Hyperinflation

During COPD, the following symptoms occur, usually in the order mucus hypersecretion, ciliary dysfunction, airflow limitation, pulmonary hyperinflation, gas exchange abnormalities, pulmonary hypertension and cor pulmonale. Acute exacerbations appear to be mainly triggered by bacteria, viruses or environmental pollutants. They lead to a worsening of lung functions, wasting and increased mortality their psychosocial impacts include depression and anxiety that may be associated with the will to die. 

Lung volume reduction surgery is a rarely performed treatment option for heterogeneous emphysema patients with high hyperinflation. Novel semi-invasive and invasive alternatives are being developed, such as bronchial valves for heterogeneous emphysema treatment, and bronchial stents for homogeneous emphysema to reduce counteiproductive collateral ventilation. 

Patients may also present with hyperinflation, use of accessory muscles to breathe, pulsus paradoxus, diaphoresis, and cyanosis. 

Observation of the patient may reveal use of accessory muscles of respiration (manifested as paradoxical movements of the chest and abdomen, in a "see-saw"-type motion), pursed-lips breathing, and hyperinflation of the chest with increased anterior-posterior diameter ("barrel chest"). 

Chest x-ray Hyperlucency and hyperinflation of the lungs suggestive of emphysematous change... 

Initial symptoms of COPD include chronic cough and sputum production patients may have these symptoms for several years before dyspnea develops. The physical examination is normal in most patients who present in the milder stages of COPD. When airflow limitation becomes severe, patients may have cyanosis of mucosal membranes, development of a barrel chest due to hyperinflation of the lungs, an increased resting respiratory rate, shallow breathing, pursing of the lips during expiration, and use of accessory respiratory muscles. 

Ventilation rates are generally sub-physiological to prevent excess barometric pressure on the lung, for example 1.5-2 ml volume at a rate of 30-80 min-1 for the rat. Periodic hyperinflation (sometimes described as a sigh ... 

Hyperinflation of the lung by vigorous exercise or repeatedly performing lung function tests may also lead to increased membrane permeability, possibly resulting from a disturbance of the intercellular junctions. 

Oxygen saturation Sp02 89%. Lungs hyperinflated, no wheeze, few right base crepitations. 

The duration of expiration is insufficient Lungs to allow the lungs to deflate (due to airway hyperinflated... 

Signs include expiratory and inspiratory wheezing on auscultation (breath sounds may be diminished with very severe obstruction), dry hacking cough, tachypnea, tachycardia, pale or cyanotic skin, hyperinflated chest with intercostal and supraclavicular retractions, hypoxic seizures if very severe, normal or slightly elevated temperature. 

O Donnel DE, Lam M, Webb KA. Measurement of symptoms, lung hyperinflation, and endurance during exercise in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1998 158 1557-1565. 

Intense toxic inhalant exposures may cause pulmonary edema within 30 to 60 minutes. Secretions from both the nasopharynx and the tracheobronchial tree are copious, with quantities of up to 1 L/ h reported.12 Severe dyspnea is so prominent that the patient may refuse to move. On physical examination, the chest may be hyperinflated. Mediastinal emphysema secondary to peripheral air trapping may dissect to the skin and present as subcutaneous emphysema. The sudden death that occurs with massive toxic inhalant exposure is thought to be secondary to laryngeal spasm.13... 

A sudden rapid decrease in barometric pressure. This may occur from loss of integrity of a pressurized aircraft cabin or recompression chamber, or in a diver who surfaces rapidly from depth due to a loss of buoyancy control. It may result in decompression sickness or pulmonary hyperinflation and air embolism. 

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