Ascites
Great overview piece from Life in the Fast Lane: http://lifeinthefastlane.com/ccc/ascitic-fluid/
Information on analysis of ascitic fluid: http://lifeinthefastlane.com/investigations/paracentesis/
Video demonstrating paracentesis: http://journals.lww.com/em-news/blog/M2E/pages/post.aspx?PostID=47