EMPYEMA GUIDELINESDr.PREETHAM KUMAR REDDYCONSULTANT PEDIATRICIAN & INTENSIVISTRAINBOW CHILDREN’S HOSPITAL

Empyema

• Pus and fluid from infected tissue in the pleural cavity.

• Also called empyema thoracis, or empyema of the chest.

• Empyema has a number of causes but is most frequently a complication of pneumonia.

Thoracic Empyema

Thoracic Empyema-- Stage 1

• Exudative effusion.

• Increased permeability of the inflammatory and swollen pleural surface.

• Corresponds to the uncomplicated parapneumonic effusion.

• Sterile, fibrin and PMN may present.

Uncomplicated Effusion

• Nonpurulent. • -ve Gram’s stain -ve culture. • Free flowing• pH 7.3• normal glucose level• LDH <1000 IU/L. • Most resolve with appropriate antibiotics

treatment and resolution of the pulmonary infection.

• Progress from stage 1 to 2 may occur quickly, often within 24–48 h .

Thoracic Empyema-- Stage 2

• Fibropurulent / true empyema / complicated pleural effusion.

• Initial-- fluid is clear :

WBC > 500 cell/μL

Protein> 2.5 g/dL

pH< 7.2,

LDH< 1000 IU/L, fibrin deposits. • Angioblastic and fibroblastic proliferation,

heavy fibrin deposition on both pleura, particularly the parietal pleura.

• Later–

• fluid purulent

• WBC 15000,

• ph <7.0,

• glucose < 50 mg/dL

• LDH > 1000 IU/L.

Thoracic Empyema-- Stage 3

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

• 3-4 week-- mature, turns into a peel. • peel prevents entry of anti-microbial drugs in

the pleural space and contributes to drug resistance.

• Thickened pleural peel restricts lung movement and leads to trapped lung and fibrothorax

Etiology

• Pneumococcal infection remains the most common isolated cause in developed countries, with Staphylococcus aureus the predominant pathogen in the developing world.

Jaffe et al. Pediatr Pulmonol. 2005; 40:148-156.

US prevalence

• After prevnar (1999-2000 vs 2001-2002)• 1) Patients admitted with empyema (per 10

000 admissions) decreased from 23 to 12.6• 2) Prevalence of S pneumoniae has

decreased from 66% to 27% • 3) S aureus has become the most common

pathogen isolated (18% vs 60%), with 78% of those being methicillin resistant.

• Schultz et al.Pediatrics. 2004 Jun;113(6):1735-40

265 children with empyema admitted to the PGIMER, 1989–98

• Culture positivity had decreased significantly (48% v 75%) over the years.

• Staphylococcus aureus commonest (77%) aetiological agent;

• Streptococcus pneumoniae cases seen during the winter and spring season.

• Gram negative rods grew in 11%.• Community acquired MRSA in 3 patients • Baranwal et al .Arch Dis Child. 2003 November; 88(11): 1009–1014.

Diagnostic Evaluation

• Radiographic Studies

PA and decubitus x-ray

• First step in diagnosis

Fluid layer is seen on dependent side

USG

• Very useful tool for diagnosis, guidance of thoraco-centesis, or pleural catheter placement.

• Sonography can distinguish solid from liquid pleural abnormalities with 92% accuracy compared to 68% accuracy with chest X-ray. When both are combined, accuracy rises to 98%

• USG shows limiting membranes suggesting the presence of loculated collections even when they are invisible by CT scan.

CT scan

Chest CT Scan

• Defines effusion

• consolidation

• abscess

• necrosis

• adhesions

• Guides interventions

Is CT Scan necessary

• Unnecessary for most cases of pediatric empyema

• Has a role in complicated casesInitial failure to aspirate pleural fluid failing medical management and particularly in immunocompromised

children where a CT scan could reveal other serious clinical problems.

Goal of treatment

1. Control of infection

2. Drainage of pus

3. Expansion of lungs

Stage 1/exudative stage

Free-flowing serous effusion pH>7.20, Sugar >60 mg/dL, LDH >3 times the upper limit of normal

Management with • Antibiotics • Drainage if effusion is significant• Give consideration to early active treatment as

conservative treatment results in prolonged duration of illness and hospital stay.

Empirical antibiotics

• Anti Staph antibiotic + Cephalosporin + Aminoglycoside

• Suspected anaerobic infection Clindamycin should be added

Antibiotics

• Parenteral therapy to be continued for 48-72 hours after abatement of fever and then oral therapy can be used to complete the course.

• Antibiotic to be continued until patient is afebrile, WBC count is normal, radiograph shows considerable

clearing • Duration of oral therapy is 1- 4 weeks.

Drainage Options

• Simple thoracocentesis Necessary for analyzing pleural fluid & to direct antibiotic therapy

• Chest tube placementIndicated for all large transudative effusions & the early exudative phase of parapneumonic pneumonias

• Repeated thoracocentesis is rarely successful

Empyema drainage

• CT or USG guided drainage if empyema collection is small

• Chest tube must be kept inside till drainage is less than 30-50 ml per day and cavity size is less than 50 ml in size

• The addition of fibrinolytic therapy may improve drainage during the fibrinopurulent stage

Who what where

• Chest drains should be inserted by adequately trained personnel to reduce the risk of complications.

• Small bore percutaneous drains should be inserted at the optimum site suggested by chest ultrasound

• The drain should be removed once there is clinical resolution or drainage is < 50 ml.

Safe triangle for insertion of chest drains

Stage 2/fibronopurulent stage

Uncomplicated<7.20, Sugar <60 mg/dL, LDH >3 times the upper limit of normal

• Antibiotics• Chest tube• Drainage• Consider fibrinolytics

Complicated

pH <7.00,Sugar <60 mg/dL, LDH>3 times the upper limit

• Antibiotics

• Chest tube drainage, consider

• fibrinolytics or

• VATS

Fibrinolytics

• There is no evidence that any of the three fibrinolytics are more effective than the others, only urokinase studied in a RCT in children so is recommended.

• tPA is used in US• Thompson et al Thorax 2002;57:343-347;

Stage 3/organizing stage Fibrinous peel, lung entrapment

• Antibiotics

• VATS

• if unsuccessful decortication

Ampofo et al. Pediatr Infect Dis J. 2007 May ; 26(5): 445–446.

Indications for SurgicalTreatment

• Gates et al (2004) in a retrospective review found that 80% of children with empyema did not require surgical intervention

• Lack of clinical & radiological response to medical treatment

• Complex empyema with significant lung pathology

Systematic Review of Optimal Treatment (Gates et al, 2004)

44 studies describing treatment of empyema in 1369 infants & children (retrospective reviews)

4 treatment strategies: chest tube drainage, chest tube + fibrinolytics, open thoracotomy + decortication & VATS

LOS was the only statistically significant difference between 4 strategies

VATS LOS = 10.5 days vs. CT 16.4 days or fibrinolytic 18.9 days

Thank You