RESUMO
The high incidence of vascular ulcers and the difficulties encountered in their healing process require the understanding of their multiple etiologies to develop effective strategies focused on providing different treatment options. This work provides a description of the principles of the physics of fluid dynamics related to vascular ulcers. The morphological characteristics of the cardiovascular system promote blood flow. The contraction force of the left ventricle is enhanced by its ability to reduce its radius of curvature and by increasing the thickness of the ventricular wall (Laplace's Law). Arterial flow must overcome vascular resistance (Ohm's equation). The elastic nature of the artery and the ability to reduce its diameter as flow rate progresses facilitate blood conduction at high speed up to arteriolar level, and this can be determined by the second equation of continuity. As it is a viscous fluid, we must discuss laminar flow, calculated by the Reynolds number, which favors proper conduction while aiming at the correct net filtration pressure. Any endothelial harmful process that affects the muscle wall of the vessel increases the flow speed, causing a decrease in capillary hydrostatic pressure, thus reducing the exchange of nutrients at the interstitial level. With regard to the return system, the flow direction is anti-gravity and requires endogenous aid to establish the Starling's equilibrium. Knowledge on the physics of vascular fluid dynamics makes it easier to understand the processes of formation of these ulcers so as to choosing the optimal healing and prevention techniques for these chronic wounds.
RESUMO
Las úlceras vasculares son lesiones que se producen en las extremidades inferiores provocadas o agravadas por algún problema en el flujo sanguíneo distal, ya sea por el aporte, en el caso de las arteriales, o por el retorno, en el caso de las venosas. El conocimiento del proceso fisiopatológico en la aparición de las mismas ayuda a entender su etiología y proceso de evolución. Además, la comprensión de los mecanismos fisiológicos que las provocan permite escoger entre las diferentes técnicas a llevar a cabo, tanto preventivas como curativas, para establecer las medidas oportunas a poner en marcha. Se consiguen así intervenciones más efectivas dirigidas a la etiología del problema, que evitan que aparezca o se agrave, o, en caso contrario, favorecen una pronta cicatrización y, por lo tanto, una mayor calidad de vida de los pacientes. Enfermería debe conocer el proceso fisiopatológico de dichas lesiones, ya que tiene por objeto fomentar medidas de prevención, así como realizar las curas de manera efectiva, reduciendo las recidivas
Vascular ulcers are wounds in the lower limbs caused or aggravated by a problem in the distal blood flow, either by the supply in the case of arterial ulcers and return in the case of venous ulcers. The knowledge of the physiopathological process behind its etiology helps to understand the cause and evolution of vascular ulcers. In addition, the understanding of the physiological mechanisms that cause them allows to choose the most effective preventive measure or the most appropriate healing treatment. Thus, more effective interventions aimed at the etiology of the problem are achieved. These measures prevent the ulcers from appearing or getting worse, or in the case of presenting them, they promote an early healing, and therefore, a higher quality of life for the patients. The nurses must know the pathophysiological process of such wounds, since it is in charge of promoting preventive measures, as well as performing the cures effectively, reducing recurrences
