Clinical evaluation of acid-base status: Henderson-Hasselbalch, or Stewart-Fencl approach?
Authors:
Karel Matoušovic 1,2; Jan Havlín 3; Otto Schück 4
Authors‘ workplace:
Interní klinika 2. LF UK a FN Motol v Praze
1; Oddělení transplantací a tkáňové banky FN Motol, Praha
2; 3. chirurgická klinika 1. LF UK a FN Motol, Praha
3; Interní klinika 2. LF UK a FN Motol, Praha
4
Published in:
Čas. Lék. čes. 2016; 155: 365-369
Category:
Review Articles
Overview
Two approaches have been used in clinical evaluation the acid-base status: traditional (bicarbonate-centered) is based on the Henderson-Hasselbalch equation complemented by calculation of the anion gap, and more recent quantitative approach proposed by Stewart and Fencl. The latter method defines the three independent variables, which regulate pH. These include: the difference between the sum of charges carried by strong plasma cations and anions termed the strong ion difference – SID (decrease causes acidosis, and vice versa); the total concentration of the weak non-volatile acids − [Atot] (inorganic phosphate and albumin, decrease causes alkalosis and vice versa), and pCO2. According to this approach, pH and bicarbonate are dependent variables. Their concentrations change if and only if one or more independent variables are altered.
The main advantage of the Stewart-Fencl approach is the calculation of the concentration of plasma acids, which are not routinely measured. In the traditional approach, their presence is inferred from the anion gap. The correction of the value of anion gap according to the serum albumin level increases the specificity. This correction brings traditional approach closer to the Stewart-Fencl method that precisely calculates unmeasured strong anions by further adjustment of the corrected anion gap according to the serum phosphate, calcium and magnesium levels. The precise calculation of unmeasured anions is important in critically ill patients with the metabolic breakdown, where the traditional approach may overlook the presence of unmeasured anions. Consideration of the sodium-chloride difference draws the attention to acid-base disturbance caused by change of the strong ion difference.
Keywords:
acid-base balance, Stewart-Fencl theory, bicarbonate, anion gap, strong anions
Sources
1. Hermanussen M et al. Auxology – Studying Human Growth and Development. Schweizerbart Science Publisher, Stuttgart, 2013.
2. Henderson LJ. Das Gleichgewicht zwischen Säuren und Basen im Tierischen Organismus. Ergeben Physiol 1909; 8: 254−325.
3. Haselbalch KA. Die Berechnung der Wasserstoffzahl des Blutes aus der freien and gebundenen Kohlesäure desselben, und die Sauerstoffbildung als Funktion der Wasserstoffzahl. Biochem Z 1916; 78: 112−144.
4. Figge J, Rossing TH, Fencl V. The role of serum proteins in acid-base equilibria. J Lab Clin Med 1991; 17: 453−467.
5. Figge J, Mydosh T, Fencl V. Serum proteins and acid-base equilibria: a follow-up. J Clin Lab Med 1992; 120: 713−719.
6. Figge J et al. Anion gap and hypoproteinemia. Crit Care Med 1998; 26: 1807−1810.
7. McAuliffe JJ et al. Hypoproteinemic alkalosis. Am J Med 1986; 81: 86−90.
8. Watson PD. Modeling the effects of proteins on pH in plasma. J Appl Physiol 1999; 86: 1421−1427.
9. Rossing TH, Maffero N, Fencl V. Acid-base effects of altering plasma protein concentration in human blood in vitro. J Appl Physiol 1986, 61: 2260−2265.
10. Salem M, Mujais S. Gaps in anion gap. Arch Int Med 1992; 152: 1625−1629.
11. Garella S, Chang BS, Kahn SI. Dilution acidosis and contraction alkalosis: review of the concept. Kidney Int 1975; 8: 279−283.
12. Winter SD et al. The fall of the serum anion gap. Arch Int Med 1990; 150: 311−313.
13. Astrup P et al. The acid-base metabolism. A new approach. Lancet 1969; 1: 1035−1039.
14. Siggaard-Andersen O. The van Slyke equation. Scand J Clin Lab Invest Suppl 1977; 146: 15−20.
15. Siggaard-Andersen O. et al. Measured and derived quantities with modern pH and blood gas equipment: calculations, algorithms with 54 equations. Scand J Clin Lab Invest 1988; 48: Suppl. 189: 7−15.
16. Siggaard-Andersen O. The acid-base status of the blood. Munksgaard, Copenhagen, 1963.
17. van Slyke DD. Current concepts of acid-base measurement. Ann NY Acad Sci 1966; 133: 90−116.
18. Stewart PA. Independent and dependent variables of acid-base control. Respir Physiol 1978; 33: 9−26.
19. Stewart PA. Modern quantitative acid-base chemistry. Can J Physiol Pharmacol 1983; 61: 1444−1461.
20. Fencl V, Rossing TH. Acid-base disorders in critical care medicine. Ann Rev Med 1989; 40: 17−29.
21. Fencl V, Leith DE. Stewart´s quantitative acid-base chemistry: applications in biology and medicine. Respir Physiol 1993; 91: 1−16.
22. Fencl V et al. Diagnosis of acid-base disturbances in critically ill patients. Am J Respir Crit Care 2000; 162: 2246−2251.
23. Boyle M, Baldwin I. Introduction to an alternative view of acid/base balance: the strong ion difference or Stewart approach. Aust Crit Care 1987; 15: 14–20.
24. Corey HE. Stewart and beyond: New models of acid-base balance. Kidney Int 2003; 64: 777−787.
25. Wooten EW. Science review: quantitative acid-base physiology using the Stewart model. Crit Care 2004; 8: 448−452.
26. Sirker AA et al. Acid-base physiology: the 'traditional' and the 'modern' approaches. Anaesthesia 2002; 57: 348−356.
27. Kurtz I et al. Acid-base analysis: a critique of the Stewart and bicarbonate-centered approaches. Am J Physiol Renal Physiol 2008; 294: F1009−F1031.
28. Kellum JA. Clinical review: reunification of acid-base physiology. Crit Care 2005; 9: 500−507.
29. Matoušovic K, Martínek V, Kvapil M. Acidobazická rovnováha tělesných tekutin a její kvantitativní, fyzikálně chemické hodnocení. Aktuality v nefrologii 2002; 8: 150−156.
30. Matoušovic K, Martínek V. Analýza a korekce poruch acidobazické rovnováhy na základě Stewartova-Fenclova principu. Vnitř Lék 2004, 50: 526−530.
31. Havlín J et al. Patofyziologie metabolické acidózy u pacientů se sníženou glomerulární filtrací podle Stewartovy- Fenclovy teorie. Vnitř Lék 2009; 55: 97−104.
32. Havlín J et al. The use of sodium-chloride difference and chloride-sodium ratio in the evaluation of metabolic acidosis in critically ill patients. Eur J Pediatr 2012; 171: 1719.
33. Havlín J. Vztah mezi pH a diferencí silných iontů (SID) ve vnitřním prostředí u pacientů s chronickým ledvinným onemocněním v predialyzačním stadiu a při chronické dialýze. Disertační práce. Univerzita Karlova, Praha, 2015.
34. Kellum JA et al. Etiology of metabolic acidosis during saline resuscitation in endotoxemia. Shock 1998; 9 : 364−368.
35. Scheingraber S et al. Rapid saline infusion produces hyperchloremic acidosis in patients undergoing gynecologic surgery. Anestesiology 1999; 90: 1265−1270.
36. Rastegar A. Clinical utility of Stewart's method in diagnosis and management of acid-base disorders. Clin J Am Soc Nephrol 2009; 4: 1267−1274.
37. Dubin A et al. Comparison of three different methods of evaluation of metabolic acid-base disorders. Crit Care Med 2007; 35: 1264−1270.
38. Doberer D et al. A critique of Stewart's approach: the chemical mechanism of dilutional acidosis. Intensive Care Med 2009; 35: 2173−2180.
39. Mallat J et al. Use of sodium-chloride difference and corrected anion gap as surrogates of Stewart variables in critically ill patients. PLoS One 2013; 8: e56635.
40. Kurt A et al. The use of cloride-sodium ratio in the evaluation om metabolic acidosis in critically ill neonates. Eur J Pediatr 2012, 171: 963−969.
41. Opatrná S et al. Importance of serum [Na+] and [Cl-] difference in acid-base status classification. Anesthesia-Analgesia 2010; 111: 243.
42. Shaer AJ. Inherited primary renal tubular hypokalemic alkalosis: a review of Gitelman and Bartter syndromes. Am J Med Sci 2001; 322: 316−332.
43. Kříž J, Schück O, Horáčková M. Reply 'Hyponatremia in spinal cord injury patients: new insight into differentiating between the dilution and depletion forms'. Spinal Cord 2015; 53: 896.
44. 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: 62−70.
45. Wilkes P. Hypoproteinemia, strong ion difference, and acid-base status in critically ill patients. J Appl Physiol 1998; 84: 1740−1748.
46. Schück O, Matoušovic K. Vztah mezi pH a diferencí silných iontů (SID) ve vnitřním prostředí. Klin Biochem Metab 2005; 34: 32−35.
47. Schück O, Matoušovic K. Relation between pH and the strong ion difference (SID) in body fluids. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2005; 149: 69−73.
48. Seifter JL. Integration of acid-base and electrolyte disorders. N Engl J Med 2014; 371: 1821−1831.
49. Kofránek J. Komplexní model acidobazické rovnováhy. In: Milena Zeithamlová (ed.). MEDSOFT 2009. Agentura Action M, Praha, 2008, s. 23−60.
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