The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Effects of inhaled furosemide on platelet-activating factor challenge in mild asthma.
Furosemide (Fur) may have an anti-inflammatory effect on airways in patients with asthma although its intrinsic mechanism remains elusive. Platelet-activating factor (PAF) is a potent proinflammatory mediator that induces systemic and respiratory effects in normal control subjects and asthmatics. The aim of this study was to assess whether pretreatment with nebulized Fur (40 mg) was able to modulate PAF-induced systemic and respiratory effects in asthma. ⋯ Although Fur did not alter PAF-induced systemic and respiratory effects, it did partially inhibit (63%; p<0.04) the increments of uLTE4 levels shown after PAF inhalation. It is concluded that furosemide is not effective in protecting against platelet-activating factor challenge in patients with asthma despite its potential inhibition of leukotriene synthesis. These findings reinforce the view that the pulmonary effects of platelet-activating factor are mediated through different pathways.
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Randomized Controlled Trial Comparative Study Clinical Trial
The effect of topical benzamil and amiloride on nasal potential difference in cystic fibrosis.
The electrochemical defect in the bronchial epithelium in cystic fibrosis (CF) consists of defective chloride secretion and excessive sodium reabsorption. The sodium channel blocker, amiloride, has been shown to reversibly correct the sodium reabsorption in CF subjects, but long term studies of amiloride have been disappointing due to its short duration of action. Benzamil, a benzyl substituted amiloride analogue, has a longer duration of action than amiloride in cultured human nasal epithelium. ⋯ The AUC value for benzamil was significantly greater than amiloride (95% confidence interval (CI) for the difference 5.3-12.7 mV, p<0.0001). t0.5 values were 4.3+/-0.7 h for benzamil and 0.6+/-0.1 h for amiloride (95% CI for the difference 2.0-5.3 h, p<0.001). It is concluded that benzamil has a similar maximal effect to amiloride but a more prolonged duration of action on nasal potential difference in cystic fibrosis. Benzamil may be a useful sodium channel blocker for the long-term treatment of the biochemical defect in the lungs of patients with cystic fibrosis.
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Randomized Controlled Trial Comparative Study Clinical Trial
The effect of inhaled mannitol on bronchial mucus clearance in cystic fibrosis patients: a pilot study.
It has been postulated that hypertonic saline (HS) might impair the antimicrobial effects of defensins within the airways. Alternative non-ionic osmotic agents such as mannitol may thus be preferable to HS in promoting bronchial mucus clearance (BMC) in patients with cystic fibrosis (CF). This study reports the effect of inhalation of another osmotic agent, dry powder Mannitol (300 mg), compared with its control (empty capsules plus matched voluntary cough) and a 6% solution of HS on BMC in 12 patients with cystic fibrosis (CF). ⋯ Values of FEV1 returned to baseline by the end of the study. Inhaled mannitol is a potential mucoactive agent in cystic fibrosis patients. Further studies are required to establish the optimal dose and the long-term effectiveness of mannitol.
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Randomized Controlled Trial Comparative Study Clinical Trial
Physiological effects of posture on mask ventilation in awake stable chronic hypercapnic COPD patients.
Stable chronic hypercapnic patients are often prescribed long-term mask noninvasive pressure support ventilation (NPSV). There is a lack of information on the effects of posture on NPSV. Therefore posture induced changes in physiological effects of NPSV in awake stable chronic hypercapnic patients were evaluated. ⋯ Inspiratory muscle effort as assessed by oesophageal pressure swings and pressure-time product per minute (from 14+/-4.8 to 6.2+/-3.5 cmH2O, and from 240+/-81 to 96+/-60 cmH2O x s x min(-1) respectively), intrinsic dynamic positive end expiratory pressure (from 2.7+/-2.3 to 1.4+/-1.3 cmH2O) and expiratory airway resistance (from 18+/-7 to 5+/-3 cmH2O x L x s(-1)) decreased during sitting NPSV, whereas VAS did not change. Changing posture did not significantly affect any parameter independently of the patients weight, whether obese or not. In awake stable hypercapnic chronic obstructive pulmonary disease patients changing posture does not significantly influence breathing pattern and respiratory muscles during noninvasive pressure support ventilation suggesting that mask ventilation may be performed in different positions without any relevant difference in its effectiveness.