BACKGROUND: The acidity of human body fluids, expressed by the pH, is physiologically regulated in a narrow range, which is required for the proper function of cellular metabolism. Acid-base disorders are common especially in intensive care, and the acid-base status is one of the vital clinical signs for the patient management. Because acid-base balance is connected to many bodily processes and regulations, complex mathematical models are needed to get insight into the mixed disorders and to act accordingly. The goal of this study is to develop a full-blood acid-base model, designed to be further integrated into more complex human physiology models. RESULTS: We have developed computationally simple and robust full-blood model, yet thorough enough to cover most of the common pathologies. Thanks to its simplicity and usage of Modelica language, it is suitable to be embedded within more elaborate systems. We achieved the simplification by a combination of behavioral Siggaard-Andersen's traditional approach for erythrocyte modeling and the mechanistic Stewart's physicochemical approach for plasma modeling. The resulting model is capable of providing variations in arterial pCO2, base excess, strong ion difference, hematocrit, plasma protein, phosphates and hemodilution/hemoconcentration, but insensitive to DPG and CO concentrations. CONCLUSIONS: This study presents a straightforward unification of Siggaard-Andersen's and Stewart's acid-base models. The resulting full-blood acid-base model is designed to be a core part of a complex dynamic whole-body acid-base and gas transfer model.

• Klíčová slova
• Acid-base modeling, Behavioral acid-base, Modelica, Physicochemical acid-base, Physiolibrary, Physiology, Siggaard-Andersen,
• MeSH
• acidobazická rovnováha * fyziologie   MeSH
• biologické modely * MeSH
• chemické modely * MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• poruchy acidobazické rovnováhy diagnóza   epidemiologie   patofyziologie   MeSH
• teoretické modely * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVE: Debate still exists as to whether the Stewart (modern) or traditional model of acid-base chemistry is best in assessing the acid-base status of critically ill patients. Recent studies have compared various parameters from the modern and traditional approaches, assessing the clinical usefulness of parameters such as base excess, anion gap, corrected anion gap, strong ion difference and strong ion gap. To compare the clinical usefulness of these parameters, and hence the different approaches, requires a clear understanding of their meaning; a task only possible through understanding the mathematical basis of the approaches. The objective of this paper is to provide this understanding, limiting the mathematics to a necessary minimum. METHOD: The first part of this paper compares the mathematics of these approaches, with the second part illustrating the clinical usefulness of the approaches using a patient example. RESULTS: This analysis illustrates the almost interchangeable nature of the equations and that the same clinical conclusions can be drawn regardless of the approach adopted. CONCLUSIONS: Although different in their concepts, the traditional and modern approaches based on mathematical models can be seen as complementary giving, in principle, the same information about the acid-base status of plasma.

• MeSH
• acidobazická rovnováha MeSH
• algoritmy MeSH
• hydrogenuhličitany krev   MeSH
• ionty MeSH
• krevní plazma chemie   MeSH
• lidé MeSH
• monitorování fyziologických funkcí metody   trendy   MeSH
• poruchy acidobazické rovnováhy * MeSH
• pufry MeSH
• software MeSH
• teoretické modely MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• hydrogenuhličitany MeSH
• ionty MeSH
• pufry MeSH