Figure 1.

Principle of microdialysis. The microdialysis probe is inserted into the tissue where substances in the extracellular fluid surround the semipermeable membrane at the tip of the catheter. Following equilibration of the tissue metabolites with the perfusion fluid, the dialysate can be analyzed for concentrations of products of energy metabolism (glucose, lactate, pyruvate) as indicators of hypoxia and ischemia. In addition, interstitial glycerol can be determined, which is a parameter of lipolysis and/or cell membrane damage.