Pleural Fluid & Synovial Fluid 7-8 PDF

Pleural Fluid 1. Definition of Pleural Fluid Pleural fluid is a thin layer of liquid that resides in the pleural space, the area between the two layers of the pleura (the membrane that covers the lungs and lines the chest cavity). This fluid acts as a lubricant, allowing the lungs to expand and con...

Pleural Fluid 1. Definition of Pleural Fluid Pleural fluid is a thin layer of liquid that resides in the pleural space, the area between the two layers of the pleura (the membrane that covers the lungs and lines the chest cavity). This fluid acts as a lubricant, allowing the lungs to expand and contract smoothly within the chest during breathing. 2. Function of Pleural Fluid Lubrication: It reduces friction between the pleural layers during respiratory movements, facilitating smooth lung expansion and contraction. Surface tension regulation: Helps keep the lungs inflated by providing surface tension between the pleura and the lungs. Barrier and immune defense: Contains proteins and immune cells that play a role in protecting the lungs from infections. 3. Natural Components of Pleural Fluid Water: Makes up the majority of pleural fluid (90-95%). Proteins: Albumin and globulin are the major proteins, providing nutrition and immune protection. Electrolytes: Sodium, potassium, chloride, and bicarbonate, which help regulate pH and osmotic balance. Glucose: Normally present in similar concentrations as in blood. Cells: Small amounts of mesothelial cells, macrophages, and lymphocytes. Enzymes: Lactate dehydrogenase (LDH) is one of the important enzymes for diagnostic purposes. 4. Method of Obtaining the Sample The procedure for obtaining pleural fluid is called thoracentesis. It involves the following steps: 1. Preparation: o The patient is typically seated or lying down, leaning forward slightly. o Local anesthesia is applied to numb the area. 2. Procedure: o A needle or cannula is inserted between the ribs into the pleural space, usually guided by ultrasound to ensure precision. o A sample of pleural fluid is withdrawn using a syringe. 3. Aftercare: o The patient is monitored for complications such as pneumothorax (collapsed lung). o The sample is sent to the laboratory for analysis. 5. Tests and Normal Values of Pleural Fluid Several tests can be performed on pleural fluid to diagnose underlying diseases. Normal values are compared to abnormal results to assess the cause of pleural effusion (excess pleural fluid). 6 ‫ من‬1 ‫الصفحة‬ Dr. Haitham ALhakimi  1. Gross appearance: o Normal: Clear, pale yellow. o Abnormal: Cloudy, bloody, or chylous (milky) fluid may indicate infection, trauma, or malignancy. 2. Biochemical analysis: o Protein: ▪ Normal: