Senile emphysema

　　The etiology of elderly pulmonary emphysema is very complex and is the result of the combined action of multiple factors. The specific causes of the disease are described as follows.

　　1. Smoking

　　Smoking is the main factor causing emphysema. Among patients with chronic obstructive pulmonary disease (COPD), 80% to 90% are smokers, and more than 20% of smokers will develop COPD. The smoke of tobacco contains various harmful components, such as tar, nicotine, carbon monoxide, nitrogen oxides, furfural, and so on. These harmful substances can directly or indirectly damage the bronchial mucosal epithelium, even causing squamous metaplasia; inhibit or damage the movement of bronchial mucosal cilia; stimulate the hyperplasia of mucus glands, excessive secretion of mucus; inhibit the phagocytic function of pulmonary macrophages; retention of secretions is prone to secondary microbial infection; and reduce the activity of alpha-1 antitrypsin, leading to an imbalance in the balance between elastase and elastase inhibitor. This is the pathogenesis pattern of smoking-emphysema-chronic bronchitis or smoking-chronic bronchitis-emphysema.

　　2. Environmental Pollution

　　Long-term exposure to organic or inorganic dust, harmful gases, is prone to emphysema.

　　3. Infection

　　Recurrent airway infections can cause bronchial mucosal congestion and edema, gland hyperplasia, increased secretion, and increased protease activity, which will lead to the occurrence of emphysema.

　　4. Genetic Factors

　　Severe deficiency of alpha-1 antitrypsin due to genetic defects can cause emphysema. This type of emphysema often occurs in young adulthood, with a short course and severe condition, and is more common in white people, while it is rare in China.

　　The complications of elderly pulmonary emphysema include lower respiratory tract infections, spontaneous pneumothorax, chronic pulmonary heart disease, and heart failure, among others. The specific symptoms of complications are described as follows.

　　1. Lower Respiratory Tract Infection

　　Pulmonary emphysema patients are prone to lower respiratory tract infections due to aging, weakness, malnutrition, decreased immune function, narrowed airways, and secretions retention. Patients often transition from a stable phase to an exacerbation phase due to this. It is noteworthy that elderly patients with concurrent infections often do not have fever and the total white blood cell count is not high. Severe cough, shortness of breath, increased sputum volume, and purulent sputum are the earliest and most important signs of lower respiratory tract infection.

　　2. Spontaneous Pneumothorax

　　It usually occurs due to the rupture of pulmonary bullae. It can be triggered by severe coughing or exertion, or it can occur without any trigger. The typical manifestations include chest pain and sudden onset of dyspnea, with hyperresonant percussion over the affected area. Elderly patients often do not have chest pain but only progressive worsening of dyspnea. Chest X-ray examination may show signs of pleural air. Due to the poor baseline pulmonary function in elderly patients, timely rescue is necessary.

　　3. Chronic pulmonary heart disease and heart failure

　　Emphysema patients may develop pulmonary hypertension due to long-term hypoxemia, hypercapnia, and a decrease in the pulmonary capillary bed, which can further lead to pulmonary heart disease. During the exacerbation period, cardiac function may become decompensated, leading to heart failure. In most cases, the decompensation leads to right heart failure, which is worth being vigilant about. It may also lead to left heart failure, which may be due to myocardial degeneration and arrhythmia caused by long-term hypoxemia and recurrent infections, leading to sepsis.

　　4. Respiratory failure

　　Severe senile emphysema patients are prone to respiratory muscle fatigue due to increased work of breathing, a flattened diaphragm, an increased curvature radius, and malnutrition. On this basis, respiratory failure is often induced due to factors such as lower respiratory tract infection, associated diseases, surgery, fatigue, and other factors. Improper use of oxygen therapy, sedatives, cough suppressants, and other iatrogenic factors may also trigger respiratory failure.

　　5. Multiple organ failure

　　Severe senile emphysema patients often experience simultaneous failure of cardiovascular function, and even complications such as disseminated intravascular coagulation, liver and kidney dysfunction, leading to multiple organ failure and threatening life.

　　6. Gastric ulcer

　　Autopsy confirmed that 18% to 30% of emphysema patients have gastric ulcers, and the pathogenesis is not yet fully understood.

　　7. Pulmonary embolism

　　Senile emphysema patients, especially those with pulmonary heart disease, may develop pulmonary embolism due to hypercoagulability, hyper黏稠状态, prolonged bed rest, arrhythmia, and sepsis. Senile emphysema patients should be vigilant about the possibility of pulmonary embolism if they suddenly experience difficulty breathing, palpitations, and increased cyanosis.

　　8. Sleep-related breathing disorders

　　Sleep-related breathing disorders include sleep apnea syndrome (SAS) and sleep hypoventilation syndrome (HPVS). They have been increasingly recognized in recent years. Foreign reports indicate that the prevalence of sleep apnea hypoventilation syndrome (SAHS) in adults is 1% to 4%, and in those over 65 years old, it is as high as 20% to 40%. The incidence of senile SAHS in emphysema is even higher. The coexistence of chronic obstructive pulmonary disease (COPD) and SAHS is called 'overlap syndrome'. Such patients may experience significant hypoxemia and carbon dioxide retention during the rapid eye movement (REM) sleep phase. Sleep-related breathing disorders in emphysema are often overlooked, but they are very harmful. Where conditions permit, 'polysomnography' should be performed on senile emphysema patients, especially those with purple emphysema, to make an accurate diagnosis and provide proper treatment.

　　The onset of senile emphysema is slow, with a long course, alternating between stable and exacerbation periods. The specific clinical manifestations are as follows.

　　1. Symptoms

　　1. Cough and sputum:Patients with emphysema often have a history of many years of coughing and sputum, with stable period cough, which can be relatively mild, and sputum can be white and sticky. When respiratory tract infection is present, coughing and sputum become more severe, and sputum becomes purulent.

　　2. Chest tightness and shortness of breath:In the early stage, shortness of breath is often felt during activities such as climbing stairs or brisk walking, and gradually develops to shortness of breath during walking on flat ground. In the later stage, shortness of breath is felt during daily activities such as washing face, brushing teeth, tying shoes, dressing, speaking, and even at rest. Patients often prefer a forward-leaning sitting position (which allows the accessory respiratory muscles to participate in activity), pursed-lip expiration, or dyspnea with expiration grunting.

　　3. Fatigue, loss of appetite, weight loss, etc.:It is very common in patients with senile emphysema.

　　4. Fever:Fever is often present when complications occur. Drowsiness or restlessness, disturbance of consciousness, headache, profuse sweating, winging tremor of the hands, and other symptoms often suggest the possibility of respiratory failure. Urinary output is reduced, lower limb edema, cyanosis of the lips and fingers, palpitations, and other symptoms often suggest the possibility of right heart failure of pulmonary heart disease.

　　II. Signs

　　1. Patients in the early stage often have no abnormalities, and severe cases may show a 'barrel chest'. Due to the late onset age of senile emphysema, the costal cartilage has already calcified at this time, so a typical barrel chest is not common in patients with senile emphysema, but there is often an increase in the intercostal space. The lung percussion sound is hyperresonant, the liver dullness border descends, the heart dullness border narrows or disappears, the respiratory and phonation sounds weaken, expiration is prolonged, and sometimes dry and wet rales can be heard at the base of the lung, and the heart sound is low and distant.

　　2. In patients with respiratory failure, hypertension, cyanosis, edema of the conjunctiva, nystagmus, unequal size of the pupils, and winging tremor of the hands may be seen.

　　3. In patients with right heart failure, cyanosis, distension of the jugular veins, intensification or splitting of the second sound of the pulmonary artery valve, enlargement of the liver, positive hepatojugular reflux sign, and pitting edema of the lower extremities may be seen.

　　The prevention of senile emphysema mainly focuses on the prevention of the etiology. Quitting smoking and actively preventing and treating respiratory tract infections are the main measures for preventing emphysema. Avoiding long-term exposure to organic or inorganic dust and harmful gases is also very important for the prevention of the disease.

　　The examination for senile emphysema includes arterial blood gas analysis, X-ray, and pulmonary function examination, etc., and the specific examination methods are described as follows.

　　1. Arterial blood gas examination

　　Arterial oxygen partial pressure (PaO2) can be within the normal range in the early stage, that is, between the expected value and -1.3 kPa (10 mmHg) (expected value: sitting 104.2 mmHg - 0.27 × age; supine: 103.5 mmHg - 0.42 × age; or 13.3 kPa - 0.04 × age); in the later stage, there may be a decrease to varying degrees [less than the expected value - 1.3 kPa (10 mmHg)]. Arterial carbon dioxide partial pressure (PaCO2) can be normal in the early stage [4.7 kPa ~ 6.0 kPa (35 mmHg ~ 45 mmHg)], and in the later stage, there may be an increase to varying degrees [greater than 6.0 kPa (45 mmHg)]. Arterial oxygen saturation (SaO2) can be normal in the early stage, and in the later stage, there may be a decrease to varying degrees (less than 95%); the alveolar-arterial oxygen partial pressure difference (A-aDO2) increases [≥2.7 kPa (20 mmHg)].

　　2. X-ray examination

　　Pulmonary translucency is enhanced, pulmonary texture is reduced, diaphragm is flat, ribs are flattened, intercostal spaces are widened, and cardiac shadow is hanging. It can also be manifested as increased pulmonary texture, enlarged cardiac shadow, and widened right lower pulmonary artery.

　　3. Pulmonary function tests

　　Total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC) increase, vital capacity (VC) is normal or decreased, maximum voluntary ventilation (MBC), forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), maximum mid-expiratory flow (MMEF), maximum expiratory flow-volume (MEFV) and other indicators reflecting ventilation function show significant decline, and carbon monoxide diffusing capacity (DLco) decreases.

　　Elderly COPD patients should eat foods with anti-inflammatory, antibacterial, and immune-enhancing properties, and should eat foods rich in dietary fiber that are easy to digest and absorb. Avoid drinking coffee, strong tea, and avoid eating spicy and greasy foods. The specific dietary precautions are described as follows.

　　1. Avoid eating spicy foods

　　Avoid eating spicy and刺激性 foods such as chili, scallion, garlic, and alcohol, as they can stimulate the tracheal mucosa, worsen symptoms such as coughing, asthma, palpitations, and trigger asthma, so they should be avoided.

　　2. Avoid eating seafood and greasy foods

　　Fish cooked in non-steamed methods, due to the excessive use of oil, is easy to cause internal heat.

　　3. Avoid eating gas-producing foods

　　Such as sweet potatoes, chives, etc., as they are not conducive to the ventilation of the lungs, more alkaline foods should be eaten.

　　4. Prohibit smoking

　　Since smoking is one of the causes of the occurrence and development of bronchitis, it should be strictly prohibited.

　　In addition, people with allergic constitution and those with high blood uric acid levels (such as gout patients) should also eat less large oil fish, such as yellow croaker, hairtail, shrimp, crab, and fatty meat, etc., to avoid causing fire and phlegm.

 

　　The treatment of elderly COPD should include the management of stable period and the treatment of exacerbation period, and the specific treatment methods are described as follows.

　　I. Management of stable period

　　The focus of stable period management is rehabilitation treatment, the purpose of which is to improve the quality of life of patients, reduce the frequency of acute attacks, and prolong survival.

　　1. Improve the general condition of patients

　　(1) Mobilize patients to quit smoking

　　Smoking is the number one risk factor for COPD, and quitting smoking can alleviate symptoms and slow the progression of lung function damage. A large amount of evidence shows that quitting smoking and long-term oxygen therapy can significantly delay the natural progression of COPD.

　　(2) Strengthen nutrition, enhance body immunity

　　Malnutrition not only damages lung function and respiratory muscle function but also weakens the body's immune mechanism. Therefore, COPD patients should strengthen their nutrition. Cold resistance training, moderate exercise (such as walking, health exercises, Tai Chi, etc.), traditional Chinese medicine for reinforcing the body's resistance, intramuscular injection of casein (casein), or freeze-dried BCG vaccine, etc., can enhance physical fitness, prevent colds and lower respiratory tract infections.

　　(3) Scientific knowledge education and guidance

　　Elderly patients with chronic obstructive pulmonary disease (COPD) often suffer from anxiety, depression, or fear due to long course of illness, recurrent attacks, and limited social activity. This is not conducive to recovery and the improvement of quality of life. Health education and guidance in health knowledge, guiding patients to carry out correct rehabilitation exercises, and enhancing mental health.

　　2. Respiratory training

　　Instruct patients to perform diaphragmatic breathing and pursed-lip exhalation - first perform pursed-lip exhalation, contract the abdominal muscles to increase abdominal pressure, and elevate the diaphragm; then inhale through the nose, relax the abdominal muscles to bulge, and contract the diaphragm to descend. This deep, slow, fine, and uniform diaphragmatic breathing can coordinate chest and abdominal breathing, increase tidal volume, reduce dead space ventilation, slow down the respiratory rate, increase oxygenation, and reduce respiratory oxygen consumption; pursed-lip exhalation can increase the pressure at the external orifice segment of the airway, shift the equal pressure point towards the central airway, prevent the early closure of small airways during exhalation, reduce lung gas retention, and alleviate the imbalance of ventilation/perfusion ratio.

　　3. Respiratory muscle exercise

　　Malnutrition and fatigue of respiratory muscles in elderly patients with emphysema are important bases and triggers for low ventilation and respiratory failure. Respiratory muscle exercise is very important for the rehabilitation of elderly patients with emphysema. Common methods of respiratory muscle exercise include resistance breathing and exercise. For example, using a respiratory resistance device for breathing increases inspiratory resistance to achieve the purpose of exercising the respiratory muscles. After exercise, the strength and endurance of the respiratory muscles can be significantly improved. It should be noted that when resistance breathing exercise is performed, too little resistance will not achieve the exercise purpose, and too much resistance will easily trigger respiratory muscle fatigue.

　　4. Home oxygen therapy

　　Oxygen therapy can improve the symptoms of patients, increase work efficiency, enhance activity intensity, expand the range of activity, and prolong survival. Continuous low-flow oxygen therapy for 15 hours a day is better than intermittent oxygen therapy. With the improvement of oxygen supply equipment, home oxygen therapy has become possible. Oxygen concentrators, liquid oxygen storage tanks, etc., are small in size, easy to use, and suitable for home oxygen therapy.

　　5. Other

　　Non-invasive mechanical ventilation is also applicable to the home management of severe emphysema patients. Under the guidance of a doctor, the use of a face mask plus intermittent辅助 mechanical ventilation can allow the respiratory muscles to rest, relieve respiratory muscle fatigue, and improve respiratory muscle function.

　　2. Treatment during the exacerbation period

　　1. Control of respiratory tract infection

　　The pathogens causing mild to moderate respiratory tract infections in patients with emphysema are mainly Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella catarrhalis, and Staphylococcus aureus; severe cases are often dominated by Gram-negative bacilli. Once infection occurs, early and adequate use of sensitive antibiotics is required, and the course of treatment also needs to be appropriately prolonged. Mild to moderate respiratory tract infections are mainly treated with oral antibiotics, and for trial treatment, carbenicillin (carboxybenzylpenicillin), new-generation macrolide antibiotics, fluoroquinolone antibiotics, and first and second-generation cephalosporin antibiotics can be chosen, with a course of treatment generally ranging from 5 to 10 days.

　　Severe respiratory tract infections are mainly treated with intravenous antibiotics. It is advisable to first choose second and third-generation cephalosporin antibiotics and fluoroquinolone antibiotics, and conduct a trial treatment for 3 to 5 days. Subsequently, antibiotics should be adjusted in a timely manner based on the results of expectoration bacteriology and drug sensitivity. In elderly patients with emphysema and severe respiratory tract infections, the proportion of anaerobic bacteria and fungal infections is relatively high, and high vigilance should be maintained. Anaerobic bacterial infections can be initially treated with tinidazole, clindamycin (chlorocycline) or third-generation cephalosporin antibiotics. Fungal infections (most of which are caused by Candida albicans) can be treated with fluconazole, with an oral dose of 100mg per time, twice a day, and the course of treatment should be at least 2 weeks.

　　The renal function of the elderly decreases significantly with age, so antibiotics that are mainly excreted by the kidney or have significant nephrotoxicity, such as aminoglycosides, should be used with caution, and appropriate dosages should be reduced when necessary.

　　2. Expectorant

　　Drugs commonly used in clinical practice are expectorants and mucus-thinning drugs. The former mostly increases respiratory tract secretions reflexively by stimulating the gastric mucosa, making phlegm thinner and easier to cough out; the latter directly breaks down viscous components, reducing the viscosity of sputum and making it easier to cough out. Ambroxol (Mucosolvan) can regulate and balance the secretory function of mucus glands and serous glands, increase serous secretion to make sputum thinner; stimulate improvement of ciliary movement, promote expectoration; stimulate the formation of pulmonary surfactant, reduce the adhesion of mucus to the terminal airways, prevent the formation of mucus clumps for easier flow, prevent the collapse of terminal airways, and keep small airways open. Ambroxol not only has a good expectorant effect but also can increase the concentration of antibiotics in the focus, making it a relatively ideal expectorant, with a daily dose of 60mg. Nebulized inhalation can also dilute respiratory tract secretions, making it easier to cough out sputum.

　　3. Antispasmodic and Anti-asthmatic

　　Patients with senile emphysema often have chronic bronchitis, and the airway obstruction caused by them is progressive, may be accompanied by high airway reactivity, and some of the manifestations are reversible. The use of antispasmodic and anti-asthmatic drugs can improve airway obstruction. The commonly used antispasmodic and anti-asthmatic drugs in clinical practice are β2-adrenergic receptor agonists, anticholinergic drugs, theophylline derivatives, and corticosteroids. β2-adrenergic receptor agonists and anticholinergic drugs should be mainly inhaled. Due to the decreased sensitivity of β-receptors in elderly patients, the effect of β2-adrenergic receptor agonists is often not very ideal. Currently, the commonly used anticholinergic drug in clinical practice is ipratropium bromide (isoproterenol bromide), which takes effect 5 minutes after inhalation, reaches its peak between 30 minutes to 90 minutes, and has a duration of action of 4 to 6 hours, is not easily absorbed, and is very safe for local application. In case of severe attacks, aminophylline can be used for intravenous infusion, and it is best to monitor the serum concentration to maintain it at (10 to 12) μg/ml. For those with nocturnal bronchospasm, theophylline controlled-release or sustained-release preparations can be used. Oral or intravenous administration of corticosteroids is usually only used for short-term in acute attacks of chronic bronchitis with wheezing or in cases of severe respiratory failure. Some elderly patients with emphysema may have adrenal cortical insufficiency, and long-term administration of 'physiological dose' of corticosteroids (such as dexamethasone 0.375mg or prednisone 2.5mg daily or every other day) is often helpful for symptom control and reducing the frequency of attacks; for some patients with emphysema who do not have signs of adrenal cortical insufficiency, long-term use of corticosteroids can also improve symptoms. However, long-term use of corticosteroids in elderly patients can have many adverse reactions, and should be used with caution. If necessary, it is best to use quantitative nebulized inhalation administration.

　　4. Improve hypoxia

　　Patients with advanced emphysema have varying degrees of hypoxia, and it is better to provide low-flow continuous oxygen. Severe emphysema patients tend to have carbon dioxide retention, and the respiratory center's sensitivity to carbon dioxide decreases. Hypoxia is the only respiratory center stimulant. High-concentration oxygen therapy or the pursuit of 'complete' correction of hypoxia may trigger respiratory failure. At this time, mechanical ventilation should be performed. In the absence of mechanical ventilation, high-frequency jet oxygen therapy + respiratory stimulants can also be tried.

　　5. Nutritional support and maintenance of water and electrolyte balance

　　Elderly patients with emphysema often have poor appetite and are often accompanied by malnutrition, which not only damages the body's immune function but also damages the function of respiratory muscles. Therefore, intravenous supplementation of calories, amino acids, and proteins is very necessary. Patients with advanced emphysema often have water and electrolyte imbalances, which should be corrected in a timely manner.

　　6. Prevention and treatment of other severe complications

　　Elderly patients with emphysema often have complications such as heart and lung failure, pneumothorax, and pulmonary embolism, which can rapidly worsen the condition and even threaten life. Emergency rescue should be provided in a timely manner.