To the Editor: We recently had the pleasure of reading the insightful article titled "Hypertonic Saline Solution Versus Mannitol for Brain Relaxation During Craniotomies: A Systematic Review and Updated Meta-Analysis" by Menegaz de Almeida et al, which presents a thorough evaluation of osmotic agents used in neurosurgical procedures.1 The systematic review and meta-analysis, covering 16 randomized controlled trials with a total of 1031 patients, provides compelling evidence regarding the efficacy of hypertonic saline (HTS) compared with mannitol for brain relaxation during craniotomies. As highlighted in the study, HTS demonstrated superior outcomes, including better brain relaxation rates (80% vs 71%), reduced need for additional doses, and lower fluid intake and urine output. These findings underscore HTS as a more effective osmotic agent in this context. However, it is crucial to emphasize the importance of setting clear goals for administering hyperosmolar solutions. Serum osmolality, primarily determined by sodium concentration and other solutes, plays a significant role in managing hypertonic states. An increase in the osmolal gap can indicate the presence of additional solutes or hypertonic treatments that might affect neurological function. Monitoring and managing hypertonicity are essential to prevent adverse neurological outcomes, ranging from mild symptoms to severe complications such as convulsions and even death. Traditional models of hypertonicity are only applicable to anuric states, as they do not take into account losses of water and solute through urine and other fluid losses that may occur during treatment.2 The 2020 Guidelines for the Acute Treatment of Cerebral Edema in Neurocritical Care Patients of the Neurocritical Care Society do not recommend a specific dosing strategy for HTS because of low quality of the evidence regarding symptom-based bolus dosing of HTS as opposed to HTS administration titrated to a target sodium concentration.3 In clinical practice, accurate determination of serum osmolality and osmolal gap is vital for diagnosing and treating disorders related to sodium and water balance, kidney function, and poisoning. Elderly patients with hypertonicity may present with lethargy, delirium, and coma, which are all fairly common in neurosurgical patients, hindering a timely diagnosis and management.4 It is imperative for practitioners to remain vigilant in their management strategies and continuously monitor sodium levels before complications can arise. More studies are needed to establish the best dosing regimen for HTS for the intraoperative treatment of cerebral edema. The detailed discussion of hyperosmolar conditions and their treatment strategies presented in this review serves as an important reminder of the broader implications of hypertonic treatments. We commend the authors for their comprehensive analysis and for improving our understanding of these critical aspects in neurosurgical care.