Intermediate
Technical
IVT
third-spacing
Pathological shift of fluid from intravascular and intracellular spaces into non-functional extracellular compartments.
Full Definition
Third-spacing refers to the abnormal accumulation of fluid in body compartments where it is not readily available for metabolic processes or circulation. This includes fluid shifts into the peritoneal cavity (ascites), pleural space, bowel wall edema, or interstitial tissues. In surgical critical care, third-spacing commonly occurs following major surgery, trauma, sepsis, or burns. It can lead to intravascular volume depletion despite total body fluid overload, creating complex fluid management challenges that require careful monitoring and targeted intervention.
Usage
Usage note: Often hyphenated as a compound modifier.
In Context
- "Significant third-spacing explained the patient's hypotension despite positive fluid balance." — Rounds note
- "The surgery was complicated by extensive third-spacing requiring aggressive resuscitation." — Operative report addendum
Also known as
fluid sequestration
capillary leak
Contrasted with
intravascular volume expansion
Don't confuse with
dehydration
volume overload