Senile aspiration pneumonia

　　The main causes of senile aspiration pneumonia are the following 3 points:

　　1. Bacteria are important factors causing aspiration pneumonia by colonizing the oropharynx.

　　2. Gastroesophageal reflux, chronic gastric diseases, gastrointestinal dysfunction, decreased secretion of gastric juice, decreased gastric acid, and other factors can increase the chance of aspiration.

　　3. Factors such as radiation, physics, and chemistry can also cause pneumonia.

　　The complications of senile aspiration pneumonia are mainly respiratory failure, followed by electrolyte and acid-base imbalance, disturbance of consciousness, arrhythmia, shock, sepsis and septicemia, heart failure, multiple organ failure, etc. This is related to the weakened functional reserve of various organs in the elderly, poor compensatory or repair function, or existing chronic diseases, organ function decline, and further exacerbation of organ function by infection. Some organs are at the edge of failure in everyday life, and under the stimulation of certain triggers, more organs are quickly involved or fail, among which chronic bronchitis, emphysema, hypertension, heart disease, arrhythmia are more common.

　　According to the cause, senile aspiration pneumonia can be roughly divided into 4 types, and their clinical manifestations are described as follows.

　　First, bacterial aspiration pneumonia

　　Most cases are insidious in onset. Senile pneumonia, due to old age or associated with underlying diseases, is often atypical, often lacks pulmonary symptoms of pneumonia, and has a high incidence and mortality rate, with many complications. Most of them have a history of aspiration and related risk factors before onset, but 29% are without clear aspiration, and they silently aspirate in sleep or other situations.

　　1, Symptoms

　　(1) Typical symptoms: Manifested as chills, fever, chest pain, cough, and expectoration of rust-colored sputum, typical respiratory symptoms are rarely seen in the elderly; The most common are fever, cough, and expectoration, accounting for 60%, even with symptoms, they are usually mild, only showing weak cough, difficulty expectorating, sputum is white or purulent, and after forming lung abscess, a large amount of purulent臭sputum is coughed up (indicating the onset of anaerobic bacterial infection); Very few cases have a high fever, mostly with low fever, body temperature below 38°C, and very few cases have chills, chest pain, and hemoptysis are rare, and typical rust-colored sputum is very rare.

　　(2) Atypical symptoms: The most common manifestation of senile pneumonia is the gradual deterioration of the patient's health status: loss of appetite, anorexia, malaise, decreased activity, acute disturbance of consciousness, nausea, vomiting, weight loss, incontinence of urine and feces, and even mental confusion, or only the deterioration or slow recovery of the underlying disease; The earliest symptoms in the elderly are often an increased respiratory rate and tachycardia (30% to 60%), and dyspnea often appears 3 to 4 days earlier than other clinical manifestations, so it is difficult to determine the onset time and duration of senile pneumonia.

　　(3) A few also show gastrointestinal symptoms, such as vomiting, diarrhea, bloating, or associated with respiratory symptoms.

　　2, Signs

　　(1) Typical signs of lung consolidation are rare, and the affected area may show increased vibration, and percussion sounds are dull.

　　(2) 25% of cases may hear pulmonary wet rales, more (49%) cannot hear wet rales.

　　(3) Some may hear dry rales.

　　(4) 1/4 have no abnormal signs.

　　(5) Pleural effusion may appear when empyema occurs.

　　Two, chemical aspiration pneumonia

　　1, Symptoms

　　Most have a history of aspiration or choking cough, related to the cause, asymptomatic in the early stage, symptoms may appear several hours after aspiration (most within 2 hours): mainly manifested as wheezing, severe cough, dyspnea, and unconsciousness during aspiration often without obvious symptoms, and aspiration pneumonia caused by sudden onset of dyspnea, cyanosis, expectoration of serous froth, hemoptysis, esophageal and bronchial fistula may occur after eating, accompanied by spastic cough and shortness of breath.

　　2, Signs

　　Tachycardia, hypotension, body temperature 32%, wet rales and wheezing can be heard in both lungs.

　　Three, lipoid pneumonia

　　Lipoid pneumonia is prone to occur in young children, the weak, elderly with Parkinson's disease, pulmonary vascular disease, and rheumatoid arthritis. Symptoms: cough, sputum, and dyspnea. Signs: crepitus can be heard at the base of both lungs; pulmonary X-ray signs: early presentation as fine nodules, interstitial fibrosis visible at the base of both lungs, and sometimes multiple granulomas in the reticular shadow, appearing granular in appearance, similar to interstitial fibrosis in connective tissue diseases, also呈局限性团块.

　　Four, obstructive aspiration pneumonia

　　Symptoms vary with the size of the inhaled material. If a large foreign body blocks the large airway, sudden asphyxiation and death may occur. If it blocks the small airway, it can cause atelectasis or obstructive pneumonia, and symptoms such as cough, sputum, and shortness of breath may appear.

　　The preventive objects of primary prevention are healthy individuals and asymptomatic patients, adopting individual defensive measures to prevent diseases without illness. Strengthen health education and publicity for the elderly to avoid risk factors that can cause oral bacterial colonization and aspiration; maintain a sitting position for 2 hours after meals to reduce gastroesophageal reflux; use drugs to improve circulation and soften blood vessels to prevent cerebrovascular diseases; enhance brain function and reflexive central activity, abstain from drinking and smoking; use sedatives, antacids, and H2 receptor blockers with caution; strengthen physical exercise, enhance physical fitness, prevent colds, and protect susceptible populations; keep indoor air fresh and circulating, and can be vaccinated with influenza vaccine or apply immunostimulants regularly to individuals with low immunity.

　　Screening for those who are in the preclinical stage but do not show clinical symptoms, timely treatment of related diseases, and paying attention to chronic infection foci in the oral cavity and upper respiratory tract, such as periodontitis, suppurative tonsillitis, sinusitis, and alveolar abscess. Do not use liquid paraffin nasal drops or as a laxative; for those who have been on long-term nasogastric feeding, it is advisable to change the gastric tube regularly and in a timely manner. For patients with unconsciousness, strengthen oral care to avoid coughing. For patients with chronic gastric disease and gastroesophageal reflux, take timely medication to promote gastrointestinal motility and reduce food reflux. For the elderly, use drugs to enhance cough and swallowing reflexes (but the drugs are currently under development, such as capsaicin and drugs that inhibit the degradation of SP); it is very important to strengthen nursing care before surgery for patients under anesthesia, and do not allow gastric emptying. For patients with unconsciousness, take a head-down and lateral position; for patients with repeated aspiration pneumonia who have poor response to internal medicine therapy, take surgical treatment.

　　The role of community healthcare in the prevention of senile aspiration pneumonia is very important. Regular visits and guidance to susceptible populations, strengthening management and protection measures, and guiding family members on the care of the elderly, and taking protective isolation measures when necessary.

　　The classification and diagnosis of senile aspiration pneumonia are carried out based on the results of the following examinations.

　　First, laboratory examination

　　1. Bacterial aspiration pneumonia

　　(1) Blood picture

　　Patients with increased white blood cells are generally in the range of (10～15)×109g/L, but half of the patients do not show significant increase in white blood cells, but 90% of the cases may have nuclear left shift, and sometimes toxic granules can be seen in neutrophils, and 50% may have anemia.

　　(2) Erythrocyte sedimentation rate

　　It tends to increase.

　　(3) It is prone to electrolyte disorder

　　Low sodium and low potassium are common, especially after poor diet, vomiting, diarrhea, and the use of diuretics.

　　(4) It often combines with hypoproteinemia

　　ALB

　　(5) Etiological examination

　　It is an important basis for diagnosing bacterial aspiration pneumonia, including sputum smear, examination of sputum and lower respiratory tract secretions, and bacterial culture of sputum and pleural fluid. The most common specimens for bacterial examination are sputum and lower respiratory tract secretions.

　　(6) Bacterial examination of sputum

　　It is an important method for determining the etiology of senile pneumonia and the basis for selecting appropriate antibiotics. It should be performed as soon as possible before the use of antibiotics. In clinical practice, it is relatively easy to make a diagnosis of pulmonary infection or pneumonia, but it is more difficult to determine the pathogen. Due to the weakened sputum expectoration ability of the elderly respiratory tract and the inability to cooperate well, the sputum specimens often do not represent the condition of the lower respiratory tract. Therefore, the collection of qualified sputum specimens is very important. Methods:

　　a. It is necessary to rinse the mouth three times, cough out deep sputum with force, place it in an aseptic sputum box, and send it for examination immediately. At the same time, sputum smear: squamous epithelial cells 25/HP, or the ratio of both (leukocytes/epithelial cells)

　　b. Cricothyroid membrane puncture sputum aspiration method.

　　c. Sputum collection by bronchoscope with protective brush: In cases of severe pneumonia or ineffective empirical treatment in elderly patients, reliable pathogenic examination is urgently needed. However, other sputum collection methods are susceptible to contamination affecting the judgment of results. The most commonly used technique at present is bronchoscopy (biopsy, lavage, protective brush sampling) or percutaneous lung biopsy. This is an invasive diagnostic technique, which is difficult and high-risk in elderly patients with concurrent diseases. The protective brush (PSB) and bronchoalveolar lavage (BAL) sampling methods reduce the contamination of specimens from the upper respiratory tract. PSB sputum collection is ideal, with a sensitivity of 70% and specificity of 90%. BAL sampling is more widespread, so it is the preferred method.

　　(7) Antigen detection

　　Clinically, methods such as immunofluorescence, enzyme-linked immunosorbent assay, counterimmunoelectrophoresis, and cooperative agglutination test are often used. After the application of antibiotics, bacteria are killed, and bacterial culture is negative, but the antigenic material exists for more than 2 weeks. Detection of antigenic material can make a pathogenic diagnosis. This method is simple and rapid and can be used to determine infections such as viruses, mycoplasma, and bacteria. For example, legionella pneumonia can detect antigens using direct fluorescent antibody staining in blood, sputum, pleural fluid, and urine.

　　2. Chemical aspiration pneumonia

　　Blood gas analysis: hypoxemia, after the development of ARDS, can be accompanied by carbon dioxide retention and metabolic acidosis.

　　2. Other auxiliary examinations

　　1. Bacterial aspiration pneumonia

　　Imaging examination: chest X-ray lacks specificity for diagnosis, but it is the most effective auxiliary diagnostic method for pulmonary infection. In the early stages of elderly onset, especially in cases of dehydration and leukopenia, chest X-rays may be normal. Bronchopneumonia, also known as lobular pneumonia, manifests as patchy, blurred shadows along the pulmonary texture, with uneven density, which can merge into larger patches. Lesions are often found in the middle and lower fields of both lungs. In the case of aspiration empyema, dense patches with pus cavities and liquid levels can be seen, and pleural effusion or hydrothorax signs can be observed if the pus breaks into the pleural cavity. Typical lobar pneumonia is rare, manifested as uniform density of lobar, segmental, or subsegmental patches.

　　2. Chemical aspiration pneumonia

　　Imaging: scattered irregularly shaped shadows with blurred edges in both lungs, the distribution is related to the aspiration position, most commonly seen in the lower posterior part of the lungs, with more in the right lung. There may be patchy, cloud-like signs of pulmonary edema spreading outward from both pulmonary hilum.

　　After timely treatment of elderly aspiration pneumonia patients, the diet should be light, with an emphasis on eating fresh fruits and green leafy vegetables, and supplementing vitamins and minerals. A reasonable diet should be balanced, and attention should be paid to dietary hygiene and adequate nutrition; smoking and drinking should be avoided, as well as spicy foods.

　　The difficulty in the treatment of elderly aspiration pneumonia lies in the atypical presentation of pneumonia, or the confusion with the manifestation of underlying diseases, which is prone to misdiagnosis and delayed diagnosis, resulting in the loss of treatment opportunities. Additionally, due to the frequent presence of underlying diseases, it brings adverse effects to the treatment. Therefore, elderly pneumonia must be treated with antibiotics as soon as possible, adopt comprehensive treatment measures, strengthen nursing, prevent complications, enhance the body's resistance to diseases, and recover as soon as possible. Before treatment, the following should be considered: ① A variety of underlying diseases and accompanying medical problems; ② The selection of drugs and the adjustment of dosages; ③ The side effects of drugs.

　　First, treatment

　　1. General treatment

　　Once diagnosed, hospitalization for treatment should be considered.

　　(1) Careful nursing is very important. For the elderly who have difficulty moving, it is necessary to turn over regularly, closely observe changes in the condition, rest in bed during the acute period, provide high-calorie diet, and pay attention to drinking plenty of water. If unable to eat, attention should be paid to fluid replacement to maintain water, electrolyte, and acid-base balance. Oxygen therapy should be provided, especially for chemical aspiration pneumonia, which is very important. Ensure that the arterial blood oxygen partial pressure is greater than 8.0 kPa, and the oxygen saturation is greater than 90%.

　　(2) Maintain the patency of the respiratory tract, encourage patients to cough sputum. For sputum that is thick, expectorant and化痰 drugs can be given, and nebulized inhalation of local medication can be administered as necessary. Strengthen sputum body position drainage, give bronchodilators to relieve bronchospasm, regularly thump the back, and aspirate sputum as necessary (fiberoptic bronchoscopy, tracheal intubation, tracheotomy for aspiration) generally without sedatives and with little use of cough suppressants.

　　(3) Strengthen nutritional support, and attention should be paid to the supplementation of parenteral nutrition, such as providing human serum albumin, fresh plasma, and sufficient vitamins. Give immunostimulating drugs or antibiotics with immunostimulating effects such as cefodizime to enhance the killing effect on pathogens.

　　2. Antibiotic therapy

　　The main measures for bacterial aspiration pneumonia are anti-infection treatment, with the principles of antibiotic use being early, adequate, targeted to the causative bacteria, and combined medication for severe cases. Initial treatment generally involves empirical therapy. The pathogens for community aspiration pneumonia are mostly Gram-positive cocci, and for past healthy patients with mild to moderate pneumonia, amoxicillin (ampicillin) is recommended. Aspiration pneumonia is often mixed infection, with pathogens mainly consisting of anaerobic bacteria, Streptococcus pneumoniae, and Staphylococcus aureus, with Gram-negative bacilli often involved as well. For severe treatment, second and third-generation cephalosporins should be used along with metronidazole or tinidazole. Fluoroquinolones such as ciprofloxacin (ciprofloxacin) have certain efficacy against anaerobic bacteria, and clindamycin has strong antibacterial activity against various anaerobic bacteria including Bacteroides fragilis, and in combination with penicillin, it has good efficacy for severe pulmonary infections and empyema. For hospital-acquired pneumonia, Gram-negative bacilli are the main pathogens and are often resistant strains. Treatment should be with third-generation cephalosporins and aminoglycoside antibiotics, and vancomycin can be used if MRSA is considered, as well as fluoroquinolones or imipenem. After identifying the causative bacteria, antibiotics should be selected based on the results of sputum drug sensitivity tests, and medication should be individualized. The characteristics of elderly medication are to extend the course appropriately, and consider stopping medication after the body temperature, blood count, and sputum are normal for 5 to 7 days. Principally, antibiotics should be administered until the shadow on the chest X-ray is basically or completely absorbed, but attention should be paid to dysbacteriosis.

　　Special considerations for elderly medication: renal function decreases with age and a decline in physical condition, decreased gastric motility, and decreased gastric acid, affecting the absorption of oral antibiotics. Therefore, it is advocated to use intravenous administration, and at the same time, consider the underlying diseases and the side effects of drugs to adjust the medication accordingly.

　　3. Treatment of complications

　　Elderly pneumonia often has complications, and it is extremely important to treat these complications, such as the occurrence of respiratory failure, the selection of artificial airways and ventilators for treatment, mechanical ventilation, heart failure is an important cause of pneumonia death. Once heart failure occurs, immediate treatment with cardiotonic diuretics is given, and other treatments such as antiarrhythmic therapy and antishock therapy.

　　4. Aspiration obstructive pneumonia

　　Because it is caused by inhaled particulate matter, treatment should be to remove the foreign body as soon as possible under bronchoscopy, and if there is infection, it should be treated with active anti-infection therapy at the same time.

　　5. Lipoid pneumonia

　　There is no specific treatment, and prevention is emphasized. When it is difficult to distinguish between mass-like lesions and lung cancer, consider surgical resection.

　　6. Chemical aspiration pneumonia

　　Treatment is similar to that for acute respiratory distress syndrome but has some differences. First, lower respiratory tract aspiration, that is, aspirate the aspirated material through bronchoscopy or tracheal intubation, at the same time, hyperoxygenate, use mechanical ventilation, maintain oxygenation with positive end-expiratory pressure ventilation, reduce lung damage, and there is controversy about the use of adrenal cortical hormones, and it is not recommended to use antibiotics prophylactically.

　　7. Optimal Treatment Plan

　　Infectious aspiration pneumonia is often mixed infection, and it is necessary to obtain pathogenic evidence as soon as possible and select antibiotics according to the results of drug sensitivity tests.

　　II. Prognosis

　　The course of general pneumonia in the elderly is long, with more complications and comorbidities, slow absorption, and can recur, with a high mortality rate, and is one of the main causes of death in the elderly. The main influencing factors of the prognosis include age, physical condition, underlying diseases, whether there are serious comorbidities, and the type of pathogen. Elderly individuals with poor renal function, malnutrition, and multiple serious diseases have a poor prognosis for elderly pneumonia; toxic pneumonia, aspiration pneumonia, and fungal pneumonia have a poor prognosis. Elderly pneumonia is prone to complications such as respiratory failure, even multiple organ failure, which is often a direct cause of death.