DISEASES OF THE PLEURA

PLEURA AND PLEURAL CAVITY

PLEURA AND PLEURAL CAVITY

FIBRINOUS (DRY) PLEURISY

DEFINITION Inflammation of the pleura characterized by fibrinous exudation and no significant degree of effusion.

ETIOLOGY A. Primary pleural disease: B. Secondary to: 1. Tuberculosis; 2. Rheumatic fever; 3. Viral disease: Coxsackie B virus may cause a recurrent pleuromyositis, named “Pleurodynia” or “Bernholm disease”; 4. Malignant (mesothelioma). B. Secondary to: 1. Lung disease: pneumonia, tuberculosis, lung abscess or pulmonary infarction; 2. Mediastinal disease: pericarditis, mediastinitis or malignancy; 3. Subdiaphragmatic disease: amoebic or subphrenic abscess.

CLINICAL FEATURES SYMPTOMS: Pleuritic pain (sudden, stitching chest pain, increasing with inspiration, coughing and movements); In diaphragmatic pleurisy the pain is referred to the shoulder (through the phrenic nerve) or to the epigastrium and lumbar region (through the lower intercostal nerves). Pleuritic cough – dry, due to irritation of pleura; Dyspnea – due to: Restriction of respiratory movements; Underlying lung disease or development of effusion. Specific etiological and general features: fever, headache, and malaise.

CLINICAL FEATURES SIGNS: Inspection Palpation Percussion Auscultation Limitation of movements on the affected side. Palpation Sometimes palpable pleural rub. Percussion Tenderness . Auscultation PLEURAL RUB

Chest X-ray must be performed in every case for detecting a thoracic cause for the pleurisy.

PLEURAL EFFUSION

DEFINITION Abnormal (excessive) accumulation of fluid inside the pleural space.

Pleural Effusion

PLEURAL EFFUSION

ETIOLOGY. PATHOGENESIS EXUDATE TRANSUDATE The term “pleural effusion”, by general consent, is applied only to serous effusions.

ETIOLOGY. PATHOGENESIS EXUDATE – definition -one or more criteria: Pleural fluid protein to serum protein ratio >0.5 Pleural fluid LDH to serum LDH ratio >0.6 Pleural fluid LDH value >2/3 upper normal limit for serum LDH (pleural fluid LDH >200U/L). Mechanisms: increased permeability of the pleural surface (due to inflammation) or by obstruction of the lymphatics (carcinoma).

ETIOLOGY. PATHOGENESIS EXUDATE – causes: Pneumonia (parapneumonic effusions) Cancer (especially mediastinal) Pulmonary embolism Rheumatic fever Empyema Tuberculosis Conective tissue disease Viral pleurisy Acute pancreatitis Uremia Chronic atelectasis Sarcoidosis Drug-related Post-myocardial infarction (Dressler`s syndrome)

ETIOLOGY. PATHOGENESIS TRANSUDATE: Pleural fluid protein to serum protein ratio < 0.5 Pleural fluid LDH < 200U/L Mechanisms: Increased in hydrostatic pressure (congestive heart failure); Decreased oncotic pressure (hypoalbuminemia); Greater negative intrapleural pressure (acute atelectasis).

ETIOLOGY. PATHOGENESIS TRANSUDATE – causes: Congestive heart failure (majority of cases); Cirrhosis with ascites; Nephrotic syndrome; Myxedema; Meigs`s syndrome (right side pleurisy, ascitis, ovarian cancer); Acute atelectasis; Constrictive pericarditis; Superior vena cava obstruction (mediastinal tumors).

CLINICAL FINDINGS SYMPTOMS: Pleuritic pain, pleural rub, irritative dry cough (a dry pleurisy often precedes the development of effusion); Dyspnea (its severity increases with the size of the effusion); General symptoms (due to the cause): Fever, night sweat, loss of weight, loss of appetite.

CLINICAL FINDINGS SIGNS: INSPECTION PALPATION PERCUSSION AUSCULTATION limitation of movements on the affected side PALPATION large effusions shift the mediastinum to the opposite side (if it is not fixed by malignancy) decreased vocal tactile fremitus PERCUSSION basal stony dullness rising to the axilla (Damoisseau line) hyper-resonance above the level of effusion (compensatory emphysema) AUSCULTATION Absent or reduced breath sounds over the area of the effusion Bronchial breathing and egophony may be heard over the upper level of effusion Physical findings are absent if less than 200-300 ml of pleural fluid is present.

Pleural Effusion

LABORATORY FINDINGS CHEST X- RAY obliteration of the costophrenic angle by a homogenous, intense opacity rising laterally to the axilla; mediastinal displacement to the opposite side; may indicate the possible etiology of the pleurisy (tuberculosis, lung cancer, lymphoma) showing the primary mediastinal lesion. Pleural fluid may become trapped (”loculated”) by pleural adhesions, forming unusual collections along the chest wall or in the lung fissures (“pseudotumors”).

LABORATORY FINDINGS DIAGNOSTIC THORACENTESIS Pleural fluid is examined for: physical, chemical, bacteriological, and cytological characteristics.

ASSESSMENT OF PLEURAL FLUID

LABORATORY FINDINGS PLEURAL BIOPSY (blind or image guided) should be considered whenever malignancy or tuberculosis is accounted in the differential diagnosis of a pleural effusion. OTHER INVESTIGATIONS ultrasonography; contrast enhanced computed tomography of thorax; bronchoscopy (if is a high index of suspicion of bronchial obstruction); medical/surgical thoracoscopy.

Emmet E. McGrath, Diagnosis of Pleural Effusion: A Systematic Approach, AJJC

POSITIVE DIAGNOSIS Pleuritic chest pain, dyspnea, pleural rub; Decreased TVF, stony dullness to percussion, distant breath sounds, egophony (large effusion); Radiographic evidence of pleural effusion; Etiological diagnosis is based mainly on thoracentesis and fluid laboratory examination.

DIFFERENTIAL DIAGNOSIS Basal lung lesions Basal consolidation Collapse Subdiaphragmatic diseases Amoebic liver abscess Subphrenic abscess Differentiation between various causes of effusion is based especially upon the laboratory examination of the fluid, in direct relationship with the clinical and imagistic data.

COMPLICATIONS Respiratory chronic distress; Secondary infection causing empyema; Fibrosis – pachypleuritis (fibrous “peel”); Permanent lung collapse.

SPECIAL FORMS OF PLEURAL EFFUSION Malignant Pleural Effusion: An effusion developed due to a pleural cancer (mesothelioma), the pleural surface being directly involved and invaded by malignant cells; Pleural fluid cytology or pleural tissue biopsy reveals evidence of malignancy; The pleural fluid is hemorrhagic with a rapid reaccumulation. Paramalignant Pleural Effusion: An unapparent cancer or visible but not pleural, the pleural space being not directly invaded by tumor.

MESOTHELIOMA OF PLEURA

SPECIAL FORMS OF PLEURAL EFFUSION Parapneumonic Pleural Effusion: In “uncomplicated” parapneumonic effusion, the pleural fluid is not infected (the pleural fluid glucose and PH are normal) – usually this effusion solve spontaneously; In “complicated” parapneumonic effusion, pleural fluid is either frank empyema or has the potential to organize into a fibrous “peel”; Tube thoracostomy is required for parapneumonic effusion if any of the following is present: The fluid resembles frank pus; Pleural fluid glucose is < 40 mg/dl; Pleural fluid PH is < 7.2. A pneumonic effusion that does not respond to drainage within 24 hours may have become loculated.

CHARACTERISTICS OF PARAPNEUMONIC PLEURAL EFFUSION BTS guidelines for the management of pleural infection, Thorax 2003

OTHER MAJOR TYPES OF PLEURAL EFFUSION EMPYEMA Is an exudative pleural effusion caused by direct infection (usually bacterial) of the pleural space (frank pus pleural fluid); The main causes: bacterial pneumonia and lung abscess; Pleural fluid PH < 7.2; Milky in appearance pleural fluid, clearing the supernatant after centrifugation.

OTHER MAJOR TYPES OF PLEURAL EFFUSION HEMOTHORAX Is the presence of frank blood in the pleural space; If the hematocrit of pleural fluid is more than 50% of the hematocrit of peripheral blood, hemothorax is present; Causes: chest trauma, cancer, or pulmonary embolism (less commonly).

HEMOTHORAX

OTHER MAJOR TYPES OF PLEURAL EFFUSION CHYLOUS PLEURAL EFFUSION Occurs in chylothorax as a result of disruption of the thoracic duct, traumatically or by cancer invasion; The pleural fluid is turbid post centrifugation; Triglyceride > 110 mg/dl.

CHYLOTHORAX

PROGNOSIS Depends on the etiology and the prognosis of the underlying disease: In malignant pleural effusion – the prognosis is poor; The rheumatic fever or viral pleural effusions have usually a better prognosis, often solving spontaneously.

TREATMENT Treatment of the underlying medical condition that is causing pleural effusion; Thoracentesis (therapeutic and diagnostic) Tube Thoracostomy (Chest Tube) Pleural Catheter (for reoccurring pleural effusion ) Pleural Sclerosis (Pleurodesis) - Doxycycline or talc Surgery Video-assisted thoracoscopic surgery (VATS) Thoracotomy

ANTIBIOTICS If are indicated should be guided by bacterial culture results. Where cultures are negative, antibiotics should cover community acquired bacterial pathogens and anaerobic organisms. Hospital acquired empyema requires broader spectrum antibiotic cover.

ANTIBIOTIC REGIMENS FOR THE INITIAL TREATMENT OF CULTURE NEGATIVE PLEURAL INFECTION BTS guidelines for the management of pleural infection, Thorax 2003

THERAPEUTIC THORACENTESIS Any pleural effusion large enough to cause severe respiratory symptoms should be drained regardless of the cause and regardless of concomitant disease-specific treatment. Relief of symptoms is the main goal of therapeutic drainage in these patients. Absolute contraindication - active cutaneous infection at the puncture site. Relative contraindications include: severe bleeding diathesis, systemic anticoagulation, and a small volume of fluid. Possible complications: bleeding, pneumothorax, infections, laceration of intra-abdominal organs, hypotension, and pulmonary edema.

TUBE THORACOSTOMY (CHEST TUBE) Tube thoracostomy allows continuous, large volume drainage of air or liquid from the pleural space. Specific indications: spontaneous or iatrogenic pneumothorax; hemothorax; penetrating chest trauma; complicated parapneumonic effusion or empyema; chylothorax; pleurodesis of symptomatic pleural effusions.

Chest computed tomographic scan with a “split pleural sign” (arrow), seen in empyema. This patient needed drainage with tube thoracostomy.

PLEURAL SCLEROSIS is considered for patients with uncontrolled and recurrent symptomatic malignant effusions, and rarely, in cases of benign effusions after failure of medical treatment. a sclerosing agent (talc, doxycycline, or tetracycline) is instilled into the pleural cavity via a tube thoracostomy to produce a chemical serositis and subsequent fibrosis of the pleura.

VIDEO-ASSISTED THORACOSCOPIC SURGERY (VATS) is very useful in managing incompletely drained parapneumonic effusions. with thoracoscopy, the loculi in the pleura can be disrupted, the pleural space can be completely drained, and the chest tube can be optimally placed.

THORACOTOMY In cases of empyema with uncontrolled sepsis or progression to the fibroproliferative phase a full thoracotomy with decortication is performed with removal of all the fibrous tissue and evacuation of all the pus from the pleural space.