DR. KOMALDEEPJUNIOR RESIDENTPULMONARY MED

TBHP

HISTORY460 BC hippocratic physicians

recommended treating empyema with open drainage.

Napolean’s surgeon dupuytren, whose name is linked to the palmar fascia contractures of liver disease, died of empyema in 1835 after declaring he would “rather die at hands of God than of surgeons”

Sir William Osler who thought “empyema needs a surgeon and 3in. Of cold steel , instead of a fool of a physician” provided a compelling description of his own empyema before succumbing to disease.

THE WORD: EMPYEMAEm=withinPyema=accumulation of pus

Empyema is known to be the formation and collection of pus within a naturally present cavity inside the body primarily the pleural cavity

Light’s : “I prefer to reserve the term empyema for those pleural effusions with thick, purulent appearing pleural fluid”.

Other descriptionsWeese et al. defined an empyema as pleural fluid

with a sp. Gravity >1.018, a WBC count >500 cells/mm3 or a protein level >2.5g/dl.

Vianna defined an empyema as pleural fluid on which the bacterial cultures are positive or the WBC count is > 15,000/mm3 and the protein level is >3.0g/dl.

•abscess

Empyema is different from an abscess because the latter is the formation And collection of pus in a newly formed cavity inside the body.

Parapneumonic effusion:

Any pleural effusion associated with bacterial pneumonia , lung abscess or bronchiectasis is a parapneumonic effusion.

Many complicated parapneumonic effusions are empyemas.

Some patients with empyema have no associated pneumonic process.

Introduction of infectionNon-traumatic Traumatic

Direct extension from an adjacent site : lung infection

Aspiration pneumonia

Post-obstructive pneumonia

Bronchiectasis, lung abscess

Instrumentation and rupture of esophagus

Leakage of an esophageal anastomosis after resection

Development of a bronchopleural fistula following pneumonectomy

Pleual aspiration/ tube drainageAbdominal sepsis: subphrenic abscess ,

liver abscessSepsis in the pharynx, thoracic spine or

chest wall may extend into the pleura via tissue planes or mediastinum

Non- surgical trauma:Gun shot wounds, blast injuries and stab

wounds.

Pathology (1) Exudative STAGEOnce infected by pathogenic organisms, the connective

tissue layers within the pleural memberanes become oedematous and produce an exudation of sterile proteinaceous fluid that starts to fill the pleural cavity.

The deepest layers of the pleural membranes are relatively impervious so that infection tends to be contained within the pleural cavity itself and spread beyond it is unusual.

At this stage, the pleural fluid is thin with a relatively low white cell count and the visceral pleura and underlying lung remain mobile.

Fluid at this stage is having a low WBC count, low LDH level and a normal glucose level and ph.

(2) Fibrinopurulent STAGEIf the infection proceeds unchecked by antimicrobial agents,

the inflammatory process continues so that newly formed layers of fibrin become laid down on the epithelial surface within the pleural cavity, particularly on the pleural cavity.

The empyma fluid now becomes more thicker and more turbid, containing, a higher white cell count.

Such empyemas may become loculated into smaller collections by the development of fibrinous bands which prevent the extension of empyema but making the work of percutaneous aspiration difficult or impossible.

With the deposition of fibrin on both pleural surfaces, lung movements in this stage may become increasingly restricted.

The pleural fluid ph and glucose levels becomes progressively lower and LDH level becomes progressively higher.

(3) ORGANIZATIONAL STAGEDepending upon the nature of the infecting organism

and whether or not antibiotics and drainage procedures have been employed, these thickened fibrinous layers organize as collagen and become vascularized by an ingrowth of capillaries.

This stage may begin within two weeks but usually takes 4-6 weeks to develop to a point at which the empyema cavity becomes surrounded by a cortex, peel or rind that may be more than 2 cm thick.

This inelastic pleural peel encases the lung and renders it virtually functionless.

By this time the empyema contains frank pus, which may be viscid.

Ultimately, an inadequately treated empyema cavity may become obliterated and its rind may calcify, producing a so-called firothorax, particularly in case of old tuberculous pleural infection.

The inner layers of the thickened empyema cortex continue to show a considerable inflammatory cell infiltrate and the fibrous outermost layers exert an increasingly restrictive effect, both compressing the underlying lung( the so called “trapped lung” effect) and also tending to draw the overlying ribs together, ultimately producing a chest deformity with a dorsal scoliosis that is concave towards the affected side.

Dry “sicca” pleuritis stage, the inflammatory process of the pulmonary parenchyma extends to the visceral pleura, causing a local pleuritic reaction.

This leads to a pleural rub and a characteristic pleuritic chest pain which originates from the sensitive innervations of the adjacent parietal pleura.

Clinical stages• Acute stage : within the first 2 weeks of the onset.

• Chronic Stage : after 2 weeks or with the formation of the

thick peel and loculations.

Causes for chronicityInadequate Tube Drainage.

Chronic pulmonary Disease( T.B. or Fungal Infection)

Immunosupressed patients.

Presence of Foreign body within the pleural space.

bacteriologic features

Influence of pre-disposing factors: CAP: pneumococcalHAP: MRSAAspiration or lung abscess: anaerobesInfection from below the diaphragm: gram negative

enteric bacilliExternal trauma/haemothorax: staph. AureusTuberculous empyema – same mechanism as TB pl.

effusion with spillage of large amount of mycobacterium into pleural space purulent effusion that requires surgical intervention and can result in pleural fibrosis and restrictive lung disease

BACTERIOLOGIC FEATURES CONT..

Influence of age: Anaerobes in elderlyS. pneumoniae in young ambulatory patientsChildren: h. influenzae

Uncommon microbial causes: fungal(cryptococcus neoformans, blastomyces,coccidioides,histoplasmosis) , actinomyces, nocardia, clostridia, echinococcus spp. , protozoa( trichomonas, entamoeba)

Clinical presentation Aerobic bacterial infections: acute febrile

illness

Anaerobic bacterial infections:Subacute illness. Median symptom duration 10 daysPredisposing factors present : h/o

alcoholism, an episode of unconsciousness , poor oral hygeine

Symptoms SignsGeneralized malaise Oral cavity: decaying teeth

Fever Finger clubbing: in chronic empyema

Pleural pain Chest examn: similar to that of pleural effusionWarm, tender and bulging ICS

Cough: If BPF patent, variable quantities of purulent sputum, can be foul smelling and associated with postural variation.

Empyema necessitans: the suppuration process if undrained and uncontrolled by AB, may extend beyond the pleural cavity, with pointing occurring in an ICS close to the sternum where chest wall is thinnest.

Dyspnoea: a. compression of underlying lung by empyemab. Primary disease involving lung itself

Discharging sinus: EN will then rupture through the chest wall to s/o tissues, ultimately reaching the skin surface leading to discharging sinus.

diagnosisHistory

Clinical features

Chest radiograph

Ultrasound chest

CT chest

Thoracentesis : empyema fluid : appearance, mirobiology, biochemistry

Chest x-rayDecubitus view: suspect side down – fluid b/w chest wall and inferior part of lung

Suspect side up : parenchymal infiltrate.

In early stages: identical to those of uncomplicated pl. eff.

As the time passes by, fibrosis develops around the empyema cavity so that fluid is contained in one location irrespective of patient’s position.

“D shaped shadow” may be visible along with obliteration of CP angle.

Parenchymal lesion may be visible : consolidation, lung abscess

Air fluid level: pneumothorax : spontaneous or iatrogenic broncho-pleural fistula presence of gas forming organisms such as clostridia

ultrasoundMay show septa when there is loculation

Also helpful in targeting an empyema for needle or tube drainage.

Portable

Helpful in distinguishing b/w Loculated pyopneumothorax AndPeripheral lung abscess

Computed tomographyAble to detect underlying abnormalities such as oesophageal

perforation , bronchial carcinoma and associated lymphadenopathy .

It also aids in the differentiation between empyema and lung abscess.

Empyemas are usually lenticular in shape, compress the lung, and create obtuse angles as they follow the contour of the chest wall.

There is usually an indistinct border between lung parenchyma and a lung abscess, which forms an acute angle where contact with the chest wall is made.

The ‘split pleura’ sign, where both parietal and visceral pleura enhances showing their separation, can be present in an

empyema. Computed tomography (CT) is not as accurate as ultrasound indetecting septations and requires transferring the patient.

Empyema fluid :GROSS EXAMN : COLOUR, TURBIDITY AND ODOR

Can be distinguished from pleural fluid that is turbid due to chyle i.e. chylothorax by use of centrifugation in which case a whitish layer of chylomicrons is found on surface of pleural fluid.

appearance: E. histolytica: anchovy sauce actinomyces: sulfur granules

Smell: putrid (FECULENT) smell in anaerobic infection.

Microbiology : ZNGram’sculture: aerobic as well as anaerobic,

mycobacterial and fungal PCRCytology : total and differential WBC counts

Ph : should not be done as it will plug up the blood gas machines.

Biochemistry of empyema fluid Low p H Low glucoseRaised LDH

Decreased pH and glucose occur as a result of leucocyte and bacterial anaerobic metabolism of glucose and process that produce lactic acid.

Exception The one situation in which pleural fluid ph is not reduced is when the offending organism is of the proteus sp.. These organisms produce ammonia by their urea splitting ability which leads to and elevated pleural fluid ph.

Non significant PE N NAUGHTY

Typical parapneumonic PE

T TINY

Borderline complicated PE

B BUTTERFLIES

Simple complicatedPE

S SUCK

Complex complicated PE

C COMPLETE

Simple empyema S SQUASH

Complex empyema C CONTAINER

complicationsRupture into the lung: Dissection

into lung parenchyma BronchoPleural fistula and

pyopneumothorax

Spread to the subcutaneous tissue: Dissection through chest wall Empyema Necessitans

Dissection into abdominal cavity.

Septicaemia & septic shock.

Management

Principles of management: Control of the Infection process.Drainage of pus form the pleura.Obliteration of the space & complete Re-

expansion of the Lung.

MANAGEMENT OPTIONS: General MedicalSurgery

generalSupportive

Bed rest Analgesia Oxygen Fluids

Identify the cause Malnutrition TB HIV

antibiotic selection If the fluid’s gram stain and culture reports are available, it should

guide the choice of AB.

The initial antibiotic selection : some do not penetrate pleura.

Metronidazole> penicillin>clindamycin>vancomycin>ceftriaxone>gentamicin

Quinolones and clarithromycin also penetrate well

1.Severe CAP : fluoroquinolones(levofloxacin, moxifloxacin, gatifloxacin or gemifloxacin)

Advanced macrolide(azithromycin or clindamycin) plus b-lactam(cefotaxime, ceftriaxone)

2. If pseudomonas suspected: piperacilin-tazobactam, imipenem, meropenem

3. Anaerobic: clindamycin or metronidazole. 4. MRSA: vancomycin until culture results are available.

Surgical management“those diseases that medicines do not cure are cured by

the knife”

TECHNIQUE DEPENDS UPON THE STAGE OF EMPYEMA

CLOSED: INTERMITTENT (REPEATED ASPIRATION OR THORACOCENTESIS)

CONTINUOUS (INERCOASTAL DRAINAGE )

OPEN: RIB RESECTION ELOESSER FLAP

CLOSED These methods are more likely to appertain in the

exudative stage but may be continued into the fibrino-purulent stage in some cases.

THORACOCENTESIS : frequency with which thoracentesis is repeated depends upon the rate at which pus reaccumulates, which in turn is judged by clinical and radiographic appearance.

Such treatment along with antibiotics is appropriate for many individuals with pleural empyema and these patients may have a shorter and less complicated stay than those by tube drainage.

Closed tube drainage

Tube is placed under local anaesthesia into most dependent part of empyema determined by USG/CT guidance and is connected to an underwater-seal drainage system.

The relatively large (28 to 36F ) tubes have been recommended because of the belief that smaller tubes would become obstructed with the thick fluid.

The advantage of the smaller tube is that it is easier to insert and is less painful to the patient.

Patency is maintained with irrigation and fibrinolytic therapy If the patient has not demonstrated significant improvement within

24hrs of initiating tube thoracostomy, either the pleural drainage is unsatisfactory(tube placed in wrong position, loculations) or the patient is receiving the wrong antibiotic.

Advantages: successful when infected material is too viscid to remove by manual aspiration.

Disadvantages: greater discomfort and immobility for the patient introduction of new infection at drainage site tube blocked by fibrin clot

Indications for removal of tube:Volume of the pleural drainage is less than 50ml for

24 hrs and until the draining fluid becomes clear yellow.

The amount of sediment (representing WBCs and debris) in the collection system should not be more than 5ml.

Tube ceases to work

Because it serves no useful purpose rather it as a conduit for pleural super-infection.

Closed drainageSuccessful:Empyema is small Is started In acute exudative or early fibrinopurulent stagees of

infectionIn this case, the wall of the empyema cavity gradually becomes

absorbed allowing re-expansion of the underlying lung and obliteration of space.

It may fail: If the pus is too thick to drain by thoracentesis or tubeBPF has developedPockets of pus become loculated and inaccessible.If drainage is inadequate, ultrasonography or CT should be

performed to delineate which factor is responsible.Then, more invasive surgical procedures are required.

Intrapleural streptokinaseThe pleural fluid loculations are produced by fibrin

membranes that prevent the spread of the infected pleural fluid throughout the body, but which make drainage of the pleural space difficult.

Intrapleural fibrinolytics will destroy the fibrin membranes and facilitate drainage of the pleural fluid.

Indications Acute or fibrino purulent stage Presence of loculations. Incomplete drainage after tube insertionContraindications: Chronic stage Post-operative empyema Empyema with BPF.

fibrinolyticsStreptokinase: 15 000U/kg in 20-50ml saline once

daily for 3 days (vial 750 000U R1400, 1 million units R2700)

Urokinase: 40 000u in 40ml saline (> 1 year) or 10 000 in 10 ml BD for 3 days(< 1 year)

tPA 0.1mg/kg in 10-30ml saline dwell time 1 hour (50mg vial R3100)

vatsAdvantages:

the loculi can be disruptedpleural space can be completely drained Chest tube can be optimally placed.

In addition, if lung is trapped(not expanded),

the VATS incision can be enlarged so that decortication can be completed with a full thoracotomy.

Pulmonary decortication In a non-medical aspect, decortication is the removal of the

bark, husk, or outer layer, or peel of an object. It is a surgical procedure that involves the removal of a

dysfunctional layer covering the lungs and evacuation of all pus and debris from the pleural space.

The primary aim of performing lung decortication is to be able to promote lung expansion and chest wall compliance.

  IF AFTER 6MONTHS, PLEURA REMAINS THICKENED

AND THE PATIENT’S PFTS IS SIGNIFICANTLY REDUCED TO LIMIT ACTIVITIES, DECORTICATION SHOULD BE CONSIDERED

Open drainageRib resection: resecting segments of one to three ribs overlying

the lower part of empyma cavity and inserting large bore tubes into the empyema cavity.

Following this, tubes are irrigated daily with a mild antiseptic solution and daily redressed.

Successful open drainage results in gradual obliteration of empyema space.

Open window thoracostomy (eloesser flap) : involves the removal of sections of two or more ribs in order to

fashion a larger stoma, which is kept open by suturing the skin to the parietal pleura/cortex thereby creating a pleurocutaneous flap, stoma closed if the underlying lung re-expands or may occasionally be left permanently open with daily dressings.

Empyema associated with bpfAdequate pleural drainage is crucial: an emergency

Pleural fluid if not drained exteriorly with chest tubes is likely to drained interiorly into the lung

The bacteria then spread throughout the broncho-pulmonary tree and an overwhelming pneumonia can result.

Drainage should be instituted immediately to prevent the possibility of contaminating the entire respiratory system by the infected pleural fluid.

How to suspect: a patient with pleural fluid collection:Raises more sputum than would be expectedWith postural variationOn x-ray(upright position): presence of an air fluid level in the

pleural space Need USG and CT chest to differentiate from a peripheral lung

abscess.

Empyema distal to an obstructed bronchus

• Contraindication for chest tube placement

• If chest tubes placed: bronchial obstruction will prevent the expansion of underlying lung.

• What should be done: appropriate AB should be administered along with therapy for obstructed bronchus: radiotherapy, endo-bronchial stent or laser therapy. Once obstruction relieved, ICT to be done.

Post traumatic empyemaFactors leading to development of empyema: Retained hemothoraxPulmonary contusionMultiple chest tube placementManagement : similar to that of other para-

pneumonic effusions.

Post pneumonectomy empyema

how to suspect : 2nd day to 7yrs (4wks)A febrile illness with signs of systemic toxicityExpectoration of large amounts of pleural fluidAn air-fluid level in the pneumonectomy spaceDrainage of purulent material from surgical incisionMediastinal shift towards contralateral side

Organism responsible: staph aureus

Diagnosis and treatment : all aptients: AB + chest tube placement

Scheme to move forwardAntibiotics Pleural aspirationChest tube drainageChest tube drainage with I/P fibrinolyticsThoracoscopyDecortication

prognosisFavourable in patients started on

appropriate antibiotic

Early chest tube drainage is beneficial.

Decortication or open drainage has decreased mortality and morbidity

Mortality 6-12%