American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Apr 1997
Interpreting small differences in functional status: the Six Minute Walk test in chronic lung disease patients.
Functional status measurements are often difficult to interpret because small differences may be statistically significant but not clinically significant. How much does the Six Minute Walk test (6MW) need to differ to signify a noticeable difference in walking ability for patients with chronic obstructive pulmonary disease (COPD)? We studied individuals with stable COPD (n = 112, mean age = 67 yr, mean FEV1 = 975 ml) and estimated the smallest difference in 6MW distances that was associated with a noticeable difference in patients' subjective comparison ratings of their walking ability. ⋯ Distances needed to differ by 54 m for the average patient to stop rating themselves as "about the same" and start rating themselves as either "a little bit better" or "a little bit worse" (95% CI: 37 to 71 m). We suggest that differences in functional status can be statistically significant but below the threshold at which patients notice a difference in themselves relative to others; an awareness of the smallest difference in walking distance that is noticeable to patients may help clinicians interpret the effectiveness of symptomatic treatments for COPD.
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Am. J. Respir. Crit. Care Med. · Mar 1997
The effects of post-treatment with lisofylline, a phosphatidic acid generation inhibitor, on sepsis-induced acute lung injury in pigs.
The effects of lisofylline [(R)-1-(5-hydroxyhexyl)-3,7-dimethylxanthine] (LSF), an inhibitor of de novo phosphatidic acid (PA) generation, on sepsis-induced acute lung injury was studied using Hanford minipigs weighing 18 to 25 kg. Sepsis was induced by an intravenous infusion of Pseudomonas aeruginosa (1 x 10(6)/colony-forming units/kg/min over 2 h). Saline was used as the control vehicle. ⋯ LSF treatment attenuated sepsis-induced pulmonary hypertension, neutropenia, and hypoxemia, and increased MPO activity and lung injury measurements in the Pre and Post-1 h groups, but its efficacy was blunted in the Post-2 h group. Plasma TNF-alpha was decreased only in the Pre group. Thus, inhibition of intracellular PA generation through de novo pathways attenuates sepsis-induced acute lung injury.
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Am. J. Respir. Crit. Care Med. · Mar 1997
Multicenter Study Clinical Trial Controlled Clinical TrialOutcomes of advance directive education of pulmonary rehabilitation patients.
We performed a two-site prospective, controlled interventional study of patients enrolled in pulmonary rehabilitation to assess effects of advance directive education on completion of (1) living wills, (2) durable powers of attorney for health care (DPAHC), (3) patient-physician discussions about advance directives, and (4) discussions about life support, in addition to (5) patient impressions that their physicians understood their end-of-life preferences. The educational group had an increase (p < 0.05) in all five study outcomes compared with baseline values; the control group had an increase in three of five outcomes. ⋯ The educational intervention was an independent explanatory factor by multivariate analysis. We conclude that patients enrolled in pulmonary rehabilitation are receptive to advance care planning, which is promoted by education on end-of-life issues.
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Am. J. Respir. Crit. Care Med. · Mar 1997
Randomized Controlled Trial Comparative Study Clinical TrialComparison of three oxygen delivery systems during exercise in hypoxemic patients with chronic obstructive pulmonary disease.
Oxygen therapy improves submaximal exercise tolerance in hypoxemic patients with chronic obstructive pulmonary disease (COPD). This study compared the standard nasal cannula, reservoir nasal cannula, and a demand flow device in 15 male hypoxemic patients with COPD. On six separate occasions each subject used, in a randomized order, all three systems while completing incremental cycle ergometry and a test circuit composed of tasks that simulate activities of daily living. ⋯ There was a trend toward lower Spo2 with the demand flow device (p = 0.103) during arm work above shoulder level. Although not statistically significant, reservoir nasal cannula use resulted in consistently lower tidal volume and minute ventilation during test circuit activities. Exercise tolerance was not significantly different between the three oxygen delivery systems.