Ch.24
Panlobular emphysema
destruction of the respiratory bronchiole, alveolar duct, and alveolus. All airspaces within the lobule are essentially enlarged, but there is little inflammatory disease. A hyperinflated (hyperexpanded) chest, marked dyspnea on exertion, and weight loss typically occur Instead of being an involuntary passive act, expiration becomes active and requires muscular effort.
Centrilobular emphysema
changes take place mainly in the center of the secondary lobule producing chronic hypoxemia hypercapnia, polycythemia (increase in red blood cells)and episodes of right-sided heart failure. This leads to central cyanosis and respiratory failure. The patient also develops peripheral edema.
3 primary symptoms of COPD and signs
chronic cough, sputum production and dyspnea; barrel-chested, tripod position when breathing
Asthma symptoms
cough, chest tightness, wheezing, and dyspnea
allergy
is the strongest predisposing factor for asthma. Chronic exposure to airway irritants or allergens also increases the risk of asthma.
Indications for exacerbation of COPD
severe dyspnea that does not respond adequately to initial therapy, confusion or lethargy, respiratory muscle fatigue, paradoxical chest wall movement, peripheral edema, worsening or new onset of central cyanosis, persistent or worsening hypoxemia, and the need for noninvasive or invasive assisted mechanical ventilation
Primary causes of exacerbation of COPD
tracheobronchial infection and air pollution.
Emphysema
Abnormal distention of air spaces beyond the terminal bronchioles with destruction of the walls of the alveoli Progresses slowly for many years. Decreased alveolar surface area increases in "dead space," (lung area where no gas exchange can occur). Hypoxemia results Increased pulmonary artery pressure may cause right-sided heart failure (cor pulmonale)
CAuses of Bronchiectasis
Airway obstruction, Pulmonary infections Diffuse airway injury Genetic disorders Abnormal host defenses Idiopathic causes
Status asthmaticus
An asthma exacerbation that can range from mild to severe with potential respiratory arrest. It is sometimes used to describe rapid onset, severe, and persistent asthma that does not respond to conventional therapy. The attacks can occur with little or no warning and can progress rapidly to asphyxiation. Infection, anxiety, nebulizer abuse, dehydration, increased adrenergic blockage, and nonspecific irritants may contribute to these episodes. An acute episode may be precipitated by hypersensitivity to aspirin.
Nursing Mgt. of COPD
Breathing Exercises With practice, this type of upper chest breathing can be changed to diaphragmatic breathing, which reduces the respiratory rate, increases alveolar ventilation, and sometimes helps expel as much air as possible during expiration (see Chapter 21 for technique). Pursed-lip breathing helps slow expiration, prevents collapse of small airways, and helps the patient control the rate and depth of respiration. It also promotes relaxation, enabling the patient to gain control of dyspnea and reduce feelings of panic. Nutritional therapy, Coping measures
Pharmacologic therapy for COPD
Bronchodilators: relieve bronchospasm by altering smooth muscle tone and reduce airway obstruction by allowing increased oxygen distribution throughout the lungs and improving alveolar ventilation. These agents can be delivered through a metered-dose inhaler (MDI) or other type of inhaler, by nebulization, or via the oral route in pill or liquid form. Bronchodilators are often administered regularly throughout the day as well as on an as-needed basis. They may also be used prophylactically to prevent breathlessness by having the patient use them before participating in or completing an activity, such as eating or walking.
Chronic Obstructive Pulmonary Disease
Characterized by airflow limitation that is not fully reversible (chronic bronchitis and emphysema) is a preventable and treatable slowly progressive respiratory disease of airflow obstruction involving the airways, pulmonary parenchyma, or both. Airflow limitation is progressive, associated with abnormal inflammatory response to noxious particles or gases Chronic inflammation damages tissue Scar tissue in airways results in narrowing Decreases elastic recoil (compliance) Causes thickened vessel lining and hypertrophy of smooth muscle (pulmonary hypertension)
Clinical Manifestation
Chronic cough Purulent sputum in copious amounts Clubbing of the fingers
Asthma
Chronic inflammatory disease of the airways that causes hyperresponsiveness, mucosal edema, and mucus production Inflammation leads to recurrent episodes; The most common chronic disease of childhood, it can occur at any age. Ethnic and racial disparities affect morbidity and mortality, which are higher in inner-city African Americans and Latinos Contributing to these disparities are epidemiology and risk factors; genetics and molecular aspects; inner-city environments; limited community assets; health care access, delivery, and quality; and lack of insurance coverage. Unlike other obstructive lung diseases, it is largely reversible, either spontaneously or with treatment. Patients may experience symptom-free periods alternating with acute exacerbations that last from minutes to hours or days
Common allergens and triggers of asthma
Common allergens can be seasonal (grass, tree, and weed pollens) or perennial (e.g., mold, dust, roaches, animal dander). Common triggers for asthma symptoms and exacerbations include airway irritants (e.g., air pollutants, cold, heat, weather changes, strong odors or perfumes, smoke, occupational exposure), foods (e.g., shellfish, nuts), exercise, stress, hormonal factors, medications, viral respiratory tract infections, and gastroesophageal reflux. Most people who have asthma are sensitive to a variety of triggers.
Chronic Bronchitis
Cough and sputum production for at least 3 months in each of 2 consecutive years Ciliary function is reduced, bronchial walls thicken, bronchial airways narrow, and mucous may plug airways Alveoli become damaged, fibrosed, and alveolar macrophage function diminishes. (macrophages play an important role in destroying foreign particles, including bacteria) The patient is more susceptible to respiratory infections A wide range of viral, bacterial, and mycoplasmal infections can produce acute episodes of bronchitis. Exacerbations are most likely to occur during the winter when viral and bacterial infections are more prevalent.
COPD Risk Factors
Exposure to tobacco smoke accounts for an estimated 80%-90% of cases of chronic obstructive pulmonary disease • Passive smoking (i.e., secondhand smoke) • Increased age • Occupational exposure—dust, chemicals • Indoor and outdoor air pollution • Genetic abnormalities, including a deficiency of alpha1- antitrypsin, an enzyme inhibitor that normally counteracts the destruction of lung tissue by certain other enzymes
Grade of COPD
Grade I (mild) greater than or less than 80% Grade II (moderate) 50%-80% Grade III (severe) less than 30%-50% Grade IV (very severe) less than 30%
Cystic fibrosis
Most common fatal autosomal recessive disease among the Caucasian population Genetic screening to detect carriers Genetic counseling for couples at risk Genetic mutation changes chloride transport which leads to thick, viscous secretions in the lungs, pancreas, liver, intestines, and reproductive tract Respiratory infections are the leading cause of morbidity and mortality
General Principles for Oxygen therapy
Oxygen therapy can be administered as long-term continuous therapy, during exercise, or to prevent acute dyspnea during an exacerbation. The goal of supplemental oxygen therapy is to increase the baseline resting partial pressure of arterial oxygen (PaO2) to at least 60 mm Hg at sea level and an arterial oxygen saturation (SaO2) to at least 90%. Long-term oxygen therapy (more than 15 hours per day) has also been shown to improve quality of life, reduce pulmonary arterial pressure and dyspnea, and improve survival The main objective in treating patients with hypoxemia and hypercapnia (excessive carbon dioxide in the blood) is to give sufficient oxygen to improve oxygenation. Patients with COPD who require oxygen may have respiratory failure that is caused primarily by a ventilation-perfusion mismatch. These patients respond to oxygen therapy and should be treated to keep the resting oxygen saturation above 90%. However, a small subset of patients with COPD and chronic hypercapnia (elevated partial pressure of arterial carbon dioxide [PaCO2] levels) may be more oxygen sensitive; their respiratory failure is caused more by alveolar hypoventilation. Administering too much oxygen can result in the retention of carbon dioxide. Patients with alveolar hypoventilation cannot increase ventilation to adjust for this increased load, and increasing hypercapnia occurs. Monitoring and assessment are essential in the care of patients with COPD on supplemental oxygen. https://www.youtube.com/watch?v=SA7ecCDStmQ Oxygen therapy is variable in patients with COPD; its aim in COPD is to achieve an acceptable oxygen level without a fall in the pH (increasing hypercapnia).
Medical Mgt.
Postural drainage Chest physiotherapy Smoking cessation Antimicrobial therapy
Assessment and Diagnostic findings of COPD
Pulmonary Function Studies Spirometry: used to help confirm the diagnosis of COPD, determine disease severity, and monitor disease progression. Also used to evaluate airflow obstruction, which is determined by the ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC). ABG's Chest x-ray, CT, genetic screening
Medications Mgt. of Asthma
Quick-relief medications Short- acting Beta2-adrenergic agonists (SABA) (albuterol [AccuNeb, Proventil, Ventolin], levalbuterol [Xopenex HFA], and pirbuterol [Maxair]) are the medications of choice for relief of acute symptoms and prevention of exercise-induced asthma. They are used to relax smooth muscle. Anticholinergics (e.g., ipratropium [Atrovent]) inhibit muscarinic cholinergic receptors and reduce intrinsic vagal tone of the airway. These may be used in patients who do not tolerate short-acting beta2-adrenergic agonists. Long-acting medications Corticosteroids are the most potent and effective anti-inflammatory medications currently available. They are broadly effective in alleviating symptoms, improving airway function, and decreasing peak flow variability. Long-acting beta2-adrenergic agonists(LABA) are used with antiinflammatory medications to control asthma symptoms, particularly those that occur during the night. Also effective in the prevention of exercise-induced asthma. Theophylline (Slo-Bid, Theo-Dur) is a mild to moderate bronchodilator that is usually used in addition to inhaled corticosteroids, mainly for relief of nighttime asthma symptoms. Leukotriene modifiers include (Singulair), (Accolate), and (Zyflo). Leukotrienes, which are synthesized from membrane phospholipids through a cascade of enzymes, are potent bronchoconstrictors that also dilate blood vessels and alter permeability.
Medical Mgt. of COPD
Smoking cessation is the single most cost-effective intervention to reduce the risk of developing COPD and to stop its progression Referral to a smoking cessation program may be helpful. Follow-up within 3 to 5 days after the quit date to review progress and to address any problems is associated with an increased rate of success Nicotine replacement—a first-line pharmacotherapy that reliably increases long-term smoking abstinence rates comes in a variety of forms: gum, inhaler, nasal spray, transdermal patch, sublingual tablet, or lozenge
S/S of Status Asthmaticus
The clinical manifestations are the same as those seen in severe asthma; signs and symptoms include labored breathing, prolonged exhalation, engorged neck veins, and wheezing. However, the extent of wheezing does not indicate the severity of the attack. As the obstruction worsens, the wheezing may disappear; this is frequently a sign of impending respiratory failure.
Exacerbation of COPD
defined as an event in the natural course of the disease characterized by acute changes (worsening) in the patient's respiratory symptoms beyond the normal day-to-day variations.
Bronchiectasis
a chronic, irreversible dilation of the bronchi and bronchioles
Pulmonary manifestations of CF
the pulmonary manifestations include a productive cough, wheezing, hyperinflation of the lung fields on chest x-ray, and pulmonary function test results consistent with obstructive disease of the airways. Chronic respiratory inflammation and infection are caused by impaired mucus clearance.