Functional capacity after pediatric liver transplantation: A pilot study Maria da Silva R, Brunow de Carvalho W, Johnston C, Borba de Castro M, Ferreira IM, Patti CL, Anthero de Azevedo R, Miziara Gonzalez A, Moura Linhares M, Augusto Salzedas-Netto A. (2014) Functional capacity after pediatric liver transplantation: A pilot study. Pediatr Transplant, 18: 586–593. DOI: 10.1111/petr.12318. Abstract: The prospective cross-sectional study investigated the 6MWT performance in pediatric group of liver transplant recipients (6–17 yr, median post-transplantation time of 22 months) and compared to the normal values obtained in healthy children as well as evaluated the reproducibility of the 6MWT. We analyzed the relationship between walked distance and the 6MWw, distance walked 9 body weight) with the anthropometric, clinical, and pulmonary functions. In post- transplanted group, the average walked distance was significantly shorter compared with control (687 Æ 80 m vs. 511 Æ 72 m, p < 0.001). The calculated ICC coefficient confirmed the reproducibility among tests. The Pearson correlation revealed that only walked distance in the 6MWT was moderately correlated with tidal volume. Conversely, the 6MWw was significantly correlated with age, weight, height, BMI, FVC, PEF rate, and volume expiratory. According to multiple regression analysis, age, VE and FVC factors explained 80% of the variance in the 6MWw. In conclusion, the pediatric liver transplant recipients’ performance in the 6MWT is significantly lower than the values for healthy children of the same age. Notably, the 6MWw may provide relevant information, constituting an additional parameter in the determination of functional capacity. Ros^ angela Maria da Silva 1 , Werther Brunow de Carvalho 2 ,C  ıntia Johnston 1 , Mariela Borba de Castro 1 , Israel Manta Ferreira 1 , Camilla L. Patti 3 , Ramiro Anthero de Azevedo 4 , Adriano Miziara Gonzalez 4 , Marcelo Moura Linhares 4 and Alcides Augusto Salzedas-Netto 4 1 Department of Pediatrics, Universidade Federal de S~ ao Paulo (UNIFESP), S~ ao Paulo, Brazil, 2 Intensive Care/Neonatology at Children’s Institute, Medical School, University of S~ ao Paulo, S~ ao Paulo, Brazil, 3 Department of Pharmacology, Universidade Federal de S~ ao Paulo (UNIFESP), S~ ao Paulo, Brazil, 4 Division of Pediatric Liver Transplantation, Department of Surgery, Universidade Federal de S~ ao Paulo (UNIFESP), S~ ao Paulo, Brazil Key words: liver transplantation – stress test – physical fitness – reproducibility – children – six- min walk test Ros^ angela Maria da Silva, Department of Pediatrics, Universidade Federal de S~ ao Paulo (UNIFESP), 04304-000, S~ ao Paulo, SP, Brazil Tel.: +55 011 96176 9119 Fax: +55 011 5081 9624 E-mail: rosangela_epm@yahoo.com.br or roseepm@gmail.com Accepted for publication 3 June 2014 Pediatric liver transplantation is one of the most successful solid organ transplantations. Over the past two decades, new immunosuppressive thera- pies, anesthesia, and surgery have contributed to the improvement in patient survival and graft success (1). Despite these continuous improve- ments, several studies (2, 3) have reported func- tional consequences of liver transplantation, such as intolerance to physical exercises (4). In fact, the exercise capacity of the recipient is remarkably hindered in the postoperative period, regardless of the type of organ transplant (5–9). There is still scarce information (10, 11) con- cerning the exercise capacity of children and ado- lescents after liver transplantation. In fact, Unnithan et al. (10) initially characterize the fit- ness levels of pediatric liver recipients. The authors reported lower exercise capacity in trans- planted children than in healthy children with gender- and age-based criterion-referenced stan- dard. Submaximal tests of functional capacity, such as the 6MWT, are easier to conduct compared with the CPET, that is, the gold standard for measuring aerobic capacity (12), especially in Abbreviations: 6MWD, six-minute walk distance; 6MWT, six-minute walk test; 6MWw, six-minute walk work; AJE, American Journal Experts; ATS, American Thoracic Soci- ety; BMI, body mass index; CPET, cardiopulmonary exer- cise test; DBP, diastolic blood pressure; FVC, forced vital capacity; HR, heart rate; ICC, intraclass correlation; LL, lower limbs; MELD, model end-stage liver disease; MEP, maximal expiratory pressure; MIP, maximal inspiratory pressure; PEF, peak expiratory flow; PELD, pediatric end- stage liver disease; RR, respiratory rate; SBP, systolic blood pressure; SEE, standard error of the estimate; VE, ventila- tion expired rate; VT, tidal volume. 586 Pediatr Transplantation 2014: 18: 586–593 © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Pediatric Transplantation DOI: 10.1111/petr.12318