American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · May 1996
Comparative StudyLung mechanics and dyspnea after lung transplantation for chronic airflow obstruction.
Single lung transplantation (SLT) is widely used to treat chronic airflow obstruction (CAO). During exercise the native lung should increase end-expiratory lung volume (EELV) and result in a different respiratory sensation compared with double lung transplantation (DLT). Eight SLT recipients and 12 DLT recipients demonstrated a similar maximal work load and achieved VO2. ⋯ Tidal flow volume loop analysis demonstrated encroachment of the expiratory limb in four of seven SLT patients but in only one of 12 DLT recipients. A lesser peak breathlessness in DLT recipients approached statistical significance (p = 0.051), although the relation of respiratory sensation versus VE or VO2% predicted did not differ between the two groups. EELV increases in SLT recipients at peak exercise, although overall aerobic response is preserved and respiratory sensation is similar.
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Am. J. Respir. Crit. Care Med. · May 1996
Relationship of isoniazid resistance to human immunodeficiency virus infection in patients with tuberculosis.
To investigate the relationship between isoniazid resistance and HIV infection in patients with tuberculosis, we evaluated data in the Los Angeles County tuberculosis registry on 1,506 patients for whom drug susceptibility results were available. Among 235 HIV-infected patients, isoniazid resistance was less common than in 1,271 patients who were HIV-seronegative or who had not been tested for HIV, with an unadjusted odds ratio of 0.3. After adjustment for other factors that affect drug resistance (ethnicity, country of birth, prior diagnosis of tuberculosis, and cavitation), the frequency if isoniazid resistance remained lower than that in patients without HIV infection, with an odds ratio of 0.4 (95% confidence interval, 0.2 to 0.8; p = 0.02). We conclude that in Los Angeles, a setting where there is no ongoing outbreak of drug-resistant tuberculosis, isoniazid-resistant tuberculosis is not more common in HIV-infected patients.
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Am. J. Respir. Crit. Care Med. · May 1996
Comparative StudyMuscle weakness in mechanically ventilated patients with severe asthma.
Patients who undergo mechanical ventilation for severe asthma are at risk of developing diffuse muscle weakness because of acute myopathy. The relative importance of corticosteroids and neuromuscular paralysis in causing the myopathy is controversial, and it is uncertain whether the chemical structure of the drug used to induce paralysis influences the risk of myopathy. Using a retrospective cohort study design, we evaluated 107 consecutive episodes of mechanical ventilation for severe asthma to assess (1) the incidence of clinically significant weakness in patients treated with corticosteroids alone versus corticosteroids with neuromuscular paralysis, (2) the influence of the duration of paralysis on the incidence of muscle weakness, and (3) the relative risk of weakness in patients paralyzed with the nonsteroidal drug atracurium versus an aminosteroid paralytic agent (pancuronium, vecuronium). ⋯ Eighteen of the 20 weak patients had been paralyzed for more than 24 h. The incidence of weakness was not reduced when paralysis was achieved with atracurium as opposed to an aminosteroid neuromuscular blocking agent. In conclusion, corticosteroid-treated patients with severe asthma who undergo prolonged neuromuscular paralysis are at significant risk for the development of muscle weakness, and the risk of weakness is not reduced by use of atracurium.
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Am. J. Respir. Crit. Care Med. · May 1996
Randomized Controlled Trial Clinical TrialEosinophil and neutrophil activity in asthma in a one-year trial with inhaled budesonide. The impact of smoking.
The object of this investigation was to study the long-term effects of antiasthma treatment on blood markers of inflammation and lung function in adult asthmatic subjects. For this purpose 85 allergic and nonallergic asthmatic subjects were randomized into three groups, which were given high-dose (1,600 micrograms/d) inhaled budesonide, low-dose (400 micrograms/d) inhaled budesonide, and oral theophylline (600 mg/d), respectively, and were followed for 11 mo with testing of lung function and blood sampling for the assay in serum of eosinophil cationic protein (ECP), eosinophil protein x/eosinophil derived neurotoxin (EPX/EDN) as eosinophil markers, and myeloperoxidase (MPO) and lactoferrin (LF) as neutrophil markers. Lung functions (FEV1% predicted, and histamine PC20) and the eosinophil markers ECP and EPX/EDN were improved and reduced, respectively, by budesonide in a dose-dependent and temporally parallel fashion. ⋯ The treatment efficacy of budesonide was attributed solely to an effect on nonsmoking asthmatic subjects, since neither lung functions nor eosinophil markers changed in smokers even with high-dose budesonide. MPO but not LF was reduced after several months of treatment in all three groups, but only in nonsmokers. We conclude that ECP and EPX/EDN may be used to monitor antiinflammatory treatment in asthmatic patients, and that smoking asthmatic subjects are resistant to inhaled corticosteroids.