No abstract

Pulmonary rehabilitation (PR) participation is the standard of care for patients with chronic obstructive pulmonary disease (COPD) who remain symptomatic despite bronchodilator therapies. However, there are questions about specific aspects of PR programming including optimal site of rehabilitation delivery, components of rehabilitation programming, duration of rehabilitation, target populations and timing of rehabilitation. The present document was compiled to specifically address these important clinical issues, using an evidence-based, systematic review process led by a representative interprofessional panel of experts. The evidence reveals there are no differences in major patient-related outcomes of PR between nonhospital- (community or home sites) or hospital-based sites. There is strong support to recommend that COPD patients initiate PR within one month following an acute exacerbation due to benefits of improved dyspnea, exercise tolerance and health-related quality of life relative to usual care. Moreover, the benefits of PR are evident in both men and women, and in patients with moderate, severe and very severe COPD. The current review also suggests that longer PR programs, beyond six to eight weeks duration, be provided for COPD patients, and that while aerobic training is the foundation of PR, endurance and functional ability may be further improved with both aerobic and resistance training.

We measured tracheal pressure (Ptr) and tracheal flow (V) in open-chest anesthetized paralyzed dogs. The lungs were maintained at a fixed volume (initial positive end-expiratory pressure 0.5 kPa) for 80 s while small-amplitude oscillations in V at 1 and 6 Hz were applied simultaneously at the tracheal opening. A bolus of histamine was given intravenously at the start of the oscillation period. The time course of lung elastic recoil pressure (Pel) was obtained by passing a running average over Ptr to smooth out its oscillations. The oscillations themselves were separated into their 1- and 6-Hz components, as were those in V. By fitting models to the 1- and 6-Hz components of Ptr and V by recursive least squares, we obtained time courses of lung resistance at 6 Hz (RL6), dynamic lung elastance at 1 Hz (EL1), and the difference between dynamic lung resistance at 1 and 6 Hz (RL1-RL6). In four dogs we studied the effects of histamine doses of 0.05, 1.0, and 20 mg. We found that Pel increased quickly and plateaued, RL6 continued to increase throughout the oscillation period, and EL1 exhibited features of both Pel and RL6. Furthermore, the ratio of RL1-RL6 to EL1 was qualitatively similar in time course to Pel. We explain these varied time courses in terms of the development of regional ventilation inhomogeneity throughout the lung as the reaction to histamine develops. In four dogs we also studied the effects of reducing the initial positive end-expiratory pressure by 0.25 kPa and found that the changes in RL6, EL1, and RL1-RL6 were greatly magnified, presumably because of the reduced forces of parenchymal interdependence.