PULMONARY REHABILITATION PROGRAMS IN LUNG TRANSPLANT: A LITERATURE REVIEW

Objective: To analyze, using a literature review, Pulmonary Rehabilitation (RP) Programs in lung transplant. Methods: A literature review in July 2014 in Ebsco Host, Periódicos Capes, BVS and Science Direct data bases using descriptors in English (“lung transplantation”, “lung transplant” AND/OR “rehabilitation”) and Portuguese ( “reabilitação” AND/OR “transplante pulmonar” ). The eligibility criterions were interventional studies of PR before and/or after lung transplant; participants who were candidates to lung transplant or lung transplant recipients; studies that applied any kind of PR program (hospital-based, home-based or outpatient) and articles published in English, Spanish or Portuguese. Literature reviews, guidelines and case reports were excluded. The search process yielded 46 articles of which two were duplicated. After title and abstract screening 13 articles remained for full text reading. Six studies met the inclusion eligibility and were included in the review. Results: The studies involved patients with Chronic Obstructive Pulmonary Disease, Cystic Fibrosis, Pulmonary Hypertension, Interstitial Lung Disease and Pulmonary Fibrosis. Pulmonary function, exercise capacity, quality of life (QoL) and quadriceps force were evaluated. Most interventions were outpatient programs with three months duration, three times a week and session with at least one hour. Protocols included physical training, educational approach and just one included nutritional, psychiatric and social assistant follow-up. The studies presented significant change in the six-minute walking distance, QoL and quadriceps force after PR programs. Conclusion: This review showed the benefits of the PR in the QoL and exercise capacity contributing to the Health Promotion of the patients. Pulmonar. Fueron evaluadas la función pulmonar, la capacidad de ejercicio, la calidad de vida (CV) y la fuerza del cuadriceps. La mayoría de las intervenciones fue de carácter ambulatorial con tres meses de duración, tres veces a la semana y sesiones de por lo menos una hora. Los protocolos incluyeron el entrenamiento físico, el abordaje educativo y solamente uno incluyó el seguimiento nutricional, psiquiátrico y del trabajo social. Los estudios presentaron cambios significativos en la distancia recogida en seis minutos, la CV y la fuerza de cuádriceps después de los programas de RR. Conclusión: Esta revisión mostró los beneficios de la RR en la CV y capacidad de ejercicio contribuyendo para la Promoción de la Salud de estes pacientes. Rehabilitación. Trasplante. Fisioterapia.

In Brazil, about seven hundred were performed and there are patients requiring lung transplant who do not even were referred to a transplant center once there are just seven active centers in the country (2) . In the last 5 years, the number of small-volume centers (<10 adult lung transplants per year) decreased, whereas high-volume centers (≥30 adult lung transplants per year) increased. Subsequently, the proportion of transplants being performed at high-volume centers increased (4) .
The success for a lung transplant depends on a very strict selection of candidates (5) as well as a preparation of the patient involving medication, economic, psychosocial and physical aspects, so that he/she may have a satisfactory survival and improve quality of life (QoL) (6,7) .
In this context, the Pulmonary Rehabilitation (PR) is, nowadays, an important intervention in the pre (8) and post-surgery of lung transplant (9) . It is a multidisciplinary program based on a thorough patient assessment followed by patient-tailored therapies that include, but are not limited to, exercise training, education, and behavior change, designed to improve the physical and psychological condition of people with chronic respiratory disease and to promote the long-term adherence to health-enhancing behaviors (10) . It aims to enhance the functional capacity (11,12) , to reduce the frequency of the exacerbations (13) and hospital admission of patients with chronic lung disease (14) and, principally, to improve their QoL (11,15,16) .
Although different studies show the benefits of the PR in COPD (11,12,15,17) and others respiratory chronic diseases (10) regarding inpatient or outpatient treatment (18,19) , somewhat is known about the physical training repercussions in candidates to lung transplant or lung transplant recipients (8,9) . Investigating PR programs in lung transplant may give a support to describe this treatment as an important allied before and after the surgery contributing to the health promotion of the patients which is the process of enabling people to increase control over, and to improve their health (20) . The PR programs are included in this context once it promotes the empowerment (21) of the patients teaching them how to lead with the disease and to control their health through the exercise training before and after the transplant.
Health promotion actions declared years ago are also important nowadays as build healthy public policy, create supportive environments, strengthen community action and develop personal skills (22) which are also part of the PR programs. Health promotion moves beyond a focus on individual towards a wide range of social and environmental interventions. The strategies for prevention and control of chronic respiratory diseases aims to identify cost-effective interventions, upgrade standards and accessibility of care at different levels of the health care system (20) . A lung transplant is an strategy of controlling chronic respiratory diseases and the PR can be an important tool to give the necessary support during the process of the pre and postsurgery (10) .
The aim of this study was to analyze, using a literature review, Pulmonary Rehabilitation Programs in lung transplant.

METHODS
The search process was performed in Ebsco Host, Journals of Capes, BVS and Science Direct electronic databases in July 2014 using specific words in English ("lung transplantation", "lung transplant" AND/OR "pulmonary rehabilitation") and in Portuguese ("reabilitação" AND/ OR "transplante pulmonar"). Four reviewers conducted an independent title and abstract screening followed by an agreement reached between them on the selection of studies. All reviewers carried out the full text reading to identify articles to be included in the review.
It was included studies that described the PR as a treatment to lung transplant recipients or candidates to lung transplant. The studies had to meet the following criteria: (1) be published between 2008 and 2014 due the scarcity of publications about this subject; (2) interventional studies with PR before and/or after the lung transplant; (3) groups of participants who were candidates to lung transplant or lung transplant recipients; (4) studies that applied any kind of PR program (hospital-based, home-based or outpatient) and (5) articles published in English, Spanish or Portuguese. Review articles, guidelines, case reports, articles for which full text was not obtained and the duplicate articles were excluded.
The literature search process yielded 46 articles of which two were duplicated, leaving 44 manuscripts. After screening the title and the abstract, 13 articles remained; of them, 7 were excluded leaving a total of six remaining for full text reading. All of these met the inclusion criteria and were finally included in the review. Figure 1 shows the selection process of the articles included in the review.
The six articles included were deeply read by all reviewers aiming to identify the clinical and sociodemographics characteristics from the investigated patients, the methodological aspects of the studies, the characteristics and the protocols applied in the PR programs and the benefits achieved by the patients with PR programs.

RESULTS
Six articles were included in this literature review (8,9,(23)(24)(25)(26) . The age of the investigated patients varied from 18 years (8) to more than 65 years (26) and it was identified almost the same number of man and woman when analyzing the total patients from the studies. The most prevalent diagnosis in the articles were the COPD (8,(23)(24)(25)(26) , the Cystic Fibrosis (8,(24)(25)(26) , the Pulmonary Hypertension (8,(24)(25)(26) , the Interstitial Pulmonary Disease (8,23,24) and the Pulmonary Fibrosis (9,25,26) . Three studies were realized with lung transplant recipients (8,24,25) and three with candidates to lung transplant (9,23,26) . Table I presents the socio-demographics and clinical data from the patients of each study. The evaluation of the patients were principally through the pulmonary function (8,9,(23)(24)(25) , exercise capacity with the Six Minute Walking Test (6MWT) (8,9,(23)(24)(25)(26) and the QoL using the generic questionnaire Short-Form 36 (SF-36) in most studies (8,9,24,26) . Quadriceps force was also investigated in some researches (23,24) . In most studies the PR program had 3 months duration (9,(23)(24)(25) with the sample varying from 19 (25) to 345 patients registered in one retrospective study (26) . Table II describes in detail the methodological aspects of each manuscript. Table III presents the characteristics of the PR programs applied in each study. Most of them were outpatient program (9,23,24,26) although some were realized in hospital setting. The frequency of the programs were three times a week with a mean of 1 hour duration for each session (9,23,24,26) . All protocols included the physical training and three included educational approach (8,9,24) and just one included nutritional, psiquiatric and social assistant followup and educational conferences (9) .     The principal results founded in the studies was the significant change in the distance walked in the 6MWT (8,9,23,24) , in the QoL evaluated by the Saint George Respiratory Questionnaire (SGRQ) which is an specific questionnaire and the SF-36 (8,9,24,25) and the quadriceps force (9,23) . Pulmonary function presented statistically significant results in those studies in which the values before and after transplant were compared (8,24) . The main results of the studies are described in table III.
In general, the protocols applied in the studies were based on exercise training (involving stretching, aerobic exercises and resistance training) and education sessions as shown in table III. The aerobic training were using a treadmill in two studies (9,26) and the bicycle in other two (8,25) . Both aerobic training were used in the protocol of two other studies (23,24) . The quadriceps force training were identified in just two of the six studies (23,26) and the stretching exercises in half of them (9,24,26) . Table IV describes the RP protocols in details.

DISCUSSION
This literature review shows a scarcity of researches about PR in candidates to lung transplant and/or lung transplant recipients although all of them presented positive results. The different sizes of the samples of the studies can be explained by the kind of the study. A retrospective study (26) , for example, allows a collected data bigger than a clinical trial (14) .
Even though there were a variability in the components of the PR programs applied in the analyzed studies, all of them had positive and statistically significant results, corroborating with the literature that does not present an specific protocol but essential aspects to the PR as the physical training and education in health (10,27) , the characteristics presented in most articles in this review. The majority of the programs applied, followed the standard guidelines of the British Thoracic Society and the American Thoracic Society of 4 to 12 weeks duration and the frequency of 2 to 5 times per week (10,28) . Just one study had 3 weeks duration and, although it was a short time intervention, it presented positive results (8) .
The PR protocols identified in this review didn´t differ of what is done in patients with chronic lung diseases without a transplant indication. Nevertheless, candidates to lung transplant and lung transplant recipients need special attention and follow-up due the delicacy of the surgery process they will undergo (29,30) . The educational approach must be directed to the surgery, the professional team must prepare the patient to the intervention as well as his/her recovery that will need care and physical training follow-up in the PR (31) .
The evaluation protocols of the analyzed studies (lung function, QoL, exercise capacity and quadriceps force) were similar to other studies in different patients (11,12,15,16) . Recent study (32) showed that the delay in the recovery of the exercise capacity after lung transplant is not associated with the delay in the improvement of the function of the transplanted organ but it results to the slow recovery of the muscular force. Thus, the authors reinforce the necessity of clinical trials to a better comprehension about the influence of the physical activity in the improvement of the exercise capacity after lung transplant. The evaluation of the respiratory muscle (33) and the activities of daily living are also important aspects to be evaluated in candidates to lung transplant (34) , although any study in this review had this aim.
The benefits of the PR programs described in this review reinforce its importance in the treatment of patients with chronic lung disease, highlighting, the election of lung transplant as the indication of this treatment (10) . Improvement in the QoL, exercise capacity and lung function certainly contributes to increase the years of life of the patients who was in advanced disease stage and had the lung transplant as the last chance to change their life (7) . Nevertheless, it is important to emphasize that the results will be maintained according to the physical activity and care inherent of lung transplant recipients, fact that reflects the adherence or not to the treatment. In the same way, patients who do not do the transplant after the PR due the clinical improvements also need the maintenance of the physical activity to control the progression of the disease (31,35) .

CONCLUSION
This literature review showed its benefits in the QoL, exercise capacity and quadriceps muscle force contributing to the Health Promotion of the patients.