Overview of Lung Abscess
Lung abscess is a purulent disease of the lungs caused by one or more pathogens mainly characterized by high fever, cough, and coughing up a large amount of sputum containing pus and foul-smelling odors mainly due to pathogenic infections and is treated by anti-infective therapy, sputum expectoration therapy, surgery, and medication.
Definition
Lung abscess is a purulent disease of the lungs caused by one or more pathogens.
Classification
Classification according to the route of infection
Inhalation lung abscess (primary lung abscess)
The pathogen originates from the mouth, nose, pharynx and other parts of the body and causes disease by inhalation.
Inhaled pathogens can cause disease due to various causes such as aspiration, decreased airway clearance and systemic immunity.
Secondary lung abscess
Secondary to pre-existing respiratory disease: on the basis of respiratory disease, lung abscesses are caused by pathogens infecting the lungs.
Secondary to diseases of non-respiratory organs or tissues close to the lungs: pathogens that cause these diseases infect lung tissue causing lung abscesses.
Hematogenous lung abscess.
Infectious diseases occurring in organs or tissues outside the lungs, and the pathogens that cause these diseases reach the lungs by blood dissemination causing a lung abscess.
Classification according to duration
Acute lung abscess: lasts less than 6 weeks.
Chronic lung abscess: lasts longer than 6 weeks.
Morbidity
Lung abscesses can occur at any age, but are more common in young adults and are more common in males than females.
In recent years, with the aging of the population, many bedridden patients elderly patients due to the increased risk of inhalation, resulting in an increase in the proportion of lung abscesses in the elderly.
Causes
Causes
Lung abscesses are mainly caused by pathogenic infections.
Inhalation lung abscess
Often a mixed infection, common pathogens include anaerobic bacteria, such as Streptococcus, Prevotella, Mycobacterium avium, Clostridium perfringens, etc.; aerobic or partially anaerobic bacteria can also be seen, such as Pneumococcus, Staphylococcus aureus, Streptococcus hemolyticus, Streptococcus oxysporus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Legionella, and Nucella.
Secondary lung abscess
Common pathogens include Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae.
Schistosoma japonicum spp. and Amoeba spp. can also cause the disease.
Hematogenous lung abscess
Common pathogens are Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus.
Predisposing factors
The following factors can increase the risk of developing this disease.
Lifestyle factors
Exposure to cold.
Severe fatigue.
Intoxication.
Poor oral hygiene.
Prolonged bed rest.
Disease Factors
Diseases of the respiratory system
Infectious diseases: e.g. tuberculosis cavities, infectious pneumonia, sinusitis.
Non-infectious diseases: e.g. bronchiectasis, bronchial cysts, bronchial obstruction, bronchopulmonary cancer.
Diseases outside the respiratory system
Infectious diseases: e.g. gingivitis, subphrenic abscess, perirenal abscess, spinal abscess, traumatic skin infection, boils, carbuncles, otitis media, osteomyelitis, right heart bacterial endocarditis.
Non-infectious diseases: e.g., epilepsy, stroke, esophageal perforation, gastroesophageal reflux disease, esophageal stricture or obstruction.
Medical factors
General anesthesia.
Drug overdose: e.g., sedative-hypnotic overdose.
Use of nasal feeding.
Had oral or nasal surgery.
Other
Advanced age, etc.
Pathogenesis
Intoxication, cerebrovascular disease, anesthesia, respiratory disease, etc. lead to a decrease in respiratory defenses and invasion of pathogens into the lungs from outside the body or from other parts of the respiratory tract.
Pathogens infecting tissues or organs outside the respiratory system reach the lungs through direct infection or blood circulation and cause infection.
Inflammatory lesions develop in lung tissue as a result of direct invasion or toxin production by pathogens infecting the lungs.
As the disease progresses, necrosis and liquefaction of the diseased tissue occur. The pathogen mixes with the necrotic, liquefied lung tissue to form an abscess.
Symptoms
Main Symptoms
High fever
Body temperature can be 39～40℃.
After coughing up a large amount of pus and sputum, the temperature can drop.
Cough and sputum
When the disease is mild, the cough symptoms are also mild, and can gradually worsen as the disease progresses.
Sputum can be mucous sputum, mucous pus sputum, and sometimes blood in sputum or hemoptysis.
When the disease is more severe, the sputum volume is larger, which can be 300 to 500 milliliters per day.
About half of the patients’ sputum may emit putrid odor.
In hematogenous lung abscess, coughing and sputum may occur a few days to two weeks after the onset of high fever, and the sputum volume is small, and hemoptysis is rare.
Other symptoms
Localized symptoms
Chest pain: most often when the lesion involves the pleura.
Shortness of breath: most often when the lesion is extensive.
Systemic symptoms
Night sweats, chills, fatigue, anorexia and other symptoms.
If the disease persists for more than 3 months, anemia and emaciation may also occur.
Symptoms of primary disease
Patients with tuberculosis and bronchopulmonary cancer may have symptoms such as emaciation and hemoptysis.
Patients with perinephric abscess may present with symptoms such as low back pain and pyuria.
In patients with stroke, symptoms such as hemiplegia, slurred speech, dizziness, and headache may occur.
Patients with amoebic liver abscesses may present with symptoms such as abdominal pain, diarrhea, nausea, and vomiting.
Patients with boils and carbuncles may present with localized skin redness, swelling, and pain.
Complications
The following complications can occur when lung abscess worsens.
Restricted fibrin pleurisy: pinprick pain in the chest may occur.
Abscessed chest, purulent pneumothorax or bronchopleural fistula: chest pain, dyspnea, and in severe cases, purple skin and lips, cold and clammy skin, decreased blood pressure, unresponsiveness and coma may occur.
Consultation
Department of Medicine
Respiratory Medicine
When symptoms such as high fever, cough, sputum (e.g. pus sputum, pus and blood sputum), chest pain and shortness of breath occur, timely consultation is recommended.
Emergency Department
For symptoms such as high fever, chills, shortness of breath, purple skin and lips, clammy skin, drop in blood pressure, unresponsiveness, coma, etc., it is recommended to consult the Emergency Department immediately.
Preparation
Preparing for your visit: registering, preparing your documents, common problems
Tips for seeking medical treatment
Chest X-rays or chest CT are often needed, so avoid wearing clothing made of metal, and inform the doctor if you are pregnant or planning to become pregnant.
Avoid taking fever-reducing medicines or antibiotics by yourself before going to the doctor, so as not to influence the doctor’s judgment of the condition. For patients with high fever, physical cooling can be used first, such as applying cold compresses to the forehead and wiping the hands, feet and armpits with lukewarm water.
Preparation Checklist for Doctor’s Visit
Symptom Checklist
Especially focus on the time of onset of symptoms, special manifestations, etc.
Is there fever? What is the highest degree?
Is there a cough? How long has the cough lasted?
Is there any sputum? What kind of sputum is it, e.g. pus, pus and blood?
Is there any chest pain, shortness of breath, dyspnea?
How long have the symptoms been present?
Medical History Checklist
Has there been recent exposure to cold, or severe fatigue?
Has there been general anesthesia, oral or nasal surgery, or nasal feeding therapy?
Any illnesses such as pneumonia, sinusitis, or bronchiectasis?
Checklist
Test results from the last six months, which can be brought to the doctor’s office
Laboratory tests: routine blood test, C-reactive protein, bacterial culture + drug sensitivity test
Imaging: Chest X-ray, Chest CT
Others: fiberoptic bronchoscopy
Medication List
Medication used in the last 3 months, if there is a box or package, you can bring it with you to the doctor’s office
Antibiotics: penicillin, cefotaxime, vancomycin, metronidazole, clindamycin
Expectorants: Ambroxol
Diagnosis
Diagnosis is based on
Medical history
Presence of cold, severe fatigue, intoxication, poor oral hygiene, prolonged supine lying.
Presence of sinusitis, gingivitis, bronchopulmonary carcinoma, pneumonia, stroke, esophageal perforation, subdiaphragmatic abscess, perirenal abscess, boils, carbuncles, etc.
History of general anesthesia, oral or nasal surgery, or nasal feeding therapy.
Excessive use of sedative-hypnotic drugs.
Advanced age.
Clinical manifestations
Symptoms.
High fever, cough, cough of mucus sputum or mucopurulent sputum, chest pain, shortness of breath, night sweats, chills, malaise, anorexia.
Physical signs
When the lesion is small or located in the deep part, there may be no obvious abnormal signs.
Turbid or solid sounds can be seen on percussion of the lungs, and bulging sounds can be seen if there is a large cavity. Auscultation can reveal weakened respiratory sounds, and wet rales can also be heard.
Patients with chronic lung abscess may have pale skin and mucous membranes, emaciation, chest depression on one side of the chest, turbidity on non-percussion, decreased breath sounds, and pestle fingers.
Laboratory Tests
Blood tests
To find out the changes of white blood cells, red blood cells and hemoglobin content.
The white blood cell count, neutrophil count, and neutrophil percentage may be significantly elevated. Red blood cell count and hemoglobin level may be decreased in chronic lung abscess.
Imaging
Chest X-ray, CT examination
To understand the condition of the chest such as bronchial tubes, lungs, and chest cavity, it can determine the location, type, and severity of the lung abscess.
Remove metal objects, such as necklaces and clothing made of metal, from your body before the examination.
Fiberoptic bronchoscopy
A flexible scope is inserted through the nostrils and penetrates deep into the lungs along the respiratory tract, allowing observation of the respiratory tract and lungs.
The location and severity of the lesion can be determined. Tissue or secretions from the lesion can be extracted for examination if necessary, or treatment can be provided by lavage and other means.
Precautions
Before the examination, the patient or family members should fully communicate with the doctor to understand the purpose and risks of the examination.
Fasting for 4-6 hours before the examination is required.
During the examination, the patient should cooperate with the doctor and avoid moving around and other behaviors that may affect the examination or cause harm to him/herself.
Pathogenetic examination and drug sensitivity test
Sputum, blood, alveolar lavage fluid, etc. are extracted for culture and drug sensitivity tests to check for the presence of pathogens, and the types of pathogens and their sensitivity to drugs can be determined.
It can identify the type of pathogen and provide information for treatment.
Note: Sputum should be extracted by rinsing the mouth and then coughing out the pharynx with force (do not send saliva as a sputum specimen for examination) and put into a container specially designed to collect sputum.
Differential diagnosis
Aspiration lung abscess is mainly differentiated from the following diseases.
Bacterial pneumonia
Similarities: Early lung abscess and bacterial pneumonia have similar symptoms, including fever, cough and sputum, and similar X-ray findings.
Differences: The color of sputum in bacterial pneumonia can be white, rusty, green, etc., and there is no putrid smell. On imaging, there will be solid changes in the lungs, but seldom appear “cavity” or “liquid-air flat”, which can be differentiated from lung abscess.
Cavitary tuberculosis
Similarities: Fever, cough, sputum, hemoptysis, chest pain.
Differences: Cavitary tuberculosis has a history of contact with tuberculosis patients; the onset of the disease is slow and the duration of the disease is long; fever is low and often occurs in the afternoon; sputum usually does not have a putrid odor. Imaging examination, tuberculin test, culture of pathogenic microorganisms can be differentiated.
Bronchopulmonary carcinoma
Similarity: both may have symptoms such as cough and sputum. When the cancerous lesion liquefies and forms a “cancerous cavity”, the chest X-ray may show similar symptoms as lung abscess.
Differences: Bronchopulmonary cancer is mostly seen in patients over 40 years old, and it can be manifested as dry cough in the early stage, and there is no fear of cold, high fever, etc. It can be detected by imaging examination and pathology. It can be differentiated by imaging examination, pathologic examination and etiologic examination.
Pulmonary herpes or pulmonary cyst co-infection
Similarity: both may have cough and sputum.
Differences: Patients with pulmonary herpes or pulmonary cyst co-infection often have no obvious toxic symptoms. They can be differentiated by history, imaging, or comparison with previous imaging reports.
Treatment
Treatment principle: Early use of targeted anti-infective drugs and sputum drainage, if necessary, surgical treatment.
If medication is needed, please use it under the guidance of a doctor, and do not use medication on your own.
Anti-infection treatment
It is the main treatment for this disease, which can inhibit the growth of pathogens or kill them.
Commonly used drugs include penicillin, clindamycin, metronidazole, gentamicin, vancomycin, etc. The drugs with targeted effects are selected according to the drug sensitivity test.
Different adverse effects may occur with the use of medications, including rash, hearing loss, and oliguria.
Treatment to promote expectoration
The patient should cough up the sputum in time, or the family members should help the patient to expel the sputum by patting the back from the bottom upward. If sputum expulsion is difficult, the following methods can be used.
Nebulization
If sputum expectoration is difficult, consider using nebulization to promote expectoration.
Oral or intravenous expectorant drugs
Used to promote phlegm expectoration when the phlegm is thick and not easy to cough up.
Common drugs include Ambroxol, etc.
Aspiration and fiberoptic bronchoscopy
If the patient is unable to expel sputum on his/her own, sputum aspiration, or fiberoptic bronchoscopy with alveolar lavage and suction may be used to promote sputum expectoration or to reduce pus in the lungs.
Surgical treatment
External drainage
Purpose of surgery: The pus within the lung abscess can be drained directly outside the body through a drainage tube to reduce the lesion.
Surgical methods: including chest wall incision and tube drainage, CT or B ultrasound-guided percutaneous puncture drainage and chest wall window drainage, of which CT or B ultrasound-guided percutaneous puncture drainage is the most commonly used.
Precautions
CT or ultrasound is performed before or during the procedure to localize or guide the puncture.
Drainage tubes will be placed and drainage bottles will be installed during the procedure to avoid dislodging or damaging the drainage tubes and bottles after the procedure.
Observe the amount of fluid in the drainage bottle and inform the doctor or nurse as required.
If there is redness, swelling, bleeding, severe pain at the location of the drainage port, or if the drainage tube is dislodged, inform the doctor promptly.
Lung lobectomy
Indications
Lung lobectomy has been used less frequently due to the use of anti-infective drugs. Consider this type of surgery in the presence of one of the following conditions
Lung abscess lasting for more than 3 months and the abscess cavity does not shrink with non-surgical treatment, or the abscess cavity shrinks but is more than 5 centimeters in diameter and cannot be closed easily.
Lung abscess causing hemoptysis that is not responding to non-surgical treatment or is life-threatening.
Accompanied by complications such as bronchopleural fistula, pyothorax, esophageal fistula, etc., which are not effective after suction, drainage and irrigation.
Bronchial lung cancer and other causes of bronchial obstruction limiting airway drainage.
Precautions
Drainage tubes will be placed and drainage bottles will be installed during surgery. Avoid dislodging or damaging the drainage tubes and bottles after surgery.
Observe the amount of fluid in the drainage bottle and inform the doctor or nurse as required.
If there is redness, swelling, bleeding, severe pain at the location of the drainage port, or if the drainage tube becomes dislodged, inform the doctor promptly.
Other treatments
Oxygenation
Hypoxia can be improved by administering oxygen.
Oxygen inhalation methods include nasal cannula and face mask.
Oxygen should be administered in the manner and at the flow rate set by the doctor. Avoid discontinuing oxygen administration or adjusting the oxygen flow rate on your own.
Supplementation
Nasogastric supplementation: If the patient has difficulty in chewing or is unable to chew, nasal nutritional drugs can be chosen for supplementation.
Intravenous supplementation
Used for poor diet and can not be fed through the mouth, nasal supplementation.
Commonly used drugs include compound amino acids, glucose, fat milk, water-soluble vitamins, fat-soluble vitamins and so on.
Postural drainage
Keep the lesion at the highest part of the body for 10 to 15 minutes at a time, 2 to 3 times a day. This method promotes drainage of pus from the lungs.
Tracheal intubation and mechanical ventilation
Used to maintain the patient’s respiratory function when there is severe respiratory failure and the patient is unconscious.
Treatment of primary disease
In case of tuberculosis, anti-tuberculosis treatment will also be given; in case of lung cancer, chemotherapy, radiotherapy and other treatments may be given.
Prognosis
Cure
Due to the widespread use of antibiotics, 90% of patients can be cured with prompt non-surgical treatment.
The cure rate for inhalational lung abscess is 90% to 95%.
The overall morbidity and mortality rate of lung abscess is 5% to 10%.
Prognostic factors
Size of the abscess cavity: patients with large abscess cavities have a poorer prognosis, especially if the diameter of the cavity is greater than 6 centimeters.
Type of lesion: necrotizing pneumonia with multiple small abscesses in adjacent lung segments has a poorer prognosis.
Age: Older patients have a poorer prognosis.
Immune function: patients with impaired immune function have a poorer prognosis.
Physical status: patients in a weakened state have a poorer prognosis.
Bronchial condition: patients with bronchial obstruction have a poorer prognosis.
Pathogen type: lung abscesses caused by aerobic bacteria such as Staphylococcus aureus and gram-negative bacteria have a poorer prognosis.
Timing of treatment: delayed treatment, especially in patients with symptoms lasting more than 6 weeks, has a poorer prognosis.
Harmfulness.
Acute lung abscess can develop into chronic lung abscess if not treated properly, causing anemia, wasting and other symptoms that affect life.
A small number of patients with amoebic lung abscess can develop pulmonary fibrosis with non-surgical treatment.
If the treatment is not timely or the condition is severe, it can cause serious conditions such as pyothorax and pus pneumothorax, which can be life-threatening.
Daily
Daily Management
Dietary management
Increase nutrition: Increase nutrients such as carbohydrates, proteins, vitamins, etc. Choose porridge, steamed buns, fish, muscles, fresh fruits or vegetables. Food should be chopped up as much as possible when cooking to facilitate digestion and absorption, and avoid being too hard.
Ensure adequate water intake, at least 1500 ml per day, or supplement as required by your doctor.
Avoid spicy and stimulating foods or drinks.
Avoid frequent consumption of fried, barbecued and pickled foods.
Abstain from alcohol.
Lifestyle management
Stay in bed and avoid activities as much as possible in acute lung abscess.
Ensure regular work and rest, get enough sleep and avoid staying up late.
Maintain oral hygiene, brush your teeth in the morning and evening, and rinse your mouth frequently.
Stop smoking.
Exercise management
Exercise should be in moderation, you can choose slow walking, fast walking, running, swimming, cycling and other exercises according to your own situation.
Exercise intensity should be gradual and avoid over-exercise, consult your doctor for details.
Emotional management
Soothe emotions and avoid tension, anxiety and fear.
Family members should pay attention to comforting the patient and helping him/her to relieve his/her bad mood.
Active treatment of other diseases
If suffering from sinusitis, gingivitis, pneumonia, amebic liver abscess, tuberculosis, boils, carbuncle, perirenal abscess, bronchopulmonary carcinoma and other diseases related to the occurrence of lung abscess, the patient should be actively treated to control the condition.
Disease monitoring
Measure body temperature on time and pay attention to changes in body temperature. If the body temperature does not fall or rises, cough worsens, hemoptysis occurs, or new symptoms develop, consult the doctor promptly.
Prevention
Maintain good oral hygiene.
Actively treat primary diseases, such as periodontitis, sinusitis, amebic liver abscess, tuberculosis, boils, carbuncles, bronchopulmonary cancer, etc.
Pay attention to daily safety and avoid skin trauma. If trauma occurs, stop bleeding and disinfect in time, or consult a doctor in time.
Maintain good dietary and living habits, and avoid exertion, drunkenness and other behaviors.
Avoid getting cold.
For patients who have been bedridden for a long time due to illness, family members should assist them to turn over regularly, expel phlegm at any time, avoid keeping supine position for a long time; they should be half-recumbent or sit up when eating or drinking.
If fever, cough, sputum, fatigue, anorexia and other symptoms occur, they should consult the doctor in time and get treatment as soon as possible to avoid serious situations.