Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2021 Dec 1;49(12):2070-2079.
doi: 10.1097/CCM.0000000000005173.

Association Between an Increase in Serum Sodium and In-Hospital Mortality in Critically Ill Patients

Chloe C A Grim  1 , Fabian Termorshuizen  2 , Robert J Bosman  3 , Olaf L Cremer  4 , Arend Jan Meinders  5 , Maarten W N Nijsten  6 , Peter Pickkers  7 , Angelique M E de Man  8 , Marcus J Schultz  9 , Peter van Vliet  10 , Joachim D Weigel  1 , Hendrik J F Helmerhorst  1 , Nicolette F de Keizer  2 , Evert de Jonge  1
Affiliations
Observational Study

Association Between an Increase in Serum Sodium and In-Hospital Mortality in Critically Ill Patients

Chloe C A Grim et al. Crit Care Med. .

Abstract

Objectives: In critically ill patients, dysnatremia is common, and in these patients, in-hospital mortality is higher. It remains unknown whether changes of serum sodium after ICU admission affect mortality, especially whether normalization of mild hyponatremia improves survival.

Design: Retrospective cohort study.

Setting: Ten Dutch ICUs between January 2011 and April 2017.

Patients: Adult patients were included if at least one serum sodium measurement within 24 hours of ICU admission and at least one serum sodium measurement 24-48 hours after ICU admission were available.

Interventions: None.

Measurements and main results: A logistic regression model adjusted for age, sex, and Acute Physiology and Chronic Health Evaluation-IV-predicted mortality was used to assess the difference between mean of sodium measurements 24-48 hours after ICU admission and first serum sodium measurement at ICU admission (Δ48 hr-[Na]) and in-hospital mortality. In total, 36,660 patients were included for analysis. An increase in serum sodium was independently associated with a higher risk of in-hospital mortality in patients admitted with normonatremia (Δ48 hr-[Na] 5-10 mmol/L odds ratio: 1.61 [1.44-1.79], Δ48 hr-[Na] > 10 mmol/L odds ratio: 4.10 [3.20-5.24]) and hypernatremia (Δ48 hr-[Na] 5-10 mmol/L odds ratio: 1.47 [1.02-2.14], Δ48 hr-[Na] > 10 mmol/L odds ratio: 8.46 [3.31-21.64]). In patients admitted with mild hyponatremia and Δ48 hr-[Na] greater than 5 mmol/L, no significant difference in hospital mortality was found (odds ratio, 1.11 [0.99-1.25]).

Conclusions: An increase in serum sodium in the first 48 hours of ICU admission was associated with higher in-hospital mortality in patients admitted with normonatremia and in patients admitted with hypernatremia.

PubMed Disclaimer

Conflict of interest statement

Drs. Termorshuizen’s and de Keizer’s institutions received funding from the National Intensive Care Evaluation Foundation. Dr. Termorshuizen received funding from the Mental Health Care Institute, Rivierduinen, Leiden. The remaining authors have disclosed that they do not have any potential conflicts of interest.

Figures

Figure 1.
Figure 1.
Association between in-hospital mortality and Δ48 hr-[Na] for ICU patients categorized by first serum sodium measurement at ICU admission. The adjusted odds ratios (ORs) for risk of in-hospital mortality using logistic regression. Adjusted for age, sex, and Acute Physiology and Chronic Health Evaluation-IV predicted mortality. Δ48 hr-[Na] of –5 to 5 mmol/L was used as reference category. Δ48 hr-[Na] = difference between mean of sodium measurements 24–48 hr after ICU admission and first serum sodium at admission in mmol/L.
Figure 2.
Figure 2.
Association between in-hospital mortality and Vmax-Δ[Na] for ICU patients categorized by first serum sodium measurement at ICU admission. The adjusted odds ratios (ORs) for risk of in-hospital mortality using logistic regression. Adjusted for age, sex, and Acute Physiology and Chronic Health Evaluation-IV predicted mortality. Vmax-Δ[Na] of –2.5 to 2.5 mmol/L/d was used as reference category. Vmax-Δ[Na] = the difference in serum sodium at admission and a sodium measurement within 48 hr after admission, divided by the time between these two measurements, maximum velocity is the highest velocity of all pairs of measurements in a patient in mmol/L/24 hr.
See this image and copyright information in PMC

Comment in

References

    1. Darmon M, Diconne E, Souweine B, et al. . Prognostic consequences of borderline dysnatremia: Pay attention to minimal serum sodium change. Crit Care. 2013; 17:R12. - PMC - PubMed
    1. Dasta J, Waikar SS, Xie L, et al. . Patterns of treatment and correction of hyponatremia in intensive care unit patients. J Crit Care. 2015; 30:1072–1079 - PubMed
    1. Sakr Y, Rother S, Ferreira AM, et al. . Fluctuations in serum sodium level are associated with an increased risk of death in surgical ICU patients. Crit Care Med. 2013; 41:133–142 - PubMed
    1. Pokaharel M, Block CA. Dysnatremia in the ICU. Curr Opin Crit Care. 2011; 17:581–593 - PubMed
    1. Oude Lansink-Hartgring A, Hessels L, Weigel J, et al. . Long-term changes in dysnatremia incidence in the ICU: A shift from hyponatremia to hypernatremia. Ann Intensive Care. 2016; 6:22. - PMC - PubMed

Publication types

MeSH terms