about ascites

If protein is what "keeps" fluid in vascular spaces and a lack of protein causes ascites as in malnutrition, then how is ascitic fluid caused by portal hypertension "protein rich"?

Ascitic fluid is not actually "albumin-rich" in cases of portal hypertension. Albumin content is always lower than one in serum in transsudate.

SAAG: The SAAG is the best single test for classifying ascites into portal hypertensive (SAAG >1.1 g/dL) and non–portal hypertensive (SAAG

Ascites Workup: Approach Considerations, Laboratory Studies, Imaging Studies

The probem is the sheer amount of this fluid and therefore the amount of protein trapped in there.

Ok, but how does the protein leave vascular volume? It states protein remains within vascular spaces to keep osmotic pressure and endothelial cells do not permit their passage except in cases of burns and such when inflammatory substances cytokines are present. How and why is protein getting in there? I understand ascites in cases of malnutrition makes perfect sense: low blood protein=low osmotic pull= fluid in peritoneal cavity but the cirrhosis ascites which states is a protein rich fluid I'm lost

Pressure in vein increases, the vein's wall is naturally more porous than arteries and has less collagen bundles, and water and albumin molecules are pushed out. Imagine putting some cottage cheese out in a sieve to drain, and then actively pressing on it - first, you 'll get only whey, then the cheese starts to escape as well, although most of it probably continue to stay in. Portal vein normally has only 8 mm Hg pressure, if it goes over 20, this purely mechanical process starts.

I hate Wiki as a source but the link below has everything you need to know about ascitis:

Ascites - Wikipedia, the free encyclopedia