Management of Patients with Advanced Lung Disease

by Chun K. Yip, M.D.

(Presented at the CAMS 1999 Semiannual Scientific Meeting)

Advanced lung disease refers to any chronic, non-neoplastic lung disease that limits ordinary activities of daily living. It includes the severe end of the spectrum of irreversible pulmonary disorders of different etiology. These include obstructive airway diseases (COPD), interstitial lung diseases (idiopathic pulmonary fibrosis, sarcoidosis), infectious dis-eases (bronchiectasis, cystic fibrosis) and pulmonary vascular diseases (primary pulmonary hypertension). They share common features: reduced pulmonary efficiency and functional reserve of lung; cause dyspnea with ordinary activity; contribute to depression and anxiety; and compromise quality of life severely.

The overall goal in the manage-ment of patients with advanced lung disease is to improve the quality of life. There are a number of remark-able advances recently in the management of such patients.

Among the medical, or non-surgical treatment, preventive measure is very important All these patients should receive appropriate immunization, including influenza and pneumococal vaccines

Long-term oxygen therapy has been shown to be of substantial benefit. Multicenter studies have demonstrated increase in survival in COPD patients with hypoxemia after long-term oxygen therapy. Survival is greatest if the patient uses the oxygen on a continuous basis. It also im-proves the quality of life and in-creases exercise tolerance. Oxygen therapy is indicated when PaO₂ is 55 mm Hg or less, or SaO₂ is 88% or less. We should aim for a PaO₂ of 60 to 65 mm Hg, or SaO₂ of 92 ± 2%.

Pulmonary rehabilitation is increasingly being recognized as an important part of the comprehensive management of these patients. Multiple trials have shown that pulmonary rehabilitation improves: exercise endurance and work capacity, dyspnea, quality of life, and health related costs. However, pulmonary rehabilitation does not improve conventional pulmonary function test scores. Pulmonary rehabilitation uses a multi-disciplinary approach. A good pulmonary rehabilitation program should include education of disease process and its treatment, respiratory techniques, physical therapy, exercise conditioning, nutritional advice, and psychological counseling.

Pulmonary cachexia is associated with early mortality. Weight gain in these patients leads to improvement in their respiratory muscle strength. Therefore, nutritional supplement in the under-weight patient is important.

When the disease process is so advanced that the patient cannot maintain an adequate alveolar ventilation, mechanical ventilation with ventilator support is required. .In addition to the traditional mechanical ventilation requiring endotracheal intubation or tracheostomy, we now have the new non-invasive positive pressure ventilation that employs a closely fitted mask in conjunction with a ventilator or BiPAP machine. No endotracheal intubation or tracheostomy is required.

Miscellaneous medical treatment includes bronchodilator therapy ($-agonist and anticholinergics, such as ipratropium) and various treatments to relieve dyspnea (oxygen, relaxation, small frequent meals, prophylaxis against deep vein thrombophlebitis and aspiration, judicious use of benzodiazepines for extreme anxiety).

When medical therapy fails, several surgical options are available.

Lung transplantation is now considered a very viable therapeutic modality for a variety of selected patients. The most common group of patients who have been transplanted have COPD (emphysema), cystic fibrosis, primary pulmonary hypertension, and idiopathic pulmonary fibrosis. Single lung transplant is most common. The double-lung is the procedure of choice for infectious disorders. Heart-lung transplants are only for those patients absolutely requiring both heart and lung. Lobar transplantation is a relatively new approach. It involves transplants from living related donors.

Currently, about 1,200 patients are transplanted each year. But the number is limited by organ availability. About 30% of patients die while on waiting list. The waiting time is from 6 to 24 months. Though survival in the peri-operative phase has improved significantly, long term 5-year survival remains less than 50%. The major causes of death are obliterative bronchiolitis and infectious complications. The former is the problem for long-term surviors and accounts for 25% of late death. At least 50% of patients will have some degree of obliterative bronchiolitis by 5 years. It signifies chronic allograft rejection and is essentially untreatable.

Aother surgical option is lung volume reduction surgery (LVRS). This is a new surgical technique, specifically for patients with severe emphysema. The aim of the surgery is to remove 20 to 30% of the most diseased parts of the lungs. In successful cases, the surgery improves pulmonary function, increases PaO_2, improves daily function, relieves dyspnea and quality of life improves. Operative mortality varies from 0 to 18%. The major complication is lung and chest air leak. Probable mechanisms of improvement with LVRS include improved lung and chest wall mechanics, improved respiratory muscle function, and decompression of relatively normal lung.

Results of LVRS varied by different techniques and different programs. There are multiple data issues in the literature, and there are concerns about mortality, morbidity and cost. There are many unanswered questions about LVRS. Therefore, medicare stopped paying for the surgery in 12/95, and a randomized trial, NETT (National Emphysema Treatment Trial), was started in 17 centers around the country in 12/96. The purpose of the study is to gain information on the following: potential role of LVRS in the treatment of emphysema patients; efficacy of LVRS as compared to medical therapy; patient selection criteria for LVRS; efficacy of LVRS by different techniques.

In summary, increasing focus on advanced-stage lung disease has led to a number of remarkable recent advances and interventions in the management of this large and growing group of patients. These interventions provide an opportunity to improve the quality, if not quantity, of the patient’s life. ðP

Dr. Yip is Associate Clinical Professor of Medicine, Columbia University.