American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Oct 2002
The burden of asthma in the United States: level and distribution are dependent on interpretation of the national asthma education and prevention program guidelines.
Asthma imposes a growing burden on society in terms of morbidity, quality of life, and healthcare costs. Although federally sponsored national surveys provide estimates of asthma prevalence, these surveys are not designed to characterize the burden of asthma by self-reported disease activity. We sought to characterize asthma burden in the United States. ⋯ These results suggest that a majority of the United States population with asthma experiences persistent rather than intermittent asthma burden. In addition, the discordance in type and distribution of asthma symptoms reported by individual subjects suggests that the exact estimate of the burden of asthma is related to how the National Asthma Education and Prevention Program classification is operationalized. Inquiry into recent day or nighttime symptoms alone underestimates the burden of asthma and may lead to inadequate treatment of asthma based on national guideline recommendations.
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Am. J. Respir. Crit. Care Med. · Oct 2002
Randomized Controlled Trial Multicenter Study Clinical TrialInfluence of combined intravenous and topical antibiotic prophylaxis on the incidence of infections, organ dysfunctions, and mortality in critically ill surgical patients: a prospective, stratified, randomized, double-blind, placebo-controlled clinical trial.
We prospectively studied the impact of an antibiotic prophylaxis regimen on the incidence of infections, organ dysfunctions, and mortality in a predominantly surgical and trauma intensive care unit (ICU) population. A total of 546 patients were enrolled and stratified according to Acute Physiology and Chronic Health Evaluation (APACHE)-II scores. They were then randomized to receive either 2 x 400 mg of intravenous ciprofloxacin for 4 days, together with a mixture of topical gentamicin and polymyxin applied to the nostrils, mouth, and stomach throughout their ICU stay or to receive intravenous and topical placebo. ⋯ Within 5 days after admission, 24 patients died in each group, whereas 28 patients receiving prophylaxis and 51 receiving placebo died in the ICU thereafter (p = 0.0589; RR, 0.640; 95% CI, 0.402-1.017). The overall ICU mortality was not statistically different (52 versus 75 fatalities), but the mortality was significantly reduced for 237 patients of the midrange stratum with APACHE-II scores of 20-29 on admission (20 versus 38 fatalities, p = 0.0147; RR, 0.508; 95% CI, 0.295-0.875); there was still a favorable trend after 1 year (51 versus 60 fatalities; p = 0.0844; RR, 0.720; 95% CI, 0.496-1.046). Surveillance cultures from tracheobronchial, oropharyngeal, and gastric secretions and from rectal swabs did not show any evidence for the selection of resistant microorganisms in the patients receiving prophylaxis.
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Am. J. Respir. Crit. Care Med. · Oct 2002
Randomized Controlled Trial Multicenter Study Clinical TrialEffectiveness of fluticasone propionate and salmeterol combination delivered via the Diskus device in the treatment of chronic obstructive pulmonary disease.
This randomized controlled trial examined the benefits of combining an inhaled corticosteroid, fluticasone propionate (F), with an inhaled long-acting beta(2)-agonist, salmeterol (S), to treat the inflammatory and bronchoconstrictive components of chronic obstructive pulmonary disease (COPD). A total of 691 patients with COPD received the combination of F and S (FSC), S (50 mcg), F (500 mcg), or placebo twice daily via the Diskus device for 24 weeks. A significantly greater increase in predose FEV(1) at the endpoint was observed after FSC (156 ml) compared with S (107 ml, p = 0.012) and placebo (-4 ml, p < 0.0001). ⋯ There were greater improvements in the Transition Dyspnea Index with FSC (2.1) compared with F (1.3, p = 0.033), S (0.9, p < 0.001), and placebo (0.4, p < 0.0001). The incidence of adverse effects (except for an increase in oral candidiasis with FSC and F) was similar among the treatment groups. We conclude that FSC improved lung function and reduced the severity of dyspnea compared with individual components and placebo.
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Am. J. Respir. Crit. Care Med. · Oct 2002
Hypercapnia and ventilatory periodicity in obstructive sleep apnea syndrome.
Prevention of acute hypercapnia during obstructive events in obstructive sleep apnea requires a balance between carbon dioxide (CO(2)) loading during the event and CO(2) unloading in the interevent period. Earlier studies have demonstrated that acute CO(2) retention may occur despite high interevent ventilation when the interevent duration is short relative to the duration of the preceding event. The present study examines the relationship between apnea and interapnea durations and relates this assessment of ventilatory periodicity to the degree of chronic hypercapnia in subjects with severe sleep apnea. ⋯ No relationship was observed between chronic Pa(CO2) and mean apnea or interapnea duration (p > 0.1). However, Pa(CO2) was directly related to apnea/interapnea duration ratio (r = 0.48; p < 0.05) such that with increasing chronic hypercapnia the interapnea duration shortens relative to the apnea duration. The present study suggests that control of the interapnea ventilatory duration relative to the duration of the preceding apnea, is an important component of the integrated ventilatory response to CO(2) loading during apnea and may contribute toward the development and/or maintenance of chronic hypercapnia in obstructive sleep apnea/hypopnea syndrome.