The effects of the chloride:sodium ratio on acid-base statusand mortality in septic patients.

BACKGROUND/AIM: Calculation of the chloride:sodium (Cl- :Na+ ) ratio is proposed to enable a quick evaluation of the effect of Cl- and Na+ on the acid-base balance in critically ill patients. In the present study, the relationship of the Cl- :Na+ ratio of septic patients with acid-base status and ICU mortality were investigated.

MATERIALS AND METHODS: In our two-center study, 434 patients who were diagnosed with sepsis were included. The patients were divided into three groups: low (<0.75), normal (≥0.75, <0.80), and high (≥0.80) Cl- :Na+ ratio groups. Patients' demographic data, blood gas values, length of ICU stay, and ICU mortality were recorded.

RESULTS: In the low and high groups, ICU mortality was significantly higher than in the normal group (29.3%, 37.1%) (P = 0.005). There was a negative correlation between the Cl:Na+ ratio and each of HCO3 - , standard base excess, and PaCO2 (r2 = 0.21, r2 = 0.19, and r2 = 0.17) (P < 0.001 for each). In the multivariate analysis, the ICU mortality was increased 2.6-fold (1.2-5.8) by low Cl- :Na+ ratio (P = 0.019).

CONCLUSION: The Cl- :Na+ ratio is a useful parameter for showing the relationship between Cl- and Na+ and their impact on acid-base status. Low Cl- :Na+ ratio at ICU admission can be used as a prognostic indicator for increased ICU mortality in septic patients.