Sodium Homeostasis and Its Correlation with Mortality in Critically Ill Patients ??? A Retrospective Study in Northeast India

Author(s): Sreemanta Madhab Baruah1, Rashmi Rajkakati2, Trinayani Barua3, John Kumar Das4, Hiranya Saikia5

Sodium is the most common electrolyte that gets imbalanced in hospitalised
patients. Serum sodium abnormalities carry unacceptably high mortality. Our main
objective was to study sodium homeostasis in critically ill patients and to correlate
sodium imbalances with mortality in critically ill patients.
This was a hospital based retrospective study conducted in Medicine Intensive
Care Unit in Assam Medical College and Hospital in Dibrugarh, Assam, India, over
a period of one year i.e., from February 2019 to January 2020. Hyponatremia has
been defined as sodium level < 135mmol / L and hypernatremia as > 145mmol/L.
All patients admitted in MICU of 12 years of age or more have been included in
this study. Investigations such as serum creatinine, BUN, sodium, serum
osmolality, urine sodium, and urine osmolality as well as neuroimaging were done.
A total of 410 patients were studied.
Out of 410 patients, 106 (25.8 %) had hypernatremia, 84 (20.48 %) had
hyponatremia and 220 (53.65 %) had normal sodium levels. 225 (54.87 %)
patients died. There was a statistically significant correlation between sodium
imbalance and death (p < 0.05). Mortality in hypernatremia (88.68%) was slightly
higher than hyponatremia (79.34 %). It was observed that mortality in
hypernatremia (OR = 20.7989, 95% CI: 10.6170 – 40.7454, p < 0.0001) and
hyponatremia (OR = 10.2015, 95% CI: 5.6651 – 18.3704, p < 0.0001) were higher
than that of normonatremia. Percentage of death was more in hypernatremia
(88.68%) than hyponatremia (79.34%), but the difference was not statistically
significant. (OR = 2.0388, 95% CI = 0.9302 to 4.4687, p = 0.0752).
Hyponatremia and hypernatremia are independent mortality factors in critically ill
patients. Hypernatremia was more prevalent than hyponatremia in our study and
accounted for more number of deaths. Timely and effective correction of sodium
levels is important to save a patient’s life. Hypernatremia is often iatrogenic.
Therefore proper monitoring of sodium is a must.