The Association Between Hyponatremia and Prognosis in Traumatic Brain Injury: A Comprehensive Meta-Analysis

This meta-analysis aimed to assess the impact of hyponatremia on prognosis in patients with traumatic brain injury (TBI), specifically regarding mortality and length of hospital stay. A systematic literature search was conducted in PubMed and Web of Science up to October 2024, using comprehensive search terms to cover all potential synonyms related to TBI and hyponatremia. Inclusion criteria required studies to be case-control in design, focus on TBI patients, and report on at least one outcome: mortality, length of stay, neurological scores (e.g., Glasgow Coma Scale), or functional recovery. Studies that were reviews, abstracts, or case reports were excluded, as were non-English publications. Data extraction and quality assessment were independently conducted by 2 reviewers, with a third reviewer resolving discrepancies. The Newcastle-Ottawa Scale (NOS) and Oxford Centre for Evidence-Based Medicine Levels were applied to assess study quality. Our findings indicate that although hyponatremia is common among TBI patients, it does not significantly increase mortality or extend hospital stay. This suggests that, although hyponatremia management is essential to prevent acute neurological complications, it may not critically impact overall patient outcomes in terms of survival or hospitalization duration. Future high-quality studies are needed to further clarify the role of hyponatremia in different TBI subtypes and its effect on long-term neurological recovery.