Comparison between bicarbonate-based and Stewart methods to assess metabolic acid-base disorders in internistic patients. A pilot study

  • Authors

    • Valenti Maria
    • Bruno Francesca
    • Demma Shirin
    • Bruno Cosimo Marcello Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
    2017-09-20
    https://doi.org/10.14419/ijm.v5i2.7946
  • Acid-Base Disorders, Stewart Disorders, Stewart Method, Metabolic Acidosis, Metabolic Alkalosis.

  • Abstract

    Aim: To assess the acid-base status in a cohort of internistic patients, using traditional and “modern†methods, to compare their different sensitivity to detect metabolic disorders and to evaluate a possible relationship between classical and alternative parameters.

    Patients and Methods: 143 assessment of acid-base and electrolytes balance on 121 internistic patients (76 males and 45 females, mean age 73.9 ± 10,8 years) were examined according to bicarbonate-based and Stewart methods.

    Results: The traditional method detected 81 cases (56.6 %) of metabolic alkalosis and 15 cases (10.4 %) of metabolic acidosis. The Stewart method detected 92 cases (64.3 %) of metabolic alkalosis and 22 cases (15.3%) of metabolic acidosis.

    Traditional method failed to detect 11 cases of metabolic alkalosis (chi square = 1.443; p = 0.226), and 7 cases of metabolic acidosis (chi square = 1.118; p = 0.290) when compared to Stewart's method. A significant relationship was observed between Strong Ion Gap (SIG) and Anion Gap corrected for albumin concentration (AGcorr) (r= 0.53; p <0.001).

    Conclusions: Our result showed that traditional method is useful to assess acid-base status in internistic clinical setting as well as Stewart's method because no significant difference was found between the two approaches. Nevertheless, the light disagreement observed between the two methods suggests that in a small percentage of cases the traditional method can fail to detect metabolic acid-base abnormalities.

  • References

    1. [1] Brønsted JN. [Einige Bemerkungen über den Begriff der Säuren und Basen [Rec Trav Chim Pay-Bas. 1923; 42(8):718-28.
      [2] Lowry TM. The uniqueness of hydrogen. Chem Ind. 1923; 42 (3):43-7. https://doi.org/10.1002/jctb.5000420302.
      [3] Singer RB, Hastings AB.An improved clinical method for the estimation of disturbances of the acid-base balance of human blood. Medicine. 1948; 27 (2): 223-42. https://doi.org/10.1097/00005792-194805000-00003.
      [4] Siggaard-Andersen O.The Van Slyke equation. Scand J Clin Lab Invest Suppl. 1977; 146:15-20. https://doi.org/10.3109/00365517709098927.
      [5] Emmet M, Narins RG. Clinical use of the anion gap. Medicine. 1977; 56 (1):38-54. https://doi.org/10.1097/00005792-197756010-00002.
      [6] Gabow PA,Kaehny WD, Fennessey PV, Goodman SI, Gross PA, Schrier RW.Diagnostic importance of an increased anion gap. New England Journal of Medicine. 1980; 303(15):854-8. https://doi.org/10.1056/NEJM198010093031505.
      [7] Severinghaus JW.Siggaard-Andersen and the “Great Trans-Atlantic Acid-Base Debateâ€. Scand J Clin Lab Invest Suppl. 1993; 214: 99-104.
      [8] Stewart PA.How to understand acid-base: A quantitative acid base primer for biology and medicine (1981), New York: Elsevier NorthHolland.
      [9] Stewart PA.Modern quantitative acid-base chemistry. Can JPhysiol Pharmacol. 1983; 61(12): 1444-61. https://doi.org/10.1139/y83-207.
      [10] Guerin C,Nesme P, Leray V, Wallet F, Bourdin G, Bayle F, Germain M, Richard JC. Quantitative analysis of acid-base disorders in patients with chronic respiratory failure in stable or unstable respiratory condition. Respir Care. 2010; 55(11):1453-63.
      [11] Fencl V, Jabor A, Kazda A, Figge J. Diagnosis of metabolic acid-base disturbances in critically ill patients. Am J Respir Crit Care Med.2000;162(6):2246-51. https://doi.org/10.1164/ajrccm.162.6.9904099.
      [12] Boniatti MM. Acid-base disorders evaluation in critically ill patients: we can improve our diagnostic ability. Intensive Care Med.2009; 35 (8): 1377-82. https://doi.org/10.1007/s00134-009-1496-2.
      [13] Balasubramanyan N, Havens PL, Hoffman GM. Unmeasured anions identified by the Fencl-Stewart method predict mortali-ty better than base excess, anion gap, and lactate in patients in the pediatric intensive care unit. Crit Care Med. 1999; 27 (8):1577-81. https://doi.org/10.1097/00003246-199908000-00030.
      [14] Kaplan LJ, Kellum JA.Comparison of acid-base models for prediction of hospital mortality after trauma. Shock. 2008; 29(6):662-6.
      [15] Moviat M,van Haren F, van der Hoeven H. Conventional or physicochemical approach in intensive care unit patients with metabolic acidosis. Crit Care. 2003; 7 (3):R41-55. https://doi.org/10.1186/cc2184.
      [16] Sirker AA,Rhodes A, Grounds RM, Bennett ED. Acid-base physiology: the traditional and the modern approaches. An-aesthesia. 2002; 57(4):348-56. https://doi.org/10.1046/j.0003-2409.2001.02447.x.
      [17] Kurtz I,Kraut J, Ornekian V, Nguyen MK. Acid-base analysis: a critique of the Stewart and bicarbonate-centered approaches. Am J Physiol Renal Physiol.2008; 294(5):F1009-31. https://doi.org/10.1152/ajprenal.00475.2007.
      [18] Rastegar A. Clinical utility of Stewart’s method in diagnosis and management of acid-base disorders. Clin J Am Soc Neph-rol. 2009; 4(7):1267-74. https://doi.org/10.2215/CJN.01820309.
      [19] Dubin A,Menises MM, Masevicius FD, Moseinco MC, Kutscherauer DO, Ventrice E, Laffaire E, Estenssoro E.Comparison of three different methods of evaluation of metabolic acid-base disorders. Crit Care Med. 2007; 35(5):1264-70. https://doi.org/10.1097/01.CCM.0000259536.11943.90.
      [20] Masevicius FD, Dubin A. Has Stewart approach improved our ability to diagnose acid-base disorders in critically ill patients? World J Crit Care Med 2015; 4(1): 62-70 https://doi.org/10.5492/wjccm.v4.i1.62.
      [21] Rastegar A, “Mixed acid-base disorders,†Gennari FJ et al. (eds.), Acid Base Disordersand Their Treatment (2005), Boca Ranton: Taylor & Francis,pp.681-96. https://doi.org/10.1201/b14402-23.
      [22] Martin M, Murray J, Berne T, Demetriades D, Belzberg H. Di-agnosis of acid-base derangements and mortality predictionin the trauma intensive care unit: The physiochemicalapproach. J Trauma. 2005; 58(2):238-43. https://doi.org/10.1097/01.TA.0000152535.97968.4E.
      [23] Westen EA, Prange HD. A reexamination of the mechanisms underlying the arteriovenous chloride shift. Physiol Biochem Zool 2003; 76: 603-614 https://doi.org/10.1086/380208.
      [24] Langer T, Zani L, Carlesso E, Protti A, Caironi P, Chierichetti M, Caspani ML, Gattinoni L.Contribution of red blood cells to the compensation for hypocapnic alkalosis through plasmatic strong ion difference variations. Critical Care 2011; 15 (Suppl 1): P134 https://doi.org/10.1186/cc9554.
      [25] Polak A, Haynie GD, Hays RM, Schwartz WB. Effects of chronic hypercapnia on electrolyte and acid-base equilibrium. I. Adaptation. J Clin Invest1961; 40: 1223-1237 https://doi.org/10.1172/JCI104353.
      [26] Morgan TJ, Cowley DM, Weier SL, Venkatesh B. Stability of the strong ion gap versus the anion gap over extremes of PCO2 and pH. Anaesth Intensive Care 2007; 35:370-373.

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  • How to Cite

    Maria, V., Francesca, B., Shirin, D., & Marcello, B. C. (2017). Comparison between bicarbonate-based and Stewart methods to assess metabolic acid-base disorders in internistic patients. A pilot study. International Journal of Medicine, 5(2), 234-238. https://doi.org/10.14419/ijm.v5i2.7946

    Received date: 2017-06-07

    Accepted date: 2017-07-07

    Published date: 2017-09-20