The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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We wished to study how pleural effusion affects dynamic mechanics of the lung and the chest wall. We also determined if these changes could be reversed by deep lung inflations. Pleural effusion was produced by saline infusion into the pleural space. ⋯ Dynamic elastance and resistance of the chest wall were little affected by these procedures. Thus, pleural effusion can have significant effects on dynamic elastance and resistance of the respiratory system (ERS, RRS). The transient nature of the change in lung parameters after deep inflation suggests that therapies based on periodic lung inflations may be of little benefit to patients with this condition.
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An L-arginine-dependent pathway, metabolising L-arginine to citrulline and nitrogen oxides, has been described in many cell types in different species, including man. Two subtypes of this nitric oxide synthase have been reported: a constitutive enzyme type, releasing nitric oxide after stimulation, is typically found in endothelial and neural cells; another subtype can be induced in macrophages after cytokine treatment. This review summarizes the literature on the known and proposed roles of this L-arginine-dependent nitric oxide production in different pulmonary processes. ⋯ The details of the role and distribution of nitric oxide synthase in the (human) lung and airways are not yet completely understood. Nitric oxide is believed to play a role in various pulmonary physiological processes, such as bronchodilation and the cytotoxic action of certain cells. The modulation of nitric oxide release will therefore, most probably lead to application of novel therapies in diseases such as asthma and inflammatory pulmonary diseases.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Sequential treatment with low dose almitrine bismesylate in hypoxaemic chronic obstructive airways disease.
Daily dose schedules of 100-200 mg of almitrine bismesylate improve arterial blood gases in patients with hypoxaemic chronic obstructive airways disease (COPD) but dose related side effects are evident. In the present study, daily doses approximately half of those previously used were employed in a randomised double blind manner in 85 patients (age 35-79 years) with hypoxaemic COPD. After a one month period to check stability of arterial blood gases, patients were allocated to almitrine (A) or placebo (P) using an unequal code (60% A, 40% P). ⋯ After withdrawal of therapy arterial blood gases and spirometry reverted to pre-treatment levels, suggesting no permanent reversal of pathophysiology. Dose related side effects of breathlessness, indigestion and peripheral neuropathy were not observed. Nerve conduction studies revealed no difference in peripheral nerve dysfunction in hypoxaemic COPD between active and placebo therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of nebulized and sprayed topical anaesthesia for fibreoptic bronchoscopy.
We compared the efficacy of nebulized (N) and sprayed (S) topical anaesthesia prior to fibreoptic bronchoscopy in a blinded study involving 54 patients aged 57 +/- 26 yrs (mean +/- SD). Cough frequency, recorded on cassette tape, was the index of efficacy. All patients received 100 mg lignocaine sprayed into the pharynx, or nebulized in random order prior to bronchoscopy, and all received intravenous diazepam sedation. ⋯ Furthermore, no differences were found in cough frequency between N and S among smokers, patients with asthma and COPD, and patients who had a biopsy procedure, although a trend was seen in all comparisons towards a lower cough frequency with the nebulized route. Most patients in the S group found the spray unpleasant, whereas only one in the N group complained. We conclude that nebulized and sprayed lignocaine have similar efficacy as topical anaesthetics in fibreoptic bronchoscopy, but patient preference favours the nebulized route.
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Randomized Controlled Trial Clinical Trial
Influence of posture on mechanical parameters derived from respiratory impedance.
The influence of posture on respiratory mechanics was investigated in 10 healthy volunteers, using the forced pseudorandom noise technique. Subjects were studied in four randomly selected positions: sitting; sitting with the head turned sideways; supine; and prone with the head turned sideways. ⋯ R4 was significantly higher in the supine position than in either of the sitting or the prone positions. These results demonstrate that changes in lung volume cannot completely explain the influence of posture on respiratory resistance, and indicate upper airway geometry as a determinant factor of respiratory resistance.