Lung Transplant for Patients with Cystic Fibrosis - Research Paper Example

LUNG TRANSPLANTS (for patients with cystic fibrosis) ID Number: of of School (University) Estimated Word Count: 1,927 Date of Submission: December 31, 2011 LUNG TRANSPLANTS FOR PATIENTS WITH CF Introduction Cystic fibrosis is a recessive genetic disease due to genetic mutation of the gene that is responsible for regulation of the bodys sweat, digestive juices and mucus. The particular gene is called the protein cystic fibrosis trans-membrane regulator (or CFTR) and people without cystic fibrosis (CF) have two copies of this specific CFTR gene. Only one CFTR gene is needed for the people to avoid CF and this ailment manifests only when both CFTR genes malfunction. Genetic tests can determine if CF is present in an unborn child or not (fetus) and a simple sweat test can be used to diagnose CF in early childhood. It is very common among Caucasians (about 1 in 25) and the probability is one childbirth with CF for every 2,000 new births. The term CF is derived from two co-occuring medical conditions which are cyst formations (begins in the pancreas) and the resulting fibrosis (scarring of tissue cells) that also affects the bodys other vital organs such as the liver, intestines and most critically, the lungs which leads to difficulty in breathing. This is caused by an abnormal transport and absorption of sodium and chloride across epithelial cells which results to thick (very viscous) mucus. Difficulty in breathing is the primary symptom that is due to lung infections which can be mitigated by use of antibiotics; other symptoms of CF are diarrhea, infertility and frequent sinus infections. The disease is incurable and progressive such that lung transplantations are necessary as the disease worsens despite treatments. This research paper discusses the most critical issues associated with lung transplants for CF mitigation and other related matters such as its side effects, the survival rates, mechanism for a new criteria in allocating lung donations and other options or alternatives being considered. The focus of this paper is lung transplantation as CF causes respiratory failure (end stage). Discussion Cystic fibrosis is an inherited disease that affects the bodys secretory glands which are the producers of sweat and mucus in which the mucus is abnormally thick and viscous (sticky). It obstructs lung passageways which leads to difficult breathing as it accumulates in the lungs. The presence of CF presents many problems in people with this ailment, such as diabetes and osteoporosis. Huge buildup of mucus in the lungs makes the environment conducive to bacterial growth which leads to frequent lung infections. A CF diagnosis means medical complications as well such as blockages in the pancreatic tubes which in turn prevent enzymes from reaching the intestines, leading to reduced absorption of vital nutrients (fats and proteins) during the digestive process that causes malnutrition and the vitamin deficiencies common in people with CF. This also causes the sweat to become salty in which the bloods chemical and mineral composition is altered markedly that results in fatigue, weakness, hypotension (or in a reduced blood pressure), dehydration and increased heart rates (National Institutes of Health, 2011, p. 1). Besides use of antibiotics to fight off lung infections, a common treatment for CF is through a broad program of pulmonary rehabilitation and long term use of oral steroids (Cheng et al., 2011, p. 1). Various treatments are considered as merely mitigation efforts to delay the worsening effects of CF, which lead to eventual impaired lung functions (end-stage respiratory failure) that is the primary cause of death among CF patients (Rosenblatt, 2009, p. 777). Among therapies, a lung transplantation has now been accepted as an effective form of treatment for patients with the signs of a progressive, irreversible respiratory failure. With this fairly-new development, the focus has now shifted to finding more viable lung donors based on efforts to increase the donor pool. Good timing is crucial for success, as with any organ transplant (Boe et al., 2003, p. 14). Survival rates – the median life expectancy (average) of CF patients has increased to a point where they now reach the adult age of 38 years versus only 27 years just two decades ago. This is due to the vast improvements in medical care from advances in medical science but other forms of therapy such as lung transplantation also contributed to this remarkable life extension. It is responsible for approximately 16% of patients with end-stage CF, with a favorable survival rate of 78% of all patients at one year, 63% at three years and 51% at five years after transplant. Further, CF patients who had lung transplantation have a more favorable long-term survival rate or outlook with a higher quality of life compared to those with a chronic obstructive pulmonary disease (COPD) like emphysema (Rosenblatt, 2009, p. 778) or those with a pulmonary fibrosis. This finding can be partly attributed to the younger age of most CF patients who lacked some of the common co-morbidities associated with other types of lung ailments in older patients. A very favorable outcome of lung transplants had led to its wider acceptance in the medical community. Determinants for Survival – several factors that help to determine whether CF patients will die or not are the use of measurements in lung function (such as forced expiratory volumes) and a thorough medical evaluation like the use of the New York Heart Association classification criteria (only class III or class IV patients are considered for transplantation) to select those who had more than a fair chance at survival (those with less than 50% chance of 2-year survival are weeded out) in a sort of triage mechanism so that lung donations are not wasted at all. In most of the cases, doctors admit there are no exact determinants or predictors but a yearly decline in term of lung function has been used more often to select patients for lung transplantation. These are to be used together with other clinical predictors such as age, height and number of hospitalization. Guidelines for Transplantation – lung centers are in a quandary when selecting patient for lung transplantation since there is no one single factor that is indicative of the prognosis. This complicates matters unnecessarily but they have developed some useful guides when choosing a patient as suitable for transplant. The forced expiratory volume (FEV) alone is not a very good predictor of survival, hence they used other means such as the rate of decline (rapidity) in lung function as a better predictor of mortality to warrant an earlier referral (ibid. p. 779). However, a single factor alone is not sufficient to determine survival rates, hence several factors are used. An example are patients who have less than 30% FEV of expected but other diagnostic measures can be included in evaluations such as exercise tolerance and pulmonary hypertension (ibid.). In this regard, forced vital capacity (FVC) is a better predictor compared to FEV. Presence of Microorganisms in CF Patients – patients diagnosed with CF are often in a debilitative or bad state of their lungs due to the damage brought about by frequent infections. However, it was found out the presence of these bacterial and other antibiotics-resistant micro-organisms do not have a significant impact on long-term survival after transplantation. It makes the presence of these microorganisms irrelevant to the decision whether to transplant or not as it does not affect the eligibility of a patient as a lung recipient as long as antibiotics are applied in a suitable manner during preoperative and post-operative conditions. With the rare exception of an infection with the B. cenocepacia which has only recently been found to be a contra-indication, all other infections by the burkholderia species do not present problems for lung transplants. All other microorganisms such as non-tuberculous mycobacteria can be contained with the right use of antibiotics treatment prior to the actual lung transplantation, with good results (ibid. p. 781). Gastro-intestinal Complications – patients with CF often develop liver diseases (8% to 17% of all CF patients) which manifest itself in various ways such as gastroparesis (the partial paralysis of the stomach which delays the emptying process) caused by surgical impact on vagus nerve, nausea resulting from multiple medicines, gastro-esophageal reflux disease (GERD) and a susceptibility to the development of the distal-intestine obstructive syndrome. All the side effects can be somewhat alleviated with a judicious use of narcotics, early ambulation and prophylactic regimes using electrolyte solution treatment protocols. However, the most important matter is the patient still has hepatocellular function essentially intact to be eligible for lung transplantation. Bone Diseases – most CF patients suffer from osteoporosis and osteopenia (condition where bone mineral density or BMD is lower than normal); it is a precursor to osteoporosis. All organ transplant patients suffer from these bone ailments but lung transplant patients suffer more because of impaired liver and pancreatic functions which affect absorption of vital nutrients like vitamin D and calcium. Moreover, hypogonadism (decreased functionality of the gonads or sex organs such as reduced production of hormones), extensive prior use of corticosteroids and the increased resorption of bone cells by cytokines further contribute to bone losses. Diabetes Mellitus – approximately 30% of CF patients 30 years or older also develop CF-related diabetes. This additional ailment complicates the process of lung transplantation but is not considered to be an exclusionary factor when selecting patients for transplant eligibility. A key consideration is that patients with diabetes prior to transplant have poorer survival rates but in those who develop diabetes after the transplantation, it does not significantly affect their long-term survival; many CF patients die from other complications such as rejection and infections. A good treatment protocol for controlling diabetes should improve the survival rate of CF patients. Sinus Disease – CF patients frequently develop sinus-related ailments due to reduced immunity. Previously, medical wisdom contends sinus presence is a contraindication but this has been solved with adequate sinus drainage, washes and surgery. The fear was the presence of the microbes in the sinuses can invade the lungs after transplantation and led to chronic rejection and frequent infections. More aggressive antibiotic washes had apparently solved this problem. Changes to the Lung Allocation Score – the previous system used to determine who is to be eligible for transplantation had relied on the length of time on the waiting list, rather than a more objective measure of the severity of the disease or the chances for survival. The scoring is now revised to reflect the two latter factors, which had markedly led to improved quality of life. The idea is to distribute the lungs to those who would benefit the most (so precious lungs are not wasted on patients who will die anyway); the new system is biased towards kids and adolescents. It is hoped the new allocation system is more efficient and equitable; however, the new system is not perfect but an attempt at judicious use of donated lungs using a variety of factors. Most kids below 12 years are not considered as eligible recipients and many young adults aged 12-17 years old die while on the waiting list. The advantage of the new scoring system is its dynamism where scoring criteria changes based on urgency and post-transplant survival rate of the patient. Conclusion With the new scoring system, it is now the focus of medical personnel to also improve the number of possible lung donors. Better surgical procedures now allow surgeons to acquire a lung which had previously been rejected as unsuitable for transplantation. Improvement of lung functions of possible donors contributed to an increase of donated lungs for this purpose such as prevention of atelectasis (collapse of alveoli) and relaxation of the donor criteria (ibid. p. 785). Reference List Boe, J., Estenne, M. & Weder, W. (2003). Lung transplantation. Sheffield, UK: European Respiratory Society (ERS). Cheng, K., Ashby, D. & Smyth, R. L. (2011, October 5). Oral steroids for long-term use in cystic fibrosis. Cochrane Database of Systematic Reviews, 10. doi: CD000407. Retrieved December 31, 2011 from http://www.ncbi.nlm.nih.gov/pubmed/21975730?tool=MedlinePlus National Institutes of Health (2011, June 1). “People science health: what is cystic fibrosis?” U.S. Department of Health and Human Services. Retrieved December 30, 2011 from http://www.nhlbi.nih.gov/health/health-topics/topics/cf/ Rosenblatt, R. L. (2009, June). Lung transplantation in cystic fibrosis. Respiratory Care, 54 (6), 777-87. Read More