PLEURAL EFFUSION lec.pptx

medicine and health

1. Respiratory system By Prof.Dr.Faisal Biochemistry of Pleural effusion

2. Overview Introduction Classification Pathogenesis Etiology Clinical features Investigations Management

3. The  pleural cavity  also known as the  pleural space , is the thin fluid-filled  space  between the two pulmonary pleurae (known as visceral and parietal) of each lung.

4. Introduction Pleural effusion, a collection of fluid in the pleural space, is rarely a primary disease process but is usually secondary to other diseases . The pleural space normally contains only about 10-20 ml of serous fluid.

5. Contd … Pleural fluid normally seeps continually into the pleural space from the capillaries lining the parietal pleura and is reabsorbed by the visceral pleural capillaries and lymphatic system. Any condition that interferes with either secretion or drainage of this fluid leads to pleural effusion.

6. CLINICAL APPROACH TO PLEURAL EFFUSIONS

7. The pleura consists of 2 layers : – parietal pleura – visceral pleura The space between the 2 layers is called the pleural space or cavity. Normally the pleural space c ontains : - 3.5 to 7.0 ml of clear liquid . - L ow protein content . - S mall number of mononuclear cells . PLEURAL SPACE

8. Pleural effusion Definition : Defined as an excess quantity of fluid in the pleural space caused either by ↑ pleural fluid formation or ↓ removal by the lymphatic system and capillaries . The fluid may be transudative or exudative.

9. Classification Transudative effusions. Exudative effusions. An important step in the evaluation of any  pleural effusion  is the classification of the fluid:

10. The first step is to determine whether the effusion is a transudate or an exudate. Determine the . . . . factors  that influence the formation and absorption of pleural fluid and the leading causes of transudative or exudative pleural effusions

11. Etiology EXUDATIVE:  Infective: Pneumonia, TB, Lung abscess, pulmonary embolism.  Collagen vascular diseases: SLE, Rheumatoid arthritis.  Neoplastic: leukemias and lymphomas Traumatic The leading causes of exudative pleural effusions are bacterial pneumonia, malignancy, viral infection, and pulmonary embolism.

12. Etiology TRANSUDATIVE : Renal cause: Nephrotic syndrome Cardiac cause: Congestive cardiac failure Hepatic cause: Cirrhosis, Hepatic failure Nutritional : Protein energy malnutrition Hypothyroidism

13. Transudative effusions . Transudate is extravascular fluid with low protein content and a low specific gravity (< 1.012 ). It has low nucleated cell counts (less than 500 to 1000 /microliter) and the primary cell types are mononuclear cells: macrophages, lymphocytes and mesothelial cells . Fluid protein/ serum protein: < 0.5 Protein content: < 2.5 g/ dL - Occur primarily in non-inflammatory conditions.

14. Causes of transudative effusion Increase hydrostatic pressure found in heart failure ( most common cause of pleural effusion). Decrease oncotic pressure ( From hypoalbuminemia ) found in cirrhosis of liver or renal disease. In this condition, fluid movement is facilitated out of the capillaries into the pleural space. Oncotic pressure is a form of osmotic pressure exerted by proteins either in the blood plasma or interstitial fluid. Hydrostatic pressure is a force generated by the pressure of fluid on the capillary walls either by the blood plasma or interstitial fluid.

15. Exudative effusions Exudative effusions occur in an area of inflammation; is an accumulation of high-protein fluid . An exudative effusion results from increased capillary permeability characteristic of inflammatory reaction . This types of effusion occurs primary to conditions such as pulmonary malignancies, pulmonary infections and pulmonary embolization.

16. Clinical features Many patients have no symptoms due to the effusion when effusion is small . Patients may show symptoms of their Underlying disease.  Pleuritic chest pain is the usual symptom of pleural inflammation . and have symptoms of pneumonia such as productive Cough, fever, and signs of consolidation.  With larger effusions, dyspnea results from lung compression .

17. Biochemical data Features Transudates Exudates Appearance Clear/Straw coloured Cloudy, purulent, opalascent Protein < 3g/100mL >3g/100mL pH >7.2 <7.2 Glucose >40mg/dL <40mg/dL LDH Low, <200IU/L High,>200IU/L Cells <1000/mm 3 >1000/mm 3

18. Pleural fluid Biochemistry pH Glucose Lactate dehydrogenase(LDH ) . Adenosine deaminase . Ratio of protein in pleural fluid to serum . Ratio of LDH values in pleural fluid to serum .

19. PLEURAL FLUID CYTOLOGY WBC Count - Predominant cell type ( neutrophil, lymphocytes, eosinophils ) - Lymphocytosis- if > 50% of leukocytosis …. then suspect TB - Malignant cells PLEURAL FLUID MICROBIOLOGY - Gram stain for bacterial infection - Acid fast stain for AFB - AFB Culture - PCR for confirmation TB infection

20. Harrison's and Kumar Pleural effusion References

21. Thank you …?