Presentation on theme: "Pathology of pleura & laboratory investigations in lung diseases DR.USHA."— Presentation transcript:
Pathology of pleura & laboratory investigations in lung diseases DR.USHA
Pleural fluid Normally 10-15ml of pleural fluid is present in the pleural cavity. Pleural fluid is produced by pairetal & visceral layers. Most of the fluid is removed by the lymphatics, remaining fluid lubricates the lung & chest wall.
Pleural effusion Is the accumulation of excess fluid in the pleural cavity. Important manifestation Normally, no more than 15ml of serous fluid present. This fluid is acellular, clear fluid that lubricates the surface.
Etiology of pleural effusion 1. Increased hydrostatic pressure, as in congestive cardiac failure. 2. Increased vascular permeability, as in Pneumonias. 3. Decreased osmotic pressure, as in Nephrotic syndrome. 4. Decreased lymphatic drainage, as in Mediastinal carcinomatosis.
Clinical features Pleuritic chest pain- increases on inspiration, coughing, sneezing Dyspnea
Clinical features 500ml of fluid should be present to produce the signs 1. Bulging of intercostal spaces on the affected side 2. Diminished mobility of chest wall 3. Shift of mediastinum to the opposite side 4. Stony dullness on percussion 5. Bronchial breath sounds on auscultation.
Types of pleural effusion Trasudate -Congestive cardiac failure -Cirrhosis of liver -Nephrotic syndrome Exudate -Pneumonias -Tuberculosis -Pulmonary embolism -Malignancy
Types of pleural effusion based on etiology Non-inflammatory effusion Inflammatory effusion
Non inflammatory effusion 1. Hydrothorax 2. Haemothorax 3. Chylothorax
Hydrothorax Accumulation of serous fluid Unilateral or bilateral depending on the cause. Causes- Congestive cardiac failure Nephrotic syndrome Cirrhosis of liver Primary & Secondary tumors
Nature of Hydrothorax Is a transudate Clear, straw colored Protein content less Very few cells.
Haemothorax Accumulation of blood Causes- -Trauma to the chest wall -Ruptured aortic aneurysm
Chylothorax Accumulation of milky fluid of lymphatic origin
Causes of chylothorax Thoracic duct trauma Obstruction to the thoracic duct by secondary malignancy Filariasis
Sequelae of pleural effusion Permanent collapse of the lung (Compression atelactesis) Pleural thickening, Adhesions Empyema
Pneumothorax Accumulation of air in the pleural cavity.
Causes of pneumothorax 1. Spontaneous: Emphysema,Bronchial asthma, Tuberculosis. 2. Traumatic: Perforating injury to the chest wall 3.Therapeutic: Was once used in treatment of tuberculosis
Types of pneumothorax 1. Closed type- the opening is very small & heals spontaneously 2. Open type- the opening is large & remains patent 3. Tension- the opening is valvular(air enters the pleural space during inspiration but cannot escape during expiration so that a positive pressure occurs in the pleural cavity.
Clinical features Pleuritic chest pain Dyspnea Collapse Crack pot sound on percussion Hyper-resonent sound on auscultation
Clinical significance of Pneumothorax 1. Compression of pleura on lung may lead to Atelactasis & leading to Respiratory distress. 2. Tension pneumothorax- results if the defect acts as ball valve permitting entry of air & preventing escape of air.
Advantages of sputum cytology Less expensive OPD based No anesthesia required Non invasive
Disadvantages Detects lesions which opens into bronchi. Peripheral lung lesions may be missed. Difficult in children, comatose patients. Contamination with oral secretions.
Bronchial washings An bronchoscope is passed via trachea into bronchioles & about 5ml of balanced salt solution is introduced. Solution introduced is aspirated back & collected in a sterile container. Solution is smeared, stained with PAPs stain & examined.
Advantages No dilution with oral secretions Useful in children
FNAC Lung Fine needle aspiration is useful in peripheral lung lesions which are missed with sputum examination & Bronchoscopy. Adv:OPD based, less expensive Dis:invasive procedure, not hit the lesion,