Pulmonary tuberculosis in the elderly

　　The decline and degeneration of elderly immune function are negatively correlated with age growth. For example, the positivity rate of tuberculin skin test is 80% at the age of 60, 70% at the age of 70, 50% at the age of 80, and 30% at the age of 90. The decline in immune function leads to an increase in the incidence of endogenous relapse and exogenous reinfection, resulting in a gradual increase in the incidence of elderly pulmonary tuberculosis. Untreated tuberculosis and elderly pulmonary tuberculosis with high rates of cavity and sputum smear positivity have become an important source of infection in society.

　　Elderly pulmonary tuberculosis often complicates with bronchiectasis, empyema, pneumothorax, pulmonary aspergillosis, chronic pulmonary heart disease, and other diseases.

　　1. Spontaneous pneumothorax

　　Pulmonary tuberculosis is a common cause of pneumothorax. Various pulmonary tuberculosis lesions can cause pneumothorax, such as subpleural focus or cavity rupture into the pleural cavity; fibrosis or scar formation of tuberculosis lesions leading to emphysema or pulmonary bullae rupture; the lesions of miliary pulmonary tuberculosis are located in the pulmonary interstitium, which can also cause interstitial emphysematous pulmonary bullae rupture. When the focus or cavity breaks into the pleural cavity, the pleural cavity often has a large amount of exudative fluid, which can form hydropneumothorax or empyema.

　　2. Bronchiectasis

　　The focus of pulmonary tuberculosis destroys the bronchial wall and the surrounding tissue of the bronchus, and bronchial tuberculosis itself can also cause bronchial deformation and expansion, known as tuberculous bronchiectasis, which may be accompanied by hemoptysis.

　　The diagnosis of tuberculosis in the elderly is often delayed, even found during post-mortem examination. The Centers for Disease Control and Prevention (CDC) reported that among 86,292 cases of tuberculosis from 1985 to 1988, only 26% of patients over 65 were diagnosed before death, and 60% were diagnosed post-mortem. The primary reason for delayed diagnosis is that doctors lack understanding and vigilance about tuberculosis and do not consider the possibility of the disease, therefore, they do not conduct corresponding examinations. In addition, the atypical clinical manifestations of pulmonary tuberculosis in the elderly are also an important reason for misdiagnosis. There are reports that 67.2% of elderly pulmonary tuberculosis cases are asymptomatic, about 1/4 of elderly pulmonary tuberculosis patients have no symptoms, which are easy to miss, and those with symptoms are also atypical, without specificity for diagnosis. Adding to the cognitive defects of the elderly, it is easy to neglect medical treatment or cannot accurately provide relevant medical history. Elderly people often have chronic cardiovascular and pulmonary diseases, malignant tumors, or other immunosuppressive diseases, which can conceal the symptoms of tuberculosis or attribute the symptoms of tuberculosis to these diseases. For example, symptoms such as fever, weight loss, and chronic cough, which are typical symptoms of tuberculosis, are often considered to be chronic bronchitis and senile changes.
　　The most common and earliest symptom of pulmonary tuberculosis in the elderly is cough. For those with persistent cough for more than 2 weeks, chest X-ray examination should be performed. Tuberculous pleurisy in the elderly is mostly secondary, 80% of which are associated with pulmonary tuberculosis, and 11.4% are hemorrhagic pleural effusion. It must be differentiated from pleural metastasis of lung cancer. When both the sputum examination and the tumor cell examination are negative, pleural biopsy should be performed to achieve early diagnosis. Granulomatous tuberculosis and extrapulmonary tuberculosis are more common in the elderly than in young people, and the misdiagnosis rate is very high. Extrapulmonary tuberculosis often has hidden symptoms without specificity, such as loss of appetite, weakness, fatigue, etc., which are often attributed to other chronic diseases or aging. However, about 1/3 of granulomatous tuberculosis chest X-ray films may show normal. Elderly patients with tuberculous meningitis or peritonitis may not have typical corresponding signs. In addition, the elderly often have other diseases. It is reported that up to 82.8% of elderly pulmonary tuberculosis patients have non-tuberculosis diseases, which is significantly higher than the middle-aged group (44.4%) and the young group (28.6%). The most common is respiratory system diseases, accounting for 45.0%, followed by cardiovascular diseases (14.4%) and diabetes (8.5%). When elderly pulmonary tuberculosis patients have respiratory system diseases and diabetes, due to the lack of typical manifestations of the primary disease and frequent visits to general hospitals, general internists lack high vigilance for tuberculosis and do not perform corresponding tuberculosis examinations, leading to long-term delayed diagnosis or misdiagnosis of elderly pulmonary tuberculosis. Literature reports indicate that the misdiagnosis rate of elderly pulmonary tuberculosis due to non-tuberculosis diseases is as high as 19% to 80%.

　　The elderly are prone to various chronic diseases such as diabetes and malignant tumors due to the weakness of the body, which not only makes the latent infection reignite or re-infect, but also increases the difficulty of diagnosis and treatment of tuberculosis in the elderly. Therefore, focusing on disease prevention is an important means to reduce the incidence of disease. The prevention of pulmonary tuberculosis in the elderly is divided into the following three levels:

　　First-level prevention

　　1. Establish a prevention and treatment system:Establish and improve the prevention and treatment institutions at all levels, responsible for organizing and implementing the systems and comprehensive management of treatment, management, and investigation. According to the characteristics of the local epidemic situation and epidemiology, formulate prevention and treatment plans, and carry out education, cultivate good living habits, train technical personnel for treatment and prevention, and promote social forces to participate in and support the prevention and treatment plans and implementation of tuberculosis.

　　2. Early detection and thorough treatment of detected patients:Case detection mainly relies on symptomatic visits, from which tuberculosis patients are detected and diagnosed in a timely manner to avoid missed or misdiagnosis. It is necessary to ensure 'diagnosis leads to treatment, and treatment must be thorough'. It is essential to thoroughly treat patients, especially those with infectious tuberculosis, to significantly reduce the density of the source of infection and effectively lower the infection rate and incidence.

　　2. Second-level prevention

　　Early detection of tuberculosis patients and timely treatment to prevent carriage and transformation into chronic tuberculosis.

　　1. Early detection:Strengthen health education, popularize knowledge about the prevention and treatment of tuberculosis, enable the masses to carry out self-examination and mutual supervision, and immediately go to the hospital for examination once a suspect is found. This is beneficial to both the patient and the whole society and is an effective means of early detection and early treatment.

　　2. Early treatment:The treatment of pulmonary tuberculosis includes the following aspects: rational use of anti-tuberculosis drugs to kill and inhibit bacteria, allowing the focus to heal; surgical resection of destructive lesions to prevent spread or transmission of the disease or to prevent infection; symptomatic treatment.

　　3. Third-level prevention

　　The prevention in this period is based on the second level of prevention, and timely treatment can reduce the occurrence of complications. The complications of pulmonary tuberculosis include:

　　1. Large-area double lung tuberculosis leads to extensive functional damage, causing bronchiectasis, which is prone to secondary pulmonary infections. Both can lead to further functional damage and even respiratory failure.

　　2. Chronic fibrotic空洞型肺结核, caused by long-term repeated attacks, further affects their pulmonary heart function.

　　3. Large-area pleural adhesions caused by improper treatment of tuberculous pleurisy can lead to restrictive ventilatory dysfunction, and even pulmonary heart disease and respiratory failure. Therefore, preventing recurrence after the cure of pulmonary tuberculosis is the key to the third level of prevention. This requires clinicians to strictly adhere to the principles of early, regular, adequate, combined, and full-course use of sensitive drugs during treatment, treating patients with care, and strengthening supervision to minimize the extent of damage to pulmonary tuberculosis patients and prevent serious adverse consequences of recurrence. Complications are often due to untimely or inappropriate diagnosis and treatment, and it is necessary to minimize the extent of damage to pulmonary tuberculosis patients as much as possible. On the basis of preventing further progression of the disease, preserving existing pulmonary heart function, and fully utilizing their potential compensatory capacity, patients can achieve functional rehabilitation.

　　For those disabled by pulmonary tuberculosis, social care and guidance are essential. First and foremost, appropriate isolation and medication supervision should be provided to those who continue to excrete bacteria, striving to control sputum bacteria during the intensive treatment process. On this basis, it is necessary to publicize to society and families, seeking care and assistance from all aspects. Strengthening patients' functional exercise and nutritional support are long-term and complex tasks that require the vigorous participation and support of family members. Psychological rehabilitation is a frequently overlooked issue for tuberculosis patients. Medical workers have the responsibility to inform patients about the etiology, pathogenesis, modes of transmission, treatment objectives, and current treatment effects of tuberculosis truthfully, to eliminate certain unnecessary psychological concerns. It is important to explain the purpose and duration of appropriate isolation measures and to clarify that tuberculosis is a communicable disease that can be largely controlled, building patients' confidence in overcoming the disease. This is beneficial for patients to actively cooperate with treatment and achieve early recovery.

　　When elderly patients have symptoms such as cough, expectoration, hemoptysis, or fever, night sweats, weight loss, fatigue, emaciation, anorexia, and other respiratory or non-respiratory symptoms, the possibility of tuberculosis should be considered and corresponding examinations should be performed. Laboratory examination shows anemia, decreased white blood cell count, hypoalbuminemia, and accelerated erythrocyte sedimentation rate in most elderly tuberculosis patients, and hypoxemia is more common in elderly tuberculosis. If elderly tuberculosis is suspected, and routine, non-invasive examinations cannot confirm the diagnosis or exclude lung cancer, efforts should be made to perform tissue biopsy.
　　First, laboratory examination
　　1. Tuberculin skin test: It is an important method to investigate whether the patient has had tuberculosis infection.
　　2. Tissue pathological biopsy methods include: superficial lymph node biopsy, pleural biopsy through the chest wall puncture, bronchoscopic bronchial biopsy, etc., which are simple, safe, and minimally invasive biopsy methods. Bronchoscopic or percutaneous lung biopsy may easily cause pneumothorax, and elderly patients should be cautious when using it.
　　3. Pathogenic examination: examination of pleural effusion, pleural biopsy, and cerebrospinal fluid to diagnose tuberculous pleurisy and tuberculous meningitis. For the diagnosis of disseminated tuberculosis, liver, bone marrow, or lymph node biopsy may be required at times, and fundus examination is performed to see if there are choroidal tubercle nodules.
　　Second, other auxiliary examinations
　　1. Chest X-ray photography is still the routine examination for diagnosing tuberculosis, and the chest X-ray changes of elderly tuberculosis are often misinterpreted. In 77% of elderly patients with hematogenous disseminated tuberculosis, the pulmonary millet-like lesions show a special manifestation of 'three non-uniformities', that is, the distribution, size, and density of millet lesions are not uniform, with a misdiagnosis rate of up to 50%, and it should be differentiated from other diffuse lung diseases.
　　2. When it is difficult to differentiate between shadow and pneumonia or lung tumor, further examinations such as tomography, CT, or magnetic resonance imaging can be performed to clarify the nature. If suspected of millet type tuberculosis with a normal initial chest X-ray, chest X-ray should be repeated after 2 to 4 weeks. Patients with long-term high-dose corticosteroid or immunosuppressive therapy may develop non-reactive tuberculosis, which is an acute tuberculous sepsis occurring under extremely low immune status. An important characteristic of this type of tuberculosis is that the diameter of a tubercle nodule in pathology is usually less than 1mm, so 2/3 of the cases have no millet-like lesions on chest X-ray, which is very easy to misdiagnose and should be vigilant.

　　Scientific and reasonable diet can improve the physical quality of the elderly and play a positive role in the prevention and treatment of diseases. The dietary principles for elderly pulmonary tuberculosis patients should pay attention to the following points:

　　1. What foods are good for elderly pulmonary tuberculosis patients?

　　1. Energy supply

　　Most pulmonary tuberculosis patients have irregular low fever symptoms for a long time, so the body's energy consumption is higher than that of normal people. Therefore, for pulmonary tuberculosis patients, the supply of energy should also be slightly higher than that of normal people, generally with an energy supply of 40 to 50 kcal per kilogram of body weight, with a total daily calorie intake of 2500 to 3000 kcal, which is appropriate to meet the physiological needs and consumption of the disease. However, for pulmonary tuberculosis patients with obesity and elderly patients with cardiovascular diseases, the energy supply should not be too high, generally controlled at about 2000 kcal.

　　2. Protein

　　Most pulmonary tuberculosis patients are thin and have poor resistance, which is related to increased body consumption and enhanced protein decomposition. In addition, protein is also the main raw material for the repair of tuberculosis foci. Therefore, pulmonary tuberculosis patients should be given a high-protein diet, with a supply of 1.5 to 2.0 grams per kilogram of body weight. The source of protein should mainly be milk, eggs, fish, meat, animal viscera, and soy products. Milk contains a rich amount of casein and calcium, which patients can consume regularly.

　　3. Carbohydrates

　　Carbohydrates are the main energy source for the human body, accounting for about 60% of total energy, mainly derived from the patient's staple food, vegetables, fruits, and sugars. The intake is generally not restricted, but for pulmonary tuberculosis patients with diabetes, the supply of carbohydrates should be limited to about 200 to 300 grams per day.

　　4. Fat

　　The intake of fat for pulmonary tuberculosis patients should be moderate, with 80 grams per day being ideal, and it is best to be of plant origin. Excessive fat can affect the appetite of patients and is not conducive to the intake of other nutrients.

　　5. Vitamins

　　Vitamins are closely related to the recovery of pulmonary tuberculosis patients, such as vitamin A, which can assist and promote cell regeneration and enhance the body's resistance; vitamin B and C participate in various metabolic processes in the body, increase appetite, and promote the healing of tuberculosis foci; vitamin D is an essential substance for the metabolism of calcium and phosphorus, promoting the absorption of calcium, and calcium is an indispensable substance for the calcification of tuberculosis foci. However, pulmonary tuberculosis is a consumptive disease, and with the prolongation of the course, various vitamins in the body of patients are lacking due to not receiving timely supplementation. Therefore, it is also necessary to add foods rich in various vitamins to the diet of pulmonary tuberculosis patients, such as fresh vegetables, fruits, and animal livers, to meet the body's demand for vitamins.

　　6. Iron

　　Patients with pulmonary tuberculosis who have recurrent hemoptysis are prone to iron deficiency anemia. Therefore, pulmonary tuberculosis patients should also eat more green leafy vegetables and fruits rich in iron, such as spinach, celery, rapeseed, amaranth, tomatoes, apricots, peaches, plums, jujubes, oranges, bayberries, and pineapples, etc.

　　2. What foods should elderly pulmonary tuberculosis patients avoid?

　　1. Foods that cause heat, inflammation, damage to yin and consumption of essence, such as greasy, fried, roasted, and spicy foods, should be avoided, as well as smoking and drinking.

　　2. Abstain from smoking, drinking, and spicy seasonings. This is because smoking and drinking can produce adverse stimulation to the trachea and bronchi, induce coughing and hemoptysis in patients; spicy seasonings can also produce adverse stimulation to pulmonary tuberculosis patients and affect the recovery of the disease, so they should also be avoided.

　　In summary, due to the toxicity of the tubercle bacillus toxin and the systemic reaction, pulmonary tuberculosis patients are often in a state of reduced appetite and decreased digestive and absorptive function. Therefore, when giving food, attention should be paid to both nutritional supplementation and the patient's digestive and absorptive condition, especially the balance of carbohydrates, fats, and proteins in the diet should be maintained, and should not be neglected. Eating should be regular, timed, and quantitative.

　　The treatment for elderly pulmonary tuberculosis is the same as that for other age groups, and should still follow the 5 principles of 'early, combined, appropriate, regular, and full course'.
　　The optional antituberculosis drugs include: isoniazid (INH) 300mg/d, rifampicin (RFP) 450-600mg/d, ethambutol (EMB) 750mg/d, which can be taken all at once in the morning. For mild cases with initial treatment, isoniazid (INH) + rifampicin (RFP) can be used, but the combination of these two drugs can increase the toxic reaction to the liver, and those with previous liver dysfunction can choose isoniazid (INH) + ethambutol (EMB). For severe tuberculosis cases, the combination of three drugs can be used initially for intensive treatment, and then switch to the combination of two drugs after 2 months, with a course of at least 9 months. Streptomycin should be used with caution in elderly patients due to its nephrotoxicity and ototoxicity to the auditory nerve, and is generally limited to severe cases, with the dose reduced to 0.5-0.75g/d. Vitamin B6 (pyridoxine) is commonly added to prevent peripheral neuritis caused by isoniazid. There are many elderly tuberculosis relapse cases, so there are also many drug-resistant cases. For all relapse cases, drug sensitivity tests must be performed before treatment, and the predetermined chemotherapy regimen can be used first based on the past medical history before the drug sensitivity test report is received. The initial intensive treatment stage generally involves the combination of 3 or 4 drugs, such as isoniazid (INH) + rifampicin (RFP) + ethambutol (EMB) or added pyrazinamide (PZA), which can at least include two sensitive tuberculosis drugs, and then adjust according to the results of the drug sensitivity test.