Effect of Severe Isolated Unilateral and Bilateral Diaphragm Weakness on Exercise Performance

Hart, Nicholas; Nickol, Annabel H.; Cramer, Derek; Ward, Simon; Lofaso, Frédéric; Pride, N. B.; Moxham, John; Polkey, Michael I.

doi:10.1164/rccm.2110016

Cited by 95 publications

(84 citation statements)

References 34 publications

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“…HART et al [7] showed an unexpectedly large reduction in exercise capacity in patients with UDP. LAROCHE et al [32] found UDP patients to be more breathless than expected.…”

Section: Discussionmentioning

confidence: 95%

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Sleep-disordered breathing in unilateral diaphragm paralysis or severe weakness

Steier

Jolley

Seymour³

et al. 2008

European Respiratory Journal

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Few data exist concerning sleep in patients with hemidiaphragm paralysis or weakness. Traditionally, such patients are considered to sustain normal ventilation in sleep.In the present study, diaphragm strength was measured in order to identify patients with unilateral paralysis or severe weakness. Patients underwent polysomnography with additional recordings of the transoesophageal electromyogram (EMG) of the diaphragm and surface EMG of extra-diaphragmatic respiratory muscles. These data were compared with 11 normal, healthy subjects matched for sex, age and body mass index (BMI).In Patients with unilateral diaphragm dysfunction are at risk of developing sleep-disordered breathing during rapid eye movement sleep. The diaphragm electromyogram, reflecting neural respiratory drive, is doubled in patients compared with normal subjects, and increases further in rapid eye movement sleep.

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“…HART et al [7] showed an unexpectedly large reduction in exercise capacity in patients with UDP. LAROCHE et al [32] found UDP patients to be more breathless than expected.…”

Section: Discussionmentioning

confidence: 95%

“…During sleep in normal subjects, ventilation depends particularly on diaphragm function [3]. In patients with diaphragm dysfunction, during both rapid eye movement (REM) sleep and wakefulness, electromyographic activity of the extradiaphragmatic respiratory muscles [4][5][6][7] is higher than normal as a compensation for diaphragm weakness.…”

mentioning

confidence: 99%

Sleep-disordered breathing in unilateral diaphragm paralysis or severe weakness

Steier

Jolley

Seymour³

et al. 2008

European Respiratory Journal

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show abstract

“…The increasing use of accessory respiratory muscles as exercise continues may distort the chest wall (34,36), reduce the mechanical efficiency of breathing (23,42) and, hence, increase the metabolic and blood flow demands of these muscles (see EXERCISE DEMANDS ON THE RESPIRATORY MUSCLES). The progressive recruitment of accessory respiratory muscles would be expected to increase sensory input to the central nervous system and, therefore, increase the intensity of dyspnea.…”

Section: Mechanisms By Which Respiratory Muscle Fatigue Could Affect mentioning

confidence: 99%

Exercise-induced respiratory muscle fatigue: implications for performance

Romer

Polkey²

2008

Journal of Applied Physiology

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253

212

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Romer LM, Polkey MI. Exercise-induced respiratory muscle fatigue: implications for performance. J Appl Physiol 104: 879 -888, 2008. First published December 20, 2007 doi:10.1152/japplphysiol.01157.2007.-It is commonly held that the respiratory system has ample capacity relative to the demand for maximal O 2 and CO2 transport in healthy humans exercising near sea level. However, this situation may not apply during heavy-intensity, sustained exercise where exercise may encroach on the capacity of the respiratory system. Nerve stimulation techniques have provided objective evidence that the diaphragm and abdominal muscles are susceptible to fatigue with heavy, sustained exercise. The fatigue appears to be due to elevated levels of respiratory muscle work combined with an increased competition for blood flow with limb locomotor muscles. When respiratory muscles are prefatigued using voluntary respiratory maneuvers, time to exhaustion during subsequent exercise is decreased. Partially unloading the respiratory muscles during heavy exercise using low-density gas mixtures or mechanical ventilation can prevent exercise-induced diaphragm fatigue and increase exercise time to exhaustion. Collectively, these findings suggest that respiratory muscle fatigue may be involved in limiting exercise tolerance or that other factors, including alterations in the sensation of dyspnea or mechanical load, may be important. The major consequence of respiratory muscle fatigue is an increased sympathetic vasoconstrictor outflow to working skeletal muscle through a respiratory muscle metaboreflex, thereby reducing limb blood flow and increasing the severity of exerciseinduced locomotor muscle fatigue. An increase in limb locomotor muscle fatigue may play a pivotal role in determining exercise tolerance through a direct effect on muscle force output and a feedback effect on effort perception, causing reduced motor output to the working limb muscles. respiratory muscles; exercise; diaphragm; abdominals; magnetic stimulation; metaboreflex THE PURPOSE OF THIS MINIREVIEW is to address the question of whether the respiratory demands of exercise contribute significantly toward exercise limitation, either directly through limitations of the respiratory muscle pump or indirectly through effects on limb blood flow and locomotor muscle fatigue. We describe the mechanical and metabolic costs of meeting the ventilatory requirements of exercise. We then ask whether the respiratory muscles fatigue with exercise, what factors contribute to any such fatigue, and what the implications of these factors are for exercise tolerance. Finally, we deal with the potential mechanisms by which respiratory muscle fatigue could compromise exercise tolerance and whether it is possible to overcome this potential respiratory limitation. Our review focuses on the healthy young adult exercising near sea level. However, we also consider special circumstances that determine the balance between metabolic demand and respiratory system capacity in the highly trained endurance ...

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“…Patients with unilateral diaphragm paralysis are usually asymptomatic but may have dyspnea on exertion (12). It is known that diaphragm paralysis has an impact on pulmonary function tests by decreasing FVC to 70 -80% of the predicted value, which is further decreased by 15 -25% in the supine position.…”

Section: Impact Of Peritoneal Dialysis On Pulmonary Function Test In mentioning

confidence: 99%