The Approach to Ascites

36 The Approach to Ascites

6. What is the difference between a transudate and a modified transudate? Name some potential differentials for each.

A transudate is low in specific gravity (<1.015), protein (<2.5 g/dl), and cells (<1500/μl). Modified transudates have specific gravities between 1.015 and 1.025, protein between 2.5 and 6.0 mg/dl, and cell concentrations of less than 7,000 cells/μl. Over time the presence of a pure transudate in the abdomen will lead to peritoneal irritation with resultant increases in protein and cell count. This will change the transudate to a modified transudate.

Pure transudates can be caused by decreased oncotic pressure, such as occurs in dogs with severe hypoalbuminemia (e.g., protein-losing enteropathy, protein-losing nephropathy). In these dogs it is not uncommon to find peripheral edema as well. Low levels of albumin can also be observed with liver disease, although the development of ascites in these dogs is usually exacerbated by the presence of portal hypertension. Portal hypertension can also lead to the formation of a transudate. Portal hypertension can be classified as prehepatic, hepatic, or posthepatic depending on the location of the obstruction to flow. In many dogs with liver disease the lesion can be at multiple sites. Pure prehepatic portal hypertension is associated with restriction of blood flow at the level of the portal vein and results initially in the formation of a transudate.

Modified transudates have higher protein levels and higher cell counts. Hepatic or posthepatic portal hypertension can cause the accumulation of a modified transudate. Posthepatic portal hypertension results when the level of the obstruction to flow is in either the hepatic vein or the caudal vena cava such as by kinking of the vein, right-sided heart failure, or cardiac tamponade. This results in increased hepatic lymph formation in the sinusoids, with subsequent leakage into the abdomen through the capsule of the liver.

< div class='tao-gold-member'>

Jul 31, 2016 | Posted by in INTERNAL MEDICINE | Comments Off on The Approach to Ascites
Premium Wordpress Themes by UFO Themes