Carrillo ER, Carrillo CJR, Carrillo CLD

Language: Spanish
References: 0
Page: 96-98
PDF size: 90.11 Kb.

ABSTRACT

All modern theories of acid-base balance are based on physiochemical principles. As thermodynamic state equations are independent of path, any one may be used to describe a physiochemical system. The traditional model of acid-base balance in plasma is based on the distribution of proton acceptor sites, whereas the Stewart model is based on the distribution of electrical charge. Although sophisticated a mathematically equivalent models may be derived from either set of parameters, proponents of the traditional or proton acceptor site approach have advocated simple formulae whereas proponents of the Stewart or electrical charge method have emphasized mathematical rigor. The Stewart model examines the relationship between the movement of ions across biologic membranes and the consequent changes in pH. The Stewart equation relates changes in pH to changes in the three variables, Total concentration of weak acids, strong ion difference and PCO₂. These variables may define a biologic system and so may be used to explain any acid-base derangement in the system. The Stewart model corrects the traditional computations of buffer curve. This model has reawakened interest in quantitative acid-base chemistry and has prompted a return to the first principles of acid-base physiology.