The American review of respiratory disease
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Am. Rev. Respir. Dis. · Aug 1991
Randomized Controlled Trial Comparative Study Clinical TrialAzathioprine combined with prednisone in the treatment of idiopathic pulmonary fibrosis: a prospective double-blind, randomized, placebo-controlled clinical trial.
Twenty-seven newly diagnosed patients with idiopathic pulmonary fibrosis (IPF) who were previously untreated for IPF were enrolled in a prospective, double-blind, randomized, placebo-controlled study to compare the therapeutic effect of combined prednisone/azathioprine (n = 14) with prednisone plus placebo (n = 13). Prednisone was started at 1.5 mg/kg/day (not to exceed 100 mg/day) for the first 2 wk followed by a biweekly taper to a maintenance dose of 20 mg/day. Azathioprine was administered at a daily dose of 3 mg/kg (not to exceed 200 mg/day). ⋯ A Cox model survival analysis shows a nonsignificant but potentially large survival advantage for azathioprine/prednisone (hazard ratio 0.48, with 95% confidence interval increasing from 0.17 to 1.38). When adjusted for age, the survival advantage of azathioprine/prednisone becomes marginally significant (hazard ratio 0.26, with 95% confidence interval increasing from 0.08 to 0.88; p = 0.02 by large sample approximation, p = 0.05 by randomization test). We conclude that combined prednisone and azathioprine is a safe and possibly effective regimen for the treatment of IPF.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. Rev. Respir. Dis. · Aug 1991
Randomized Controlled Trial Clinical TrialOral mucosal stimulation modulates intensity of breathlessness induced in normal subjects.
Patients with chronic obstructive pulmonary disease (COPD) often report an increase in breathlessness when they breathe through a mouthpiece. We hypothesized that stimulation of receptors in the oral mucosa modulates the sensation of breathlessness. We studied 10 normal naive volunteers in whom breathlessness was induced by having them breathe for 4 min with an inspiratory resistive load (18 cm H2O/L/s) while breathing was stimulated by CO2 inhalation (end-tidal PCO2 maintained at 55 mm Hg). ⋯ Six subjects repeated the protocol on 2 additional days: 1 day with inhalation of warm (34 degrees C), humidified air and 1 day after topical application of 4% lidocaine to the oral mucosa. Both these interventions abolished the differences in breathlessness between mask and mouthpiece and mask alone. We conclude that afferent information from oral mucosal stimulation influences the intensity of breathlessness.
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Am. Rev. Respir. Dis. · Jun 1991
Randomized Controlled Trial Clinical TrialDistribution of ventilation and perfusion with different modes of mechanical ventilation.
We compared pulmonary gas exchange during synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV), and airway pressure release ventilation (APRV). Nine subjects aged 56 to 75 yr were studied from 4 to 19 h after cardiac operations. When subjects were ready to be weaned from mechanical ventilation their ventilation-perfusion distribution was estimated using the multiple inert gas elimination technique during SIMV. ⋯ Minute ventilation was lower during APRV (7.5 +/- 0.07 L/min) than during SIMV (9.4 +/- 0.6 L/min) and PSV (9.0 +/- 0.5 L/min) (p less than 0.05). Hemodynamic variables were similar during all three modes. We conclude that all three modes provide acceptable oxygenation and ventilatory support.
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Am. Rev. Respir. Dis. · Mar 1991
Randomized Controlled Trial Clinical TrialPressure-time product during continuous positive airway pressure, pressure support ventilation, and T-piece during weaning from mechanical ventilation.
The objective of this study was to compare the effects of continuous positive airway pressure (CPAP), pressure support ventilation (PS), and T-piece on the pressure-time product (PTP) during weaning from mechanical ventilation. The PTP is an estimate of the metabolic work or oxygen consumption of the respiratory muscles. We studied 10 intubated patients recovering from acute respiratory failure of various etiologies. ⋯ The contribution of the decrease in PEEPi to the reduction in PTP(es) amounted to 36%. With PS-5, respiratory system mechanics and PEEPi were not significantly different compared with T-piece. With CPAP-0, PTP tended to be lower than with T-piece.(ABSTRACT TRUNCATED AT 250 WORDS)
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Am. Rev. Respir. Dis. · Mar 1990
Randomized Controlled Trial Comparative Study Clinical TrialExercise tolerance during nasal cannula and transtracheal oxygen delivery.
Previous studies have reported that exercise tolerance improves with transtracheal oxygen delivery. However, patients were not blinded to the delivery technique used, introducing a potential source of bias. The purpose of this study was to compare exercise tolerance during nasal cannula and transtracheal delivery using a randomized double-blinded technique. ⋯ We conclude that exercise tolerance improves when oxygen is delivered by transtracheal catheter. This improvement is unrelated to an increase in SaO2. We speculate that the increase in exercise tolerance may be related to other physiologic effects of flow through the catheter.