PARAPNEUMONIC EMPYEMA

• Uncomplicated effusion.

• Thoracic empyema.

Uncomplicated Effusion

• Nonpurulent. • Negative Gram’s stain result, negative

culture. • Free flowing, pH 7.3, normal glucose level,

LDH less than 1000 IU/L. • Most resolve with appropriate antibiotics

treatment and resolution of the pulmonary infection.

Thoracic Empyema

• Bacteria invade the normally sterile pleural space.

• Three stage

• Table 58-1

Thoracic Empyema-- Stage 1

• Exudative effusion.

• Increase permeability of the inflammatory and swollen pleural surface.

• Correspond to the uncomplicated parapneumonic effusion.

• Sterile, fibrin and PMN may present.

Thoracic Empyema-- Stage 2• Fibropurulent, true empyema, complicated pleural

effusion.• Initial-- fluid is clear : WBC greater than 500

cell/μL, gravity greater than 1.08, protein level greater than 2.5 g/dL, ph less 7.2, LDH reach 1000 IU/L, fibrin deposit.

• Angioblastic and fibroblastic proliferation, heavy fibrin deposition on both pleura, particularly the parietal pleura.

• Later– fluid purulent, WBC 15000, ph less 7.0, glucose less than 50 mg/dL, LDH greater 1000 IU/L.

Thoracic Empyema-- Stage 3

• 1 week after infection-- collagen organization, entrapment the underlying lung.

• 3-4 week-- mature, turned peel. • Chronic-- dense fibrosis contraction and trapping

the lung, atelectasis and prolonged pulmonary infection, reduction the size of hemithorax.

• Fibrothorax-- invasion the chest wall and narrow the intercostals space-- As the end stage of the process.

Complication of Empyema

• Early or late.

• Necrosis of visceral pleura.

• Bronchopleural fistula.

• Necrosis parietal pleura and chest wall.

• Osteomyelitis of rib or spine.

• Esophageal fistula.

• Metastatic spread （ brain abscess ） .

BACTERIOLOGY

• Before antibiotics （ 1941 ） , 10% pf pneumonia develop the empyema, the streptoccus and pneumococcus were most frequently.

• After antibiotics, the empyema decrease as mortality. Staphylococcus became the most prevalent.

• Recently, the penicillin-resistant staphylococcus, gram’s –negative, anaerobic been predominant microbes.

BACTERIOLOGY

• Predominant aerobic-- Streptococcus pneumonia, Staphylococcus aureus, E. coli, Klebsiella pneumoniae, Hoemophilus influenzae.

• Predominat anaerobic-- Anaerobic cocci, pigmented prevotella, porphyromonas, bacteroid fragilis, fusobacterium spp.

BACTERIOLOGY

• Older children-- Most commonly caused by pneumococcus.

• Child-- 40% empyema caused by S. pneumoniae, 15% were penicillin-resistant, 44% negative culture （ pretreatment with antibiotics in community setting ） .

BACTERIOLOGY

• S. pneumoniae responsible for 60%-75% community acquired pneumonia, only 2% develop empyema.

• S. aures account 1-2% community-acquired pneumonia, 10% adult and 50% children develop empyema.

• In hospital, the staphylococcus and gram’negative are most common.

CLINICAL FEATURE

• Shortness of breath, cough , chest pain-- common to pneumonia.

• Febrile respiratory illness, accentuation, prolongation the symptoms in pneumonia-- alert the possibility of empyema.

• Aerobic empyema-- acute febrile illness. • Anaerobic empyema-- more indolent,

usually 10 days.

DIAGNOSIS

• Chest x-ray—The posterior lateral diaphragmatic angle-- The most dependent position-- Most empyema are found. (Inverted D or pregnant lady sign).

• Sonography– guide thoracocentesis. • Fluid analysis. • Aerobic pus-- little odor. • Anaerobic-- foul smelling.

Differential diagnosis

• Lung abscess.

• Bronchopleural fistula.

• Lung abscess-- air-fluid level in both PA and lateral view.

• Empyema-- air-fluid level rare in same in these view.

MAMAGEMENT

• Effective management require:

1) Control infection and sepsis by antibiotics.

2) Evacuation of pus from pleural space.

3) Obliteration the empyema cavity.

﹡Delay in drainage increase mortality from 3.4% to 16%.

Antibiotics Therapy

• Blood, empyema culture, gram stain.

• Community-acquired--- Third-generation cephalosporin or clindamycin.

• Gram negative or anaerobes-- third generation cephalosporin and clindamycin.

• Hospital-acquired-- should guide by culture.

Thoracocentesis

• 18-gauge needle.

• Fluid analysis.

• Chest x ray repeated in 24 hours.

• Repeated thoracocentesis if volume increased.

Chest tube drainage

• First step in treatment of acute empyema. • Highly effective in treating-- Uncomplicated

parapneumonic effusion and classic empyema without loculation.

• 36 Fr, suction –20 cmH2O.

• Clinical improve in 48-72 hour.• Remove-- drainage less than 50 ml within 24 hour,

lung re-expansion. Usually within 5-10 day. • Antibiotics should continue 6 week.

Intrapleural fibrinolytic agents

• Empyema cavity– Composed of fibrin. • Fibrolysis agent—Streptokinase and

Streptodornase— Significant systemic reaction, unsatisfactory.

• Purified streptokinase, urokinase– Not allergic– • Success rate– 80% for streptokinase （ 250000

U/100ml normal saline ） , 90% for urokinase （ 100000U/100ml normal saline ） .

Open drainage

• Cutting off the chest tube a few centimeter from the skin.

• Anchoring it with safety pin and tape.

• Tube may withdrawn a few centimeter each week as the granulation tissue fill the tract.

Video-assisted thoracoscopy （ VATS ）

• Primary modality for treating complicated empyema after initial therapy.

• Adhesiolysis and débridement with better exposure and mini-thoracotomy, decortation for lung expansion.

• Higher successful rate （ 90% ） , shorter hospital stay, less cost.

• Three-port triangle approach. • Morbidity low, chest tube can be removed 3-4 day.

Chronic Empyema.

• Chronicity– continued infection associated with both fibrosis and bronchopleural fistula.

• Uncommon.

• Thoracotomy and decortication

• Empyemectomy.

• Thoracoplasty.

EMPYEMA IN CHILDREN

• Associated with pneumonia.

• Incidence– Decrease greatly in successful treatment of pneumonia with antibiotics.

• Past– H. influenzae, β-hemolytic streptococci, S. pneumoniae, anaerobes.

• Recently– S. pneumoniae, often penicillin resistant is most.

EMPYEMA IN CHILDREN

• S/S– Fever, cough, dyspnea, tactile and vocal fremitus tachypnea, tachycardia.

• Goal of therapy– Antibiotics, chest tube drainage, aggressive care.

• Early thoracotomy– Led early recovery and excellent long-term results.

• VATS. • Open drainage– Not indicated-- because of late

skeletal deformities. • Enzyme– Not used.