Pulmonary rehabilitation improves training in cystic fibrosis lung transplant candidates
Key takeaways:
- Researchers captured exercise capacity measures during the first week of pulmonary rehabilitation to the session before transplant.
- Treadmill speed and two muscle training volumes went up between the two points.
Between the first week of pulmonary rehabilitation and the last recorded session before transplantation, lung transplant candidates with cystic fibrosis had maintained or increased their rehabilitation measures, according to study data.
“The present study highlights the importance of physiological reserve as a majority of the CF lung transplant candidates in our study were younger compared to other pulmonary rehabilitation populations,” J. Michael Nicholson, MD, FRCPC, adjunct professor at Schulich Medicine and Dentistry, Western University, told Healio.
“It is important to recognize that the aerobic and muscle training volume response improved despite frequent respiratory exacerbations and disease severity,” he continued. “These findings in CF patients are also relevant to the non-CF population.”
In this single-center, retrospective cohort study published in Respiratory Medicine, Nicholson, along with Dmitry Rozenberg, MD, PhD, FRCPC, respirologist at the University Health Network and assistant professor in the department of medicine at the University of Toronto, and colleagues assessed 86 adult lung transplant candidates (mean age, 32 years; 51% women; mean FEV1, 23% predicted) with CF to determine how pulmonary rehabilitation two to three times a week (median, 24-36 sessions) impacted various aerobic and muscle training volumes, as well as 6-minute walk distance (6MWD).
Nicholson noted that having at least one exacerbation was found in over three-fourths of the population (78%) in the period before transplantation. He also said over half (55%) needed hospitalization.
“An interesting finding in the present study was the high incidence of respiratory exacerbations in this CF cohort (July 2009-June 2019) awaiting lung transplantation,” Nicholson told Healio.
Other important baseline characteristics included the use of supplemental oxygen by 88% of candidates and the use of home noninvasive ventilation by 37% of candidates, according to the study.
With pulmonary rehabilitation participation, researchers reported significant improvements in three measures between the first week of rehabilitation and the last measurement available before transplantation.
Treadmill speed was one of these measures, going up from 1.72 mph to 2.13 mph (mean of differences, 0.36; 95% CI, 0.23-0.48; P < .0001). The remaining measures pertained to training volumes. According to the study, biceps training volume rose from a median of 50 lbs*repetitions to 70 lbs*repetitions (mean of differences, 23; 95% CI, 11-35; P = .0003) and quadriceps training volume went up from a median of 30 lbs*repetitions to 50 lbs*repetitions (mean of differences, 19; 95% CI, 11-27; P < .0001).
In terms of 6MWD, the study highlighted that the first week measure did not significantly differ from the last available measure (421 m vs. 415 m). Other measures that did not significantly change from the measurement taken in the first week of pulmonary rehabilitation to the last available measurement included mean peak Borg dyspnea score after treadmill exercise, resting heart rate and end of treadmill exercise heart rate.
“With pulmonary rehabilitation we observed stability in the exercise capacity pre-transplant despite progressive, advanced lung disease and pulmonary exacerbations,” Nicholson told Healio. “This is important as exercise capacity has been shown to be an important marker of mortality in lung transplant candidates.”
Lastly, researchers analyzed the link between respiratory exacerbations and training volumes and found a significant reduction of 0.36 mph (95% CI, –0.67 to –0.04) in treadmill speed if candidates had at least one exacerbation.
“Respiratory exacerbations were an important contributor to deconditioning,” Nicholson told Healio.
“Despite the fantastic improvements in CF care, unfortunately there will continue to be patients who require lung transplantation; those with or without highly effective modulatory therapy (HEMT) therapy,” Nicholson added. “This article helps to demonstrate that there are ongoing training improvements that can be achieved by CF patients, despite very severe ventilatory limitations prior to the era of HEMT.”
Looking ahead, Nicholson said studies will likely focus on HEMT.
“Although HEMT has changed the number of CF patients referred for lung transplantation, the focus on exercise training and lifestyle before referral for transplantation will be important,” Nicholson told Healio.
“This will be especially true for those that are on HEMT and the fewer numbers awaiting lung transplantation, as we are not entirely sure how their exercise tolerance and outcomes will evolve,” Nicholson continued.
For more information:
J. Michael Nicholson, MD, FRCPC, can be reached at michael.nicholson@sjhc.london.on.ca.
Dmitry Rozenberg, MD, PhD, FRCPC, can be reached at dmitry.rozenberg@uhn.ca.