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Ascites is the excess accumulation of fluid in the peritoneal cavity. The fluid can be defined as transudate or exudate. Amounts of up to 25 liters are fully possible. Roughly, transudates are a result of increased pressure in the portal vein (> 8 mmHg), such as cirrhosis; while exudates are actively secreted fluid due to inflammation or malignancy. The most useful measure is the difference between ascitic and serum albumin concentrations. A difference of less than 1.1 g/dl (10 g/L) implies an exudate. There is no genetic background for ascites. On gross pathology, clear to pale yellow fluid accumulation in peritoneal space are characteristic findings of ascites under normal condition, but it may be chylous, psudochylous, or bloody.
- Ascites is the excess accumulation of fluid in the peritoneal cavity. The fluid can be defined as a transudate or an exudate. Amounts of up to 25 liters are fully possible.
- Roughly, transudates are a result of increased pressure in the portal vein (> 8 mmHg), such as cirrhosis; while exudates are actively secreted fluid due to inflammation or malignancy.
Serum Albumin Ascites Gradiant (SAAG)
- The most useful measure is the difference between ascitic and serum albumin concentrations.
- A difference of less than 1.1 g/dl (10 g/L) implies an exudate.
- The main pathophysiology of ascites in cirrhotic patients consists of three interrelated mechanisms, include:
- There is a nitric oxide overload in cirrhotic patients from an unknown source. Therefore, they involved in hypovolemia secondary to the systemic vasodilation.
- The vasodilation induced by nitric oxide would trigger the stimulation of juxta-glumerular system to upregulate antidiuretic hormone (ADH) and sympathetic drive. Excess ADH causes water retention and volume overload.
- Despite the normal physiology of vessels, angiotensin would not cause vasoconstriction in cirrhotic patients and vasodilation becomes perpetuated.
- Portal hypertension leads to more production of lymph, to the extend of lymphatic system overload. Then, the lymphatic overflow will directed into to peritoneal cavity, forming ascites.
- Peritoneal malignancy produces some protein factors into the peritoneum, which may lead to osmotic drainage of water and fluid accumulation. Tuberculosis and other forms of ascites are induced through the same mechanism and osmotic fluid shift.
- Pancreatic and biliary ascites are induced through leakage of pancreatic secretions or bile into the peritoneal cavity, which may lead to inflammatory fluid shift and accumulation.
|↑Renin-angiotensin system||↑Sympathetic nervous system||↑Antidiuretic hormone|
|Systemic circulation||Renal circulation|
|Arterial vasoconstriction||↑Tubular Na and H2O reabsorbtion||Renal vasoconstriction|
|Arterial hypertension||Na and H2O excretion||Hepatorenal syndrome|
|Fluid overload||Dilutional hyponatremia|
- There is no genetic background for ascites.
- Ascites syndrome, also called pulmonary hypertension, is in fact a genetic disorder in broilers and poultry.
Associated conditions with ascites are as following:
- Heart failure
- Portal hypertension
- Viral hepatitis
- Pancreatic disease
- Biliary disease
- On gross pathology, clear to pale yellow fluid accumulation in peritoneal space are characteristic findings of ascites under normal condition.
- Chylous ascites gross pathology is milky presentation of ascites fluid, which is reflective of high amounts of chylomicrons.
- On gross pathology, milky appearance of ascitic fluid is characteristics of the followings:
- Pseudochylous is the condition in which on gross pathology the ascitic fluid appearance is cloudy and/or turbid.
- The following conditions can lead to pseudochylous:
- On gross pathology, bloody appearance of ascitic fluid is characteristics of the followings:
- On microscopic histopathological analysis, characteristic findings of cirrhosis, as the most common cause of ascites, are based on Robbins definition (all three is needed for diagnosis):
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- Pakdel, A.; van Arendonk, J.A.M.; Vereijken, A.L.J.; Bovenhuis, H. (2010). "Genetic parameters of ascites-related traits in broilers: effect of cold and normal temperature conditions". British Poultry Science. 46 (1): 35–42. doi:10.1080/00071660400023938. ISSN 0007-1668.
- Moore KP, Aithal GP (2006). "Guidelines on the management of ascites in cirrhosis". Gut. 55 Suppl 6: vi1–12. doi:10.1136/gut.2006.099580. PMC 1860002. PMID 16966752.
- Huang LL, Xia HH, Zhu SL (2014). "Ascitic Fluid Analysis in the Differential Diagnosis of Ascites: Focus on Cirrhotic Ascites". J Clin Transl Hepatol. 2 (1): 58–64. doi:10.14218/JCTH.2013.00010. PMC 4521252. PMID 26357618.
- Fukunaga, Naoto; Shomura, Yu; Nasu, Michihiro; Okada, Yukikatsu (2011). "Chylous Ascites as a Rare Complication After Abdominal Aortic Aneurysm Surgery". Southern Medical Journal. 104 (5): 365–367. doi:10.1097/SMJ.0b013e3182142b7d. ISSN 0038-4348.
- Tarn, A. C.; Lapworth, R. (2010). "Biochemical analysis of ascitic (peritoneal) fluid: what should we measure?". Annals of Clinical Biochemistry. 47 (5): 397–407. doi:10.1258/acb.2010.010048. ISSN 0004-5632.
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- "File:Cirrhosis high mag.jpg - Libre Pathology".
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