Usefulness of serum ascites albumin difference in separating transudate
from exudative ascites.
No significant correlations were found with tuberculosis (rho = -0.9614, P = 0.6265), transudates
(rho = 0.1805, P = 0.4336), parapneumonics (rho = -0.1321, P = 0.6387), empyemas (rho = -0.5663, P = 0.1511), squamous-cell carcinomas (rho = 0.0714, P = 0.9063), or lymphomas (rho = 0.4000, P = 0.7500).
For example, one might define a gravitationally dependent and water attenuating effusion as simple, but this does not necessarily denote a transudate
. (7) For example, a parapneumonic effusion represents an exudate (likely from vessel permeability and leakage of inflammatory cells) but is typically sterile at the outset and may appear simple.
Peritoneal fluids may also be identified as an exudate or a transudate
. Exudates are most often associated with infections, neoplasms, trauma, pancreatitis, or ruptured gall bladder.
 Estimation of total proteins (TP) from pleural fluid (PF) is routinely used to differentiate transudates
from exudates with a cutoff of 3 g/dL, frequently being used but many times this has led to the misinterpretation of effusions.
(19) Other imaging techniques such as ultrasound, CT and MRI may be helpful in localising effusions and distinguishing transudate
may be followed up conservatively (awaiting resolution), but exudates need further evaluation of the pleural fluid and possible sampling of pleural tissue.
Among the transudates
, CCF was the most common cause.
In contrast, pleural IFN-[gamma] was less specific, probably due to the different types of patients NTPE included in the control group, which contained malignant effusions and parapneumonic exudates, transudates
and miscellaneous exudates.
The initial step of the investigation is the distinction between transudates
and exudates, as this gives an indication of the pathophysiologic mechanisms, the differential diagnosis and the need for further investigations.
It is helpful to identify effusions in body cavities as transudates
or exudates to aid in identification of the pathologic condition responsible for the excess fluid.