Limiting Factors of Exercise Performance 1 Year After Lung Transplantation

Abstract

Background: After lung transplantation (LTx) exercise capacity frequently remains limited, despite significantly improved pulmonary function. The aim of this study was to evaluate maximal exercise capacity and peripheral muscle force before and 1 year after LTx, and to determine whether peripheral muscle force and lactate threshold (LT) limit exercise capacity 1 year after LTx. Methods:Twenty-five subjects (mean age 43 years, 8 women and 17 men, 4 single-lung transplantations) were included in the study. Measurements included maximal exercise capacity, lactate threshold (symptom-limited bicycle ergometer test) and muscle force test (hand-held dynamometer) were performed before and 1 year after LTx. Results:Before LTx, all patients showed severe exercise intolerance (mean Ϯ SD): work capacity (W peak ), 11.6 Ϯ 18 W; peak oxygen uptake (VO 2 ), 8.6 Ϯ 3.6 ml/min/kg. After LTx, exercise capacity improved significantly: W peak , 69 Ϯ 27 W (p Ͻ 0.001); peak VO 2 , 15.7 Ϯ 4.3 ml/min/kg (p Ͻ 0.001). Ventilatory factors did not appear to limit exercise capacity. Quadriceps muscle force pre-vs post-LTx was: 248 Ϯ 73 N vs 281 Ϯ 68 N (p Ͻ 0.05). Post-LTx, a significant correlation was found between LT and exercise capacity (r ϭ 0.76, p Ͻ 0.001), between muscle force and exercise capacity (r ϭ 0.41, p Ͻ 0.05) and between the LT and muscle force (r ϭ 0.53, p Ͻ 0.01). Conclusions:The occurrence of an early and pathologic LT and peripheral muscle weakness contributes to the limitation of exercise capacity and reflects a peripheral deficit post-LTx.

Use of exercise testing in the evaluation of interventional efficacy: an official ERS statement

“…Rehabilitation in PAH patients increases V′O 2 peak by 1-1.5 mL·min [48,49], and a similar responsiveness is observed in IPF patients [50]. Lung transplant surgery [55,56] and successful lung volume reduction surgery [57] also consistently result in a greater post-intervention V′O 2 peak (table 3). V′O 2 peak has been also shown to be responsive to oxygen therapy both in patients with COPD and those with cystic fibrosis who desaturate during exercise [58,59].…”

Pulmonary Rehabilitation in Lung Transplantation

“…Bu durumun cerrahi öncesi akciğer hastalığı, kronik dekondüs-yon ve postoperatif faktörlerin (uzamış hospitalizasyon, immünsupresif medikasyonyan etkileri gibi) kombinasyonu sonucu oluştuğu düşünülmektedir (25,26).…”

“…Ventilatuar ve kardiyak faktörle-rin egzersiz limitasyonuna neden olduğunu gösteren kanıtlar yetersizdir. Birçok çalışma ise azalmış egzersiz kapasitesinin ana nedeninin periferal kas limitasyonu-na bağlı (iskelet kası oksijen sunumu, alımı ve kullanı-mındaki problemler) olduğunu belirtmektedir (7,12,24,25). Transplantasyon uygulanan hastaların çoğunluğu egzersizi bacak yorgunluğuna bağlı olarak sonlandır-maktadır (10,24,27,28).…”

“…Transplantasyon sonrası hastalarda kas fonksiyonunun incelendiği çalışmaların sonuçları; kas kütlesi ve kuvvetinde azalma (25,30), tip 1 kas lifi oranında azalma (31,32), azalmış kalsiyum alımı ve salınımı (31), kas pH'ında erken düşüş (33) (25,30). Tüm bu etkilenimler göz önüne alındığında hastane dışı rehabilitasyon fazında hastaların sık sık egzersiz toleransı açısından değerlendirilmesi ve en erken dönemde uygun egzersiz programına başlaması gerekmektedir (3).…”

The Importance of Rehabilitation before and after Lung Transplantation

“…[1][2][3][4][5][6][7] Persistent limitations in exercise capacity and skeletal muscle function have been observed for more than 1 year after transplantation. 8 Investigations of muscle function in LTx recipients reveal decreased muscle mass and strength, reductions in type 1 fiber proportion, decreased calcium uptake and release, decreased mitochondrial enzyme activity, and impaired oxidative capacity of the peripheral muscles.…”