Respiratory medicine
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Respiratory medicine · Apr 1995
Randomized Controlled Trial Clinical TrialEffect of body position on gas exchange in patients with unilateral pleural effusion: influence of effusion volume.
The objective of this study was to evaluate the effect of lateral body position on gas exchange in patients with unilateral pleural effusion, with special reference to the influence of effusion volume. Thirty consecutive patients with unilateral pleural effusion, without evidence of parenchymal pulmonary involvement, were entered into the study. Arterial blood gas tensions (PaO2, PaCO2) were randomly measured in both right and left lateral decubitus body positions, while breathing room air. ⋯ Mean PaO2 with the normal-side (control) down (PaO2-N) (81.4 +/- 8.5 mmHg) was higher, but without significant statistical difference, than mean PaO2 with the effusion-side down (PaO2-E) (78.0 +/- 12.5 mmHg). PaO2-N was higher than PaO2-E in 22 of 30 patients (conventional), and lower in eight patients (paradoxical). No consistent relationship was found for alterations in PaO2 in different positions with the volume of effusion, either when estimated by a roentgenographic method or when using spirometric or plethysmographic values.(ABSTRACT TRUNCATED AT 250 WORDS)
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Respiratory medicine · Jan 1995
Randomized Controlled Trial Comparative Study Clinical TrialSedation for fibre optic bronchoscopy.
Most current sedative regimens for fibre optic bronchoscopy use an opioid, a benzodiazepine or a combination of both. This study compares midazolam (M) (a benzodiazepine), alfentanil (A) (an opioid) and a combination of both drugs (M+A). One hundred and three patients were randomized in double-blind manner into groups M(35), A(33) and M+A(35). ⋯ There was a trend for Group M+A to desaturate more than the other two with a significant difference between desaturation in Group M+A and Group A (P = 0.033). Alfentanil is a more effective anti-tussive agent than midazolam for outpatient fibre optic bronchoscopy. The combination of alfentanil and midazolam does not provide any better anti-tussive effect and may have the risk of a greater degree of desaturation secondary to increased sedation.
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Respiratory medicine · Sep 1994
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialThe efficacy and tolerability of inhaled salmeterol and individually dose-titrated, sustained-release theophylline in patients with reversible airways disease.
In a double-blind, double-dummy, cross-over, multicentre study, 141 patients with moderate reversible airways disease were randomized to receive either 50 micrograms salmeterol via a metered dose inhaler or individually dose-titrated oral theophylline, both twice daily for a 2-week period. Just over half (n = 77) the patients had received theophylline before, but 64 patients were new to theophylline therapy. Efficacy was based on lung function data and symptom scores. ⋯ There was also a significant increase in the number of nights (P = 0.013) and days (P < 0.001) on salmeterol when no additional salbutamol was required compared with theophylline. Theophylline produced a higher incidence of adverse events compared with salmeterol. The results of this study show that inhaled salmeterol is more effective and better tolerated than individually dose-titrated oral theophylline over a 2-week study period in patients with moderate asthma.
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Respiratory medicine · May 1994
Randomized Controlled Trial Comparative Study Clinical TrialReduced protection against exercise induced bronchoconstriction after chronic dosing with salmeterol.
The purpose of the present study was to assess the degree of protection of inhaled salmeterol against exercise-induced bronchoconstriction (EIB) after chronic compared with single dosing in patients with asthma. Twelve patients with exercise-induced asthma took part in a randomized double-blind crossover study to compare the duration of action of inhaled salmeterol 50 micrograms twice daily for 4 weeks with that of placebo. ⋯ The percentage fall in FEV1 after exercise challenge at 6 h was (first dose): placebo 34.8 +/- 4.9% vs. salmeterol 11.9 +/- 2.8% (P < 0.05); (4 weeks): placebo 32.9 +/- 5.3% vs. salmeterol 24.0 +/- 4.4% (NS). These results suggest that tachyphylaxis may develop to the functional antagonism of salmeterol against EIB.
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Respiratory medicine · Jul 1993
Randomized Controlled Trial Clinical TrialVoluntary suppression of cough induced by inhalation of capsaicin in healthy volunteers.
The aim of the present study was to investigate the voluntary suppression of cough in response to capsaicin inhalation in healthy volunteers, and to determine if the dose-response curve to capsaicin was significantly altered when volunteers were asked to suppress their cough response. The quantification of the degree of voluntary suppression of induced cough could provide a new methodology for screening antitussive agents as antitussives may act by influencing voluntary control of cough. Cough was induced by inhalation of capsaicin. ⋯ In the non-suppressed challenge 23/24 subjects coughed on inhalation of capsaicin (3.33 x 10(-4) M) with a mean number of coughs of 2.92 +/- 0.34, whereas in the suppressed challenge only 3/24 subjects coughed with a mean number of coughs of 0.29 +/- 0.18 (P < 0.001). These results demonstrate that cough induced by inhalation of capsaicin can be voluntarily suppressed. The mechanism of voluntary suppression of cough is discussed in relation to capsaicin challenge and the screening of antitussive medications.