PLEURAL EFFUSION, PYOTHORAX & PNEUMOTHORAX

Dr Sarika Gupta, Asst. Professor

DEFINITION

Pleural effusion: inflammation of the pleura, accompanied by collection of fluid in the pleural space.

Normal Pleural fluid: 0.3 ml/kg BWProtein: 1.5 g/dLpH: alkaline (7.60)Cells: 1700 cells/ml (75% macrophages, 23% lymphocytes & 2% mesothelial cells)

Pleural space should be virtually fluid free

Pleural fluid is produced by the parietal pleura and absorbed by the visceral pleura as a continuous process

Fluid accumulates in the pleural space by three mechanisms:

increased drainage of fluid into the space increased production of fluid by cells in the space decreased drainage of fluid from the space

Development of Pleural Effusion pulmonary capillary pressure (CHF) capillary permeability (Pneumonia) intrapleural pressure (atelectasis) plasma oncotic pressure (hypoalbuminemia) pleural membrane permeability (malignancy) lymphatic obstruction (malignancy) diaphragmatic defect (hepatic hydrothorax) thoracic duct rupture (chylothorax)

CAUSES

EXUDATIVE (usually unilateral)Parapneumonic effusionTuberculosisConnective tissue disordersMalignancyPancreatitisSubphrenic abscessSevere dengueRadiation pleuritis

TRANSUDATIVE (usually bilateral )Congestive heart failureCirrhosisNephrotic syndromeConstrictive pericarditisPeritoneal dialysis

CHYLOUSCongenital chylothoraxPost-traumatic

HEMOTHORAXBlunt traumaMalignancy

CLINICAL FEATURES

History: Small pleural effusion: asymptomatic Large pleural effusion: pleuritic chest pain, abdominal pain,

pain during inspiration or coughing The child may prefer to lie on the affected side (to decrease

respiratory excursions) Cough Fever Respiratory distress, dyspnea, orthopnea, or cyanosis

CLINICAL FEATURES

Examination: Tracheal deviation to the opposite side Bulging chest wall on the affected side with reduced movement Decreased vocal fremitus Dullness to percussion Decreased or absent breath sounds Diminished whispering pectoriloquy & decreased vocal

resonance Egophony-audible at the upper level of pleural effusion due to

prtially collapsed underlying lung

CLINICAL FEATURES

Examination: Pleural friction rub: Inflamed parietal & visceral pleurae rub against each other leathery, rough in character Heared in both inspiration and expiration Disappears rapidly as the size of effusion increases If a child remains pyrexial or unwell 48 hours after admission

for pneumonia, parapneumonic effusion/empyema must be excluded. 

DIAGNOSIS

Chest radiograph (x-ray)

-able to distinguish >200ml of fluid (blunted costophrenic angles)

-Chest radiographs acquired in the lateral decubitus position are more sensitive and can pick up as little as 50 ml of fluid.

Pleural fluid analysis Chest ultrasound

-locates small amounts or isolated loculated pockets of fluid

-able to give precise position of accumulation Computed Tomography (CT) scan

-Differentiates between fluid collection, lung abscess, or tumor

PLEUAL EFFUSION

Created by an abnormal collection of fluid in the pleural space

Seen in chest X-ray with presence of about 200ml pleural fluid

Fluid in X-ray seen as a dense, white shadow with a concave upper edge (fluid level)

CT scan of chest showing loculated pleural effusion in left side. Some thickening of pleura is also noted.

Pleural fluid analysis

1. Routine tests Gross examination Pleural fluid/serum protein ratio Pleural fluid/serum LDH ratio Cytology and culture

Pleural fluid analysis

2. Tests in selected cases Pleural fluid cholesterol Pleural fluid/serum cholesterol ratio Lactate Enzymes Interferon ᵞ CRP Tumor markers

Gross examination

Transudates: typically clear, pale yellow to straw-colored, odorless & do not clot.

Exudates: show variable degrees of cloudiness or turbidity & they often clot if not heparinized

A feculent odor may be detected in anaerobic infections

Gross examination

A bloody pleural effusion (hematocrit >1%) suggests trauma, malignancy, or pulmonary infarction.

A pleural fluid hematocrit greater than 50% of the blood hematocrit is good evidence for a hemothorax

Turbid, milky, and/or bloody specimens should be centrifuged and the supernatant examined. If the supernatant is clear, the turbidity is most likely due to cellular elements or debris. If the turbidity persists after centrifugation, a chylous effusion is likely

Chemical analysis

Light’s Criteria (Sensitivity 99%, Specificity 98%)

) Criteria Transudate Exudate

Pleural fluid protein:serum protein ratio

≤0.5 > 0.5

Pleural fluid LDH:serum LDH

≤0.6 > 0.6

Pleural fluid LDH ≤200 >200

Microbiological examination: The sensitivity of the Gram stain is approximately 50% For patients with suspected M. tuberculosis, direct staining of

tuberculous effusions for acid-fast bacteria has a sensitivity of 20%–30% and positive cultures are found in 50%–70% of cases

Chemical analysis

Glucose: The glucose level of normal pleural fluid, transudates, and

most exudates is similar to serum levels

Decreased pleural fluid glucose, accepted as a level below 60 mg/dL (3.33 mmol/L) or a pleural fluid/serum glucose ratio less than 0.5, is most consistent and dramatic in rheumatoid pleuritis and grossly purulent parapneumonic exudates

Lactate: Pleural fluid lactate levels: useful adjunct in the rapid

diagnosis of infectious pleuritis Levels are significantly higher in bacterial and tuberculous

pleural infections than in other pleural effusions Values greater than 90 mg/dL (10 mmol/L) have a positive

predictive value for infectious pleuritis of 94% and a negative predictive value of 100%

Amylase: Elevations above the serum level (usually 1.5–2.0 or more

times greater) indicate the presence of pancreatitis, esophageal rupture, or malignant effusion

Elevated amylase derived from esophageal rupture or malignancy is the salivary isoform, which differentiates it from pancreatic amylase

Lactate dehydrogenase: Pleural fluid LD levels rise in proportion to the degree of

inflammation In addition to their use in separating exudates from

transudates, declining LD levels during the course of an effusion indicate that the inflammatory process is resolving

Conversely, increasing levels indicate a worsening condition requiring aggressive workup or treatment

Adenosine deminase: >40 unit/l Tuberculosis

Interferon-γ: Pleural fluid interferon (IFN)-γ levels are significantly

increased in the pleural fluid of patients with tuberculous pleuritis

The sensitivity of levels of 3.7 IU/L or greater is 99%, and the specificity is 98%

Consider when ADA is unavailable or nondiagnostic

pH: Pleural fluid pH measurement has the highest diagnostic

accuracy in assessing the prognosis of parapneumonic (pneumonia-related) effusions

A parapneumonic exudate with a pH greater than 7.30 generally resolves with medical therapy alone

A pH less than 7.20 indicates a complicated parapneumonic effusion (loculated or associated with empyema), requiring surgical drainage.

A pH below 6.0 is characteristic of esophageal rupture, although the pH in severe empyema may be 6.0 or less

Lipids: Helpful in identifying chylous effusions Pleural fluid triglyceride levels > 110 mg/dL indicate a

chylous effusion values from 60–110 mg/dL require lipoprotein

electrophoresis to confirm a chylothorax Nonchylous effusions : triglyceride levels <50 mg/dL & no

chylomicrons on electrophoresis

Immunologic studies: Approximately 5% of patients with RA and 50% with SLE

develop pleural effusions RF is commonly present in pleural effusions associated with

seropositive RA ANA titers may be useful in the diagnosis of effusion due to

lupus pleuritis

TREATMENT

1. Therapy should be aimed at the underlying disease

Transudative effusion by fluid overload as in cardiac or renal failure: diuretics & fluid management

Nephrotic syndrome and cirrhosis of liver: Albumin infusion

Tubercular pleural effusion: Anti-tubercular drugs

TREATMENT

Chylous pleural effusion: Thoracocentesis or placement of ICD tube followed by

feeding with MCT Continuous development: discontinuation of oral feeds and

TPN Somatostatin & Octreotide Traumatic hemothorax: drainage of blood with proper

replacement Recurrent pleural effusion due to malignancies: prolonged

placement of catheter or pleurodesis

TREATMENT

Parapneumonic effusion Analgesia Supplemental oxygen Systemic antibiotics based on the in vitro sensitivities of the responsible organism

(Staphylococcus, S. pneumoniae, and H. influenzae) Duration: 2 wk. With staphylococcal infections: systemic

antibiotic therapy for 3-4 wk; anaerobic empyema-6-12 weeks

Instillation of antibiotics into the pleural cavity does not improve results

TREATMENT

Thoracentesis Diagnostic thoracentesis

A needle is inserted into

the chest wall to remove the

collection of fluid 50-100ml of fluid is sent

for analysis; Determines the type of fluid (transudate or exudate)

temporarily relieve symptoms Potential complications: bleeding, infection & pneumothorax

TREATMENT

BUT if sufficient fluid reaccumulates to cause respiratory embarrassment, chest tube drainage should be performed

Rapid removal of ≥1 L of pleural fluid may be associated with the development of reexpansion pulmonary edema

Chest tube drainage

TREATMENT

Thrombolytic therapy Promote drainage, decrease fever, lessen need for surgical

intervention & shorten hospitalization Streptokinase 15,000 U/kg in 50 mL of 0.9% saline daily for

3-5 days and urokinase 40,000 U in 40 mL saline every 12 hr for 6 doses

Anaphylaxis with streptokinase & both drugs can be associated with hemorrhage

TREATMENT

Video-assisted thoracoscopic surgery (VATS) or Open decortication

The child who remains febrile & dyspneic >72 hr after initiation of therapy with intravenous antibiotics and thoracostomy tube drainage, surgical decortication via VATS or, less often, open thoracotomy may speed recovery

If pleural fluid septa are detected on ultrasound, immediate VATS can be associated with a shortened hospital course

EMPYEMA

DEFINITION

Empyema or Purulent Pleurisy: Empyema is an accumulation of pus in the pleural space

Most often associated with pneumonia due to Staphylococcus aureus & Streptococcus pneumoniaea

The relative incidence of Haemophilus influenzae empyema has decreased (Hib vaccination)

Also produced by rupture of a lung abscess into the pleural space, by contamination introduced from trauma or thoracic surgery or by mediastinitis or the extension of intra-abdominal abscesses

EPIDEMIOLOGY

Most frequently encountered in infants & preschool children Predisposing factors: preceding history of pustules, blunt

trauma to the chest, viral infection, severe malnutrition, contiguous extension

PATHOLOGY

Empyema has 3 stages: exudative, fibrinopurulent, and organizational

Exudative stage: 1-3 days Fibrinopurulent stage: 4-14 days Organizational stage: After 14 days

PATHOLOGY

Exudative stage: fibrinous exudate forms on the pleural surfaces

Fibrinopurulent stage: fibrinous septa form, causing loculation of the fluid & thickening of the parietal pleura

If the pus is not drained, it may dissect through the pleura into lung parenchyma, producing bronchopleural fistulas and pyopneumothorax, or into the abdominal cavity or through the chest wall (empyema necessitatis)

Organizational stage: fibroblast proliferation; pockets of loculated pus develop into thick-walled abscess cavities or the lung may collapse & become surrounded by a thick, inelastic envelope (peel)

CLINICAL MANIFESTATIONS

The initial signs & symptoms are primarily those of bacterial pneumonia

Children treated with antibiotic agents may have an interval of a few days between the clinical pneumonia phase & the evidence of empyema

Most patients are febrile (fever may be absent in immunocompromised patients), develop increased work of breathing or respiratory distress & often appear more ill

Physical findings are identical to those for uncomplicated parapneumonic effusion & the 2 conditions are differentiated only by thoracentesis

DIAGNOSIS

The effusion is empyema if bacteria are present on Gram staining, the pH is <7.20, glucose<40 mg/dl and LDH>1000 IU/L and there are >100,000 neutrophils/µL

Cultures of the fluid must always be performed Blood cultures also have a high yield

COMPLICATIONS

1. Bronchopleural fistulas Usually respond to adequate drainage, nutritional support &

sealing of the open communication over the lung surface Prolonged bronchopleural fistulas (>2-3 weeks) requires

decortication, lobectomy or thoracoplasty

COMPLICATIONS

2. Pyopneumothorax

3. Purulent pericarditis & pulmonary abscesses

4. Peritonitis from extension through the diaphragm & osteomyelitis of the ribs

5. Septic complications: meningitis, arthritis

6. Septicemia is often encountered in H. influenzae and pneumococcal infections

7. Peel: may restrict lung expansion and may be associated with persistent fever and temporary scoliosis

8. Empyema necessitans

9. Gastropleural fistula

TREATMENT

Systemic antibiotics Staphylococcus aureus: cloxacillin & aminoglycoside or 3 gen

cephlosporin & aminoglycoside Gram-ve organism: cefotaxim & aminoglycoside Gram stain inconclusive: cefotaxim & cloxacillin Resistant Staphylococcus: vancomycin, teicoplanin & linezolid Thoracentesis

TREATMENT

Chest tube drainage with or without a fibrinolytic agent

Indications for surgical treatment:

a) Pleural thickening

b) Loculated empyema

c) Non-expansion of lungs with intercostal drainage

d) Bronchopeural fistula

1. Video-assisted thorascopic surgery: effective in lysis of adhesions in multiloculted effusions & removal of fibrinous material from pleural cavity

2. Open decortication: significant pleural thickening

TREATMENT

The long-term clinical prognosis for adequately treated empyema is excellent & follow-up pulmonary function studies suggest that residual restrictive disease is uncommon, with or without surgical intervention

PNEUMOTHORAX

PNEUMOTHORAX

DEFINITION

Accumulation of extra pulmonary air within the chest, most commonly from leakage of air from within the lung

ETIOLOGY

Closed pneumothorax-Pulmonary diseaseForeign bodyRDSRespiratory infectionsBronchial asthmaCystic fibrosisChemical pneumonitisDiffuse lung diseaseTumors-IatrogenicMechanical ventilationCentral venous catheterization

Open pneumothoraxInvasive pleural & pulmonary proceduresChest trauma

Spontaneous pneumothoraxIdiopathic (ruptured subpleural blebs)Familial

PATHOGENESIS

The tendency of the lung to collapse is balanced in the normal resting state by the inherent tendency of the chest wall to expand outward, creating negative pressure in the intrapleural space

When air enters the pleural space, the lung collapses In simple pneumothorax, intrapleural pressure is atmospheric,

and the lung collapses up to 30%. In complicated, or tension pneumothorax, continuing leak

causes increasing positive pressure in the pleural space, with further compression of the lung, contralateral shift of mediastinal structures & decreases in venous return and cardiac output

CLINICAL MANIFESTATIONS

Sudden onset Dyspnea, pain, & cyanosis Trachea & heart may be shifted toward the unaffected side Hyperinflation & reduced movements on affected side Respiratory distress with retractions Decreased vocal fremitus & vocal resonance Markedly decreased breath sounds and a tympanitic

percussion note over the involved hemithorax When fluid is present, there is usually a sharply limited area

of tympany above a level of flatness to percussion

CLINICAL MANIFESTATIONS

Succussion splash: to rule out hydropneumothorax Coin test Friction test

DIAGNOSIS

By radiographic examination When the possibility of diaphragmatic hernia is being

considered, a small amount of barium may be necessary to demonstrate that it is not free air but is a portion of the gastrointestinal tract that is in the thoracic cavity

Ultrasound can also be used to establish the diagnosis

TREATMENT

Extent of the collapse & nature and severity of the underlying disease

A small (<5%) or even moderate-sized pneumothorax in an otherwise normal child may resolve without specific treatment, usually within about 1 wk

Needle aspiration: tension pneumothorax & primary spontaneous pneumothorax

If the pneumothorax is recurrent, secondary or under tension or there is >5% collapse: chest tube drainage

Pneumothorax complicating malignancy: chemical pleurodesis or surgical thoracotomy

TREATMENT

Closed thoracotomy: adequate to reexpand the lung in most patients

Chemical pleurodesis: recurrent pneumothoraces; introduction of talc, doxycycline, or iodopovidone into the pleural space

Open thoracotomy: plication of blebs, closure of fistula, stripping of the pleura and basilar pleural abrasion; Stripping and abrading the pleura leaves raw, inflamed surfaces that heal with sealing adhesions

VATS: preferred therapy for blebectomy, pleural stripping, pleural brushing and instillation of sclerosing agents; less morbidity than with open thoracotomy