Definition
By definition, the term, empyema, denotes collection of thick pus in the pleural cavity. It is fairly common in infancy.
Etiology
The most common organism responsible for empyema is Staphylococcus. Infrequently, Streptococcus pneumoniae, Haemophilus influenzae, and even Mycoplasma pneumonia account for a small proportion of the cases. Usually, it is the outcome of a complication of:
- Pneumonia (usually staphylococcal)
- Lung abscess
- Bronchiectasis
- Subdiaphragmatic abscess/liver abscess (rupture)
- Septicemia
- Metastatic spread of suppurative foci from distant lesions such as osteomyelitis.
Clinical Features
- Clinical manifestations, if present, are those of pneumonia.
- Fever, dyspnea, cough, chest pain (which may be referred to the abdomen), and toxemia are the usual presenting features.
- In case of marked respiratory distress, the child is cyanotic too.
- Long-standing cases develop clubbing, anemia, and other manifestations of malnutrition.
- A category of children, in spite of empyema, do not manifest the symptomatology described above. They may, however, suffer from growth failure and vague symptoms. Empyema in such cases is usually detected when the child is subjected to a detailed clinical check-up.
- Chest signs are similar to pleural effusion and include diminished movement on the affected side, widening, and dullness (at times, edema) of the intercostal spaces, dull percussion note, reduced vocal fremitus and vocal resonance, diminished air entry,* and mediastinal shift to the opposite side.
- It is worth remembering that empyema must be ruled out in any infant with localized dullness of the percussion note. The term empyema necessitance implies a pulsatile swelling over the chest.
Complications
- Bronchopleural fistulas
- Pyopneumothorax
- Purulent pericarditis
- Pulmonary abscesses
- Peritonitis
- Osteomyelitis of ribs
- Meningitis
- Arthritis
- Septicemia.
Diagnosis
- Clinical suspicion
- X-ray chest: In addition to the mediastinal shift to the opposite side, it shows a diffuse density suggestive of pleural fluid. In most of the cases, the opacities are basal and costophrenic angle is obliterated. Loculated empyema may, however, occur in the fissures or at the apex.
- Diagnostic pleural tap: The fluid is purulent (turbid) and should be examined biochemically (for high protein and low sugar) as also bacteriologically (for causative pathogens).
Treatment
- Antibiotics should be started as soon as the diagnosis is arrived at. Staphylococcal empyema is best treated with systemic penicillin G or, in case of penicillinase- producing organisms, with cloxacillin, vancomycin, linezolid, or teicoplanin pneumococcal empyema shows a gratifying response to penicillin G. For H. influenzae empyema, ampicillin, chloramphenicol, or third- generation cephalosporin is recommended.
Response to staphylococcal empyema is slow. Antibiotic therapy should, therefore, be continued for 3–4 weeks. Closed continuous intercostal drainage is strongly recommended. It needs to be controlled by underwater seal or continuous suction. Controlling empyema by this method should be the choice rather than the multiple aspirations of the pleural cavity.
- Surgical drainage after rib resection (thoracotomy or thoracoscopy) may be resorted to in case of severe respiratory difficulty, when improvement fails to occur after 3 weeks, in loculated pus, or in the presence of marked mediastinal shift. Surgical decortications are mandatory in case of loculation in the pleura.
In addition to the aforesaid, symptomatic measures, as and when needed, should be resorted to.
Prognosis
Empyema is a serious disease. Before antibiotic era, the prognosis used to be very bad. Today, following proper treatment, in-time, prognosis is excellent in the long-run. Some cases may be left with restrictive disease.
