Outcomes with Sodium Overcorrection in Chronic Hyponatremia: A Systematic Review and Meta-analysis

Chronic hyponatremia is a common electrolyte disturbance associated with adverse outcomes. The optimal rate of correction remains uncertain, with current guidelines emphasizing avoidance of overcorrection. This systematic review and meta-analysis aimed to synthesize the existing evidence on patient and healthcare utilization outcomes associated with overcorrection in adults with chronic hyponatremia.

This study followed a pre-registered protocol (PROSPERO CRD42024606516). Medline and EMBASE were searched from inception to May 2024. Eligible studies included original experimental or observational research. Included studies reported outcomes for adult patients with chronic hyponatremia who experienced overcorrection, and those who did not. The outcomes of interest were neurologic complications, acute care utilization (hospital and intensive care unit length of stay, re-admission) and mortality. Study quality was assessed using the Newcastle-Ottawa Quality Assessment Scale. Meta-analyses were performed using the Hartung-Knapp-Sidik-Jonkman random effects models when data allowed; otherwise, outcomes were synthesized narratively.

Forty-three studies were included. Overcorrection of hyponatremia was associated with an increased odds of neurologic complications (OR 4.23, 95% CI 2.93 - 6.11, I² = 0%) but lower odds of mortality (OR of 0.67, 95% CI 0.47 - 0.97, I² = 82.3%). In sensitivity analyses restricted to studies at low risk of bias, the association between overcorrection and neurologic complications was no longer statistically significant (OR 3.22, 95% CI 0.40-25.83, I² = 25.4%). Given the observational nature of included studies, indirect evidence, and high risk of bias across studies, the certainty of evidence is very low.

While sodium overcorrection appears to be associated with increased risk of neurologic complications but lower risk of mortality, the limitations of the current literature warrant cautious application of these findings. Given the potential risks of under- and overcorrection, a reframing of practice to achieve adequate correction, rather than focusing on overcorrection avoidance alone may be warranted.