Clinical Manifestations
Common symptoms include high fever, rapid pulse, tachypnea, loss of appetite, chest pain, generalized fatigue, and other signs. Patients with significant pus accumulation may also experience chest tightness, cough, and sputum production. Physical examination findings on the affected side include diminished tactile fremitus, dullness to percussion, and reduced or absent breath sounds on auscultation. Severe cases may be accompanied by cyanosis and shock.
Diagnosis
A combination of chest CT, ultrasound, and thoracentesis facilitates the diagnosis of empyema.
Chest CT is the most commonly used diagnostic method and aids in evaluating the location and volume of fluid, the presence of loculated abscesses, pulmonary parenchymal changes, and bronchial lesions. It also helps distinguish between empyema and lung abscess.
Chest X-ray findings of dense opacities caused by pleural effusion often indicate the need for further chest CT examination.
Chest ultrasound is an effective way to determine the extent of empyema and provides precise localization. It assists with thoracentesis targeting and real-time interventional treatment.
Thoracentesis is the primary method for definitive diagnosis. This involves evaluating the characteristics of the pus, including its appearance, consistency, and odor, followed by smear microscopy, bacterial culture, and antibiotic sensitivity testing to guide clinical therapy.
Bronchoscopy helps identify the presence of bronchopleural fistulas if suspected.
Treatment
The treatment principles for acute empyema include:
- Controlling the primary infection by selecting effective antibiotics based on the sensitivity of the pathogenic bacteria.
- Completely draining the pus to promote rapid lung re-expansion.
There are two methods for draining the pus: thoracentesis and closed thoracic drainage.
Thoracentesis is suitable for localized empyema or cases with a small amount of pleural effusion. In this procedure, antibiotics can also be instilled into the pleural cavity. If the pus is too thick to aspirate, or if there is no reduction in pus volume or improvement in symptoms after treatment, or if a large amount of gas is detected suggesting a bronchopleural or esophagopleural fistula or putrid empyema, early closed thoracic drainage is required.
Closed drainage can be performed using two approaches: intercostal tube insertion and subcostal tube insertion. Intercostal tube insertion is typically conducted at the bedside. A drain is introduced into the pleural cavity via a trocar and connected to a drainage system. Subcostal tube insertion is generally performed in an operating room and is used for cases such as multiloculated empyema or those where intercostal drainage is insufficient. This involves making an incision in the skin and muscles over the abscess site, resecting a 3–4 cm segment of the rib, and opening the pleura through the subcostal space. The empyema cavity is explored manually, and any fibrous septa are disrupted to facilitate drainage. A large drainage tube (greater than 20F) with side holes is then inserted, secured in place via sutures, and connected to a drainage system. Antibiotic irrigation of the empyema cavity may also be performed via a catheter at its apex. As pus is drained, the lung gradually expands, and the two layers of pleura come into contact, ultimately closing the empyema cavity. In cases where cavity closure is slow or unsatisfactory, early thoracotomy and decortication may be indicated. Empyema cavities that fail to close over time may progress to chronic empyema.
In recent years, video-assisted thoracoscopic surgery (VATS) has been increasingly used in the treatment of acute empyema, yielding satisfactory results. Its advantages include direct visualization, enabling complete removal of pus and necrotic pleural tissue, elimination of loculations, accelerated lung re-expansion, and closure of the empyema cavity.
The effectiveness of treatment for acute empyema is primarily assessed by the degree of lung re-expansion, resolution of symptoms, and the volume of drained fluid.