Total weak acid concentration and effective dissociation constant of nonvolatile buffers in human plasma.

This research article focuses on finding the exact values for total plasma nonvolatile buffers concentration (A(tot)) and the related effective dissociation constant (K(a)) in human plasma by using a strong ion approach. The study found these values to be significantly different from those derived from other sources such as horse plasma, and this information can help understand how changes in certain variables can affect plasma pH in humans, potentially aiding in the management of acid-base disturbances.

Understanding the Study

• The study used the strong ion approach, a method that offers an accurate way to explain acid-base imbalances. This approach depends on knowing the total concentration of plasma nonvolatile buffers and the effective dissociation constant for these buffers.
• Before this study, these values had not been defined accurately for human plasma, which created a gap in understanding the acid-base behavior in the human body. This study aims to fill that gap.
• The researchers used in vitro strong ion titration and CO2 tonometry to calculate the required values. In vitro means the experiments were conducted outside a living organism, and titration refers to a common lab method used to determine the concentration of a known reactant.

Results and Significance

• The estimated values for A(tot) and K(a) in human plasma turned out to be 24.1 mmol/l and 1.05 x 10(-7) respectively. These values were found to be significantly different from those observed in horse plasma.
• The study also showed that the experimentally determined values for human plasma were unlike the theoretical values previously assumed.
• The study also calculated the derivatives of pH concerning three variables in the strong ion approach – the strong ion difference, PCO2 concentration, and A(tot). These derivatives helped in estimating the impact of changes in these variables on plasma pH.
• The findings obtained through the study have important implications for understanding and applying the strong ion approach in dealing with acid-base disturbances in humans.