EMPYEMA

ALOK SINHADepartment of Medicine

Manipal College of Medical SciencesPokhara, Nepal

EMPYEMA presence of pus in the pleural space

empyema continues to be a significant cause of morbidity and mortality even in developed countries

Associated with delay in the diagnosis or instigation of appropriate therapy

as thin as serous fluidso thick that it is impossible to aspirate even through a wide-bore needle

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Aetiology

• Mostly secondary to infection in a neighbouring structure - usually the lung bacterial pneumonias T.B. rupture of a subphrenic abscess

through the diaphragm infection of a haemothorax Iatrogenic – following pleural aspiration

Pathology Both layers of pleura are covered with a

thick, shaggy inflammatory exudate pus is under considerable pressure &

may rupture into a bronchus causing

track through chest wall with formation of

• bronchopleural fistula • pyopneumothorax

• subcutaneous abscess

• sinus

empyema can heal • by eradication of the infection • obliteration of the empyema space

Early apposition of the visceral & parietal pleural layers are essential

Factors keeping pleura apart• air entering through a broncho pleural

fistula • underlying disease in the lung, such as

Bronchiectasis bronchial carcinoma pulmonary TB

prevents re-expansion

In these circumstances empyema become chronic. Surgical intervention required for healing

Clinical features empyema should be suspected in patients

with pulmonary infection • persistence or recurrence of pyrexia despite

the administration of a suitable antibiotic Some times first definite clinical features

may be due to the empyema itself Once an empyema has developed, two

separate groups of clinical features are found

1. Systemic features

Pyrexia, usually high and remittent Rigors, sweating, malaise and weight loss Polymorphonuclear leucocytosis, high CRP

2. Local features

Symptoms:Pleural painbreathlessnesscough and sputum – underlying lung disease copious purulent sputum – empyema ruptures into a bronchus Signs:Clubbing – regular feature in pyogenic infectionsClinical signs of fluid in the pleural space Cause restrictive defect

Empyema necessitans A very rare condition in which an

empyema goes undetected over a long period of time and progresses to the chronic stage

Eventually the empyema erodes through the chest wall and spontaneously drains onto the surface of the body

INVESTIGATIONS

Radiological examination: indistinguishable from those of

pleural effusion Loculated fluid may be seen When air is present in addition to pus

pyopneumothorax -horizontal 'fluid level'

Homogenous density Loculated Loss of cardiophrenic angle Loss of lateral portion of  diaphragmatic  silhouette

Ultrasound

position of the fluid extent of pleural thickening single collection or multiloculated

CT

useful in assessing the underlying lung parenchyma and patency of the major bronchi

Aspiration of pus confirms presence of empyema

performed using a wide-bore needle under Ultrasound or CT guidance

pus frequently sterile when antibiotics

have already been given

Distinction between tuberculous and non-tuberculous disease can be difficult and often requires pleural histology and culture

.

intercostal tube with water-seal drain inserted in acutely ill ptient

If initial aspirate – turbid or frank pus or loculated -tube should be put on suction (5-

10 cm H2O) and flushed regularly with 20 ml normal saline

Pus culture & appropriate antibiotic given for 2-4 weeks

SURGICAL INTERVENTION Decompression of lung secured at an

early stage by removal of all the pus from the pleural space to prevent visceral pleura becoming grossly thickened & rigid

surgical intervention required when pus is

thick or loculated

Surgical 'decortication' of the lung - required if gross thickening of the visceral pleura prevents re-expansion of the lung