Thoracic empyema: The presence of pus in the pleural cavity.
Causes
• Pulmonary
tuberculosis (PTB) is the most common cause in Tanzania
• Postpneumonic
or parapneumonic
• Lung
abscess
• Thoracic
trauma
• Gastrointestinal
tract (from oesophagus or through diaphragm)
• Extension
of a non-pleural-based infection (e.g. mediastinitis)
• Instrumentation
of the pleural space, such as in thoracentesis, or tube thoracostomy
• Subdiaphragmatic
abscess
• Thoracic
vertebral osteomyelitis
• Retropharyngeal
abscess
Pathophysiology
• An
empyema is either acute or chronic
• The
formation of an empyema has 3 stages:
o
Exudative stage: Protein-rich pleural
fluid remains free-flowing.
The
number of neutrophils is rapidly increasing.
Glucose
and pH levels are normal.
Drainage
of the effusion and appropriate antimicrobial therapy are normally
sufficient
for treatment.
o
Fibrinolytic stage: Viscosity of the
pleural fluid is increasing.
Coagulation
factors are activated, and fibroblast activity begins coating the pleural
membrane
with an adhesive meshwork.
Glucose
and pH levels are lower than normal.
o
Organizing stage: Loculations are
forming.
-Fibroblast
activity causes adherence to the visceral and parietal pleura.
-This
activity may progress with the formation of pleural peels in which the pleural
layers
are indistinguishable.
-Pus,
which is a protein-rich fluid with inflammatory cells and debris, is present in
the
pleural space.
-Surgical
intervention is often required at this stage.
Clinical Features, Investigations
and Differential Diagnosis of Thoracic
Empyema
Clinical Features
• The
patient's history may reveal the following findings:
o
Recent diagnosis and treatment for
pneumonia
o
Recent history of penetrating chest
trauma
o
Cough productive of bloody sputum that
frequently has a fetid odour or offensive
smell
o
High-grade fever
o
Shortness of breath
o
Anorexia and weight loss
o
Night sweats
o
Pleuritic chest pain during early
stages
o
Malaise
• Physical
examination may reveal the following findings:
o
Temperature frequently elevated
o
Tachypnea
o
Rales/crepitations
o
Rhonchi
o
Tubular breath sounds
o
Decreased breath sounds
o
Decreased fremitus
o
Stony dullness to percussion
Investigation
• Chest
X- ray may reveal:
o
Underlying disease (e.g. pneumonia,
lung abscess)
o
Pleural fluid
• Pleural
aspiration; appearance is turbid or purulent fluid
• Sputum
gram staining ± culturing and sensitivity testing
• Full
blood count
Differential Diagnosis
• Pleural
effusion
• Pneumonia
• Tuberculosis
• Pulmonary
abscess
Management of Thoracic Empyema
Objectives of Treatment
• Control
infection
o
Parenteral antibiotics are prescribed
to control the infection
o
Anti TB if indicated
• Drain
the purulent fluid
o
Insert a chest tube to completely drain
the pus.
• Eradicate
the sac to prevent chronicity and allow re-expansion of the affected lung to
restore
function.
o
Decortication (peeling away the lining
of the lung) may be indicated if the lung does
not
expand properly.
• Note:
Remember drainage of the purulent fluid and eradication of the sac (objectives
2
and
3) should be done in a district/regional specialized hospital.
References
• Das,
S. (2008). Concise Textbook of Surgery (5th ed.).
India.
• Fraser
L., Moore, P., & Kubba, H.
(2008, March). Atypical Mycobacterial
Infection of
the
Head and Neck in Children: A 5-Year Retrospective Review. Otolaryngology – Head
and Neck Surgery, 138(3):311-4.
• Friedmann
A.M. (2008, February). Evaluation and Management of Lymphadenopathy in
Children. Pediatric Review, 29(2):53-60.
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