1. Basic science of fluid therapy
Robert Hahn, MD, PhD
Research Director, Södertälje sjukhus
Adj. Professor of Anaesthesia & Intensive Care, Karolinska institutet
Malmö 2017 1

2. Conclusions, Crystalloids
Volume kinetics is pharmacokinetics of infusion fluids.
Distribution of crystalloid fluid requires 30 min to be completed, both in conscious and anesthetized patients.
Distribution is temporarily arrested during induction of anesthesia. This is due to the reduction of MAP.
Urinary excretion is very low during general anesthesia. Recent data suggest a direct dependence on MAP and (inversely) on age.

3. Conclusions, Colloids
Colloids have no distribution phase, but an intravacsuar persistence half-life of 2-3 hours.
Colloid fluid kinetics is probably not affected by MAP.
Crystalloid fluid infused after a colloid will be poorly excreted and aggravate peripheral edema.
Colloid fluid may promote diuresis during surgery, but acts to retain fluid during the postoperative phase.