Parapneumonic Effusions and Empyema

Parapneumonic Effusions and Empyema

Journal Club

Preethi Yeturu and Navneesh Sharma

February 18, 2009

Journal Club

Preethi Yeturu and Navneesh Sharma

February 18, 2009

Pleural EffusionsPleural Effusions

Abnormal accumulation of fluid in the pleural space due to a disruption of the equilibrium across pleural membranes

Normal pleural fluid clear ultrafiltrate of plasma pH 7.6 - 7.64 Protein content <2%, WBC <1000 LDH <50% of plasma LDH

Two types Transudate Exudate

Abnormal accumulation of fluid in the pleural space due to a disruption of the equilibrium across pleural membranes

Normal pleural fluid clear ultrafiltrate of plasma pH 7.6 - 7.64 Protein content <2%, WBC <1000 LDH <50% of plasma LDH

Two types Transudate Exudate

TransudateTransudate

Increased capillary hydrostatic pressure or decreased colloid oncotic pressure Pleural membranes intact Permiability of capillary membranes normal

Fluid is an ultrafiltrate of plasma Causes

CHF Cirrhosis Nephritic syndrome

Increased capillary hydrostatic pressure or decreased colloid oncotic pressure Pleural membranes intact Permiability of capillary membranes normal

Fluid is an ultrafiltrate of plasma Causes

CHF Cirrhosis Nephritic syndrome

ExudateExudate Altered permeability of pleural membranes

and capillaries or obstruction of lymphatic drainage of pleural space

Light’s criteria: one or more of following must be present Pleural fluid/serum protein >0.5 Pleural fluid/serum LDH>0.6 Pleural fluid specific gravity >1.018

Causes Parapneumonic TB Malignancy PE

Altered permeability of pleural membranes and capillaries or obstruction of lymphatic drainage of pleural space

Light’s criteria: one or more of following must be present Pleural fluid/serum protein >0.5 Pleural fluid/serum LDH>0.6 Pleural fluid specific gravity >1.018

Causes Parapneumonic TB Malignancy PE

Parapneumonic EffusionsParapneumonic Effusions

Any pleural effusion associated with bacterial pneumonia, lung abscess or bronchiectasis

Most common cause of exudative pleural effusions in US 40-60% of bacterial pneumonias result in pleural

effusions Three types

Uncomplicated parapneumonic effusion Complicated parapneumonic effusion Empyema

Any pleural effusion associated with bacterial pneumonia, lung abscess or bronchiectasis

Most common cause of exudative pleural effusions in US 40-60% of bacterial pneumonias result in pleural

effusions Three types

Uncomplicated parapneumonic effusion Complicated parapneumonic effusion Empyema

Uncomplicated EffusionsUncomplicated Effusions

Parenchymal infection leads to increased interstitial fluid that causes accumulation of sterile pleural effusion

Pleural fluid is often small (<10mm) sterile w/ small amount of PMNs glucose and pH wnl

Resolve with resolution of pneumonia and treatment w/ antibiotics

Parenchymal infection leads to increased interstitial fluid that causes accumulation of sterile pleural effusion

Pleural fluid is often small (<10mm) sterile w/ small amount of PMNs glucose and pH wnl

Resolve with resolution of pneumonia and treatment w/ antibiotics

Complicated EffusionsComplicated Effusions

Persistent bacterial infection of previously sterile pleural fluid

Pleural fluid Many PMNs, bacteria and cell debris Acidosis - pH and glucose decrease LDH increases

Possible deposition of fibrin on pleura - formation of multiple locules

Persistent bacterial infection of previously sterile pleural fluid

Pleural fluid Many PMNs, bacteria and cell debris Acidosis - pH and glucose decrease LDH increases

Possible deposition of fibrin on pleura - formation of multiple locules

EmpyemaEmpyema

Characterized by bacteria seen on gram stain or aspiration of pus 60% from complicated

parapneumonic effusions 20% after thoracic surgery

Pleural fluid Possible formation of

pleural peel that can encase the lung and hinder reexpansion

Characterized by bacteria seen on gram stain or aspiration of pus 60% from complicated

parapneumonic effusions 20% after thoracic surgery

Pleural fluid Possible formation of

pleural peel that can encase the lung and hinder reexpansion

Clinical ManifestationsClinical Manifestations History

Acute febrile episode Dyspnea Cough - w/ purulent sputum Pleuritic chest pain Weight loss

Physical exam Dullness to percussion Diminished breath sounds in affected hemithorax Decreased tactile fremitus Egophony Pleuritic friction rub

History Acute febrile episode Dyspnea Cough - w/ purulent sputum Pleuritic chest pain Weight loss

Physical exam Dullness to percussion Diminished breath sounds in affected hemithorax Decreased tactile fremitus Egophony Pleuritic friction rub

Diagnosis - ImagingDiagnosis - Imaging

CXR blunting of

costrophrenic angle on upright films

Lateral decubitus films - better view of subpulmonic effusions, show if effusion is freely-flowing, thickness of effusion

CXR blunting of

costrophrenic angle on upright films

Lateral decubitus films - better view of subpulmonic effusions, show if effusion is freely-flowing, thickness of effusion

Diagnosis - ImagingDiagnosis - Imaging

CT - w/ IV contrast is optimal

Allow for differentiation betwn parenchymal and pleural disease

Contrast enhances pleural surface

CT - w/ IV contrast is optimal

Allow for differentiation betwn parenchymal and pleural disease

Contrast enhances pleural surface

DiagnosisDiagnosis

Thoracentesis Sample if any of following are present

Free flowing but >10mm in lateral decubitus film Loculated Associated w/ thickened parietal pleura on CT - suggests

empyema Complications - pain, bleeding, pneumothorax,

puncture of liver or spleen

Thoracentesis Sample if any of following are present

Free flowing but >10mm in lateral decubitus film Loculated Associated w/ thickened parietal pleura on CT - suggests

empyema Complications - pain, bleeding, pneumothorax,

puncture of liver or spleen

Analysis of Pleural FluidAnalysis of Pleural Fluid

Gross examination for color, turbidity and odor

Microbiology - gram stain and cultures pH or glucose, LDH, protein CBC w/ differential

Gross examination for color, turbidity and odor

Microbiology - gram stain and cultures pH or glucose, LDH, protein CBC w/ differential

Analysis of Pleural FluidAnalysis of Pleural Fluid

Characteristics of Pleural Fluid Characteristics of Pleural Fluid  Simple parapneumonic

effusionComplicated parapneumonic

effusionEmpyema

Appearance May be slightly turbid Cloudy Pus

Biochemical markers pH >7.30 pH <7.20 n/a

LDH maybe slightly elevated LDH >1000 IU/L

Glucose >60 mg/dL or pleural/serum ratio >0.5

Glucose <35 mg/dL

Nucleated cell count Neutrophils usually <10,000 cells/μL

Neutrophils + + (usually >10,000 cells/μL)

n/a

Microbiology: Gram stain

Negative May be positive May be positive

Microbiology: culture Negative May be positive May be positive

Categories risk for poor outcomes

Categories risk for poor outcomes

Pleural Space Anatomy

  Pleural Fluid Bacteriology

  Pleural Fluid Chemistry

Category Risk of Poor Outcome

Drainage

A0: Minimal, free-flowing effusion (<10 mm on lateral decubitus)

and Bx: Culture and Gram stain results unknown

and Cx: pH, glucose unknown

1 Very low No

A1: Small to moderate free-flowing effusion (>10 mm and <½ hemithorax)

and B0: Negative culture and Gram stain

and C0: pH ≥ 7.20, glucose > 60 mg/dL

2 Low No

A2: Large, free-flowing effusion (≥½ hemithorax), loculated effusion, or effusion with thickened parietal pleura

or B1: Positive culture and Gram stain

or C1: pH < 7.20, glucose < 60 mg/dL

3 Moderate Yes

    B2: Pus     4 High Yes

TreatmentTreatment Depends on type and category of effusion

Uncomplicated - category 1 or 2 Resolves w/ antibiotic treatment alone Does not need drainage

Complicated - category 3 Variable response to antibiotics alone - thus often treated like

empyema Empyema - category 4

Requires complete drainage Goal of therapy:

Sterilization of cavity - antibiotics for 4-6 weeks Complete drainage as evidenced by minimal chest tube output

and CT documentation that no residual loculations persist Obliteration of empyema cavity w/ adequate lung expansion

Depends on type and category of effusion Uncomplicated - category 1 or 2

Resolves w/ antibiotic treatment alone Does not need drainage

Complicated - category 3 Variable response to antibiotics alone - thus often treated like

empyema Empyema - category 4

Requires complete drainage Goal of therapy:

Sterilization of cavity - antibiotics for 4-6 weeks Complete drainage as evidenced by minimal chest tube output

and CT documentation that no residual loculations persist Obliteration of empyema cavity w/ adequate lung expansion

Drainage of EffusionDrainage of Effusion Theurapeutic thoracentesis Tube thoracotomy

Often left until rate of drainage <50mL/day and cavity is closed W/ fibrinolytics - intrapleural administration was suggested for

loculated effusions Reported data does not demonstrate benefit in most pts

Thoracoscopy Alternative treatment for multiloculated empyema

Open thoracostomy Open drainage at inferior border of empyema cavity w/ chest

tube Preferred in pts who cannot tolerate thoracotomy

Theurapeutic thoracentesis Tube thoracotomy

Often left until rate of drainage <50mL/day and cavity is closed W/ fibrinolytics - intrapleural administration was suggested for

loculated effusions Reported data does not demonstrate benefit in most pts

Thoracoscopy Alternative treatment for multiloculated empyema

Open thoracostomy Open drainage at inferior border of empyema cavity w/ chest

tube Preferred in pts who cannot tolerate thoracotomy

Drainage of EffusionDrainage of Effusion

Thoracotomy w/ decortication For pts who require

additional drainage after trial of tube thoracostomy and thoracoscopy

Or pt who have fibrin deposition that hinders ability of lung to expand

Thoracotomy w/ decortication For pts who require

additional drainage after trial of tube thoracostomy and thoracoscopy

Or pt who have fibrin deposition that hinders ability of lung to expand

Thank you!!Thank you!!