Résumé
L’interprétation de l’état acidobasique peut se faire par deux approches : classique, centrée sur le bicarbonate, ou moderne ou approche de Stewart, dans laquelle le bicarbonate est considéré comme une variable dépendante. L’analyse classique repose sur l’interprétation simultanée de la bicarbonatémie et de la PCO2. Le base excess (BE) permet de quantifier la part métabolique d’un désordre acidobasique. Le trou anionique plasmatique (TAP, corrigé par l’albuminémie) vise à détecter la présence d’anions indosés. L’approche dite moderne de Stewart repose sur quatre grands principes de la physique-chimie : l’équilibre de dissociation de l’eau, la loi de dissociation des acides faibles, l’électroneutralité et la conservation de la masse. Elle identifie trois variables indépendantes : la différence des ions forts (SID), la concentration totale d’acide faible et la pression partielle de dioxyde de carbone (PCO2). Les ions forts sont les ions totalement dissociés au pH plasmatique: acides forts (Cl-et lactate, pKa < 4) et bases fortes (Na+, K+, Ca++ et Mg++, pKa > 12). Le SID est physiologiquement de 40 mEq/l, ce qui correspond aux anions des acides faibles totaux. Ils sont quantifiés par la somme de l’albuminate, des phosphates et des bicarbonates, étroitement corrélée au BE de l’approche classique. Stewart définit un strong ion gap (SIG) équivalent au TAP moins la bicarbonatémie. On parle ainsi d’acidose à SID diminué et de SIG normal à la place d’acidose hyperchlorémique à TAP normal. Cette revue tente de démontrer comment ces deux approches regardent à travers des prismes différents les mêmes phénomènes complexes d’équilibration entre les tampons.
Abstract
The interpretation of acid-base status can be achieved by two approaches: the classic bicarbonate-centred one and the modern one based on Stewart approach, in which bicarbonate is considered as a dependent variable. The classic analysis is based on the simultaneous interpretation of plasma bicarbonate and the partial pressure of carbon dioxide (PCO2). The Base Excess (BE) allows quantifying the metabolic contribution to the acid-base disorder. The plasma anion gap (TAP, corrected by the albumin) aims to detect the presence of non-dosed anions. The so-called modern Stewart analysis is based on four main principles of physics and chemistry: the equilibrium dissociation of water, the law of dissociation of weak acids, electroneutrality and conservation of mass. It identifies three independent variables: the strong ion difference (SID), the total concentration of weak acid and PCO2. Strong ions are plasma ions completely dissociated: strong acids (Cl− and lactate, pKa < 4) and strong bases (Na+, K+, Ca++ and Mg++, pKa > 12). The SID physiologically equals 40 mEq/l, corresponding to the whole weak acids buffers. The latter is quantified by the sum of albuminate, phosphate and bicarbonate, a term that is closely related to the BE of the classical approach. Stewart defines a strong ion gap (SIG) equivalent to TAP which is subtracted by bicarbonatemia. Low SID acidosis with normal SIG is used instead of hyperchloremic acidosis with normal anion gap. This review attempts to demonstrate that these two approaches look at the complex phenomena of equilibration between buffers through different prisms.
Références
Kurtz I, Kraut J, Ornekian V, Nguyen MK (2008) Acid-base analysis: a critique of the Stewart and bicarbonate-centered approaches. Am J Physiol 294:F1009–F1031
Halperin ML, Goldstein MB, Kamel KS (2010) Fluid, electrolyte, and acid-base hysiology. Elsevier Health Sciences
Blanchard A, Vargas-Poussou R, Haymann JP (2014) Exploration des fonctions tubulaires rénales. Encyclopédie médico-chirurgicale, néphrologie (sous presse)
Weiner ID, Verlander JW (2011) Role of NH3 and NH4 + transporters in renal acid-base transport. Am J Physiol 300:F11–F23
Rosen RA, Julian BA, Dubovsky EV, et al (1988) On the mechanism by which chloride corrects metabolic alkalosis in man. Am J Med 84:449–458
Singer RB, Hastings AB (1948) An improved clinical method for the estimation of disturbances of the acid-base balance of human blood. Medicine 27:223–242
Siggaard-Andersen O (1977) The van Slyke equation. Scand J Clin Lab Invest 146:15–20
Frazer SC, Stewart CP (1959) Acidosis and alkalosis: a modern view. J Clin Pathol 12:195–206
Kraut JA, Nagami GT (2013) The serum anion gap in the evaluation of acid-base disorders: what are its limitations and can its effectiveness be improved? Clin J Am Soc Nephrol 8:2018–2024
Figge J, Jabor A, Kazda A, Fencl V (1998) Anion gap and hypoalbuminemia. Crit Care Med 26:1807–1810
Stewart PA (1983) Modern quantitative acid-base chemistry. Can J Physiol Pharmacol 61:1444–1461
Stewart PA (1978) Independent and dependent variables of acidbase control. Respir Physiol 33:9–26
Rinaldi S, De Gaudio A (2005) Strong ion difference and strong anion gap: the Stewart approach to acid base disturbances. Curr Anaesth Crit Care 16:395–402
Rossing TH, Maffeo N, Fencl V (1986) Acid-base effects of altering plasma protein concentration in human blood in vitro. J Appl Physiol (1985) 61:2260–2265
Smuszkiewicz P, Szrama J (2013) Theorethical principles of fluid managment according to physicochemical Stewart approach. Anaesthesiol Intensive Ther 45:99–105
Hofmann-Kiefer KF, Chappell D, Kammerer T, et al (2012) Influence of an acetate- and a lactate-based balanced infusion solution on acid base physiology and hemodynamics: an observational pilot study. Eur J Med Res 17:21
Morgan TJ (2005) The meaning of acid-base abnormalities in the intensive care unit: part III — effects of fluid administration. Crit Care (London, England) 9:204–211
Gattinoni L, Carlesso E, Cadringher P, Caironi P (2006) Strong ion difference in urine: new perspectives in acid-base assessment. Crit Care (London, England) 10:137
Corey HE (2003) Stewart and beyond: new models of acid-base balance. Kidney Int 64:777–787
Kellum JA (2005) Clinical review: reunification of acid-base physiology. Crit Care (London, England) 9:500–507
Rastegar A (2009) Clinical utility of Stewart’s method in diagnosis and management of acid-base disorders. Clin J Am Soc Nephrol 4:1267–1274
Quintard H, Hubert S, Ichai C (2007) What is the contribution of Stewart’s concept in acid-base disorders analysis? Ann Fr Anesth Reanim 26:423–433
Ring T, Frische S, Nielsen S (2005) Clinical review: renal tubular acidosis: a physicochemical approach. Crit Care (London, England) 9:573–580
Moviat M, Pickkers P, van der Voort PH, van der Hoeven JG (2006) Acetazolamide-mediated decrease in strong ion difference accounts for the correction of metabolic alkalosis in critically ill patients. Crit Care (London, England) 10:R14
Sirker AA, Rhodes A, Grounds RM, Bennett ED (2002) Acidbase physiology: the “traditional” and the “modern” approaches. Anaesthesia 57:348–356
Kellum JA (1999) Acid-base physiology in the post-Copernicanera. Curr Opin Crit Care 5:429–435
Adrogue HJ, Gennari FJ, Galla JH, Madias NE (2009) Assessing acid-base disorders. Kidney Int 76:1239–1247
Matousek S, Handy J, Rees SE (2011) Acid-base chemistry of plasma: consolidation of the traditional and modern approaches from a mathematical and clinical perspective. J Clin Monit Comput 25:57–70
Morris CG, Low J (2008) Metabolic acidosis in the critically ill: part 2. Causes and treatment. Anaesthesia 63:396–411
Guerin C, Nesme P, Leray V, et al (2010) Quantitative analysis of acid-base disorders in patients with chronic respiratory failure in stable or unstable respiratory condition. Respir Care 55:1453–1463
Berend K, van Hulsteijn LH, Gans RO (2011) Chloride: the queen of electrolytes? Eur J Intern Med 23:203–211
Wagner CA, Mohebbi N, Capasso G, Geibel JP (2011) The anion exchanger pendrin (SLC26A4) and renal acid-base homeostasis. Cell Physiol Biochem 28:497–504
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Blanchard, A., Lorthioir, A., Zhygalina, V. et al. Approche de Stewart : ou comment faire du neuf avec du vieux ?. Réanimation 23, 359–369 (2014). https://doi.org/10.1007/s13546-014-0889-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13546-014-0889-6