行政院衛生署桃園醫院胸腔內科李世偉醫師 Effusions from parapneumonic infections and empyema

行政院衛生署桃園醫院

胸腔內科李世偉醫師

Effusions from parapneumoEffusions from parapneumonic infections and empyemanic infections and empyema

AGENDA• The clinical importance o

f infection in the pleural space

• Historical perspective• The epidemiology of pleu

ral infection• The pathophysiology of p

leural infection• Bacteriology• The diagnosis and clinical

asessment of pleural infection

• Differential diagnosis• Predictors of clinical out

come in pleural infection

• Radiology• Antibiotics• Chest catheter drainage• Intrapleural fibrinolytics• Future directions

NICK A MASKELL AND ROBERT JO DAVIES

TEXTBOOK OF PLEURAL DISEASE

The clinical importance of infection in the pleural space• Frank purulent pleural empyema has an overall m

ortality up to 20%, which rise further to about 35% in the immunocompromised host.

• The actual mortality rise from empyema is substantially influenced by the presence of co-morbid disease.

• In addition to this mortality, up to 40% of patients will fail treatment which chest tube drainage and antibiotics alone and still require surgical drainage of their pleural collection.

• Simple parapneumonic effusions arise in up to 57% of cases of pneumonia.NICK A MASKELL AND ROBERT JO DAVIES


The clinical importance of infection in the pleural space• Parapneumonic effusion occurred in 20 to 40

% of patients who are hospitalized with pneumonia.

• The mortality in patients with parapneumonic effusion is higher than that in patients with pneumonia without a parapneumonic effusion.

• Some of the excess mortality is due to mismanagement of the parapneumonic effusion.

Light RW. Pleural diseases, 4th ed. Baltimore: Lippincott, Williams and Wilkins; 2001.

Definition• Parapneumonic effusion is any pleural eff

usion secondary to pneumonia ( bacterial or viral ) or lung abscess.

• Empyema is , by definition, pus in the pleural space.

• A complicated parapneumonic effusion is a parapneumonic pleural effusion for which an invasive procedure is necessary for its resolution, or a parapneumonic effusion on which the bacterial cultures are positive.

Light RW. Pleural diseases, 4th ed. Baltimore: Lippincott, Williams and Wilkins; 2001.

Historical perspective• 500BC. Hippocrates: open thoracic drainage.• 1876-1891: chest tube and under water seal.• 1919 First World War: open early surgical drainage, mortalit

y as high as 70%.• Hewitt and Bulau: adequate pus drainage with a closed che

st tube, avoidance of early open drainage, obliteration of the pleural space, proper nutritional support. Reduced the mortality to 4.3%.

• 1940s: Penicillin• 1940s Tillett: intrapleural fibrinolytic therapy; frequent anti

genic side effects• 1897 Estlander and 1890 Schede: thoracoplasty• 19th Century end Fowler and Beck: decortication of the ple

ura• Video assisted thoracoscopic surgery ( VATS)

NICK A MASKELL AND ROBERT JO DAVIES TEXTBOOK OF PLEURAL DISEASE

The epidemiology of pleural infection• More common in the elderly and childhood.

• Men are affected twice as often as women.• Higher in those with diabetes, alcoholism

and substance abuse, rheumatoid arthritis and chronic lung disease.

• Poor dentition and risk factors for aspiration are associated with an increase prevalence of anaerobic infection.


Parapneumonic effusion 70%

post bacterial pneumonia

hospital acquired pneumonia

Primary empyema 4%

Post operative 12%

Traumatic 3%

blunt trauma

penetrating trauma

Iatrogenic 4%

e.g. post chest tube insertion

Abdominal infection 2%

e.g. subphrenic abscess

Miscellaneous 3%

esophageal perforation

bacteremia

rupture of lung abscess into pleural cavity

intravenous drug abuse ( contaminated needles )


0%

5%

10%

15%

20%

25%

30%

35%

Community acquired

Streptococcus milleri

Other

Proteus

Enterobacteriacea

H influenzae

Anaerobic

Staphylococcus

Pneumococcus

Other streoptcoccus


0%

5%

10%

15%

20%

25%

30%

Hospital-acquired

MRSA

Enterobacteriacea

Entercocci

Staphylococci

Pseudomonas

Streoptococci

Anaerobes

Others

S. milleri


The pathophysiology of pleural infection • Development of the initial pleural effusi

on: the exudative phase• The evolution of infection: the fibropuru

lent phase• Natural healing: the organizing stage

Andrews NC, Parker EF, Shaw RR, Wilson NJ, Webb WR. Management of nontuberculous empyema. Am Rev Respir Dis 1962;85:935–936.

Development of the initial pleural effusion: the exudative phase

• There is rapid outpouring of fluid into the pleural space.

• Most of the fluid is due to increased pulmonary interstitial fluid traversing the pleura to enter the pleural space but some of this is due to increased permeability of the capillaries in the pleural space.

• The pleural fluid in this stage is characterized by negative bacterial studies, a glucose level above 60 mg/dl, a pH above 7.20, and a lactic acid dehydrogenase (LDH) level of less than three times the upper normal limit of serum.

• If the patient does not see a physician or receives the wrong antibiotic, the effusion may proceed to the second stage, which is the fibropurulent stage. The Proceedings of the American Thoracic Society 3:75-80 (2006)

The evolution of infection: the fibropurulent phase• The pleural fluid in this stage is characterized

by positive bacterial studies, a glucose level below 60 mg/dl, a pH below 7.20, and a pleural fluid LDH more than three times the upper normal limit for serum.

• In this stage, the pleural fluid becomes infected and progressively loculated.

• The pleural fluid needs to be drained in this stage and drainage becomes progressively difficult as more loculations form.

• If a stage 2 effusion is not drained, the effusion may progress to the third stage.The Proceedings of the American Thoracic Society 3:75-80 (2006)

Natural healing: the organizing stage• Fibroblasts grow into the pleural fluid

from both the visceral and parietal pleurae, producing a thick pleural peel.

• The peel over the visceral pleura prevents the lung from expanding.

• Because the pleural space must be eradicated if a pleural infection is going to be eliminated, this peel must be removed if the infection is going to be cured. The Proceedings of the American Thoracic Society 3:75-80 (2006)

Light’s classification of parapneumonia effusions and empyema

Class1-Non significant Small<10mm thick on decubitus

No thoracentesis needed

Class2-Typical parapneumonic >10mm thick

Glucose>40, pH>7.2, Gram stain and culture negative

Class3-Borderline complicated pH 7.0-7.2 or LDH>1000

Gram stain and culture negative

Class4-Simple complicated pH<7.0 , Gram stain and culture positive, no loculated or frank pus

Class5-Complex complicated pH<7.0, Gram stain and culture positive, multiple loculation

Class 6-Simple empyema Frank pus, single locule or free

Class 7-Complex empyema Frank pus, multiple loculations

Aerobic and gram positive (180) Viridan streptococcus 46

48% S milleri group 44

Staphylococcus group 39

S pneumonia 31

Other streptococcus spp. 14

Enterococcus spp. 6

Aerobic gram-negative (101) Klebsiella pneumonia 43

27% Pseudomonas spp. 15

Escherichia coli 14

Haemophilus spp. 10

Enterobacter spp. 8

Proteus mirabilis 5

E. Corrodens 4

Salmonella spp. 2

Anaerobes (86 ) Peptostreptococcus spp. 24

23% Bacteroides spp. 23

Fusobacterium spp. 18

Prevotella spp. 7

Veillonella spp. 4

Porphyromonas spp. 3

‘anaerobes’ mixed Actinomycetes spp 2

Miscellaneous/ Others (8 ) 2%

Bacteriology• Aerobic organisms are the most frequent organi

sms identified from infected pleural fluid.• These are most commonly Gram-positive organi

sms from Streptococcal species, followed by Staphylococcus aureus.

• Gram-negative empyema is more frequent in patients with underlying diseases, especially those with diabetes and alcoholism.

• Staphylococcus aureus and Gram-negative enteric bacteria such as Klebsiella pneumonia have a particular propensity to cause pleural infection.


History, examination and CXR

Pleural effusion and evidence for infection

Start antibiotics Perform diagnostic pleural aspiration

With image guidance if required

Frank purulent pleural fluid?

Measure pleural fluid pHRequest fluid Gram’s stain and culture

No Gram’s stain positiveOr culture positive

Or pH<7.2

Pleural infection unlikelyTreat with antibiotics provided

Clinical progress is good

No

Pleural infection likelyProceed to chest drainage

Yes

Yes

Yes

Flow diagram describing a diagnostic pathway for patients with possible pleural infection

The diagnosis and clinical asessment of pleural infection

Differential diagnosis• Pleural involvement occurs in up to 5

% of patients with rheumatoid arthritis.

• Pleural malignancy• Chylothorax and pseudochylous effusi

on• Pulmonary embolism• Esophageal ruptureNICK A MASKELL AND ROBERT JO DAVIES


Predictors of clinical outcome in pleural infection• Pleural infection has a high mortality an

d morbidity and presents a clinical challenge in the timing of surgical intervention.

• Frankly purulent pleural fluid, co-morbid diabetes, delayed referral and pleural drainage, the presence of fluid loculation and a low pleural fluid white count may predict a poor outcome.


Radiology

• The presence of fever, pulmonary infiltrates and fluid should always alert clinician to the possibility of a parapneumonic collection.

• Ultrasound is good visualizing septations within loculations that are not usually seen on CT images, but may not identify some separate fluid loculations in inaccessible areas of the thorax.


Tu, C.-Y. et al. Chest 2004;126:1274-1280

Five basic ultrasound patterns of pleural effusions

• Top left, I = anechoic pattern: no echogenic density within the effusion

• Top right, IIB = complex nonseptated and relatively nonhyperechoic pattern: some visible bright spots as echogenic density within the effusion, and the echogenic shape changed with respiration

• Center left, IIA = complex nonseptated and relatively hyperechoic pattern: predominant hyperechoic spots visible within the effusion, and the echogenic shape not changed with respiration

• Center right, III = complex septated pattern: prominent fibrinous septation visible within the effusion

• Bottom, IV = homogenously echogenic pattern: echogenic spots den

sity evenly distributed within the effusion

Five basic ultrasound patterns of pleural effusions

Tu, C.-Y. et al. Chest 2004;126:1274-1280

Pleural Effusions in Febrile Medical ICU Patients* Chest Ultrasound Study

Chih-Yen Tu, MD (Chest. 2004;126:1274-1280.)

Antibiotics

• Antibiotics• 40% culture negative• It is not uncommon to need at least 2

weeks of therapy and some times longer.

• Decisions on the length of treatment can be guided by repeated measurements of serum CRP.


Mark Cohen and Steven A. Sahn Chest, May 2001; 119: 1547.

Chest catheter drainage• Optimal size of catheter?• Excellent outcomes may be achieved with such small cath

eter especially when combined with fibrinolytic therapy.• Drainage may fail if the fluid is of high viscosity and direct

blocks the tube.• The balance of forces drawing it down the tube is inadequ

ate.• If the fluid is partitioned by fibrinous septaeFig.ppt.• The rapidity of chest tube drainage might be improved by i

ncreasing the drain size, but the successful drainage is unchanged.

• Here again, provide that the catheter is patent, its bore is irrelevant.


Intrapleural fibrinolytics• 1949 Tillet and Sherry: partial purified streptococcal fibrin

olysin• Highly purified streptokinase: 250000IU• Urokinase: 100000IU• It form a complex with plasminogen that converts additio

nal circulating plasminogen to plasmin. Plasmin lyses fresh fibrin clot and digests prothrobin and fibrinogen.

• Improvement in the chest radiograph and greater volume pleural drainage, not outcome of mortality, surgical frequency, or hospital stay.

• Tube drainage with streptokinase and early surgical intervention showed reduced length of hospitalization

• Potential side effect: hemorrhage, pleuritic pain and feverNICK A MASKELL AND ROBERT JO DAVIES


Surgery for pleural infecetion• No definite data that define the point at which a p

atient with empyema should proceed to surgical intervention.

• Open thoracotomy with decortication• Mini-thoracotomy• Video-assisted thoracoscopic surgery (VATS)• Rib resection with open drainage• VATS: reduced hospital inpatient time, postoperat

ive complications and length of operating time• VATS: failures are with empyema in the organizing

stage of the diseaseNICK A MASKELL AND ROBERT JO DAVIES


Copyright ©2003 BMJ Publishing Group Ltd.

Jaffe, A et al. Arch Dis Child 2003;88:839-841

Figure 2 Surgical scars: open decortication.

Copyright ©2003 BMJ Publishing Group Ltd.

Jaffe, A et al. Arch Dis Child 2003;88:839-841

Figure 1 Surgical scars: VATS.

Luh, S.-P. et al. Chest 2005;127:1427-1432

Future Directions

• Increasing resistant micro-organism• intrapleural fibrinolytics still no know

if they actually reduce mortality and need for surgical intervention.

• Comparing the use of intrapleural fibrinolytics with early VATS


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行政院衛生署 桃園醫院 胸腔內科 李世偉醫師 Effusions from parapneumonic infections and empyema

行政院衛生署桃園醫院胸腔內科李世偉醫師 Effusions from parapneumonic infections and empyema