Introduction/Background: Starling’s law is the culprit that dictates many errors and misconceptions on fluid therapy that mislead physicians into giving too much fluid during the resuscitation of shock inducing volumetric overload shocks (VOS) and cause the acute respiratory distress syndrome (ARDS).

Aims/Objectives: To report hydrodynamic of a porous orifice (G) tube as replacement for the wrong Starling’s law.

Materials and Methods: Hydrodynamics of the porous orifice (G) tube, built based on capillary ultra-structure, were studied, and contrasted to Poiseuille’s tube. The effect of changing G tube orifice diameter, proximal pressure and distal pressure on the side pressure and chamber (C) pressure were evaluated. The physiological proof that the capillary works as G tube not Poiseuille’s tube is provided.

Results:Hydrodynamics of the G tube showed that proximal, akin to arterial, pressure induces a negative side pressure gradient on the G tube wall, which is negative causing suction maximum near the inlet and turns positive near the exit causing filtration. This created the unique, rapid, autonomous magnetic field-like fluid circulation phenomenon between G and C.- akin to capillary-interstitial fluid space fluid transfer The physiological evidence on the hind limb of sheep proves that the capillary works as G tube.

Discussion and Conclusions: Hydrodynamic of the G tube challenges the role attributed to arterial pressure as a filtration force in Starling’s law. A literature review shows that oncotic pressure does not work, and the law has failed to explain the capillary–ISF transfer. A concept based on the new hydrodynamic phenomenon of the G tube is proposed to replace Starling’s law. A rapid autonomous dynamic magnetic field-like G–C circulation occurs. Factors which initiate, regulate, and affect G–C circulation, its physiological proof and relevance to clinical importance are given. A physiological evidence on capillary working as G tube not Poiseuille’s tube is provided.

Keywords: Capillary physiology, Starling’s law,Hydrodynamics, Shock, Oedema ARDS