Cytology 3 .docx

Cytology Part III Transudates & Exudates Fluid Analysis Objectives - General clinical signs of the patient with pleural or abdominal effusion - Techniques of obtaining various fluid samples - Classification of effusions - How to prepare samples - How to evaluate various samples...

Cytology Part III Transudates & Exudates Fluid Analysis Objectives - General clinical signs of the patient with pleural or abdominal effusion - Techniques of obtaining various fluid samples - Classification of effusions - How to prepare samples - How to evaluate various samples Abdominal and Thoracic Fluid - Bathed in and lubricated by by a small amount of fluid - When there is more fluid coming in than going out, that is when problems arise - Most effusions are not noticed by the pet owner until they are severe - Clinical signs include: - Dyspnea - Crouched sternal recumbency - Extension of the head and neck - Open mouth breathing - Forceful abdominal contractions  - Fluid analysis with cytology is a quick, easy, inexpensive and relatively safe way to obtain information for diagnosis, prognosis, and treatment of diseases resulting in abdominal and thoracic fluid  Thoracocentesis - Pleural effusions - Typically abundant and bilateral - Mild cases can be unilateral and compartmentalized - Lung auscultation - Radiographs and ultrasound help determine the extent and location - Sample of effusion is collected in an EDTA tube - Total nucleated cell count (TNCC) - Total Protein (TP) - Cytologic examination - Culture and sensitivity tube - Red top tube (chemical analysis) Sample Preparation - Depends on the character (clear or cloudy) and quantity of the fluid - Whether it will be evaluated in the hospital lab or sent to a pathologist (call and ask for directions) - Sediment smears should be made on all non-turbid samples using the squash or routine pull technique - it is not possible to centrifuge you can use the line smear technique from fresh, well mixed samples - Opaque samples may only require a direct smear using the squash or pull technique from fresh, well mixed samples Evaluation - TNCC (total nucleated cell count) can be done with automated or manual methods - Automated method may count debris so only relatively clear samples should be used - Manual count utilizes the Unopette system for WBC count - Cell clumping, cell fragmentation, and noncellular debris can cause errors with both methods - Note the presence of RBCs but a count or PCV is usually not done - Total Protein is taken to classify effusions as either: - Transudates - Modified transudate - Exudates - Can be estimated by refractometry or biochemically - the fluid is opaque it is best to use supernatant to determine TP - Culture and Sensitivities can be obtained by drawing the fluid up in a syringe or placing the fluid in a sterile tube  Cells Seen in Effusions - Neutrophils - Present in most effusions and can be the predominate cell in effusions associated with inflammation - Degenerate vs nondegenerate - Toxic changes can be evident - Mesothelial - Mesothelial cells line the pleural, peritoneal and visceral surfaces - Present in variable numbers in effusions Macrophage Mesothelial cells - Lymphocytes - Eosinophils - Mast cells - Erythrocytes - Neoplastic cells - Microfilaria - Basket cells-ruptured nucleated cells; chromatin spreads out and stains eosinophilic Classification of Effusions - Classification is based solely on TNCC and TP - Classification helps determine the general mechanism of fluid accumulation - May help in differentiating infection from neoplasia - Generally all findings have to be interpreted with the historical, physical and clinical findings to achieve a definitive diagnosis Transudates - Clear, colorless - Low protein concentrations (\7,000) - Neutrophils are the predominate cell type because most exudates are a inflammatory exudates - bacteria are present most of the cells will be degenerated - Occasionally an exudate develops because of abundant exfoliation of cells from a tumor or chylous effusion Effusion Synovial Fluid - Arthrocentesis - Synovial fluid does not clot - Blood contaminates will clot unless processed immediately or added to EDTA - Limited tests because of the generally small yield Sample Handling and Test - Color-straw yellow - Turbidity-nonturbid - Viscosity-sticky - Cytology- normal morphology: 90% mononuclear cells and less than 10% neutrophils - Mucin clot test (heparin) - Cell count if enough fluid is available (\ - Useful in confirming the presence and type of primary CNS disease - EDTA and sterile RTT - Colorless and transparent - TNCC - Protein concentration normally very low - 50mg/dl of albumin - Cytologic examine - Should be done as fast as possible(within 15 minutes) because cells begin to degenerate very quickly - Cells Types - Mononuclear cells - Lymphocytes 95-100% CSFCell TypesMelonomamast cellSpindle2Eosgranuloma Review - Clinical presentation of animals with possible effusions - Techniques involved in obtaining various samples - How are effusions classified - Laboratory techniques used to evaluate fluid - Cell types involved