  
Stefane Cristina de Souza ◽  
Maria Imaculada de Lima Montebelo ◽  
Irineu Rasera Júnior ◽  
...  

Abstract Introduction: The gastroplasty post-operative period can alter respiratory mechanics and predispose patients to respiratory complications. Objective: The objective was to evaluate the effects of exercises with inspiratory load on respiratory muscle function and on the prevalence of atelectasis after gastroplasty. Method: 40 participants were randomly allocated into two groups: Control Group (CG), its members underwent conventional respiratory physical therapy (CRP) and the Inspiratory Load Group (ILG), its members performed exercises with linear inspiratory pressure load, with 40% of the maximum inspiratory pressure (MIP), associated with CRP. Therapy procedures were conducted twice during the immediate post-operative period and thrice on the first post-operative day. In addition to evaluating the MIP, the nasal inspiratory pressure (NIP) and the sustained maximum inspiratory pressure (SMIP) were evaluated before and after treatment. Analysis of variance followed by the Bonferroni correction were applied considering a 5% significance level (p < 0.05). Results: There was no significant difference in NIP and SMIP values when the pre- and post-operative periods were compared for the ILG; however, these values were significantly lower for the CG, also with intergroup differences in NIP values. Atelectasis prevalence was 5% for ILG and 15% for CG, with no intergroup difference. Conclusion: The inspiratory muscle strength and resistance of the respiratory muscles were maintained in the group that performed exercises with inspiratory load associated with CRP, with a low rate of atelectasis after gastroplasty.


Author(s):  
Maura Rigoldi Simões da ROCHA ◽  
Stefane SOUZA ◽  
Carolina Moraes da COSTA ◽  
Daniela Faleiros Bertelli MERINO ◽  
Maria Imaculada de Lima MONTEBELO ◽  
...  

ABSTRACT Background: Bariatric surgery can trigger postoperative pulmonary complications due to factors inherent to the procedure, mainly due to diaphragmatic dysfunction. Aim: To evaluate and compare the effects of two levels of positive pressure and exercises with inspiratory load on lung function, inspiratory muscle strength and respiratory muscle resistance, and the prevalence of atelectasis after gastroplasty. Methods: Clinical, randomized and blind trial, with subjects submitted to bariatric surgery, allocated to two groups: positive pressure group, who received positive pressure at two levels during one hour and conventional respiratory physiotherapy and inspiratory load group, who performed exercises with load linear inspiratory pressure, six sets of 15 repetitions, in addition to conventional respiratory physiotherapy, both of which were applied twice in the immediate postoperative period and three times a day on the first postoperative day. Spirometry was performed for pulmonary function analysis, nasal inspiratory pressure for inspiratory muscle strength and incremental test of respiratory muscle resistance for sustained maximal inspiratory pressure, both preoperatively and on hospital discharge on the second postoperative day. Results: There was no significant difference (p> 0.05) in the expiratory reserve volume and in the tidal volume in the pre and postoperative periods when compared intra and intergroup. There was no significant difference (p>0.05) in the nasal inspiratory pressure and the maximal inspiratory pressure maintained in the inspiratory load group in the intragroup evaluation, but with a significant difference (p<0.05) compared to the positive pressure group. The prevalence of atelectasis was 5% in both groups with no significant difference (p>0.05) between them. Conclusion: Both groups, associated with conventional respiratory physiotherapy, preserved expiratory reserve volume and tidal volume and had a low atelectasis rate. The inspiratory loading group still maintained inspiratory muscle strength and resistance of respiratory muscles.


1998 ◽  
Vol 84 (5) ◽  
pp. 1487-1491 ◽  
Author(s):  
Hidenori Edo ◽  
Hiroshi Kimura ◽  
Mafumi Niijima ◽  
Hideo Sakabe ◽  
Masato Shibuya ◽  
...  

Vibratory stimulation applied to the chest wall during inspiration reduces the intensity of breathlessness, whereas the same stimulation during expiration has no effect or may increase breathlessness. The purpose of the present study was to determine whether vibration reduced the intensity of breathlessness during progressive hypercapnia with and without the addition of an external resistive load. A second objective was to see whether the mouth occlusion pressure at 0.2 s (P0.2) was reduced by the vibratory stimulation. Hypercapnic ventilatory response was conducted in 10 healthy male volunteers with simultaneous measurement of visual analog scale, P0.2, and minute ventilation. Hypercapnic ventilatory response was performed and randomly combined with or without vibratory stimulation (100 Hz) as well as with or without inspiratory load. With inspiratory load, in-phase vibration did not cause any significant changes in the slopes of P0.2 and minute ventilation to CO2, whereas the slope of visual analog scale to CO2 significantly decreased from 0.47 ± 0.15 to 0.34 ± 0.11 (SE) cm/Torr ( P < 0.05). We conclude that in-phase vibration could decrease the slope of breathlessness elicited by inspiratory load combined with hypercapnia without changing motor output.


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