Abstract

Objective:

The diagnosis and treatment of electrolyte and acid-base imbalances in intensive care unit (ICU) patients have critical importance. The value of Stewart’s approach in revealing acid-base disorders is known. There are parameters defined according to this approach. This study investigates the impact of the chloride effect (ClEffect), sodium effect (NaEffect), sodium-chloride effect (Na-ClEffect), strong ion difference (SIDnl) and Cl/Na ratio values calculated according to Stewart’s approach on ICU mortality.

Materials and Methods:

Two thousand patients whose Na, Cl, K, standard base excess (SBE), pH values were recorded and SIDnl, ClEffect, NaEffect, Na-ClEffect, Acute Physiology Assessment and Chronic Health Evaluation-II (APACHE-II) and Sequential Organ Failure Assessment (SOFA) scores calculated are included in this study. ClEffect, NaEffect, Na-ClEffect, SIDnl, Cl/Na ratio values were evaluated with a multivariable logistic regression model in terms of ICU mortality.

Results:

Abnormal ranges of SIDnl (SIDnl <30 or SIDnl ≥43) were significantly increased in non-survivors than survivors (p=0.026). ClEffect, NaEffect, Na-ClEffect, Cl/Na ratio and their percentages of abnormal ranges were similar between survivor and non-survivor patients.In the multivariate logistic regression model, the likelihood of mortality was 3.5-fold (2.9-4.3), 1.7-fold (1.4-2.1) and 1.2-fold (1.0-1.5) increased by APACHE-II ≥26, SOFA >7, and SIDnl <30 or SIDnl ≥43 (p<0.001, p<0.001, p=0.041, respectively).

Conclusion:

SIDnl is associated with ICU mortality, but pH, SBE, ClEffect, NaEffect, Na-ClEffect and Cl/Na ratio is not. SIDnl is one of the independent variables of Stewart’s approach and is a valuable parameter in blood gas evaluations.

Keywords: Acid-base, strong ion difference, sodium, chloride, base excess, intensive care unit, mortality

References

  1. Gunnerson KJ, Kellum JA. Acid-base and electrolyte analysis in critically ill patients: are we ready for the new millennium? Curr Opin Crit Care 2003;9:468-73.
  2. Zanella A, Langer T, Caironi P, Gattinoni L, Pesenti A. Reply by Zanella et al. to Swenson. Am J Respir Crit Care Med 2020;202:908-9.
  3. Moviat M, van den Boogaard M, Intven F, van der Voort P, van der Hoeven H, Pickkers P. Stewart analysis of apparently normal acid-base state in the critically ill. J Crit Care 2013;28:1048-54.
  4. Dubin A, Menises MM, Masevicius FD, Moseinco MC, Kutscherauer DO, Ventrice E, et al. Comparison of three different methods of evaluation of metabolic acid-base disorders. Crit Care Med 2007;35:1264-70.
  5. Cove M, Kellum JA. The end of the bicarbonate era? A therapeutic application of the Stewart approach. Am J Respir Crit Care Med 2020;201:757-8.
  6. Gilfix BM, Bique M, Magder S. A physical chemical approach to the analysis of acid-base balance in the clinical setting. J Crit Care 1993;8:187-97.
  7. 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;162:2246-51.
  8. Magder S, Emami A. Practical approach to physical-chemical acid-base management. Stewart at the bedside. Ann Am Thorac Soc 2015;12:111-7.
  9. Story DA. Stewart acid-base: a simplified bedside approach. Anesth Analg 2016;123:511-5.
  10. Gucyetmez B, Atalan HK. Non-lactate strong ion difference: a clearer picture. J Anesth 2016;30:391-6.
  11. Schork A, Moll K, Haap M, Riessen R, Wagner R. Course of lactate, pH and base excess for prediction of mortality in medical intensive care patients. PLoS One 2021;16:e0261564.
  12. de Meneses FA, Bezerra I, Ribeiro E, Furtado AH Junior, Peixoto AA Junior. Base excess and early mortality in patients admitted to the general intensive care unit at a university hospital in Fortaleza. Crit Care 2007;11(Suppl 3):P13.
  13. Azevedo L, Park M, Sanga R, Ferreira G, Palma L, Brauer L, et al. Base excess and lactate as predictors of mortality in medical ICU patients. Crit Care 2004;8(Suppl 1):P328.
  14. Palma L, Ferreira G, Amaral A, Brauer L, Azevedo LCP, Park M. Acidosis and mortality in severe sepsis and septic shock evaluated by base excess variation. Crit Care 2003;7(Suppl 3):P39.
  15. Alevrakis E, Gialelis N, Vasileiadis I. Strong ion difference in urine: A measure of proton excretion or of the net plasma charge alteration? Acta Physiol (Oxf) 2020;230:e13559.
  16. Bie P. Strong ion difference: Inconsistencies lining up. Acta Physiol (Oxf) 2021;232:e13616.
  17. Vasileiadis I, Alevrakis E, Gialelis N. Stewart’s approach: just a heresy or another lens into acid-base physiology? Acta Physiol (Oxf) 2021;232:e13622.
  18. Bie P. Strong ion difference: questionable stewardship. Acta Physiol (Oxf) 2021;233:e13667.
  19. Janssen JW, van Fessem JMK, Ris T, Stolker RJ, Klimek M. The hidden secrets of a neutral pH-blood gas analysis of postoperative patients according to the Stewart approach. Perioper Med (Lond) 2021;10:15.
  20. Berndtson AE, Palmieri TL, Greenhalgh DG, Sen S. Strong ion difference and gap predict outcomes after adult burn injury. J Trauma and Acute Care Surg 2013;75:555-60; discussion 560-1.
  21. 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;32:1120-4.
  22. Atalan HK, Güçyetmez B. The effects of the chloride:sodium ratio on acid-base statusand mortality in septic patients. Turk J Med Sci 2017;47:435-42.
  23. Gucyetmez B, Tuzuner F, Atalan HK, Sezerman U, Gucyetmez K, Telci L. Base-excess chloride; the best approach to evaluate the effect of chloride on the acid-base status: A retrospective study. PLoS One 2021;16:e0250274.
  24. Stewart PA. Modern quantitative acid-base chemistry. Can J Physiol Pharmacol 1983;61:1444-61.
  25. Gharipour A, Razavi R, Gharipour M, Modarres R, Nezafati P, Mirkheshti N. The incidence and outcome of severe hyperlactatemia in critically ill patients. Intern Emerg Med 2021;16:115-23.
  26. Haas SA, Lange T, Saugel B, Petzoldt M, Fuhrmann V, Metschke M, et al. Severe hyperlactatemia, lactate clearance and mortality in unselected critically ill patients. Intensive Care Med 2016;42:202-10.
  27. Ferreruela M, Raurich JM, Ayestarán I, Llompart-Pou JA. Hyperlactatemia in ICU patients: Incidence, causes and associated mortality. J Crit Care 2017;42:200-5.
  28. Rishu AH, Khan R, Al-Dorzi HM, Tamim HM, Al-Qahtani S, Al-Ghamdi G, et al. Even mild hyperlactatemia is associated with increased mortality in critically ill patients. Critic Care 2013;17:R197.
  29. Naved SA, Siddiqui S, Khan FH. APACHE-II score correlation with mortality and length of stay in an intensive care unit. J Coll Physicians Surg Pak 2011;21:4-8.
  30. Ho KM. Combining sequential organ failure assessment (SOFA) score with acute physiology and chronic health evaluation (APACHE) II score to predict hospital mortality of critically Ill patients. Anaesth Intensive Care 2007;35:515-21.
  31. Raith EP, Udy AA, Bailey M, McGloughlin S, MacIsaac C, Bellomo R, et al. Prognostic Accuracy of the SOFA Score, SIRS Criteria, and qSOFA Score for In-Hospital Mortality Among Adults With Suspected Infection Admitted to the Intensive Care Unit. JAMA 2017;317:290-300.

Copyright and license

Copyright © 2023 The Author(s). This is an open access article distributed under the Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium or format, provided the original work is properly cited.

How to cite?

1.
Tontu F, Aşar S, Ören Bilgin B, Yıldız GÖ, Arslan Tontu K, Çukurova Z. Stewart’s Approach for Acid-base Disorders: Does the Strong Ion Difference and Effects Have an Impact on Intensive Care Unit Mortality?. Turk J Intensive Care. 2023;21(1):25-32. https://doi.org/10.4274/tybd.galenos.2022.83007