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Critical Care

Open Access

Cl:Na ratio on ICU admission as a prognostic indicator of mortality in sepsis patients

  • HK Atalan1,
  • B Gucyetmez2 and
  • N Cakar3
Critical Care201418(Suppl 1):P230

Published: 17 March 2014


The aim of the study is to investigate the relationship between Cl:Na ratio disturbances and mortality in sepsis patients. Stewart's strong ion theory can be used in the interpretations of acid- base abnormalities [1]. The Cl:Na ratio is a simple alternative test that obviates the need to solve the complex strong ion gap (SIG) equations[2].


A total of 434 sepsis and severe sepsis patients hospitalized in the ICU of two centers between 2006 and 2012 were included in the study. Three groups were formed as patients having low (<0.75), normal (>0.75 to <0.80) and high (<0.80) Cl:Na ratio within the first 24 hours in the ICU. Patients' age, gender, APACHE II score, SOFA score, pH, PaCO2, HCO3, base excess, Na, K, Cl, Ca, lactate, strong ion difference, anion gap, length of ICU stay and mortality were recorded. Logistic regression analysis was used to calculate odd ratios and 95% CIs for the association of Cl:Na with mortality. In the fully adjusted model, pH, BE, AG, lactate and Cl:Na ratio were entered into the model. P < 0.05 was considered statistically significant.


The distribution of the patients was as follows: low Cl:Na (75, 17%), normal Cl:Na (243, 56%), high Cl:Na (116, 27%). Univariate analysis revealed that in low and high Cl:Na ratio patients, mortality was higher by 1.56-fold (0.87 to 2.81) and 2.22-fold (1.36 to 3.61) (P = 0.135 and P < 0.01). In multivariate analysis, increased mortality by 1.95-fold (0.92 to 4.12) and 2.02-fold (1.01 to 4.03) was found in low and high Cl:Na ratios (P = 0.081 and P = 0.046) (Figure 1).
Figure 1

In the multivariate model, effect of Cl:Na ratio group was adjusted for pH, lactate, anion gap and base excess.


Stewart's strong ion theory provides assessment for the etiology of acid-base disturbances. This evaluation can be performed easier and faster with the Cl:Na ratio. This study demonstrates that the disturbed Cl:Na ratio is associated with increased mortality in sepsis and severe sepsis patient groups.

Authors’ Affiliations

Atasehir Memorial Hospital, Istanbul, Turkey
International Hospital, Istanbul, Turkey
Istanbul Medical Faculty, Istanbul, Turkey


  1. Stewart PA: Can J Physiol Pharmacol. 1983, 61: 1441-1461.View ArticleGoogle Scholar
  2. Durward A, et al.: Intensive Care Med. 2001, 5: 828-835.View ArticleGoogle Scholar


© Atalan et al.; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.