Assessment of respiratory muscle performance, functional capacity, fatigue, and quality of life in liver transplant candidates

Abstract

Purpose: This study aimed at assessment of respiratory muscle performance (RMP), functional capacity (FC), feeling of fatigue, and quality of life (QOL) in liver transplant candidates and to correlate these variables with each other and with the Model for End-Stage Liver Disease (MELD). Methods: A prospective study carried out from January/2008 to June/2009 including 130 liver transplant candidates on waiting–list at the São Paulo Health Transplant System, followed at the Unit of Liver Transplantation - Unicamp with cirrhosis of any etiology, independent of gender, age, and degree of liver function impairment as classified by the MELD score. Respiratory muscle performance was determined by respiratory muscle strength (RMS - PIMAX and PEMAX), vital capacity (VC), and FC measured during six-minute walk tests (6MWT). Fatigue was evaluated using the Fatigue Severity Scale (FSS), and QOL was assessed using the SF-36 questionnaire. Results: Expressed as the mean SD and percentage of the predicted value: MELD=16+4, VC=4.0+0.9L - (97%+16%), PIMAX=77+28cmH2O -(71+25%), PEMAX=76+26cmH2O (76+26%), 6MWT=453.9+81.2m (73+13%), FSS=34+17, and compromised QOL, particularly in physical (48+41) and emotional (57+41) aspects, vitality (58+26) and general state (58+24). Predicted VC was negatively correlated with MELD (p=0.0034) and positively correlated with RMS and 6MWT (p=0.0217). Greater distances in the 6MWT were associated with a higher RMS and QOL and less fatigue. Greater FSS scores resulted in lower QOL scores. Conclusion: A decrease in VC was related to the severity of liver disease and a decrease in RMS and FC, which, in turn, correlated with greater fatigue and lower QOL.