Pneumonia after surgery and trauma

　　Due to insufficient pulmonary ventilation, poor diaphragmatic activity, impaired or suppressed cough reflex, bronchospasm, and dehydration after surgery and trauma, bronchial secretions can accumulate, leading to atelectasis of the lung segments, and then pulmonary infection, causing various inflammatory reactions.

　　Complications are similar to those caused by other bacterial pneumonia, but there are more cases of pneumonia with empyema after trauma or surgery involving the lung and mediastinum. The manifestations are:

　　1. Recurrent fever (low fever), loss of appetite, chest dull pain, shortness of breath, cough, and in patients with bronchopleural fistula, coughing up a large amount of purulent sputum.

　　2. Chronic consumptive appearance, emaciation, anemia, malnutrition (plasma protein reduction), collapse of the affected side of the chest wall, displacement of the trachea to the affected side, narrowing of the intercostal spaces, limited respiratory movement, dullness on percussion, decreased or absent breath sounds, scoliosis, and clubbing (toes).

　　It is the same as other pneumonia caused by the same bacteria. Chest X-ray examination can show lung infiltration foci and/or atelectasis, and sometimes there is evidence of pulmonary embolism and infarction, the latter usually accompanied by bloody sputum. Purulent sputum often indicates infection, but sometimes small amounts or mucus-like sputum also contain a large number of pathogens. Bacterial culture of sputum and bronchial secretions shows Gram-negative bacilli, Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, or a mixture of these bacteria.

　　For patients with smoking, acute and chronic respiratory tract infections, chronic bronchitis, emphysema, and asthma, smoking should be quit before surgery, chest physical therapy should be performed, and targeted comprehensive treatment should be carried out to control infection, relieve spasm, relieve asthma, expectorate phlegm, and support therapy. The surgery should be performed after achieving a satisfactory lung function state. Generally, after 1 to 2 weeks of preparation, there can be significant effects, and pulmonary function tests should be conducted before and after treatment. Comprehensive medical treatment should continue throughout the operation and postoperative period.

　　1. Quitting Smoking:According to statistics, the incidence of PPC after surgery in smokers is about 4 to 6 times that of non-smokers. Smoking increases small airway resistance and reduces lung immune function. Long-term heavy smokers often have chronic bronchitis and emphysema. It has been reported that quitting smoking 6 to 8 weeks before surgery can improve the function of the respiratory tract cilia mucus transport system, significantly reduce PPC; on the day before immediate surgery, the blood carboxyhemoglobin (half-life about 6h) and P50 values are close to normal, and the patient's blood oxygen transport capacity is enhanced.

　　2, Chest physical therapy:Before surgery, teaching patients deep breathing, coughing to expel sputum can reduce airway resistance, reduce the chance of infection, increase respiratory muscle strength, and is an effective method for preventing and treating PPC. The method is to take a deep breath to the total lung capacity, hold the breath for 3 to 4 seconds, and then cough 3 times to exhale the air. It is necessary to assist with turning and patting the back, anti-infection, bronchodilation, expectoration, and other therapies. After surgery, it can be instructed to use soft cotton pads to press on the incision to practice, in order to reduce pain. Inspiratory capacity meter (IS) practice can also improve respiratory muscle strength and endurance, increase functional residual capacity (FRC), and reduce complications such as atelectasis. IS is to let patients blow into the inspiratory capacity meter every day after surgery. The method is to take a deep breath and hold it for 2 to 3 seconds, and then exhale deeply and slowly. It is required that the tidal volume (VT) blown each day should increase, lasting for 30 minutes each time, 6 times a day, which is one of the recognized best physical therapies. IS also needs to be learned by patients before surgery.

　　3, Control infection:For respiratory tract infections, empirical treatment can be given before surgery, and then timely adjusted according to the results of sputum bacterial culture and drug sensitivity tests.

　　4, Antispasmodic, antitussive, and expectorant:For patients with chronic bronchitis, emphysema, or asthma who have bronchospasm, theophylline is mainly used in combination with isopropyl bromide and (or) β2 receptor agonists for inhalation. Asthma patients should also use inhaled corticosteroids. There are different methods of administration of inhaled agents, including metered-dose inhalers (MDI) and spacer inhalation, dry powder inhalation, and nebulized inhalation with aqueous solution, which can be selected according to circumstances. For patients with thick sputum, ambroxol hydrochloride (ambroxol) can be taken orally or inhaled by nebulization, or administered intravenously.

　　5, Other:It is quite common for elderly people to be obese (more than 30% of the standard body weight). Obesity leads to reduced chest compliance, atelectasis of alveoli, decreased respiratory reserve, and dysfunction of pulmonary gas exchange, which can increase PPC after surgery by twice. Elderly obese patients often have sleep apnea syndrome (SAS) and obesity-hypopnea syndrome. For patients with SAS and obesity-hypopnea syndrome, nasal (or nasal-oral) mask continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), and necessary medication (such as propoxyphene) should be given before and after surgery.

　　The diagnosis of postoperative and post-traumatic pneumonia relies not only on clinical manifestations but also on chest X-ray examination, sputum and bronchial secretion bacterial examination, just like other infectious pneumonia.

　　Postoperative and post-traumatic pneumonia should be light in diet, eat more vegetables and fruits, rationally match the diet, and pay attention to sufficient nutrition. It is forbidden to eat刺激性食物 such as cigarettes, alcohol, coffee, strong tea, and various spicy seasonings such as scallions, ginger, garlic, chili, pepper, curry, etc.

　　The main treatment method is to use antibiotics targeted at the pathogen, as it is meaningless to examine anaerobic bacteria during expectoration, so the commonly used method is quantitative culture of tracheal aspirates, bronchial aspirates, or pleural fluid. Patients with aspiration pneumonia outside the hospital generally have anaerobic bacterial infections, but aspiration pneumonia in the hospital usually involves a variety of microorganisms, including Gram-negative bacilli, Staphylococcus aureus, and anaerobic bacteria. For anaerobic bacterial infections, the commonly used drug is clindamycin 600mg intravenous injection, once every 6 to 8 hours. Metronidazole can also be used in combination with clindamycin. For hospital-acquired aspiration pneumonia, Gram-negative bacilli and Staphylococcus aureus are the main components of mixed infections. These microorganisms are easily found in the culture of expectorated sputum, and in vitro drug sensitivity tests help in the selection of antibiotics. For empirical antibiotic use in critically ill cases, aminoglycosides or ciprofloxacin can be combined with one of the following: third-generation cephalosporins, imipenem, penicillin resistant to Pseudomonas, or beta-lactamase inhibitors (such as ticarcillin plus clavulanate). Patients allergic to penicillin can choose aztreonam in combination with clindamycin.

　　Lower airway mechanical obstruction can be caused by aspiration of neutral liquids or granular substances (such as in drowning victims, seriously impaired consciousness patients may aspirate non-acidic gastric contents or food ingested, etc.). Such patients need to undergo tracheal suction immediately. Granular substances may also remain in the lower airways. The most common objects are plants (such as peanuts). Such accidents are common in children whose oral cavity is still in the developmental stage, but adults can also experience them, especially when inhaling meat during meals --- 'restaurant coronary syndrome'. Symptoms depend on the diameter of the object and the airway. High tracheal obstruction can cause acute asphyxia, often resulting in aphonia and rapid death. Obstruction of the more distal airways can cause刺激性 chronic cough, often accompanied by repeated infections on the distal side of the obstruction. Chest X-ray examination can clearly show incomplete or excessive expansion of the affected lung during expiration; partial obstruction can cause the heart shadow to move towards the healthy side during expiration. Another diagnostic clue is repeated lung parenchymal infection in the same lung segment. Treatment includes removal of the obstructive material, usually using a bronchoscope.