third space fluid

Last reviewed 01/2018

Transcellular water is found in:

  • cerebrospinal fluid
  • the gastrointestinal tract
  • the urinary tract
  • the ducts of glands
  • serous cavites

Transcellular water is also termed the 'third space'.

Pathologic third compartment fluid may be in:

  • ileus fluid - can be the most acute in onset
  • ascites
  • pleural effusions

Transcellular fluid comes from the plasma and extracellular fluid; thus excessive expansion of the third space is an important cause of hypovolaemia and subsequent renal failure.