Several contributing factors have been linked to emphysema and chronic bronchitis, the most common of which is cigarette smoking. Smoking increases the aggregation of neutrophils and alveolar macrophages, which begin the immune response to rid the body of foreign materials. One theory suggests that emphysema is the result of an imbalance between the protective antiprotease enzymes that protect the delicate structures of the lungs and the protease enzymes that lyse or break down tissue. This imbalance leads to the loss of the elastic recoil of the lung architecture. The small airways depend upon the adjacent elastic tissue of the parenchyma to recoil and assist with expiration and to provide airway stability to allow for effective inspiration. Another theory currently under examination is the role that smoking plays in the observed elevated rate of apoptosis or cell death of the alveolar cells, followed by the failure to repair the structures to a functional state. There is also an increase in platelet and neutrophil aggregation, which destroys the small capillary beds. This leads to a decrease in the gas exchange function of the lungs and pulmonary hypertension (Higenbottam, 2005; Provinciali et al., 2011).

Exposure to air pollutants and occupational factors is also associated with an increased incidence of emphysema and chronic bronchitis. There is an increased incidence in the development and progression of COPD as the number of respiratory infections increases. The increased frequency and dose exposure to systemic steroids, for example prednisone, has also been linked to the progression of COPD.

Finally, age and genetic factors have also been linked to the development of COPD. With the increase in the age of the population there has been a significant rise in the prevalence of COPD (Akgun et al., 2012; Rycroft et al., 2012). There is a genetic link with a predisposition to emphysema and chronic bronchitis, with a reported association with a decrease in the level of alpha-1-antitrypsin (Akgun et al., 2012). This enzyme is a protease inhibitor which protects tissue from enzymes of inflammatory cells, such as neutrophil elastase. With the reduction in alpha-1-antitrypsin there is an increased rate of cellular breakdown. Within the lungs this leads to emphysema.

The clinical presentation of patients with COPD has an insidious onset and goes undiagnosed for many individuals. Common symptoms are nonspecific and include chronic cough, dyspnea, possible sputum production and high-pitched wheezing. With the progression of the disease there is an increased work of breathing and a reduction in activity level (Vorrink et al., 2011). Upon auscultation, there are diminished normal breath sounds and high-pitched wheezing, particularly associated with exertion. There is an elongated expiratory phase because the patient tries to slow down the change in airway pressure during expiration to minimize the degree of air trapping or obstruction. Accessory respiratory muscles are commonly hypertrophied and there is a decrease in the excursion of the diaphragm as the lungs hyperinflate. On percussing over the intercostal spaces, there is hyper-resonance. With exertion, there is a marked increase in muscle recruitment, both for inspiration and expiration. Shortness of breath is the leading cause of exercise intolerance.

Patients who have a mismatch between ventilation and perfusion have the clinical presentation of desaturation because of the disruption of gas exchange. There may be areas of the lung where there is good blood flow through the pulmonary capillaries but poor ventilation. There may also be areas with an increase in the dead space in patients with COPD, which means that there is sufficient ventilation occurring in areas of the lungs where the capillary bed has been destroyed or pruned. This mismatch between ventilation and perfusion leads to hypoxia and the retention of carbon dioxide.

Examination of pulmonary function tests in patients with COPD reveals a classic pattern. Patients have a marked reduction in the ability to expel air rapidly, measured by the forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC). The decline in FEV₁ is associated with the degree of dyspnea or shortness of breath. Exercise limitations because of dyspnea are associated with a FEV₁ of less than 50% of the predicted value for age, height and weight (Barnes & Fromer, 2011). When the patient is dyspneic at rest, the FEV₁ may be as low as 25% of the predicted value. There is also a marked increase in total lung capacity and residual volume, which clearly represents the increased compliance of the lung and the degree of air trapping or obstruction (see Fig. 45.3). It is recommended by the American Association of Respiratory Care and COPD Foundation that questionnaires should be commonly used on all adult patients to identify risk factors for COPD and simple hand-held spirometer or peak flow meters to motor airflow. For those individuals with risk factors and low expiratory flow a high-quality spirometry testing should be completed (Barnes & Fromer, 2011).

Although the majority of patients with COPD have mixed features of both emphysema and chronic bronchitis, there are certain clinical signs and symptoms that are associated more with emphysema than with chronic bronchitis. With emphysema, there is a long history of dyspnea on exertion and little sputum production. These patients favor a posture of forward trunk flexion; this is to fixate their upper extremities so that accessory muscle recruitment is increased and the influence of gravity is decreased. The patient with emphysema is more likely to practice pursed lip breathing or grunt during expiration to keep the airways open. The patient will present with an elevated minute ventilation (respiratory rate×tidal volume), which aids in maintaining a sufficient arterial oxygen concentration at least through the early to mid-stages of the disease. In addition, a patient who suffers predominantly from emphysema will have an underweight to cachectic appearance (Hogg, 2004; American Lung Association, 2010).

In contrast, a patient who suffers predominantly from chronic bronchitis usually presents with a long history of a chronic and productive cough. Initially, the productive cough may occur only during the winter months; however, as the disease progresses in duration, frequency and severity, there is excessive sputum production and mucopurulent infections. By the time the patient experiences exertional dyspnea, there is a severe degree of airway obstruction. These patients have a tendency to be overweight and cyanotic, with a lower minute ventilation than patients with emphysema (Hogg, 2004).

As these diseases progress to end-stage, there will be further declines in lung function. The destruction of the respiratory bronchioles and acini lead to additional difficulties with proper ventilation, an increased airway resistance and a significant increase in the work of breathing. The disruption of the capillary bed within the lung causes a rise in pulmonary pressure and places a strain on the right ventricle. Over time, the patient will develop cor pulmonale, or right heart failure, which is associated with peripheral pitting edema, ascites and enlargement of the liver, jugular vein distension and anorexia.

Beyond behavioral modifications there are many pharmacological options to assist in the management of the disease and the associated symptoms. Short- and long-acting β₂-agonists or bronchodilators such as albuterol can be used to minimize bronchospasm and decrease wheezing and airway resistance. Anticholinergic drugs, such as atrovent, can block bronchoconstriction; xanthine-derived medications, such as theophylline, also produce bronchodilation and accelerate the mucociliary transport system and limit the inflammatory response. Corticosteroids, such as prednisone or flovent, are used for their anti-inflammatory benefits. Considerations need to be made when prescribing these medications to older adults due to pharmacokinetic and pharmacodynamic differences due to effects of aging. It is critical for patients with lung disease to receive a flu shot annually to decrease the risk of infection. When a patient has a history of recurrent infections, antibiotics play a critical role not only in the treatment of a recurrent infection but also as part of prophylactic care (Valente et al., 2010; Abbatecola et al., 2011; Jen et al., 2012).

These patients may also benefit from airway clearance techniques, including postural drainage, percussion and assistive breathing techniques, mobilization, or the use of an oscillating device to mobilize secretions. Finally, supplemental oxygen is used to correct hypoxemia and minimize secondary pulmonary hypertension. Oxygen therapy has been shown to reduce the level of dyspnea, decrease pulmonary hypertension, reduce the incidence of cardiac arrhythmias and improve quality and quantity of life. In the patient who presents with hypercapnia and respiratory insufficiency, bilevel positive airway pressure (BiPAP) ventilation has become recognized as an effective device in the management of patients with progressive disease. The ventilator provides positive airway pressure to decrease the work of inspiration and minimize the air trapping, which can reduce the retention of carbon dioxide.

Pulmonary rehabilitation has become a widely accepted intervention in the care of patients with COPD, with the ultimate goal of improving quality of life. The therapy program should consist of a comprehensive educational program to address such issues as nutrition, weight management, pathology and medical management, including the proper use of medications, work simplification and coping strategies. The program should stress and progress aerobic tolerance and include weight training to improve the muscular strength and endurance of the upper body; this will increase the effectiveness of the accessory respiratory and antigravity muscles in maximizing breathing and promoting functional mobility. The exercises should be functional and weight-bearing in nature to aid in the management of osteopenia and osteoporosis, which are very common in this patient population. Oxygen saturation should be monitored closely and supplemental oxygen adjusted to provide sufficient perfusion to support aerobic training. With training, the majority of patients with COPD will improve their exercise capacity, and note a decrease in the perception of dyspnea, an increase in self-control and a marked improvement in quality of life (Barnes & Fromer, 2011; Burtin et al., 2011; Nagarajan et al., 2011).

There are surgical options for the treatment of emphysema and chronic bronchitis. In the presence of a large bulla, which is a large airspace that is no longer contributing to gas exchange and is compressing adjacent tissue, surgical resection of this tissue (bullectomy) can be performed. Volume reduction surgery is an option for patients with emphysema, in which about 20% of dysfunctional lung tissue is surgically removed to decrease hyperinflation and improve ventilation and perfusion. Finally, lung transplantation has become a viable option for patients with end-stage COPD who have maximized medical therapy (Nathan et al., 2004).

The prognosis for patients with COPD varies depending upon the degree of obstruction, the presence of hypercapnia, the level of hypoxemia, functional mobility, body mass index, the recurrence of infections and country that the individual resides in; the 1-year mortality rate for all disease levels was reported at 27.7% and 5.1% in Canada and Sweden respectively (Rycroft et al., 2012). It is generally accepted that a FEV₁ of less than 25% is associated with a 50% mortality rate within 2 years. In chronic bronchitis, the prognosis is dependent upon age, smoking and the degree of airway obstruction. The 10-year survival rates for individuals with COPD over the age of 50 years is less than 30%, approximately 50% and 63% stratified by severe, moderate and mild disease (Shavelle et al., 2009).

Despite the range of etiologies that result in pulmonary fibrosis, patients present with a similar clinical picture of a variable rate of progressive decline, exertional dyspnea, a nonproductive cough that worsens with exertion and severe cyanosis. Along with severe dyspnea, patients generally experience severe desaturation with exertion. There is a decrease in normal breath sounds and the development of rales and clubbing of the nail beds. The breathing pattern is typically shallow with an elevated rate and there is a reduction of rib cage mobility, leading to a marked increase in the work of breathing. Anorexia, malaise and muscle weakness are also common clinical signs. Finally, pulmonary fibrosis is commonly associated with pulmonary hypertension and right heart failure (Markovitz & Cooper, 2010).

Conventional chest radiography reveals diffuse infiltrates, and honeycombing develops in the later stages of pulmonary fibrosis. When pulmonary function tests are examined, there is a decrease in lung volume, especially vital capacity (VC) and total lung capacity (TLC), a decrease in the gas exchange ability of the respiratory system (diffusion capacity; measured using the diffusing capacity of the lung for carbon monoxide [DLCO] test) and a decreased pulmonary compliance with a normal FEV₁–FVC ratio (see Fig. 45.3). A ventilation–perfusion mismatch occurs as ventilation declines and is associated with severe hypoxia. It has also been documented that there is skeletal muscle dysfunction (e.g. a reduction in type 2 muscle fibers) in patients with pulmonary fibrosis which is linked to disuse atrophy, adverse effects of medication therapy and the untoward effects of a prolonged elevated level of inflammatory markers (Markovitz & Cooper, 2010).

The best defense against pneumoconiosis is prevention; this is achieved with the use of proper respiratory filter devices and appropriate ventilation in the work area. Management includes the use of corticosteroids to minimize the inflammatory response and monitoring the progression of the disease with radiological studies, pulmonary function tests and exercise testing. Medications that inhibit the immune response are also utilized in the treatment of IPF. Cyclophosphamide impairs the function of neutrophils, eventually decreasing fibroblast and collagen proliferation. Azathioprine and cyclosporin (ciclosporin) suppress the production and maturation of T and B cells involved in the immune response. With the progression of the disease, medical care may include the use of supplemental oxygen and prostacyclin drugs for the treatment of right heart failure resulting from pulmonary hypertension. Non-invasive mechanical ventilatory support may be helpful to decrease the work of breathing, improve oxygen delivery and allow for rest periods. In the presence of isolated pulmonary fibrosis, lung transplantation should be considered on a case-by-case basis (Harari & Caminati, 2010).

Pulmonary rehabilitation can also be beneficial for patients with pulmonary fibrosis with improvement in 6-minute walk distance, decrease in dyspnea levels and improvement in quality of life. Once again, the ultimate goal is to improve the quality of life. An educational and exercise program, similar to that described in the COPD section, should be provided for this patient population but the clinician should expect the rehabilitation progress to be much slower than with COPD patients. It is important that the exercise program be tailored to the individual patient with pulmonary fibrosis (Markovitz & Cooper, 2010). The program should include stretching exercises to maintain chest wall mobility and, in the presence of pulmonary hypertension, interval exercises. Prescribed rest times are essential to decrease the strain on the right ventricle. The rehabilitation prescription should also include aerobic training, functional muscle strength and endurance training. These patients typically require high levels of supplemental oxygen to prevent severe hypoxia so the rehabilitation clinician will need to work closely with the pulmonologist and respiratory therapist to prescribe the proper supplemental oxygen delivery systems and oxygen prescriptions. The disease progression is generally aggressive, so work simplification training is also valuable and the program should be focused on maintaining functional mobility.

The prognosis is generally poor for patients with pulmonary fibrosis because of refractory hypoxemia, right heart failure and the increased risk of bronchogenic carcinoma in patients who smoke and those with occupational exposure pulmonary fibrosis. In ARDS, the mortality rate is as high as 60%, but has been decreasing to 22–35%, with a higher death rate in older patients (Matthay et al., 2012). In general, the mean survival time in cases of pulmonary fibrosis is 2–5 years but this will vary based on the aggressiveness and type of disease, duration of symptoms and response to therapy (Harari & Caminati, 2010; Noble et al., 2010).

The progression of dyspnea and the early onset of fatigue are typically the first symptoms of pulmonary hypertension, although many patients associate this with aging and deconditioning. Patients may begin to complain of presyncopal symptoms or may experience syncope. Chest pain, muscle fatigue, hypoxemia and hemoptysis are other common symptoms related to pulmonary hypertension. As the patient develops cor pulmonale, the signs and symptoms of right heart failure become present, which include jugular vein distension, peripheral edema and hepatic congestion. (See Chapter 42 for descriptions of the signs and symptoms of heart failure.)

Upon examination, the right ventricle may be palpable in the lower left sternal or subxiphoid area and abnormal heart sounds are present, including S4 gallop and a split S2 sound. As the disease progresses, S3 gallop can be heard, indicating advanced right heart failure. Abnormal valvular heart sounds may also be audible, including a systolic ejection click and tricuspid murmur. The electrocardiogram (ECG) is consistent with right ventricular hypertrophy and changes in the T wave. As the disease progresses, there will be clear signs of right heart failure, in most cases including jugular vein distension, hepatic congestion, peripheral edema, ascites and systemic hypotension (Higenbottam, 2005).

The treatment of pulmonary hypertension involves treating the primary cause of it. Drugs to decrease strain on the right side of the heart, such as digitalis and diuretics, and supplemental oxygen therapy to treat the hypoxemia may be effective. Continuous intravenous prostacyclins, for example Flolan and Iloprost, may decrease pulmonary hypertension by vasodilatation when infused into the pulmonary arterial system. The most common positive effects of the intravenous use of prostacyclins are an improvement in exercise tolerance and a decrease in symptoms experienced at rest and with exertion. Endothelin receptor antagonists, such as bosentan, reverse the effects of endothelin, and sildenafil (Viagra) and tadalafil (Cialis) are vasodilators also used in the management of pulmonary hypertension. Anticoagulation medications may be used to decrease the risk of thromboembolic events because of polycythemia, which may develop as a compensatory mechanism to offset hypoxemia. In the case of heart failure, ventricular assist devices may be used to manage, and in some cases reverse, the levels of pulmonary hypertension (Mikus et al., 2011).

The most pronounced clinical presentation in cases of pulmonary embolism includes unexplained dyspnea of rapid onset, pleuritic chest pain and hypotension with no obvious cause. The presence of hemoptysis indicates pulmonary hemorrhage or infarction (McLenon, 2012).

During evaluation, it is important to develop a differential diagnostic list and proceed with testing to enable a clinical diagnosis to be formulated. The differential diagnosis may include the following conditions: acute myocardial infarction (MI), asthma, pneumothorax, congestive heart failure (CHF), acute pulmonary edema, pleurisy, pericarditis, musculoskeletal trauma to the chest wall, sepsis, tamponade and aortic dissection. Risk factors associated with PE and prognosis include age>80, male gender, history of cancer, heart failure, chronic lung disease, previous DVT or PE, renal or liver disease, recent trauma or surgery (Geersing et al., 2012).

Upon physical examination there may be a low-grade fever, cyanosis, tachycardia, jugular vein distension, tachypnea and hypotension. Upon auscultation, there may be a pleural rub and a split of the S2 heart sound may be heard over the pulmonic valve. The degree of respiratory compromise is dependent on the size of the pulmonary embolism and the preexisting cardiopulmonary reserves. An echocardiogram may be suggestive of right heart strain or ischemia and the ECG may demonstrate T-wave inversion.

The key to appropriate medical care is the identification of patients who are at high risk and implementation of effective prophylactic treatment. Treatment includes prevention such as early mobilization and the use of graduated compression devices and TED stockings. The use of intermittent pneumatic compression stockings provides peripheral pumping to encourage venous return and reduce venous stasis. Many patients will be prescribed anticoagulants for the prevention and treatment of DVT formation. In patients who cannot take anticoagulants, an inferior vena cava filter may be placed to decrease the risk of a pulmonary embolism occurring from a lower extremity or pelvic thrombus. Thrombolytic therapy has also been used successfully to break down the DVT or pulmonary embolism, but is associated with a risk of hemorrhage (McLenon, 2012). Finally, pulmonary endarterectomy has become a viable surgical option to remove the emboli from the pulmonary artery or arteries. It is performed through a sternotomy and can be complicated by persistent hypoxia and prolonged mechanical ventilation as well as management of heart failure.

The prognosis for a patient suffering from a pulmonary embolism is dependent upon the size of the pulmonary embolism, the underlying compromise of the cardiopulmonary system and the promptness of medical care. Mortality rate for PE has been reported to be as high as 30% if untreated and 80% of unexplained hospital deaths were related to undiagnosed PE. There is a 10% 1-year mortality for individuals in the first year after diagnosis of PE. Mortality can be as high as 40% within 5 years in individuals who stopped anticoagulation therapy (Geersing et al., 2012; Ouellette & Mosenifar, 2013).