Tiêu đề All respiratory Disease .pdf ✅

Obstructive pulmonary diseases • 567 17 irradiation are employed to treat obliterative bronchiolitis but late organ failure remains a significant problem. The major factor limiting the availability of lung transplantation is the shortage of donor lungs. To improve organ availability, techniques to recondition the lungs in vitro after removal from the donor are being developed. Obstructive pulmonary diseases Asthma Asthma is a chronic inflammatory disorder of the airways, in which many cells and cellular elements play a role. Chronic inflammation is associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night and in the early morning. These episodes are usually associated with widespread but variable airflow obstruction within the lung that is often reversible, either spontaneously or with treatment. The prevalence of asthma increased steadily over the latter part of last century. As asthma affects all age groups, it is one of the most common and important long-term respiratory conditions in terms of global years lived with disability (Fig. 17.16). The development and course of asthma and the response to treatment are influenced by genetic determinants, while the rapid rise in prevalence implies that environmental factors are critically important in the development and expression of the disease. The potential role of indoor and outdoor allergens, microbial exposure, diet, vitamins, breastfeeding, tobacco smoke, air pollution and obesity have been explored but no clear consensus has emerged. capacity and quality of life. The various types of non-invasive (via a face or nasal mask) or invasive (via an endotracheal tube) ventilation are detailed on page 202. Respiratory stimulant drugs, such as doxapram, have been superseded by intubation and mechanical ventilation in patients with CO2 narcosis. Home ventilation for chronic respiratory failure NIV is of great value in the long-term treatment of respiratory failure due to spinal deformity, neuromuscular disease and central alveolar hypoventilation. Some patients with advanced lung disease, e.g. cystic fibrosis, also benefit from NIV for respiratory failure. In these conditions, type II respiratory failure can develop slowly and insidiously. Morning headache (due to elevated PaCO2) and fatigue are common symptoms but, in many cases, the diagnosis is revealed only by sleep studies or morning blood gas analysis. In the initial stages, ventilation is insufficient for metabolic needs only during sleep, when there is a physiological decline in ventilatory drive. Over time, however, CO2 retention becomes chronic, with renal compensation of acidosis. Treatment by home-based NIV overnight is often sufficient to restore the daytime PCO2 to normal, and to relieve fatigue and headache. In advanced disease (e.g. muscular dystrophies or cystic fibrosis), daytime NIV may also be required. Lung transplantation Lung transplantation is an established treatment for carefully selected patients with advanced lung disease unresponsive to medical treatment (Box 17.18). Single-lung transplantation may be used for selected patients with advanced emphysema or lung fibrosis. This is contraindicated in patients with chronic bilateral pulmonary infection, such as cystic fibrosis and bronchiectasis, because the transplanted lung is vulnerable to cross-infection in the context of post-transplant immunosuppression, and for these individuals bilateral lung transplantation is the standard procedure. Combined heart–lung transplantation is still occasionally needed for patients with advanced congenital heart disease, such as Eisenmenger’s syndrome, and is preferred by some surgeons for the treatment of primary pulmonary hypertension unresponsive to medical therapy. The prognosis following lung transplantation is improving steadily with modern immunosuppressive drugs: over 50% 10-year survival in some UK centres. Chronic rejection with obliterative bronchiolitis continues to afflict some recipients, however. Glucocorticoids are used to manage acute rejection, but drugs that inhibit cell-mediated immunity specifically, such as ciclosporin, mycophenolate and tacrolimus (p. 89), are used to prevent chronic rejection. Azithromycin, statins and total lymphoid 17.18 Indications for lung transplantation Parenchymal lung disease • Cystic fibrosis • Emphysema • Pulmonary fibrosis • Obliterative bronchiolitis • Langerhans cell histiocytosis (p. 613) • Lymphangioleiomyomatosis (p. 613) Pulmonary vascular disease • Primary pulmonary hypertension • Thromboembolic pulmonary hypertension • Veno-occlusive disease • Eisenmenger’s syndrome (p. 532) Fig. 17.16 The burden of asthma, measured by disability life years (DALYs) per 100 000 population. The burden of asthma is greatest in children approaching adolescence and the elderly. The burden is similar in males and females at ages below 30–34 but at older ages the burden is higher in males. From The Global Asthma Report 2014. Copyright 2014 The Global Asthma Network. 80+ 70–74 75–79 65–69 60–64 55–59 50–54 45–49 40–44 35–39 30–34 25–29 20–24 15–19 10–14 5–9 1–4 DALYs (per 100 000) 0 200 400 600 800 1000 Females Males Years