The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Pulmonary hyperinflation is a major medical problem in patients with advanced chronic obstructive pulmonary disease (COPD) or acute asthma. The apparent beneficial effects of pulmonary hyperinflation on lung mechanics, such as an increased airway patency and lung elastic recoil, are by far overwhelmed by the deleterious effects on the pressure generating capacity of the respiratory muscles. Moreover, the ventilatory workload can be remarkably increased: 1) by the displacement of the respiratory system toward the upper, flat portion of the pressure-volume curve; 2) by the need to expand the chest wall and not only the lungs; and 3) by the intrinsic positive end-expiratory pressure (PEEPi) systematically associated with dynamic hyperinflation. ⋯ In mechanically ventilated patients, pulmonary hyperinflation increases the risk of barotrauma and may hamper weaning due to the excessive burden of PEEPi, which can even lead to ineffective inspiratory efforts. Because of its harmful consequences, pulmonary hyperinflation must be treated aggressively by pharmacological therapy and, when needed, by ventilatory treatment. The setting of the ventilator must be predetermined to ensure the longest possible time for expiration, and positive end-expiratory pressure can be applied to prevent an excessive workload for the patient and ineffective inspiratory efforts.
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In patients with severe chronic obstructive pulmonary disease (COPD) using long-term oxygen therapy (LTOT), few studies have investigated activities of daily living (ADL). We examined the relationships between ADL, quality of life, mood state and airways obstruction in patients using long-term oxygen therapy (LTOT) and in patients not requiring LTOT. We studied 23 patients (14 males, 9 females; median age 71, range 60-84 yrs) with COPD who received LTOT using oxygen concentrators (LTOT group). ⋯ Significant correlations (p<0.001) with Nottingham EADL score were found for Hospital Anxiety and Depression (HAD) score (rho=0.59), SGRQ Total score (rho=0.65) and percentage predicted forced expiratory volume in one second (FEV1) (rho=0.66). In conclusion, in patients with severe chronic obstructive pulmonary disease and broadly similar health status, those using long-term oxygen therapy were less independent in activities of daily living than those not requiring long-term oxygen therapy. Reduced independence in activities of daily living is, however, associated with the extent of airflow limitation, depression and poor health status, and does not, therefore, appear to be simply a result of restriction in movements imposed by the stationary device.