Compliance with medical practice guidelines: the case of home oxygen.

Standard and straight forward practice guidelines for administration of home oxygen therapy have been long established and widely accepted. Medical records for 418 patients prescribed home oxygen through hospital-based programs at seven Veterans Administration medical centers (VAMCs) were reviewed to determine compliance with practice guidelines at the time of initial and current prescriptions. Rates of appropriate prescription at some VAMCs were very high but were too low at other VAMCs, especially given the criteria's simplicity and clarity. Practice guidelines should be implemented in conjunction with regular review mechanisms or other controls in place to ensure compliance.

Effect of quinolone antimicrobials on theophylline pharmacokinetics.

The purpose of the research was to ascertain the comparative differences of quinolone antibiotics on theophylline pharmacokinetics. Eight healthy male volunteers were randomly assigned to four treatments. Each was administered norfloxacin (NOR) 800 mg/d, ciprofloxacin (C) 1 g/d, nalidixic acid (NAL) 2 g/d and placebo (P) for 7 days. On the seventh day of each treatment, theophylline (5 mg/kg) iv was administered. The elimination half-life (T 1/2), total body clearance (CL) and volume of distribution at steady state (Vss) of theophylline were calculated using model-independent methods. ANOVA for repeated measures was used for data comparisons. The mean (SD) theophylline results were: CL l/kg/h--NOR .038 (.006), C .033 (.006), NAL .045 (.008), P .044 (.007); T 1/2 h--NOR 9.2 (1.8), C 10.6 (1.8), NAL 8.3 (1.8), P 7.5 (1.4). Theophylline Vss differences by treatment were not significant. NOR and C significantly decreased theophylline's clearance and the clearance change can be of clinical significance.

The efficacy of inhaled beclomethasone in chronic obstructive airway disease.

The objective of this study was to examine the effectiveness of inhaled beclomethasone in the treatment of stable chronic obstructive airway disease (COAD). Eight patients completed a randomized, double-blind, placebo-controlled, crossover trial of inhaled beclomethasone and oral prednisone. Each patient received 3 treatment regimens given for 14 days: inhaled beclomethasone, prednisone, and placebo. There were no statistically significant differences in pulmonary function tests, oxygen cost diagram, or 12-minute walking distance test among the regimens. The only improvement in arterial blood gasses was partial pressure of oxygen, which was negligibly increased during prednisone treatment compared with beclomethasone and with placebo (p less than 0.05). Evaluation of 95% confidence intervals indicated that clinically significant mean differences were unlikely with either beclomethasone or prednisone. Larger studies are required to determine if a responsive subgroup exists, and to determine if this form of therapy has a role in treatment of COAD.

Therapy for chronic obstructive lung disease.

CAO is a chronic, degenerative disease of the lung that produces a number of serious physiologic abnormalities in respiratory function. It is progressive and, in general, responds poorly to medical therapy. Cigarette smoking is almost universally the cause of the disease, and stopping smoking clearly slows the progress of the disorder. Therapy is of marginal value at best in a substantial number of patients with this problem, and even in those who respond well, improvement in function is not great. A conservative approach to therapy is advised, but only when its value can be documented. As the illness progresses, chronic oxygen therapy in hypoxic patients may be of value in preventing or treating cor pulmonale.

Penetration of cefotaxime into respiratory secretions.

The objective of this study was to quantitate cefotaxime and its active metabolite, desacetyl cefotaxime, in the distal airways and to compare these levels to concentrations in plasma. Respiratory secretions were obtained from the subsegmental level in 17 adult patients undergoing fiber-optic bronchoscopy within 2 h after receiving four doses of cefotaxime (2 g intravenously every 6 h). In 11 patients, cefotaxime levels measured by high-pressure liquid chromatography in bronchial secretions were below detectable limits (less than 0.5 mg/liter); however, levels of desacetyl cefotaxime exceeded 1.5 mg/liter in 9 of these 11 patients (range, 1.6 to 10 mg/liter). Concentrations of desacetyl cefotaxime in lung secretions (6.9 +/- 0.85 [standard error] mg/liter) was 77% of mean levels of desacetyl cefotaxime in plasma (8.9 +/- 1.26 mg/liter). In summary, concentrations of desacetyl cefotaxime in bronchial secretions are markedly higher than those of cefotaxime.

Bronchial secretion concentrations of tobramycin.

The mean concentrations of tobramycin in bronchial secretions from patients with pneumonia were almost two times greater than secretions from patients free of lung infection. Mean tobramycin bronchial secretion to serum concentration ratios also were higher when obtained from infected lungs (0.66 versus 0.17) These data suggest that lung infection enhances the concentrations of tobramycin in bronchial secretions.

[Volumetric correction of the maximal expiratory flow 25-75% in chronic obstructive bronchopneumopathies]. / Correction volumétrique de débit maximum expiratoire 25-75% dans les bronchopneumopathies chroniques obstructives.

After inhalation of a bronchodilator aerosol, indices of airway obstruction usually improve whereas the forced expiratory flow between 25 and 75% (FEF25-75%) of the forced vital capacity (FVC) commonly remains the same or may decrease. This is due to the fact that the FEF25-75% after bronchodilatation is measured at lower absolute lung volumes with subsequently less elastic recoil pressure. A goal of this study was to analyze this test after volume adjusting so that the flows before and after a bronchodilator are compared at equal volumes (isovolume). Thirty-seven men with chronic obstructive pulmonary disease (COPD) performed maximal forced expiratory maneuvers before and 15 minutes after isoproterenol (0.15 mg) inhalation. The mean value of isovolume (0.56 +/- .30 1. sec-1) was significantly greater (p less than 0.001) than the FEF25-75% recorded before (0.45 +/- .26 1. sec-1) and after (0.50 +/- .27 1. sec-1, p less than 0.01) bronchodilator inhalation. The FVC was improved in 18 patients but only 6 (33%) had an improved conventional FEF25-75%. On the other hand, isovolume FEF improved in 12 (66%) patients. Isovolume FEF also improved twice as frequently as conventional FEF25-75% in those demonstrating an improvement in forced expiratory volume in the first second (FEV1). Furthermore, when the conventional FEF25-75% demonstrated no improvement after isoproterenol inhalation, isovolume improved in 8/26 (31%) of these patients. Our results suggest that volume adjusting the FEF25-75% after isoproterenol inhalation increases its sensitivity for detecting acute bronchodilation in patients with COPD, and that this methods appears practical in routine pulmonary function testing.

Isoproterenol challenge during placebo and oral theophylline therapy in chronic obstructive pulmonary disease.

Because it is common to perform a bronchodilator challenge while a patient continues oral methylxanthines, we wanted to determine if this procedure might be misleading for subsequent therapy. Thirty-eight men with a long smoking history and a clinical diagnosis of chronic obstructive pulmonary disease (COPD) were given placebo and oral theophylline (each for one month) in a double-blind, single-crossover manner. Pulmonary functional tests were performed before and after isoproterenol nebulization on the final day of each 4-wk period. There were significantly larger increases in FVC (p less than 0.001) and FEV1 (p less than 0.01) after isoproterenol challenge when receiving placebo than when receiving theophylline. According to the intermountain Area rating criteria, only the results after isoproterenol challenge during placebo therapy would indicate improvement. These results suggested that isoproterenol inhalation challenge be performed after methylxanthines have been discontinued if used to predict which patients with COPD may respond to oral theophylline therapy.

Comparison of antibacterial and antiimmune effects of certain rifamycins.

Comparison of the in vivo and in vitro immunosuppressive activities of the five rifamycins with their in vitro antibacterial and anti-ribonucleic acid polymerase activities indicated that correlation was poor. Examination of their activities on mitogen-induced blastogenesis in human peripheral blood leukocytes and inhibition of delayed-type hypersensitivity to partially purified protein derivative in immunized mice demonstrated that correlation was usually good. Antibacterial activity in cultures and the activities of the rifamycins inhibiting deoxyribonucleic acid-dependent ribonucleic acid polymerase appeared to correlate well. However, when these two types of activity, antiimmune and antibacterial, were compared, correlation was poor on occasion and indicated that the antiimmune activities and antibacterial activities of the rifamycins are probably not related.

beta-Lactamase activity in slow-growing nonpigmented mycobacteria and their sensitivity to certain beta-lactam antibiotics.

It has been reported that certain nonpigmented, slow-growing mycobacteria do not have a constitutive beta-lactamase and are more sensitive to benzyl penicillin than M. tuberculosis. Thirty-nine isolates of these organisms, most of them belonging to the M. avium-intracellulare complex, were found to be sensitive to less than 10 micrograms of benzyl penicillin per ml in vitro. Approximately half of these isolates were inhibited by 1 microgram per ml. By contrast of 32 isolates of M. tuberculosis, only one was inhibited by 10 micrograms of benzyl penicillin. Sensitivity studies with cephalothin yielded similar results. Analysis of beta-lactamase activity in some of these species showed no activity, confirming earlier observations of this deficit.

Treatment of chronic obstructive pulmonary disease with orally administered theophylline. A double-blind, controlled study.

Theophylline is commonly prescribed for chronic obstructive pulmonary disease (COPD), although controlled studies do not exist to support this use. We administered theophylline and placebo orally to 40 ambulatory COPD patients in a double-blind, crossover manner. Pulmonary function tests were conducted before and after isoproterenol nebulization on the final day of each four-week study period. Theophylline therapy produced small, but significant, increases over placebo in mean values. However, only the forced expiratory volume in 1 s was "improved," according to published criteria. There were no significant differences in subjective effects between treatment periods. Six patients were identified as "responders"; responder status could be predicted on the basis of improvement in flow rates after isoproterenol nebulization. Theophylline therapy is not beneficial to most COPD patients, and potential responders should be given carefully monitored therapeutic trials rather than arbitrarily being given maintenance therapy.