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CHAPTER 46

Pleural Effusion and Empyema

Francis A. Uba
Donald E. Meier
Eric S. Borgstein

Introduction
In Africa, as elsewhere, the surgeon is often requested to insert a chest
tube for the drainage of pleural fluid. The most common reason for
such a request is a postpneumonic infected effusion, or empyema. A
chest tube, however, is often an adequate solution to this problem;
in some cases, more complicated therapy is required. It is therefore
important that the paediatric surgeon appreciates all aspects of pleural
space infections (PSIs) in children.
A pleural effusion (PE) is any collection of fluid in the pleural space.
Parapneumonic exudative effusions occur in up to 50% of pneumonias.
Empyema thoracis (ET) is the accumulation of pus in the pleural
space. ET remains a very significant cause of childhood mortality and
morbidity in the developing world. Poverty, ignorance, inappropriate
antibiotic use, malnutrition, delay in seeking treatment, and lack of
supportive care are major impediments to adequate treatment. 1-3
Empyema is an infected pleural effusion and is usually the result
of uncontrolled pulmonary infection or pneumonia. Indiscriminate use
of antibiotics and the emergence of antibiotic-resistant organisms have
resulted in an increase in the frequency of empyema complicating
pneumonia. ET has the reputation of being the worst treated of the
common disorders of the chest. Empyema is often recognised after
the patient has already received antibiotics, and culture and gram stain Source: Adeloye A, ed. Companion to Surgery in Africa, 2nd ed. Churchill Livingstone, 1987.
may be negative in up to 30% of patients. Reports of anaerobic bacteria Figure 46.1: Empyema. Sources of infection.
isolated from pleural fluid have ranged from 38% to 76%. Current
4,5
treatment of empyema in children is highly variable, due in part to both The causes of ET in children include (see Figure 46.1):
provider experiences and the variable clinical presentations.
The management of ET in children has evoked considerable 1. Pneumonia (usually caused by Staphylococcus aureus, S.
6,7
controversy. The literature provides many options but assists little in pneumoniae, group A streptococci or Haemophilus influenza). There
establishing the ideal treatment. 6-15 Generally, recommendations have may be anaerobic infections, infections secondary to aspiration, or
been based on institutional traditions, personal experience, and limited infections with Mycoplasma pneumoniae and viruses.
case reviews. Decisions about individual cases are further influenced by 2. Mycobacterial infections (especially in immunosuppressed
varying criteria, such as patient age, clinical status, antibiotic response, patients) and fungal infections.
stage and duration of the empyema, and the organism cultured. 16 3. Ruptured lung abscess (usually caused by S. aureus).
Demographics 4. Trauma (e.g., penetrating trauma to the lungs, fracture of ribs, or
The incidence of empyema thoracis is unknown, although about perforated oesophagus).
50–70% of children admitted with ET have pneumonia. ET affects 5. Amoebiasis (from amoebic abscess).
17
both sexes equally. 6. Contiguous infections of the oesophagus, mediastinum, or
Aetiology/Pathophysiology subdiaphragmatic region.
A pleural effusion is either an exudate or a transudate, which are dis- 7. Spread of infections of the retropharyngeal, retroperitoneal,
tinguished on the basis of protein content. An exudate is characterised paravertebral, or subphrenic spaces.
by a protein content of >3 g/l. A lactate dehdrogenase (LDH) level
8. Malignancy, including Kaposi sarcoma in children with human
of >200 is also diagnostic. Plasma/serum ratios of protein (>0.5) or
immunodeficiency virus (HIV) infection.
LDH (>0.6) are more accurate but seldom available. A transudate is
Host factors that contribute to alterations in pleural permeability,
usually caused by medical conditions such as congestive heart failure,
such as noninfectious inflammatory diseases, infection, trauma, or
nephrotic syndrome, and liver cirrhosis; the pleural tap is generally
malignancy, may allow accumulation of a thin serous fluid (pleural
clear and straw-coloured. Exudates are found in postinfective effu-
effusion or parapneumonic effusion) in the pleural space, which may
sions, malignancy, tuberculosis (TB), and other conditions. ET is never
become secondarily infected. As the body attempts to fight off infection,
a primary condition. A parapneumonic effusion is the most common
the cavity starts filling up with pleural fluid, pus, and dead pleura cells.
cause of empyema in childhood.