Serousal Fluids The closed cavities of body are lined by serosal membranes (pleura – pericardium and pertoneum) The fluid is a plasma filtrate from capillaries of the parietal membrane The fluid is reabsorbed through the lymphatics and venules of the visceral membrane The small amounts of fluid facilitates movement of two membranes The serosal fluids are plasma ultra filtration and mesothelial lining does not add any substance For laboratory assessment needle aspiration is done (Thoracocentesis – Pericardiocentesis – Paracentesis)
Serousal Fluids Evaluation of serous fluids directed first toward differentiating transudate from exudate Transudative effusions (usually bilateral in pleura) have mechanical process owning to systemic conditions, leading to increase capillary hydrostatic pressure or decreased plasma oncotic pressure Exudative effusions (usually unilateral in pleura) have inflammatory process, associated with disorders of vascular permeability or interfere with lymphatic resorption Transudate and Exudate
Serousal Fluids Transudate Exudate Appearance Clear Cloudy Specific gravity Total protein 3.0 gr/dl F/S protein ratio 0.5 LD 200 IU F/S LD ratio 0.6 Cell count 1000/ul Spontaneous clotting No Yes Total leukocyte and red cells counts are of limited use in the evaluation of serousal Fluids
Serousal Fluids Transudates generally require no further work-up additional testing for cholestrol and albumin gradient may discriminate effusions with equivocal Light’s criteria (the first three criteria) PF/S protein ratio > 0.5 PF/S LD ratio > 0.6 Pleural Fluid LD > 2/3 upper limit of serum Pleural Fluid cholestrol > 45 mg/dl PF/S cholestrol ratio >0.3 Serum-pleural fluid albumin gradient < 1.2 g/dl PF/S bilirubin ratio > 0.6 * Bilirubin measurement has not help as a strong discreminator Pleural Fluid
Serousal Fluids Indications of thoracocentesis: 1. Any undiagnoesd pleural effusion 2. Therapeutic purposes in massive effusions Collection: 1. Heparinized tubes to avoid clotting 2. Except for an EDTA tube for all counts and differentials Inoculation into the blood culture medium at the bed side * If necessary fresh specimen for cytology may be stored up to 48 hours in the refrigerator with satisfactory results. Pleural Fluid
Amylase: measurement of this enzyme is recommended for all pleural effusions with unknown ethiology Increased levels found in esophageal rupture PH value > 7.3 is related to uncomplicated cases PH < 7.2 is related to complicated cases such as bacterial pneumonia, Tb or malignancy PH < 6.0 is characteristic of esophageal rupture Pleural fluid TG > 110 mg/dl indicate a chylous effusion Values between mg/dl are less certain and require lipoprotein electrophoresis for chylomicrons Pleural fluid TG < 50 mg/dl indicate a pseudochylous effusion, seen in chronic inflammatory process Adenosine deaminase (ADA) is a rapid chemical evidence of Tb. ADA-2 from lymphocytes Serousal Fluids Pleural Fluid
Serousal Fluids Formal cell counts have little practical value Pleural fluid Hct > 50% of blood is a good evidence for hemothorax A bloody pleural effusion (Hct >1% or RBC> 100,000/ul) suggest trauma, malignancy and pulmonary infarction Differential cell count on an air-dried Romanowski’s stain Filtration or automated concentration methods with Papanicolaou stain for cytologic evaluation Preparation of cell block is unnecessary except for effusions in which malignancy is a consideration Pleural Fluid
Neutrophils: Predaminate in pleural fluid with inflammation. Over 10% of transudates also have a predominance of neutrophils but has no clinical significance Lymphosytes: Associated with transudate and no clinical significance * Most are small but medium, large and reactive variants may be seen * Nuceloi and nuclear cleaving are more prominent in effusions than in prepheral blood * Low grade NHL or CLL may be difficult to distinguish from benign lymphocyte-rich serous effusions. In conjunction with cellular morphology, immunophenotyping by flowcytometry or immunocytochemistry is usually helpful Serousal Fluids Pleural Fluid
Eosinophils: an eosinophilic effusion is defined as having > 10% eosinophils * The most common causes are related to the presence of air or blood in the pleural cavity * Most are exudates * in about 35% of patients the ethiology is unknown * though not of much assistance in diagnosing an effusion, eosinophilia does appear to independently associated with longer survival Serousal Fluids Pleural Fluid
Mesothelial cells: Are common in pleural fluid from inflammatory process. * Rare in patients with Tb pleurisy, empyema, RA and patients who have pleurodesis * Fibrin deposition and fibrosis occurring in these conditions prevent exfoliation of mesothelial cells * Carcinoma cells may form easily recognized tumor clusters or closely mimic mesothelial cells a panel of immunocytochemistry stains may be necessary for conformation Serousal Fluids Pleural Fluid
Serousal Fluids Pleural Fluid
Serousal Fluids Pleural Fluid
Up to 50 ml Fluid normally present in peritoneal cavity Peritoneal effusion is called Ascites Laboratory criteria for dividing ascitic fluid into transudate and exudate is not well defined as it is for pleural fluid Diagnostic peritoneal lavage (DPL) have limited use: 1. Rapid screening for significant abdominal hemorrhage 2. Evaluation of hollow viscus injuries Peritoneal dialysis: submitted to check for infection Peritoneal washing: performed intra operatively to document early intra abdominal spread of gynecologic and gastric Ca. Serousal Fluids Peritoneal Fluid
Total leukocyte useful in spontaneous bacterial peritonitis (SBP) Approximately 90% of (SBP) have leukocyte count > 500/ul and over 50% neutrophiles Eosinophilia > 10% most commonly associates with chronic peritoneal dialysis. Also in CHF, vasculitis, lymphoma and ruptured hydatid cyst Overall sensitivity of cytology for malignant ascitis is 40-65% Peritoneal carcinomatosis accounts for two thirds of malignant effusions Immunocytochemical stains are useful in characterizing atypical cells Serousal Fluids Peritoneal Fluid
Amylase activity in normal peritoneal fluid is similar to blood levels A fluid amylase level greater than three times of serum value is good evidence of pancreas-related ascitis and also in GI perforation Increased peritoneal BUN and Cr + increased serum BUN + normal serum Cr (due to back diffusion of urea) suggests bladder rupture CEA sensitivity 40-50% specificity 90% using cut off point of 3 ng/ml Increase CEA in peritoneal washing suggest a poor prognosis of gastric Ca CA-125 extremely high in epithelial Ca of ovary, follopian tube or endometrium Serousal Fluids Peritoneal Fluid
Serousal Fluids Peritoneal Fluid
Serousal Fluids Peritoneal Fluid
Serousal Fluids Peritoneal Fluid
ml fluid normally present in pericardial space Causes of pericardial effusion: 1)infection 2)neoplasm 3)MI 4)hemorrhage 5)methabolic 6)RA HIV infected patients commonly have asymptomatic pericardial effusion In HIV associated cardiac temponade 45% are idiopathic, Tb and bacterial infections each accounts for 20% of cases Large effusions (>350 ml) most often caused by malignancy or uremia Blood-like fluid represent hemorrhagic effusion or aspiration of blood from the heart Hct comparable to peripheral and blood gas analysis help to differentiate Serousal Fluids Pericardial Fluid
Postpericardiotomy syndrome common but nonspecific complication of cardiac surgery, days to weeks following the injury Exudative pericardial effusion developed in over 80% of cases Presence of antimyocardial Abs suggests an immune mediated process Hct and RBC count have limited value in differential diagnosis of pericardial effusions. Total WBC > 10,000/ul suggests bacterial, Tb or malignant pericarditis Metastatic Ca of lung and breast are most frequent cause of malignant pericardial effusion Serousal Fluids Pericardial Fluid