Risk factors for overcorrection of severe hyponatremia: a post hoc analysis of the SALSA trial

Abstract

Background: Hyponatremia overcorrection can result in irreversible neurologic impairment such as osmotic demyelination syndrome. Few prospective studies have identified patients undergoing hypertonic saline treatment with a high risk of hyponatremia overcorrection. Methods: We conducted a post hoc analysis of a multicenter, prospective randomized controlled study, the SALSA trial, in 178 patients aged above 18 years with symptomatic hyponatremia (mean age, 73.1 years; mean serum sodium level, 118.2 mEq/L). Overcorrection was defined as an increase in serum sodium levels by >12 or 18 mEq/L within 24 or 48 hours, respectively. Results: Among the 178 patients, 37 experienced hyponatremia overcorrection (20.8%), which was independently associated with initial serum sodium level (≤110, 110-115, 115-120, and 120-125 mEq/L with 7, 4, 2, and 0 points, respectively), chronic alcoholism (7 points), severe symptoms of hyponatremia (3 points), and initial potassium level (<3.0 mEq/L, 3 points). The NASK (hypoNatremia, Alcoholism, Severe symptoms, and hypoKalemia) score was derived from four risk factors for hyponatremia overcorrection and was significantly associated with overcorrection (odds ratio, 1.41; 95% confidence interval, 1.24-1.61; p < 0.01) with good discrimination (area under the receiver-operating characteristic [AUROC] curve, 0.76; 95% CI, 0.66-0.85; p < 0.01). The AUROC curve of the NASK score was statistically better compared with those of each risk factor. Conclusion: In treating patients with symptomatic hyponatremia, individuals with high hyponatremia overcorrection risks were predictable using a novel risk score summarizing baseline information.

Management for Electrolytes Disturbances during Continuous Renal Replacement Therapy

“…In patients with renal failure and severe hyponatremia, the initiation of CRRT can potentially result in a rapid correction of hyponatremia that increases the risk of osmotic demyelination syndrome 24) . The lower the initial sodium concentration, the higher risk of overcorrection 25) . If sodium concentration decreases by 2 or more within the first 6 hours after CRRT initiation, lowering the CRRT dose or sodium concentration of CRRT solution should be considered 21 26) .…”

Point‐of‐care ultrasound is a useful adjunct tool to a clinician's assessment in the evaluation of severe hyponatraemia

“…6 Both American and European hyponatraemia guidelines suggest bolus hypertonic saline use in symptomatic hyponatraemia patients, 2,7 but recent studies indicate dangerous sodium overcorrection trends in approximately a quarter of patients who received hypertonic saline. 8 Therefore, it is vital to accurately evaluate fluid status and appropriately manage to prevent morbidity/ mortality. Unfortunately, emergency hyponatraemia management in the initial hours of admission remains suboptimal due to (a) subjective physical examination/assessment, (b) biochemistry-focused international guidance, (c) delayed investigation turnover times in busy admission units and (d) over-enthusiastic bolus hypertonic saline use.…”

Overcorrection versus osmotic demyelination syndrome: what should we watch out for during management of symptomatic chronic hyponatremia?

“…In the SALSA (Efficacy and Safety of Rapid Intermittent Correction Compared With Slow Continuous Correction With Hypertonic Saline In Patients With Moderately Severe or Severe Symptomatic Hyponatremia) trial, a randomized clinical trial for management of symptomatic hyponatremia [ 1 ], overcorrection was defined as an increase in serum sodium level by >12 mEq/L or >18 mEq/L within the first 24 or 48 hours, respectively. As a post hoc analysis of the SALSA trial, in this issue, Yang et al [ 8 ] attempted to identify risk factors of overcorrection and to develop a new score called the NASK (hypoNatremia, Alcoholism, Severe symptoms, and hypoKalemia) score to calculate the probability of overcorrection during management of symptomatic hyponatremia. In this study, the variables that were included in the new score were initial serum sodium level and presence of hypokalemia, severe symptoms, and chronic alcoholism ( Table 1 ).…”

“…There has only been one prior study to be compared with the study by Yang et al [ 8 ]; Woodfine et al [ 6 ] proposed the SHOR (Severe Hyponatremia Overcorrection Risk) score using data from a single-center retrospective cohort to predict overcorrection during management of hyponatremia. Unlike the study by Yang et al [ 8 ], Woodfine et al [ 6 ] did not have a predefined threshold for overcorrection.…”

“…There has only been one prior study to be compared with the study by Yang et al [ 8 ]; Woodfine et al [ 6 ] proposed the SHOR (Severe Hyponatremia Overcorrection Risk) score using data from a single-center retrospective cohort to predict overcorrection during management of hyponatremia. Unlike the study by Yang et al [ 8 ], Woodfine et al [ 6 ] did not have a predefined threshold for overcorrection. Therefore, they had to use a latent class analysis to define overcorrection based on 14 criteria, which resulted in four classes of overcorrection status: none, unlikely, possible, and definite.…”