Goal Directed Fluid Therapy Revised: Indirect Monitoring of Interstitial Fluid Accumulation During Mini Fluid Challenges with Crystalloids

Goal directed fluid therapy (GDT) implies administration of fluid boluses with the aim of optimizing cardiac performance. There is a major concern that maximization of cardiovascular performance can be achieved in expense of deterioration in body hydration processes. Also, these methods require semi invasive devices. However, monitoring of the whole body hydration status and interstitial fluid accumulation during fluid loading is not possible in everyday clinical practice. A new method, minimum Volume Loading Test (mVLT), uses evaluation of plasma dilution efficacy in small fluid boluses (2.5 – 5.0 ml kg) of isoosmotic crystalloid solutions followed by 5 min periods without fluids. The invasively measured arterial and venous hemoglobins, and simultaneous non-invasively measured hemoglobin (SpHb from Radical-7, Masimo inc., Irvine, USA) are used for estimation of plasma dilution which serves as an indication of plasma