Respiration; international review of thoracic diseases
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Randomized Controlled Trial Clinical Trial
Lung function changes and exercise-induced ventilatory responses to external resistive loads in normal subjects.
The aim of this study was (1) to assess the value of common lung function variables in the follow-up of patients with obstructive lesions of the larynx and trachea and (2) to study the respiratory response to progressive upper airway stenosis at rest and during exercise. ⋯ It is suggested that the experimental use of inspiratory and expiratory extrinsic loads can mimic rigid obstructive lesions of the larynx and trachea. Among all conventional lung function values, PEF and, to a certain degree, PIF, seem to be the best suitable follow-up parameters to assess airway mechanics before and after surgical/endoscopic procedures. Upper airway stenosis involving surface areas of no more than 50 mm2 can be overcome using adequate respiratory compensation. But any additional narrowing below this limit will result in hypoventilation, inappropriate oxygen uptake and retention of CO2. Thus, experimental evidence indicates that laryngotracheal obstruction within a critical range below 50 mm2 surface area (diameter of circular orifice < 8 mm) compromises respiratory efforts enough to be of clinical importance.
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Case Reports
Long-term course of bronchiectasis and bronchiolitis obliterans as late complication of smoke inhalation.
We describe the long-term course of a patient with bronchiectasis and bronchiolitis obliterans, both of which developed as late complications of a smoke inhalation injury. Sequential chest X-rays obtained during the observation period showed gradual progression of bronchiectasis from the saccular to the cystic type. Symptoms, spirometry and blood gas analysis, however, remained stable for 15 years. We believe that symptoms and physiological derangement were due mainly to bronchiolitis obliterans, and that once the pathophysiological condition had been established following the initial injury, it could be maintained by conservative medical management.
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Airway disease in cystic fibrosis (CF) is characterized by neutrophil-dominated chronic inflammation with an excess of uninhibited neutrophil elastase (NE), which is regarded as an important factor in progressive lung destruction. Therefore, inhalation of alpha 1-proteinase inhibitor (alpha 1-PI) seems to be a reasonable therapeutic approach. To estimate its therapeutic potential, we quantitatively investigated the in vitro interactions of exogenous alpha 1-PI with CF sputum samples (n = 28). ⋯ Corresponding to inhibition of NE activity, CF sputum-induced secretion was also inhibited by exogenous alpha 1-PI; > 90% inhibition was also achieved at 10 micrograms/ml alpha 1-PI. Incubation of exogenous alpha 1-PI with CF sputum for 24 h did not reduce the inhibitory effects. From our in vitro results we conclude that inhalation of alpha 1-PI might effectively inhibit both NE activity and airway gland hypersecretion in CF airways.
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Respiratory failure is the leading cause of death in patients with amyotrophic lateral sclerosis (ALS). We review the physiology of respiratory compromise in ALS and techniques of monitoring respiratory function. Treatment options, including pharmacologic interventions, aspiration precautions, and invasive and noninvasive modes of mechanical ventilation are reviewed. ⋯ Four of 18 patients who elected to receive noninvasive ventilation decided to discontinue treatment. Four of 13 patients who were receiving mechanical ventilation elected to discontinue life support. The decision to utilize these modalities must be made with realistic considerations of the patient's quality of life.
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The influence of acculturation to a sedentary lifestyle upon the growth and development of lung volumes has been studied in Inuit children aged 9-19 years. Surveys were conducted in the circumpolar community of Igloolik (69 degrees 40'N, 81 degrees W) in 1969/70, 1979/80 and 1989/90. Over this period, the children showed little change of height or body mass at any given age, but a progressive loss of what initially had been a high level of health-related fitness. ⋯ Nevertheless, lung volumes show the anticipated increase as a logarithmic function of stature. Furthermore, statistically fitted curves show only minor inter-survey differences in volumes for a given standing height. We thus conclude that the deterioration in other aspects of health-related fitness has not yet influenced the growth and development of respiratory function within this Inuit population.