Exercise training for adult lung transplant recipients

BACKGROUND

Pulmonary transplantation is the final treatment option for people with end-stage respiratory diseases. Evidence suggests that exercise training may contribute to speeding up physical recovery in adults undergoing lung transplantation, helping to minimize or resolve impairments due to physical inactivity in both the pre- and post-transplant stages. However, there is a lack of detailed guidelines on how exercise training should be carried out in this specific sub-population.

OBJECTIVES

To determine the benefits and safety of exercise training in adult patients who have undergone lung transplantation, measuring the maximal and functional exercise capacity; health-related quality of life; adverse events; patient readmission; pulmonary function; muscular strength; pathological bone fractures; return to normal activities and death.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 6 October 2020 using relevant search terms for this review. Studies in the CKTR are identified through CENTRAL, MEDLINE, and EMBASE searches, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were included comparing exercise training with usual care or no exercise training, or with another exercise training program in terms of dosage, modality, program length, or use of supporting exercise devices. The study population comprised of participants older than 18 years who underwent lung transplantation independent of their underlying respiratory pathology.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed all records identified by the search strategy and selected studies that met the eligibility criteria for inclusion in this review. In the first instance, the disagreements were resolved by consensus, and if this was not possible the decision was taken by a third reviewer. The same reviewers independently extracted outcome data from included studies and assessed risk of bias. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Eight RCTs (438 participants) were included in this review. The median sample size was 60 participants with a range from 16 to 83 participants. The mean age of participants was 54.9 years and 51.9% of the participants were male. The median duration of the exercise training programs for the groups undergoing the intervention was 13 weeks, and the median duration of training in the active control groups was four weeks. Overall the risk of bias was considered to be high, mainly due to the inability to blind the study participants and the selective reporting of the results. Due to small number of studies included in this review, and the heterogeneity of the intervention and outcomes, we did not obtain a summary estimate of the results. Two studies comparing resistance exercise training with no exercise reported increases in muscle strength and bone mineral density (surrogate outcomes for pathological bone fractures) with exercise training (P > 0.05), but no differences in adverse events. Exercise capacity, health-related quality of life (HRQoL), pulmonary function, and death (any cause) were not reported. Three studies compared two different resistant training programs. Two studies comparing squats using a vibration platform (WBVT) compared to squats on the floor reported an improvement in 6-minute walk test (6MWT) (28.4 metres, 95% CI 3 to 53.7; P = 0.029; and 28.3 metres, 95% CI 10.0 to 46.6; P < 0.05) with the WBVT. Supervised upper limb exercise (SULP) program improved 6MWT at 6 months compared to no supervised upper limb exercise (NULP) (SULP group: 561.2 ± 83.6 metres; NULP group: 503.5 ± 115.2 metres; P = 0.01). There were no differences in HRQoL, adverse events, muscular strength, or death (any cause). Pulmonary function and pathological bone fractures were not reported. Two studies comparing multimodal exercise training with no exercise reported improvement in 6MWT at 3 months (P = 0.008) and at 12-months post-transplant (P = 0.002) and muscular strength (quadriceps force (P = 0.001); maximum leg press (P = 0.047)) with multimodal exercise, but no improvement in HRQoL, adverse events, pulmonary function, pathological bone fractures (lumbar T-score), or death (any cause). One study comparing the same multimodal exercise programs given over 7 and 14 weeks reported no differences in 6MWT, HRQoL, adverse events, pulmonary function, muscle strength, or death (any cause). Pathological bone fractures were not reported. According to GRADE criteria, we rated the certainty of the evidence as very low, mainly due to the high risk of bias and serious imprecision.

AUTHORS' CONCLUSIONS

In adults undergoing lung transplantation the evidence about the effects of exercise training is very uncertain in terms of maximal and functional exercise capacity, HRQoL and safety, due to very imprecise estimates of effects and high risk of bias.