|Title:||Work of breathing and respiratory drive in obesity||Authors:||CHING-KAI LIN
|Issue Date:||2012||Journal Volume:||17||Journal Issue:||3||Start page/Pages:||402-411||Source:||Respirology||Abstract:||
Obesity, particularly severe central obesity, affects respiratory physiology both at rest and during exercise. Reductions in expiratory reserve volume, functional residual capacity, respiratory system compliance and impaired respiratory system mechanics produce a restrictive ventilatory defect. Low functional residual capacity and reductions in expiratory reserve volume increase the risk of expiratory flow limitation and airway closure during quiet breathing. Consequently, obesity may cause expiratory flow limitation and the development of intrinsic positive end expiratory pressure, especially in the supine position. This increases the work of breathing by imposing a threshold load on the respiratory muscles leading to dyspnoea. Marked reductions in expiratory reserve volume may lead to ventilation distribution abnormalities, with closure of airways in the dependent zones of the lungs, inducing ventilation perfusion mismatch and gas exchange abnormalities. Obesity may also impair upper airway mechanical function and neuromuscular strength, and increase oxygen consumption, which in turn, increase the work of breathing and impair ventilatory drive. The combination of ventilatory impairment, excess CO 2 production and reduced ventilatory drive predisposes obese individuals to obesity hypoventilation syndrome. ? 2011 Asian Pacific Society of Respirology.
|ISSN:||1323-7799||DOI:||10.1111/j.1440-1843.2011.02124.x||SDG/Keyword:||4 aminobutyric acid; adenosine; carbon dioxide; dopamine; leptin; article; bicycle ergometer; blood brain barrier; breathing muscle; dyspnea; exercise; expiratory flow; expiratory reserve volume; functional residual capacity; human; hypercapnia; lung compliance; lung gas exchange; lung minute volume; lung ventilation distribution; lung ventilation perfusion ratio; muscle function; muscle strength; obesity; obesity hypoventilation syndrome; oxygen consumption; oxygen dissociation curve; positive end expiratory pressure; priority journal; respiratory function; respiratory tract examination; sleep apnea syndrome; supine position; tidal volume; wakefulness; Airway Resistance; Animals; Dyspnea; Exercise; Female; Humans; Male; Neurotransmitter Agents; Obesity; Oxygen Consumption; Rats; Respiration; Respiration Disorders; Respiratory Muscles; Respiratory System; Sleep Apnea Syndromes; Work of Breathing
|Appears in Collections:||醫學系|
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