1 Dr. SIRAJ WALI

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3 PLEURAL SPACE The pleura consists of 2 layers 1 – parietal pleura 2 – visceral pleura The space between the 2 layers is called the pleural space Normal width of the pleural space is  m

Parietal pleura cover the inner surface of the thoracic cavity, including the diaphragm, and ribs. Visceral pleura envelope all surfaces of the lungs, including the interlobar fissures. At the Hilum where pulmonary vessels, bronchi, and nerves enter the lung tissue, the parietal pleura is continuous with the visceral pleura.

5 PLEURAL EFFUSION Normally the pleural space contains: 3.5 to 7.0 ml of clear liquid low protein content small number of mononuclear cells

6 The rate of fluid formation is 0.01 ml/kg/hour. The rate of fluid clearance is 0.2 ml/kg/hour. PLEURAL FLUID FORMATION AND ABSORTION

7 PLEURAL EFFUSION Pleural effusion: presence of large amount of fluid in the pleural space irrespective of the underlying causes

8 PLEURAL SPACE INTERCOSTAL MICROVESSELS PLEURAL FLUID VEIN ARTERY LYMPHATICS TO MEDIASTINAL NODES STOMA ? BRONCHIAL MICROVESSELS VEIN ARTERY VISCERAL PLEURAL PARIETAL PLEURAL PLEURAL SPACE PLEURAL FLUID FORMATION AND ABSORTION

9 STOMA There are openings between mesothelial cells called stoma, range in size from 2-6nm, found only on the parietal pleural surface. These stoma communicate directly with Lymphatic locunae. Stoma are the exit point for pleural liquid protein + cells that are removed from the pleural space.

10 BLOOD SUPPLY The visceral pleura is supplied by branches of the bronchial circulation. The venous return from the visceral pleura is largely into pulmonary veins. The parietal pleura is supplied by branches of arteries that flow to the adjacent chest wall. Venous returned from parietal pleura drains into the bronchial veins.

11 MOVEMENTS OF FLUID IS BASED ON STARLING ’ S LOW STARLING ’ S LOW : Q f = L. A [ (P CAP – P Pl ) – (  CAP –  Pl ) ] L: Filtration coefficient A: Surface area Cap: Capillary Pl: Pleural

12 HYDROSTATIC PRESSURE MOVEMENTS OF FLUID BASED ON STARLING ’ S LOW PARIETALPLEURALVISCERAL PLEURALSPACE PLEURA [30 – (-5)] = =[24-(-5)]Net pressure [ 35 – 29 ] = 6 0 = [ 29 – 29 ] [ 34 – 5 ] = = [ 5 – 34 ] ONCOTIC PRESSURE

13 PLEURAL SPACE INTERCOSTAL MICROVESSELS PLEURAL FLUID VEIN ARTERY LYMPHATICS TO MEDIASTINAL NODES STOMA ? BRONCHIAL MICROVESSELS VEIN ARTERY VISCERAL PLEURAL PARIETAL PLEURAL PLEURAL SPACE PLEURAL FLUID FORMATION AND ABSORTION

Development of Pleural Effusion pulmonary capillary pressure (CHF) capillary permeability (Pneumonia) plasma oncotic pressure (hypoalbuminemia) diaphagmatic defect (hepatic hydrothorax) thoracic duct rupture (chylothorax) lymphatic obstruction (malignancy) Systemic Vascular pressure (RVF/ SVCO) II Decreased Pleural Fluid Absorption IIncreased Pleural Fluid Formation

* key symptom > shortness of breath Fluid filling the pleural space makes it hard for the lungs to fully expand, causing the patient to take many breaths so as to get enough oxygen. * If parietal pleura is irritated > mild pain or a sharp stabbing pleuritic type of pain. ** Some patients will have a dry cough.

Occasionally > no symptoms at all. * This is more likely when the effusion results from: recent abdominal surgery, cancer, or tuberculosis. * Examination of the chest shows dullness, and decrease breath sound

x Ray The fluid itself can be seen at the bottom of the lung or lungs, hiding the normal lung structure. If heart failure is present, the x-ray shadow of the heart will be enlarged. Ultrasound may disclose a small effusion that caused no abnormal findings during chest examination. C.T. scan is very helpful if the lungs themselves are diseased. Diagosisn of pleural effustion

Pleural effusion Homogenous density Density in dependent portion. Silouhetting of diaphragm.

Management of Pleural effusion 23

25 Indication for Thoracentesis Diagnostic ( detect underlying diagnosis) Therapeutic (relief shortness of breath) PLEURAL EFFUSION

26 DIAGNOSTIC THORACENTESIS CONTRAINDICATIONS Bleeding tendency Thrombocytopenia (decrease platelets less u3/dl ) Prolonged PT or PTT greater than twice normal, A very small volume of pleural fluid PLEURAL EFFUSION

27 Color of FluidSuggested Diagnosis Pale yellow (straw)Transudate, some exudates Red (bloody)Malignancy or embolism or TB Turbid Infected effusion Pus Empyema White (milky)Chylothorax or cholesterol effusion Color of Fluid

28 1.Pleural Protein divided by serum protein >0.5 2.Pleural fluid LDH divided by Serum LDH >0.6 3.Pleural fluid LDH > 2/3 the upper limit of normal for the serum LDH. Transudates vs Exudates LIGHT ’ S CRITERIA*

29 CELL COUNT Transudate 1000 and rarely > 10,000/mm 3 Exudate > 1000/mm 3 Limited value (unless > 50,000/mm 3  emphyema) PLEURAL EFFUSION

30 PF LYMPHOCYTE-PREDOMINANT EXUDATES (>80%) PLEURAL EFFUSION Causes TB Lymphoma Chronic lymphocytic leukaemia

31 BIOCHEMISTY Glucose < 3.3 mmol/L or 1/2 serum glucose (simultaneous) -Rheumatoid pleurisy (85%) -Empyema (80%) -Malignancy (40%) -TB (20%) -Lupus pleuritis (20%) PLEURAL EFFUSION

32 The mechanism responsible for pleural fluid low glucose include; Decreased transport of glucose from blood to pleural fluid Increased utilization of glucose by constituents of pleural fluid, such as neutrophils, bacteria (empyema), and malignant cells PLEURAL EFFUSION

33 BIOCHEMISTY Pleural fluid pH: -Normal pleural fluid pH is > 7.6 -Transudates – pH Exudates – pH is Should always be measured in a blood gas machine Parapneumonic - pH < 7.0 predicts “complicated effusion” that is unlikely to resolve without chest tube drainage. Malignant effusion with a pH < 7.3 is associated with poor survival. If pH < 6.0 think of ruptured esophagus PLEURAL EFFUSION

34 The mechanism responsible for pleural fluid acidosis (pH <7.30) include; Increased acid production by pleural fluid cells and bacteria Decreased hydrogen ion efflux from the pleural space, due to pleuritis, tumor, or pleural fibrosis. PLEURAL EFFUSION

35 DIAGNOSES ASSOCIATED WITH PLEURAL FLUID ACIDOSIS (pH <7.30) AND LOW GLUCOSE CONCENTRATION (PF/SERUM <0.5) PLEURAL EFFUSION DiagnosisUsual pH (Incidence)Usual Glucose Concentration (mg/dL) Empyema (-100%)<40 Esophageal rupture (-100%)<60 Rheumatoid pleurisy 7.00 (80%)0-30 Malignancy (33%)30-59 Tuberculous pleurisy (20%)30-59 Lupus pleritis (20%)30-59

36 CYTOLOGY  positive in about 60% of patients with malignant effusion PLEURAL EFFUSION

37 Patients with Abnormal Chest Radiograph Suspect pleural disease Lateral decubitus chest radiographs YES Blunting of costophrenic angle? Fluid thickness > 10mm Yes No Diagnostic thoracentesis Observe PLEURAL EFFUSION

38 Diagnostic thoracentesis Any of the following met? PF/serum protein >0.5 PF/serum LDH >0.6 PF LDH >2/3 upper normal Serum limit Exudate Transudate Appearance of plueral fluid, pH & glucose, cytology and differential cell count of pleural fluid SUMMARY PLEURAL EFFUSION YesNo Treat CHF, cirrhosis, or nephrosis

direct treatment at what is causing it, rather than treating the effusion itself

40 LISTS HELPFUL FOR DIFFERENTIAL DIAGNOSIS PLEURAL EFFUSION

41 Pleural Effusion (PE) not associated with C X-ray Abnormalities (Disease below Diaphragm) Pancreatic Disease Meigs ’ Syndrome Chylous Ascites Subphrenic Abscess Splenic Abscess Hepatic hydrothorax Nephrontic Syndrome (NS) Urinothorax Peritoneal Dialysis (PD) ExudatesTransudates PLEURAL EFFUSION

42 Patients who typically present with bilateral effusions Malignancy SLE Yellow-nail Syndrome CHF NS Hypoalbuminemia PD Constrictive Pericarditis ExudatesTransudates PLEURAL EFFUSION

43 Diseases with the classic trial: PH 1000 u/L Complicated parapneumonic effusion Rheumatoid pleurisy Pleural paragonimiasis PLEURAL EFFUSION

44 The only diseases that may cause a glucose level of zero Empyema Rheumatoid pleural effusion Esophageal rupture PLEURAL EFFUSION

45 Percutaneous Pleural Biopsy: Diagnostic in > 90% of patients with TB Requires the presence of pleural fluid in the pleural cavity to avoid trauma to the underlying lung. Not used routinely in the evaluation of malignancy because of the high yield of thoracentesis (70-80%). Thoracoscopy: Enables biopsy under direct vision. PLEURAL EFFUSION ADDITIONAL INVESTIGATION

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