Paracentesis (from Greek κεντάω, "to pierce") is a form of body fluid sampling procedure, generally referring to peritoneocentesis (also called laparocentesis or abdominal paracentesis) in which the peritoneal cavity is punctured by a needle to sample peritoneal fluid.

The procedure is used to remove fluid from the peritoneal cavity, particularly if this cannot be achieved with medication. The most common indication is ascites that has developed in people with cirrhosis.

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