07/04/2022
Measures to diagnose and treat lung abscess
Lung abscess is an acute necrotizing inflammatory condition that creates pus-filled foci in the lung parenchyma, which after embolism will form caverns in the lungs. To treat lung abscess effectively, it is necessary to choose appropriate antibiotics along with actively draining the lung abscess for the patient.
1. What is a lung abscess?
Lung abscess is an acute inflammation of the lung parenchyma not due to tuberculosis, causing necrosis, destruction of alveolar membranes, capillaries, and formation of a pus-filled cavity.
Patients with lung abscess often have impaired airway defense mechanisms. Normally, mucus in the nasopharynx containing bacteria can be sucked into the lungs during sleep, but a local lung defense mechanism will eliminate the bacteria. When this protective mechanism is reduced, lung abscess has conditions to develop. The reduced lung protection mechanism is common in immunocompromised people, alcohol abusers, to***co users, exhaustion, etc.
2. Methods of diagnosing lung abscess
To diagnose a patient with a lung abscess, the doctor will rely on the following factors:
2.1 Clinical symptoms of patients with lung abscess
Patients with lung abscess have the following clinical symptoms:
- Fever 38.5oC, sometimes higher, may or may not be accompanied by chills.
- Chest pain on the affected side, patients with lower lobe lung abscess may present with abdominal pain.
- The patient coughs up purulent sputum. The sputum often has a stench, can spit a lot of pus, sometimes it can spit up pus and blood, and even cough a lot of blood.
However, there are cases of only a dry cough.
- The patient has difficulty breathing, may show respiratory failure such as rapid breathing, purple in the lips, the tip of the extremities. On lung examination, crackles, moist rales, snoring rales can be seen, sometimes cavernous syndrome, condensate syndrome are seen.
2.2 Subclinical diagnosis
The test results, subclinical imaging of the patient with abscessed pneumonia gave the following results:
- Complete blood count: white blood cell count increased, usually > 10 giga/liter, erythrocyte sedimentation rate increased.
- Chest X-ray: The chest radiograph shows that the abscess cavity usually has a relatively even wall with air-fluid levels, one or more abscesses can be seen, unilaterally or bilaterally. It is necessary to take a lateral chest X-ray to determine the exact location of the abscess to help choose an appropriate method of drainage.
- Direct endoscopic staining and bacterial culture from sputum, bronchial fluid or abscess pus. Blood culture when fever > 38.5oC, do antibiotics if bacteria are found.
2.3 Diagnosing the cause
Determining the cause is based on the results of microbiological examination of sputum, bronchial fluid, blood or other specimens.
The causative agents of lung abscess are usually anaerobic bacteria, staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa, parasites (amoeba),... Favorable factors of the disease are immunocompromised patients due to HIV or due to the use of immunosuppressive drugs, alcoholics, smokers, ...
2.4 Differential diagnosis of lung abscess with other lung diseases
- Distinguish from pneumothorax: in pneumothorax, the water-air level images on straight and slanted chest x-ray have different lengths. In a lung abscess, these two dimensions are approximately equal.
- Differentiate from abscessed lung cancer: besides lung abscess symptoms, abscessed lung cancer may have other symptoms such as choking, hoarseness, clubbing, cupped nails, coat edema , pain in the joints,... The chest X-ray film shows that the cave has thick walls, often eccentric, surrounded by thorns, with little image of water v***r level. The disease usually occurs in patients over 45 years of age, history of smoking, pipe to***co, ...
- Differentiate from cavernous pulmonary tuberculosis: pulmonary tuberculosis usually progresses slowly with general emaciation, collapse, cough, expectoration of sputum or blood, and fever in the afternoon. Acid-resistant bacilli (AFB) were found in the sputum, and the erythrocyte sedimentation rate increased. X-ray images are seen against the background of infiltrative or fibrotic lesions with one or more caverns, usually located at the apex of the lung.
- Differentiate from pulmonary hematoma: patients with pulmonary hematoma have a history of trauma, cough less, no sputum, if sputum is present, sputum is not purulent. In the early stages, there may be coughing up blood.
3. Treatment of lung abscess
3.1 Medical treatment of lung abscess
3.1.1 Antibiotic treatment
Patients will be treated with a combination of two or more antibiotics, administered intravenously or intramuscularly and using high doses from the start. Antibiotics are used as soon as the microbiological specimens are obtained and the antibiotics are changed based on the clinical course or the results of the antibiogram. The duration of antibiotic use is at least 4 weeks, can be extended to 6 weeks depending on the clinical and radiographic findings of lung abscess.
The antibiotics that can be used are:
- Penicillin G is used from 10-50 million units depending on the patient's condition and weight, intravenous phase injection 3-4 times/day. Use Penicillin in combination with an aminoglycoside antibiotic such as gentamycin (3-5mg/kg/day IM once) or amikacin (15mg/kg/day IM once or IV phase in 250ml NaCl 0.9 solution. %).
- Use Amoxicillin + clavuanic acid or ampicillin + sulbactam instead of penicillin G if beta-lactamase-producing bacteria are suspected, the dose is 3-6g/day.
- If anaerobic lung abscess is suspected, one of the following combinations can be selected:
- Group beta lactam + clavuanic acid 3-6g/day in combination with metronidazol dose 1-1.5g/day, intravenous infusion 2-3 times/day or
- Penicillin G from 10-50 million units combined with metronidazole 1-1.5g/day intravenous infusion
- Penicillin G 10-50 million units combined with clindamycin 1.8g/day intravenously.
- If staphylococcal abscess is suspected, use Oxacillin 6-12g/day or vancomycin 1-2g/day. If drug-resistant staphylococci are suspected, combine the above drugs with amikacin.
- If Pseudomonas aeruginosa lung abscess is suspected: use Ceftazidim 3-6g/day in combination with quinolone antibiotics such as ciprofloxacin 1g/day, levofloxacin 750mg/day.
- If lung abscess is caused by amoeba, use Metronidazole 1.5g/day intravenously 3 times/day in combination with other antibiotics.
3.1.2 Drainage of lung abscess
The patient will be drained to make the amount of pus in the abscess drain out as much as possible. Methods of draining a lung abscess include:
- Postural drainage, thoracic flutter: choose the most appropriate drainage position for the patient based on the chest x-ray or computed tomography image. Conduct postural drainage several times a day, at first, drain for a short time, then gradually lengthen depending on the patient's tolerance, the drainage time can be up to 15-20 minutes/time .
- Flexible bronchoscopy to aspirate pus in the bronchi to help drain the abscess.
- Puncture drainage of pus through the chest wall when the lung abscess is in the periphery without communicating with the bronchi, the abscess is close to the chest wall, or is attached to the pleura. A 7-14F catheter is inserted into the abscess to drain the pus through a continuous suction system.
3.2 Surgical treatment of lung abscess
Patients will be surgically removed lung segments or lobes of the lung or a whole lung, depending on the extent of the spread with the patient's condition or the respiratory function within the allowable limits. Surgery is performed in the following cases:
- Abscess socket >10cm
- Chronic treatment is ineffective.
- Patients with recurrent hemoptysis or severe, life-threatening hemoptysis.
- Abscess associated with severe focal bronchiectasis, with complications of bronchopleural fistula.
During treatment, it is necessary to strengthen the diet so that the patient has enough health to fight the disease. To prevent disease, it is necessary to pay attention to oral hygiene, nose and throat. When there are infections of the teeth, mouth, nose and throat, they must be treated thoroughly. In particular, for patients who eat with a nasogastric tube, caregivers when feeding patients must closely monitor, to avoid the patient choking on food.
