One of the most challenging aspects of critical care is determining when fluid resuscitation should end and fluid removal should begin.
Many critically ill patients receive substantial volumes of intravenous fluids during the initial phase of shock. While this may be appropriate early in resuscitation, persistent positive fluid balance is associated with worse outcomes across numerous critical care populations.
CRRT offers a powerful tool for controlled de-resuscitation, but successful fluid removal requires an understanding of plasma refill physiology.
When ultrafiltration removes fluid from the intravascular compartment, the body attempts to replace that volume through movement of fluid from the interstitial space into the circulation. This process is known as plasma refill.