International Journal of General Medicine (Jun 2023)
Advances in the Physiology of Transvascular Exchange and A New Look At Rational Fluid Prescription
Abstract
Mario E Alamilla-Sanchez,1 Miguel A Alcala-Salgado,2 Beatriz Cerezo Samperio,1 Pamela Prado Lozano,1 Juan Daniel Diaz Garcia,1 Carolina Gonzalez Fuentes,1 Martin Benjamin Yama Estrella,1 Enrique Fleuvier Morales Lopez1 1Department of Nephrology, Centro Medico Nacional “ 20 de Noviembre”, Mexico City, Mexico; 2Department of Nephrology, Hospital “Christus Muguerza”, Saltillo, Coahuila, MexicoCorrespondence: Mario E Alamilla-Sanchez, Tel +52 5541334931, Email [email protected]: The Starling principle is a model that explains the transvascular distribution of fluids essentially governed by hydrostatic and oncotic forces, which dynamically allow vascular refilling according to the characteristics of the blood vessel. However, careful analysis of fluid physiology has shown that the principle, while correct, is not complete. The revised Starling principle (Michel-Weinbaum model) provides relevant information on fluid kinetics. Special emphasis has been placed on the endothelial glycocalyx, whose subendothelial area allows a restricted oncotic pressure that limits the reabsorption of fluid from the interstitial space, so that transvascular refilling occurs mainly from the lymphatic vessels. The close correlation between pathological states of the endothelium (eg: sepsis, acute inflammation, or chronic kidney disease) and the prescription of fluids forces the physician to understand the dynamics of fluids in the organism; this will allow rational fluid prescriptions. A theory that integrates the physiology of exchange and transvascular refilling is the “microconstant model”, whose variables include dynamic mechanisms that can explain edematous states, management of acute resuscitation, and type of fluids for common clinical conditions. The clinical-physiological integration of the concepts will be the hinges that allow a rational and dynamic prescription of fluids.Keywords: Starling principle, transvascular exchange, glycocalyx, capillary refilling, volume kinetics
