1. Felicity Meikle, FRACS Waikato Cardiothoracic Unit
EMPYEMA
Felicity Meikle, FRACS
Waikato Cardiothoracic Unit

2. Pleura Serous membrane
Pleural cavity is potential space between visceral and parietal pleura
Normally contains a small amount of fluid
Parietal pleura very sensitive to pain
Improves respiration and transmission of forces to lungs
Humans have separate
pleural cavities

3. Pleural fluid Serous fluid Produced by parietal pleura
Reabsorbed by lymphatic system
Continuously produced and reabsorbed
Reabsorption rate will increase up to 40 times the normal rate before significant fluid is seen

4. Parapneumonic effusion
Bacterial pneumonia associated with pleural effusion (35-40% of hospitalized pneumonia)
Pneumococcal – 60% effusion rate
Uncomplicated – negative gram stain, no loculations, resolve spontaneously
Complicated (20%) – empyema or loculated effusions, require drainage
Low ph <7.2, high LDH >1000 suggests complicated effusion

5. Empyema thoracis Purulent pleural effusion Oldest surgical diseases
Hippocrates 400 BC
Predominantly parapneumonic
Pulmonary abscess, suppurative pneumonia
Underlying conditions
Age
Alcoholism, IVDU
Chronic pulmonary disease, - TB, bronchiectasis
DM, RA
Immunosuppression - steroids, malignancy
Debilitation, malnutrition
Poor oral hygiene
GORD/aspiration

6. Other causes - trauma Penetrating injury 1.6% incidence
Organic foreign bodies being carried into pleural space
Haemothorax
Haemopneumothorax more likely to become infected
Secondary infection from chest tube – highlights importance of strict asepsis

7. Other causes - surgery 2-4% risk after pulmonary resection
Improved with:
Surgical technique
Patient selection

8. Other causes Rupture of oesophagus
Infection from posterior region of the neck
Chest wall infections
Thoracic spine
Subphrenic infections – tend to be reactive
Haematogenous spread in immunocompromised patient

9. Bacteriology
Pre antibiotics era – pneumococci 64%, S. pneumoniae (Ehler 1941)
Greater lung destruction more abscess formation
Recently –
No inoculate found in 80%
Streptococcus species 30% – S pneumoniae/pyogenes/milleri
Staph aureus ~34% - post op/trauma
Gram -ve – klebsiella, pseudomonas, haemophilus
Anaerobes 35% - bacteroides, peptostreptococcus
Complex inoculates – aspiration pneumonia

10. Stages 3 stages over 3-6 week period
Stage 1: Exudative: 2-5 days - pleural membranes swell and discharge thin exudate, neutrophils present, no organisms
Increased capillary permeability
Stage 2: Fibrinopurulent: 5-10 days - heavy deposition of fibrin, pleural fluid turbid, loculations, no organisms
Bacterial infection
Stage 3: Organising: within 3-4 weeks over 2-3 weeks – thick viscous fluid, thick fibrous peel forms, lung becomes trapped

11. Diagnosis
Suspect empyema in patients with acute respiratory tract illness and pleural effusion
Persistent fever following AB therapy
Symptoms
Dyspnoea - 82%
Fever - 81%
Cough - 70%
Pleuritic pain 67%
Tachypnoea, Tachycardiac
Malaise, anorexia, weight-loss
Signs – reduced chest wall movement, breath sounds and dullness

12. bloods Leukocytosis Left shift of neutrophils CRP Blood cultures
Sputum culture

13. Radiology CXR – pleural effusion (pneumonia/lung abscess)
Lateral film – posterolateral collection
“pregnant lady sign” – inverted D shape
Decubitus views to assess fluidity of collection
USS – differentiate between consolidated lung and
fluid and guide drainage
Uncomplicated – simple effusion
Complicated – stranding, loculations
Empyema – echogenic, septations

14. CT scan
Gold standard
Visualisation of thickened and separated pleural surfaces
Compression of lung parenchyma
Pleural thickening

15. Pleural fluid Clear – uncomplicated Turbid – complicated
Purulent - established empyema
Increased leukocyte activity and increased acid production within pleural space leads to reduced pH and increased LDH
pH<7.2, LDH >1000u/l, glucose <3.4mmol/L, WCC >50000cells/uL
Effusions with high pH can be managed with antibiotics and repeat thoracocentesis (Sahn 1989)
If pH low then effusion requires drainage with chest tube or surgery (VATS)

16. Empyema complications
Lung fibrosis
Contraction of chest wall
Empyema necessitans
Bronchopleural fistula
Sepsis
Distant abscess formation
Osteomyelitis
Mediastinitis
Pyopericardium
Trans-diaphragmatic drainage
Death 5-20% – elderly, comorbidities

17. Management Acute empyema (stage 1 and 2)
Antibiotics and fluid drainage
Repeat thoracocentesis if toxicity is well controlled
Controversial – only useful if implemented early enough
May develop multiloculated collections that are difficult to drain
VATS drainage may improve survival and shorten hospital stay (Ferguson1990)
Uniloculation of space
Washout of space
Better drain placement

18. ACCP Guidelines Uncomplicated effusion: <10mm on CXR
Antibiotics
Uncomplicated effusion: >10mm, pH>7.2, gluc >3.4
Thoracocentesis or Intercostal drain insertion if large symptomatic effusion
Complicated effusion: large/loculated effusion pH<7.2, gluc<3.4
Thoracocentesis/drainage
Intrapleural fibrinolysis
Early surgical intervention
Empyema: pus
Drainage/fibrinolysis
Surgical decortication

19. Antibiotic therapy
Guided by local antibiotic resistance patterns and policies
Common causative organisms
CAP/HAP/VAP
Severity of illness
CAP
Penicillin, co-amoxiclav, clindamycin
Cephalosporins
Metronidazole
HAP
Consider MRSA
Ideally should be continued for 2-4 weeks

20. Methods of drainage Tube thoracostomy (28-36fr)
beware of the retracted diaphragm
can revert to open system by cutting tube
Pigtail catheter
Often block
Less useful when fluid thick
70-90% success rate when used early

21. VATS
Shown to have reasonable success rate (18/18) in early empyema (Wakabayashi 1991)
Benefits
Direct vision
Break down all loculations and evacuate pus
Remove fibrinous membranes
Irrigate pleural cavity
Lung re-expansion
Direct drains appropriately
Mortality 0-3% in larger studies with success rate 80-97% in stages 2-3 (Luh 2005, Wurnig 2006, Solaini 2007)

23. Streptokinase? Fibrinolytic Used since 1949
Initial problems with bleeding and allergy
Davies 1997
RCT streptokinase vs saline flushes for 3 days
24 patients
Increased fluid drainage, greater radiographic improvement
Wait 1997
Compared VATS and fibrinolytic therapy
VATS improved efficacy, shorter hospital stay and lower cost

24. MIST (management of intrapleural sepsis trial) 2005, 2011
I 454 patients streptokinase u BD for 3 days vs placebo – no benefit
Primary end point: Death&surgery = 31% SK vs 27% placebo p0.43
Increased serious adverse events 7% vs 3% p0.08
No increased risk of bleeding during surgery
II double blind/ double dummy 193 patients DNase 5mg, t-PA 10mg BD for 3 days
Primary end point reduction in effusion size – tPA/DNase better than placebo or with tPA or DNase alone
Referral for surgery lower in tPA/DNase group than placebo. 4%vs 16% p0.03
Reduced hospital stay in tPA/DNase group than placebo 11.8 vs 17days p0.006
Mortality rates similar 4%(placebo)/8%(t-PA&DNase)/8%(t-PA)/13%(DNase) p0.46
Pleural thickening increases risk of failure of fibrinolytic therapy

25. Other care Treatment of underlying respiratory disease Nutrition
Chest physio
Promote lung re-expansion
Prevent chest wall collapse

26. Chronic empyema Delay in diagnosis Improper drainage
Inadequate antibiotic therapy
Continued reinfection
Foreign body Tb
Fungal infection

27. Simple treatment Eloesser flap Window thoracostomy and rib resection
Minor procedure (under GA)
Debilitated patients
Small spaces
BPF with fixed space
Long recovery period

28. Space sterilisation Drain space Claggett procedure
Irrigation with antiseptics and/or antibiotic solution (Modified)
Useful in post pneumonectomy empyema (if no bronchopleural fistula)
Irrigate window thoracostomy (Classic)

29. Space filling procedures
Ideally fill space with lung
Decortication “is seldom required because most patients with parapneumonic effusions are treated before this stage”
Removal of constricting peel over lung
Empyemectomy – removal of visceral and parietal pleura with contents of empyema intact – not generally necessary

30. Decortication Timing controversial
3 months – maximal functional respiratory recovery
Early – less bloody, not as adherent to lung
Performed before fibrosis extends into lung tissue – less chance of lung injury
May need to remove lung tissue at same time

31. Other options? Pleural plombage 1930-1950 Air Olive oil Mineral oil
Parafin wax
Rubber sheets/balls
Lucite balls (PMMA)
Glass balls used initially
Complications – infection, haemorrhage, fistulisation
Therefore not an option for pleural infection

32. Muscle transposition Obliterating the space with viable tissue
Reinforcement of stump (bronchopleural fistula)
Type of muscle flap taken depends on size and shape and location of cavity
Lat dorsi/serratus/pectoralis/intercostal
Omentum
Take care to preserve blood supply, bulk and innervation

33. Thoracoplasty
Rib resection to collapse infected space 1st described in 1879 (Estlander)
Alexander redefined this to a posterior extramusculoperiosteal approach
Used for Tb predominantly
Felt to be mutilating
Some usefulness in post
resectional empyema

34. Alexander Thoracoplasty

35. Surgical considerations
Infection must be treated
Drain
Tube/Open window thoracostomy
Extent of thoracoplasty
Apical – extrapleural lysis to allow apex to collapse
Disarticulate posterior rib ends
Resection of scapula tip if entrapment occurs
Used in conjunction with muscle flap/omental transfer
Thoracopleuroplasty (Andrews thoracoplasty)
Useful for post pneumonectomy empyema

36. Post pneumonectomy empyema
Uncommon
Life threatening
Treatment depends on timing and extent of BPF
Degree of pleural contamination
General condition of the patient
Control infection
(Close fistula)
Sterilise closed pleural space

37. Bronchopleural fistula
4.5-20% following pneumonectomy
0.5% following lobectomy
Etiology
Endobronchial Tb, contamination of pleural space during procedure
Devascularisation of bronchus
Right sided resection
Previous radiotherapy
Long bronchial stump
Concomitant illness – DM, steroids, cirrhosis
Infection
Residual tumour at bronchus
Post pneumonectomy ventilation

38. Symptoms Coughing up serosanguinous fluid or pus Fever Malaise
General unwellness (“flu like illness”)
CXR – new air fluid level, sudden disappearance of pleural effusion or mediastinal shift

39. Emergency management of Post pneumonectomy BPF
Prevent soiling of remaining lung
Nurse with resected side down,
Selectively intubate remaining lung
Bronchoscopy
Closure of fistula/buttress stump
If infected drain space
Open/closed

40. Conclusion Complicated pneumonia is common.
Mortality continues to improve as techniques for dealing with empyema and antibiotic therapy improves 50% -> 5-20%
Ongoing battle with physicians who don’t want to traumatise patients with large bore drains and so inappropriately rely on pigtail drainage
Appropriate timing of surgery is key to optimal outcome and avoidance of complications or disfiguring surgery. (Argumentative!)
May be a place for fibrinolysis in comorbid/inoperable patients
Thoracoplasty reserved for end of the line treatment for patients who can tolerate this procedure
Beware the post Pneumonectomy Empyema – can be subtle.