Influence of Early Dysnatremia Correction on Survival of Critically Ill Patients

International audience; BACKGROUND: Increasing evidence suggests that dysnatraemia at ICU admission may predict mortality. Little information is available, however, on the potential effect of dysnatraemia correction.Patients and MethodsObservational multicentre cohort study in patients admitted between 2005 and 2012 to 18 French ICUs. Hyponatraemia and hypernatraemia were defined as serum sodium concentration < 135 and > 145 mmoL/L, respectively. We assessed the influence on day-28 mortality of dysnatraemia correction by day 3 and of the dysnatraemia correction rate. RESULTS: Of 7067 included patients, 1830 (25.9%) had hyponatraemia and 634 (9.0%) hypernatraemia at ICU admission (day 1). By day 3, hyponatraemia had been corrected in 1019 (1019/1830, 55.7%) and hypernatraemia in 393 (393/634, 62.0%) patients. After adjustment for confounders, persistent hyponatraemia or hypernatraemia on day 3 was independently associated with higher day-28 mortality (odds ratio [OR], 1.31; 95% confidence interval [95%CI], 1.06-1.61; and OR, 1.86; 95%CI, 1.37-2.54; respectively). Hyponatraemia corrected by day 3, hypernatraemia corrected by day 3, and ICU-acquired hyponatraemia were not associated with day-28 mortality. Median correction rate from days 1 to 3 was 2.58 mmoL/L per day (IQR, 0.67-4.55). Higher natraemia correction rate was associated with lower crude and adjusted day-28 mortality rates (OR per mmoL/L per day, 0.97; 95%CI, 0.94-1.00; p = 0.04; and OR per mmoL/L per day, 0.93; 95%CI, 0.90-0.97; p = 0.0003, respectively). CONCLUSION: Our results indicate that dysnatraemia correction is independently associated with survival, with the effect being greater with faster correction rates of up to 12 mmoL/L/day.