Thorax
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Some patients started on nasal intermittent positive pressure ventilation (NIPPV) with the Monnal D ventilator deteriorate after a period. The effects of changing them to the Nippy ventilator were investigated. ⋯ Support with NIPPV using the Monnal D ventilator may fail after an interval and changing to the Nippy ventilator can reverse this deterioration, probably because of its superior responsiveness to leaks and patient effort. The regular follow up of patients on long term NIPPV is necessary if secondary treatment failure is to be identified and effectively treated.
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Clinical Trial Controlled Clinical Trial
Effect of allergen challenge on airway responsiveness to histamine and sodium metabisulphite in mild asthma.
Airway responsiveness to histamine and methacholine, direct smooth muscle spasmogens, is increased following inhalation of allergen. Although the aetiology of this phenomenon is unclear, increased cellular or neural activity may be involved since allergen also induces increases in airway responsiveness to the mast cell stimulus adenosine-5'-monophosphate (AMP) and the neural stimulus bradykinin. ⋯ These data suggest that activation of airway sensory nerves is unlikely to contribute to the increase in airway responsiveness following inhalation of allergen. The previously observed allergen induced increase in airway responsiveness to bradykinin and AMP may involve non-neural pathways.
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Accurate assessment of diaphragm strength can be difficult. Transdiaphragmatic pressure (PDI) measurements during volitional manoeuvres are useful but it may be difficult to ensure maximum patient effort. Magnetic stimulation of the phrenic nerves is easy to perform and the results are reproducible in normal subjects. The purpose of the present study was to evaluate the usefulness of magnetic stimulation of the phrenic nerves in the assessment of diaphragm weakness in patients. ⋯ TwPDI following magnetic stimulation of the phrenic nerves is a clinically useful measurement when assessing diaphragm weakness.
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Randomized Controlled Trial Clinical Trial
Effect of adenosine infusion on oxygen induced carbon dioxide retention in severe chronic obstructive pulmonary disease.
In normal subjects intravenous adenosine infusion has been shown to stimulate ventilation with a consequent fall in arterial partial pressure of carbon dioxide (Paco2), probably by an action on the carotid bodies. The objective of this study was to determine whether the increase in Paco2 seen when patients with ventilatory failure secondary to chronic obstructive pulmonary disease (COPD) are given a high concentration of oxygen to breathe might be ameliorated by an intravenous infusion of adenosine. ⋯ The increase in PtcCO2 seen when patients with stable ventilatory failure secondary to severe COPD are given a high concentration of oxygen to breathe is counteracted by a continuous intravenous infusion of adenosine.
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The polymerase chain reaction has improved the detection of picornaviruses and rhinoviruses and our understanding of their role in reversible airways disease. The effects of colds on lower respiratory morbidity and bacterial colonisation in cystic fibrosis remain uncertain. ⋯ Picornavirus and non-picornavirus colds are associated with pulmonary function abnormalities and disease progression in patients with cystic fibrosis, and predispose to secondary bacterial infection and colonisation.