Which procedure is used to obtain pleural fluid for analysis?

Which procedure is used to obtain pleural fluid for analysis?

• A. Thoracentesis
• B. Echocardiography
• C. Bronchoscopy
• D. Lung biopsy

Answer: (A)

Thoracentesis is the procedure used to obtain pleural fluid for analysis. It involves inserting a needle or catheter through the chest wall into the pleural space to withdraw fluid, usually with the patient seated upright or in a lateral position. Ultrasound guidance helps locate the fluid pocket and minimize injury, and local anesthesia is given before access is gained. The collected fluid is sent for multiple analyses to classify the effusion and identify its cause: appearance, cell count, protein and LDH for Light’s criteria, pH and glucose levels, Gram stain and culture, cytology for malignancy, and specific infectious studies when indicated. This approach not only helps diagnose infections, malignancies, or inflammatory conditions but also distinguishes transudates from exudates to guide further management. Other procedures listed—echocardiography visualizes the heart, bronchoscopy examines the airways and collects airway samples, and a lung biopsy yields tissue—do not obtain pleural fluid.

Thoracentesis is the procedure used to obtain pleural fluid for analysis. It involves inserting a needle or catheter through the chest wall into the pleural space to withdraw fluid, usually with the patient seated upright or in a lateral position. Ultrasound guidance helps locate the fluid pocket and minimize injury, and local anesthesia is given before access is gained. The collected fluid is sent for multiple analyses to classify the effusion and identify its cause: appearance, cell count, protein and LDH for Light’s criteria, pH and glucose levels, Gram stain and culture, cytology for malignancy, and specific infectious studies when indicated. This approach not only helps diagnose infections, malignancies, or inflammatory conditions but also distinguishes transudates from exudates to guide further management. Other procedures listed—echocardiography visualizes the heart, bronchoscopy examines the airways and collects airway samples, and a lung biopsy yields tissue—do not obtain pleural fluid.