Advances in the Physiology of Transvascular Exchange and A New Look At Rational Fluid Prescription

Figures & data

Table 1 Hemodynamic Factor According to Vascular Area

Component	Artery	Vein	Capillary
Wall shear stress	Aorta: 10–40 dynes/cm^2	1–5 dynes/cm^2	Highly variable depending on vascular bed: 1–70 dynes/cm^2
	Coronary arteries: 10–17 dynes/cm^2	Long saphenous vein: 0.5–4 dynes/cm^2

Figure 1 Classical Starling principle. Relationship between transvascular flow (Jv) and hydrostatic pressure (Pc); when Jv = 0, the hydrostatic and oncotic pressure difference of the intravascular and interstitial space reach an “equilibrium” (ΔP = σΔπ), which results in the absence of vascular leakage. When Pc < σΔπ there is fluid reabsorption.

Figure 2 Revised Starling’s principle. In the transient state with abrupt reduction of Pc (green line), Jv < 0 when Pc < σΔπ and there is fluid reabsorption. In the steady state with constant maintenance of Pc (purple line), Jv = 0 when Pc < σΔπ contrary to the expected reabsorption.

Figure 3 Interendothelial space and clefts. The revised model of the Starling Principle proposes the glycocalyx as a major determinant in the maintenance of the Δπ in the face of changes in Pc. The arrow indicates the path of flow of solvent and solutes through the interendothelial cleft.

Figure 4 General scheme of body fluid compartments. The formulas that describe the movement of fluids or solutes in each compartment are included.

Figure 5 Mrs Fanna Gebresilassie reports grants from Comitato Collaborazione Medica project, during the conduct of the study. Microconstant model for fluids (kinetic analysis).