Thorax
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Eleven patients with unilateral diaphragm paralysis of recent onset were studied to investigate the effect of the paralysis on inspiratory muscle function. Nine of the patients had noticed a decrease in exercise tolerance, which was not explained by any other pathological condition. Hemidiaphragm dysfunction was confirmed by the demonstration of a greatly reduced or absent transdiaphragmatic pressure on stimulation of the phrenic nerve in the neck, by means of surface bipolar electrodes (unilateral twitch Pdi), compared with normal values on the contralateral side. ⋯ It is concluded that recent hemidiaphragm paralysis causes a reduction in transdiaphragmatic pressure that is associated with a reduction in maximum inspiratory mouth pressure. Phrenic nerve stimulation is a useful technique with which to confirm and quantify hemidiaphragm dysfunction. Measurement of phrenic nerve conduction time provides useful information about the underlying pathology.
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Comparative Study Clinical Trial Controlled Clinical Trial
Subcutaneous adrenaline versus terbutaline in the treatment of acute severe asthma.
Subcutaneous adrenaline and terbutaline have been compared in a double blind study of 20 patients with acute severe asthma presenting to an accident and emergency department. Ten patients received adrenaline 0.5 mg (0.5 ml) and 10 terbutaline 0.5 mg (0.5 ml) subcutaneously. Further treatment with nebulised salbutamol (5 mg), hydrocortisone (200 mg), and aminophylline (0.9 mg/kg/hour) was started 15 minutes later. ⋯ There was no significant difference in PEF, FEV1, heart rate, blood pressure, or pulsus paradoxus between the two groups at any time. Continuous electrocardiographic recording showed no abnormalities in either group. Thus in this study subcutaneous adrenaline (0.5 mg) and terbutaline (0.5 mg) produced effective rapid bronchodilatation without serious side effects.
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of breathing supplemental oxygen before progressive exercise in patients with chronic obstructive lung disease.
A study was carried out to determine whether supplemental oxygen before exercise would improve maximum exercise performance and relieve exertional dyspnoea in 20 patients with chronic obstructive lung disease (mean FEV1 0.79 l; forced vital capacity 2.30 l). Patients performed two progressive treadmill exercise tests to a symptom limited maximum, with at least 30 minutes rest between tests. They received compressed air or supplemental oxygen from nasal prongs for 10 minutes before exercise in a double blind randomised trial with a crossover design. ⋯ The study had a power of 93% for detecting an increase of 50 metres in maximum distance walked. There was an order effect, with better performance on the second test; but the magnitude of the difference was small. It is concluded that administration of supplemental oxygen sufficient to raise SaO2 above 90% for 10 minutes before exercise is unlikely to improve maximum exercise performance or breathlessness on exertion in patients with chronic obstructive lung disease.
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Randomized Controlled Trial Clinical Trial
Comparative bronchial responses to hyperosmolar saline and methacholine in asthma.
Airway responsiveness to inhaled methacholine and to ultrasonically nebulised hyperosmolar saline was compared in 20 asthmatic subjects. Each subject had two hyperosmolar inhalation tests and a methacholine challenge in random order at least 48 hours apart over a period of two weeks. Hyperosmolar challenge, carried out with doubling concentrations of saline from 0.9% to 14.4% to obtain a dose-response curve, was well tolerated by all subjects. ⋯ The peak bronchoconstrictor effect of hyperosmolar saline inhalation occurred at 3 minutes and its mean total duration (FEV1 less than 90% of baseline) was 50 minutes. There was no significant correlation between the PO20 and the PC20 methacholine (the concentration inducing a 20% fall in FEV1). Thus by using a new method to obtain a quantitative airway response to inhaled hyperosmolar saline we found that the airway response to hyperosmolar inhalation differs from the airway response to methacholine.