Skip to main content

The strong ion gap and outcome after cardiac arrest in patients treated with therapeutic hypothermia: a retrospective study

Intensive Care Medicine volume 35, pages 232–239 (2009)Cite this article

Abstract

Objective

This study investigates whether the strong ion gap (SIG) is associated with long-term outcome after cardiac arrest in patients treated with therapeutic hypothermia. The hypothesis of the study was that an elevated SIG was associated with unfavourable outcome after cardiac arrest.

Design

Retrospective review of records from 1995 to 2007 of patients who received cardiopulmonary resuscitation.

Setting

Emergency department of a university hospital.

Patients

Patients who were successfully resuscitated after cardiac arrest (n = 288) and treated with mild therapeutic hypothermia.

Interventions

None.

Measurements and results

Acid–base variables were calculated according to Stewart’s approach, as modified by Figge and Fencl, and were determined immediately on admission and 12 h after the return of spontaneous circulation. Acid–base variables were determined at 37°C and are reported without correction for patient temperature. Differences in SIG were compared between patients with favourable (survival 6 months with cerebral performance category 1 or 2) and unfavourable outcomes.

SIG on admission and 12 h after return of spontaneous circulation was higher in patients with unfavourable outcome (n = 151; 52%). SIG 12 h after return of spontaneous circulation was identified as an independent predictor of outcome. A SIG > 8.9 mmol/L was associated with an increased cumulative hazard of death.

Conclusions

An elevated SIG 12 h after return of spontaneous circulation may be associated with unfavourable outcome in patients after cardiac arrest treated with mild therapeutic hypothermia. The unmeasured anions hidden behind an elevated SIG may represent markers of tissue damage.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

43,34 €

Price includes VAT (Finland)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2

References

  1. Figge J, Mydosh T, Fencl V (1992) Serum proteins and acid–base equilibria: a follow-up. J Lab Clin Med 120:713–719

    PubMed  CAS  Google Scholar 

  2. Gunnerson KJ (2005) Clinical review: the meaning of Acid–base abnormalities in the intensive care unit part I—epidemiology. Crit Care 9:508–516

    PubMed  Article  Google Scholar 

  3. Makino J, Uchino S, Morimatsu H, Bellomo R (2005) A quantitative analysis of the acidosis of cardiac arrest: a prospective observational study. Crit Care 9:R357–R362

    PubMed  Article  Google Scholar 

  4. Balasubramanyan N, Havens PL, Hoffman GM (1999) Unmeasured anions identified by the Fencl–Stewart method predict mortality better than base excess, anion gap, and lactate in patients in the pediatric intensive care unit. Crit Care Med 27:1577–1581

    PubMed  Article  CAS  Google Scholar 

  5. Dondorp AM, Chau TT, Phu NH, Mai NT, Loc PP, Chuong LV, Sinh DX, Taylor A, Hien TT, White NJ, Day NP (2004) Unidentified acids of strong prognostic significance in severe malaria. Crit Care Med 32:1683–1688

    PubMed  Article  CAS  Google Scholar 

  6. Kaplan LJ, Kellum JA (2004) Initial pH, base deficit, lactate, anion gap, strong ion difference, and strong ion gap predict outcome from major vascular injury. Crit Care Med 32:1120–1124

    PubMed  Article  CAS  Google Scholar 

  7. Cummins RO, Chamberlain DA, Abramson NS, Allen M, Baskett PJ, Becker L, Bossaert L, Delooz HH, Dick WF, Eisenberg MS (1991) Recommended guidelines for uniform reporting of data from out-of-hospital cardiac arrest: the Utstein Style. A statement for health professionals from a task force of the American Heart Association, the European Resuscitation Council, the Heart and Stroke Foundation of Canada, and the Australian Resuscitation Council. Circulation 84:960–975

    PubMed  CAS  Google Scholar 

  8. Eisenburger P, List M, Schorkhuber W, Walker R, Sterz F, Laggner AN (1998) Long-term cardiac arrest survivors of the Vienna emergency medical service. Resuscitation 38:137–143

    PubMed  Article  CAS  Google Scholar 

  9. Bur A, Mullner M, Sterz F, Hirschl MM, Laggner AN (1997) The emergency department in a 2000-bed teaching hospital: saving open ward and intensive care facilities. Eur J Emerg Med 4:19–23

    PubMed  CAS  Google Scholar 

  10. (2000) Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 102:I1-I384

  11. Arabi Y, Ahmed QA, Haddad S, Aljumah A, Al-Shimemeri A (2004) Outcome predictors of cirrhosis patients admitted to the intensive care unit. Eur J Gastroenterol Hepatol 16:333–339

    PubMed  Article  Google Scholar 

  12. (2002) Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest. N Engl J Med 346:549–556

  13. Holzer M, Janata A, Haugk M, Krizanac D, Sterz F (2007) Efficacy and safety of a novel rapid non-invasive surface cooling device for induction of therapeutic hypothermia in patients after cardiac arrest. Resuscitation 116:930

    Google Scholar 

  14. Uray T, Wandaller C, Holzer M, Sterz F, Haugk M, Kliegel A, Losert H, Laggner A (2006) Selective head and collar cooling after cardiac arrest in humans: a feasibility study. Resuscitation 69:147

    Google Scholar 

  15. Haugk M, Sterz F, Grassberger M, Uray T, Kliegel A, Janata A, Richling N, Herkner H, Laggner AN (2007) Feasibility and efficacy of a new non-invasive surface cooling device in post-resuscitation intensive care medicine. Resuscitation 75:76–81

    PubMed  Article  Google Scholar 

  16. Uray T, Malzer R (2008) Out-of-hospital surface cooling to induce mild hypothermia in human cardiac arrest: a feasibility trial. Resuscitation 77:331–338

    PubMed  Article  Google Scholar 

  17. Kliegel A, Losert H, Sterz F, Kliegel M, Holzer M, Uray T, Domanovits H (2005) Cold simple intravenous infusions preceding special endovascular cooling for faster induction of mild hypothermia after cardiac arrest—a feasibility study. Resuscitation 64:347–351

    PubMed  Article  Google Scholar 

  18. Kliegel A, Janata A, Wandaller C, Uray T, Spiel A, Losert H, Kliegel M, Holzer M, Haugk M, Sterz F, Laggner AN (2007) Cold infusions alone are effective for induction of therapeutic hypothermia but do not keep patients cool after cardiac arrest. Resuscitation 73:46–53

    PubMed  Article  Google Scholar 

  19. Holzer M, Mullner M, Sterz F, Robak O, Kliegel A, Losert H, Sodeck G, Uray T, Zeiner A, Laggner AN (2006) Efficacy and safety of endovascular cooling after cardiac arrest: cohort study and Bayesian approach. Stroke 37:1792–1797

    PubMed  Article  Google Scholar 

  20. Safar P, Bircher N (1988) Cardiopulmonary cerebral resuscitation: guidelines by the World Federation of Societies of Anesthesiologists (WFSA). Saunders, Philadelphia

    Google Scholar 

  21. Eisenburger P, Sterz F, Haugk M, Scheinecker W, Holzer M, Koreny M, Kaff A, Laggner A, Herkner H (2006) Cardiac arrest in public locations—an independent predictor for better outcome? Resuscitation 70:395–403

    PubMed  Article  Google Scholar 

  22. Siggaard-Andersen O, Wimberley PD, Fogh-Andersen N, Gøthgen IH (1988) Measured and derived quantities with modern pH and blood gas equipment: calculation alorithms with 54 equations. Scand J Clin Lab Invest Suppl 48:7–15

    Article  Google Scholar 

  23. Stewart PA (1983) Modern quantitative acid–base chemistry. Can J Physiol Pharmacol 61:1444–1461

    PubMed  CAS  Google Scholar 

  24. Bland M (2003) Clinical measurement an introduction to medical statistics. Oxford University Press Inc, New York, pp 268–293

    Google Scholar 

  25. Donnino MW, Miller J, Goyal N, Loomba M, Sankey SS, Dolcourt B, Sherwin R, Otero R, Wira C (2007) Effective lactate clearance is associated with improved outcome in post-cardiac arrest patients. Resuscitation 75:229–234

    PubMed  Article  CAS  Google Scholar 

  26. Mitchell H Katz (2006) Relationship of independent variables to another. In: Mitchell H Katz (ed) Multivariable analysis. Cambridge University Press, Cambridge, pp 68–72

  27. De BD (2003) Lactic acidosis. Intensive Care Med 29:699–702

    Google Scholar 

  28. Dueck MH, Paul M, Wiesner RH, Boerner U (2004) Why does blood have a pH-value of 7.4? The theory of acid–base management. Anaesthesist 53:1046–1053

    PubMed  Article  CAS  Google Scholar 

  29. Forni LG, McKinnon W, Lord GA, Treacher DF, Peron JM, Hilton PJ (2005) Circulating anions usually associated with the Krebs cycle in patients with metabolic acidosis. Crit Care 9:R591–R595

    PubMed  Article  Google Scholar 

  30. Kellum JA, Bellomo R, Kramer DJ, Pinsky MR (1995) Hepatic anion flux during acute endotoxemia. J Appl Physiol 78:2212–2217

    PubMed  CAS  Google Scholar 

  31. Kneidinger N, Lindner G, Fuhrmann V, Doberer D, Dunkler D, Schneeweiss B, Funk GC (2007) Acute phase proteins do not account for unmeasured anions in critical illness. Eur J Clin Invest 37:820–825

    PubMed  Article  CAS  Google Scholar 

  32. Hayhoe M, Bellomo R, Liu G, McNicol L, Buxton B (1999) The aetiology and pathogenesis of cardiopulmonary bypass-associated metabolic acidosis using polygeline pump prime. Intensive Care Med 25:680–685

    PubMed  Article  CAS  Google Scholar 

  33. Hilton PJ, McKinnon W, Lord GA, Peron JM, Forni LG (2006) Unexplained acidosis of malnutrition: a study by ion-exchange chromatography/mass spectrometry. Biomed Chromatogr 20:1386–1389

    PubMed  Article  CAS  Google Scholar 

  34. McKinnon W, Pentecost C, Lord GA, Forni LG, Peron JM, Hilton PJ (2007) Elevation of anions in exercise-induced acidosis: a study by ion-exchange chromatography/mass spectrometry. Biomed Chromatogr 22:301–305

    Article  Google Scholar 

Download references

Acknowledgments

The authors thank Peter Straganz for his help in data abstraction.

Conflict of interest statement

No financial support, including any institutional departmental funds, has been used for this study.

Author information

Affiliations

  1. Department of Respiratory and Critical Care Medicine, Otto Wagner Spital, Vienna, Austria

    Georg-Christian Funk

  2. Department of Clinical Pharmacology, Medical University of Vienna, Allgemeines Krankenhaus, Vienna, Austria

    Daniel Doberer

  3. Emergency Medicine, Medical University of Vienna, Allgemeines Krankenhaus, Vienna, Austria

    Fritz Sterz, Nina Richling & Philip Eisenburger

  4. Internal Medicine III, Intensive Care Unit 13H1, Medical University of Vienna, Allgemeines Krankenhaus, Vienna, Austria

    Nikolaus Kneidinger & Bruno Schneeweiss

  5. Intensive Care Unit 13I3, Medical University of Vienna, Allgemeines Krankenhaus, Vienna, Austria

    Gregor Lindner

  6. Universitätsklinik für Notfallmedizin, Medizinische Universität Wien, Währinger Gürtel 18–20/6D, 1090, Vienna, Austria

    Fritz Sterz

Authors
  1. Georg-Christian Funk
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Daniel Doberer
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Fritz Sterz
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Nina Richling
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Nikolaus Kneidinger
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Gregor Lindner
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Bruno Schneeweiss
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Philip Eisenburger
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Fritz Sterz.

Additional information

This article is discussed in the editorial available at: doi:10.1007/s00134-008-1316-0.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Funk, GC., Doberer, D., Sterz, F. et al. The strong ion gap and outcome after cardiac arrest in patients treated with therapeutic hypothermia: a retrospective study. Intensive Care Med 35, 232–239 (2009). https://doi.org/10.1007/s00134-008-1315-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00134-008-1315-1

Keywords

  • Acidosis
  • Lactate
  • Cardiopulmonary resuscitation
  • Hypothermia
  • Anion gap
  • Outcome