Fluid and Electrolyte Disorders in Traumatic Brain Injury: Clinical Implications and Management Strategies

Area of Science:

• Neuroscience
• Endocrinology
• Nephrology

Background:

• Traumatic brain injuries (TBIs) induce direct central nervous system damage.
• Secondary injury mechanisms include compression, impaired cerebral perfusion, and altered sodium levels, leading to cellular edema or dehydration.
• Plasma osmolality (Posm) is a critical indicator of solute concentrations (sodium, glucose, urea) and is vital in TBI patient management.

Purpose of the Study:

• To review the complexities of osmoregulation following TBI.
• To highlight the clinical implications of osmoregulatory dysregulation in TBI patients.
• To emphasize the importance of accurate Posm measurement and understanding tonicity.

Main Methods:

• Narrative review of scientific literature on TBI and osmoregulation.
• Discussion of the roles of osmolality, tonicity, and key solutes (sodium, urea, glucose).
• Explanation of the brain's osmoreceptor-vasopressin axis and its regulation.

Main Results:

• TBI can lead to dysregulation of osmoregulation, impacting neurological outcomes.
• Accurate Posm measurement is preferred over calculation for clinical accuracy.
• Distinguishing between osmolality and tonicity is crucial due to differential solute effects.

Conclusions:

• Osmoregulation disturbances are common after TBI and significantly affect patient outcomes.
• Conditions such as diabetes insipidus, SIADH, and abnormal thirst are potential complications.
• Maintaining normal plasma osmolality is essential for homeostasis and neurological recovery in TBI patients.