Acid-base equilibrium: The best clinical approach

  • Raúl E. Aristizábal-Salazar a. Adult Intensive Care Unit, Saludcoop Clinic, Pereira, Colombia. b. Pinares Clinic, Pereira, Colombia.
  • L. Felipe Calvo-Torres Pharmacoepidemiology and Pharmacovigilance Research Group, Universidad Tecnológica de Pereira, Pereira, Colombia
  • Luis Alfonso Valencia-Arango Universidad Tecnológica de Pereira, Pereira, Colombia
  • Oscar Barbosa-Gantiva Universidad Tecnológica de Pereira, Pereira, Colombia
  • Vanessa Hincapié-Baena Health Sciences School, Universidad Tecnológica de Pereira, Pereira, Colombia
Keywords: Acidosis, Alkalosis, Colombia, Acid-Base Imbalance, Anesthesia


Acid-base balance disorders can be found in a primary or secondary form in patients with a disease process such as Diabetes Mellitus or acute renal failure, among others. The objective of this article is to explain and guide the correlation ship between the clinical findings in the patient and the parameters of arterial blood gases in a simple and precise manner, in order to make the correct acid-base balance diagnosis and adequate therapeutic interventions. A non-systematic review of the scientific literature was conducted through a search in the PubMed, Science Direct, Scopus, and OvidSP databases. The conclusion was that base excess or deficit in arterial blood gases is a useful tool which along with the clinical history, pH, and partial pressure of CO2, provides an accurate estimate of the metabolic component of the acid-base balance.


1. Story DA. Bench-to-bedside review: a brief history of clinical acid-base. Crit Care. 2004;8:253-8.
2. 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:F1009-31.
3. Corey HE. Stewart and beyond: new models of acid-base balance. Kidney Int. 2003;64:777-87.
4. Paulev PE, Zubieta-Calleja GR. Essentials in the diagnosis of acid-base disorders and their high altitude application. J Physiol Pharmacol. 2005;56:155-70.
5. Prieto de Paula JM, Franco Hidalgo S, Mayor Toranzo E, Palomino Doza J, Prieto de Paula JF. Alteraciones del equilibrio acido-base. Dial Traspl. 2012;33:25-34.
6. Durward A, Murdoch I. Understanding acid-base balance. Paediatr Child Health. 2003;13:513-9.
7. Edwards SL. Pathophysiology of acid base balance: the theory practice relationship. Intensive Crit Care Nurs. 2008;24:28-38.
8. Guidet B, Soni N, Della Rocca G, Kozek S, Vallet B, Annane D, et al. A balanced view of balanced solutions. Crit Care. 2010;14:325.
9. Boron WF. Acid-base transport by the renal proximal tubule. Am J Physiol Renal Physiol. 2006;17:2368-82.
10. Tresguerres M, Buck J, Levin LR. Physiological carbon dioxide, bicarbonate, and pH sensing. Pflugers Arch. 2010;460:953-64.
11. Koeppen BM. The kidney and acid-base regulation. Adv Physiol Educ. 2009;33:275-81.
12. Greenbaum J, Nirmalan M. Acid-base balance: the traditional approach. Curr Anaesth Crit Care. 2005;16:137-42.
13. Story DA, Kellum JA. Acid-base balance revisited: Stewart and strong ions. Semin Anesth. 2005;24:9-16.
14. Greenbaum J, Nirmalan M. Acid-base balance: Stewart's physicochemical approach. Curr Anaesth Crit Care. 2005;16:133-5.
15. Rice M, Ismail B, Pillow MT. Approach to metabolic acidosis in the emergency department. Emerg Med Clin N Am. 2014;32:403-20.
16. Poupin N, Calvez J, Lassale C, Chesneau C, Tome D. Impact of the diet on net endogenous acid production and acid-base balance. Clin Nutr. 2012;31:313-21.
17. Moe OW, Fuster D. Clinical acid-base pathophysiology: disorders of plasma anion gap. Best Pract Res Clin Endocrinol Metab. 2003;17:559-74.
18. Liborio AB, da Silva Alexandre C, Noritomi DT, Andrade L, Seguro AC. Impact of chloride balance in acidosis control: the Stewart approach in hemodialysis critically ill patients. J Crit Care. 2006;21:333-8.
19. Derksen R, Scheffer GJ, van der Hoeven JG. Quantitative acid-base physiology using the Stewart model. Does it improve our understanding of what is really wrong? Eur J Intern Med. 2006;17:330-3.
20. Wooten EW. Science review: quantitative acid-base physiology using the Stewart model. Crit Care. 2004;8: 448-52.
21. Rinaldi S, De Gaudio AR. Strong ion difference and strong anion gap: the Stewart approach to acid base disturbances. Curr Anaesth Crit Care. 2005;16:395-402.
22. Maciel AT, Park M. Differences in acid-base behavior between intensive care unit survivors and nonsurvivors using both a physicochemical and a standard base excess approach: a prospective, observational study. J Crit Care. 2009;24:477-83.
23. Rastegar A. Clinical utility of Stewart's method in diagnosis and management of acid-base disorders. Clin J Am Soc Nephrol. 2009;4:1267-74.
24. Morgan TJ. The meaning of acid-base abnormalities in the intensive care unit: part III - effects of fluid administration. Crit Care. 2005;9:204-11.
25. Kaplan LJ, Frangos S. Clinical review: acid-base abnormalities in the intensive care unit - part II. Crit Care. 2005;9:198-203.
26. Cowley NJ, Owen A, Bion JF. Interpreting arterial blood gas results. BMJ. 2013;346:f16.
27. FitzSullivan E, Salim A, Demetriades D, Asensio J, Martin MJ. Serum bicarbonate may replace the arterial base deficit in the trauma intensive care unit. Am J Surg. 2005;190:941-6.
28. Noritomi DT, Soriano FG, Kellum JA, Cappi SB, Biselli PJ, Liborio AB, et al. Metabolic acidosis in patients with severe sepsis and septic shock: a longitudinal quantitative study. Crit Care Med. 2009;37:2733-9.
29. Boyle M, Baldwin I. Introduction to an alternate view of acid/base balance: the strong ion difference or Stewart approach. Aust Crit Care. 2002;15:14-20.
30. Martin MJ, FitzSullivan E, Salim A, Brown CV, Demetriades D, Long W. Discordance between lactate and base deficit in the surgical intensive care unit: which one do you trust? Am J Surg. 2006;191:625-30.
31. Englehart MS, Schreiber MA. Measurement of acid-base resuscitation endpoints: lactate, base deficit, bicarbonate or what? Curr Opin Crit Care. 2006;12:569-74.
32. Zehtabchi S, Soghoian S, Sinert R. Utility of Stewart's strong ion difference as a predictor of major injury after trauma in the ED. Am J Emerg Med. 2007;25:938-41.
33. Morgan TJ. Invited commentary: putting standard base excess to the test. J Crit Care. 2009;24:492-3.
34. 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:R41-5.
35. Mallat J, Michel D, Salaun P, Thevenin D, Tronchon L. Defining metabolic acidosis in patients with septic shock using Stewart approach. Am J Emerg Med. 2012;30:391-8.
36. Wooten EW. A new predictive formula for calculation of equilibrium pH: a step back in time. Am J Physiol Renal Physiol. 2010;298:F471.
37. Adrogue HJ, Gennari FJ, Galla JH, Madias NE. Assessing acid-base disorders. Kidney Int. 2009;76:1239-47.
38. Berend K. Acid-base pathophysiology after 130 years: confusing, irrational and controversial. J Nephrol. 2013;26:254-65.
39. Kaplan LJ, Kellum JA. Initial pH, base deficit, lactate, anion gap, strong ion difference, and strong ion gap predict outcome from major vascular injury. Crit Care Med. 2004;32:1120-1.
40. Laverde Sabogal CE, Correa Rivera AF, Joya Higuera AY. Lactate and base deficit in trauma: prognostic value. Rev Colomb Anestesiol. 2014;42:60-4.
41. Kellum JA, Song M, Li J. Science review: extracellular acidosis and the immune response: clinical and physiologic implications. Crit Care. 2004;8:331-6.
42. Arnett TR. Extracellular pH regulates bone cell function. J Nutr. 2008;138:415S-8S.
43. Wiener SW. Toxicologic acid-base disorders. Emerg Med Clin NAm. 2014;32:149-65.
44. Day J, Pandit JJ. Analysis of blood gases and acid-base balance. Surgery (Oxford). 2011;29:107-11.
45. Dzierba AL, Abraham P. A practical approach to understanding acid-base abnormalities in critical illness. J Pharm Pract. 2011;24:17-26.
46. Palmer BF. Approach to fluid and electrolyte disorders and acid-base problems. Prim Care. 2008;35:195-213.
47. Whittier WL, Rutecki GW. Primer on clinical acid-base problem solving. Dis Mon. 2004;50:122-62.
48. Baylis C, Till C. Interpretation of arterial blood gases. Surgery. 2009;27:470-4.
49. Goel N, Calvert J. Understanding blood gases/acid-base balance. Paediatr Child Health. 2012;22:142-8.
50. Centor RM, Wargo KA. ABCs of ABGs: a guide to interpreting acid-base disorders. Hosp Pharm. 2008;43:808-15.
51. Kellum JA. Disorders of acid-base balance. Crit Care Med. 2007;35:2630-6.
52. Mahaldar AR. Acid base and fluid electrolyte disturbances in chronic kidney disease. Clin Queries: Nephrol. 2012;1:295-9.
How to Cite
Aristizábal-Salazar RE, Calvo-Torres LF, Valencia-Arango LA, Barbosa-Gantiva O, Hincapié-Baena V. Acid-base equilibrium: The best clinical approach. Colomb. J. Anesthesiol. [Internet]. 2015Jul.1 [cited 2021May12];43(3):219-24. Available from:


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How to Cite
Aristizábal-Salazar RE, Calvo-Torres LF, Valencia-Arango LA, Barbosa-Gantiva O, Hincapié-Baena V. Acid-base equilibrium: The best clinical approach. Colomb. J. Anesthesiol. [Internet]. 2015Jul.1 [cited 2021May12];43(3):219-24. Available from:
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