2025 Southeastern Residency Conference

Title: Comparative Effects of 3% Sodium Chloride Continuous Infusion Versus Intermittent Boluses on Renal Outcomes


Authors: Abbygail Wilbourn, Braiden Sorgenfrei, Alex Ewing, Jenna Sorgenfrei, Michael Wagner


Objective: Identify hypertonic saline administration that leads to decreased adverse renal outcomes while achieving target serum sodium levels for intracranial pressure management.


Self Assessment Question: What strategy does the 2024 American College of Surgeons (ACS) Trauma Quality Improvement Program (TQIP) guidelines recommend for ICP management in TBI?


Background: Cerebral edema, often resulting from traumatic brain injury (TBI), can lead to elevated intracranial pressure (ICP), which is associated with poorer outcomes. American College of Surgeons and Neurocritical Care Society guidelines recommend hyperosmolar therapy, such as hypertonic saline or mannitol, for managing elevated ICP; however, these guidelines primarily focus on bolus dosing, with limited data on continuous infusion strategies. This study aims to evaluate whether intermittent bolus therapy reduces the incidence of acute kidney injury (AKI) compared to continuous infusion of hypertonic saline, with the goal of improving safety and informing best practices for hyperosmolar therapy at a 864-bed academic medical center in South Carolina, USA.


Methods: This single-center, retrospective study at a 864-bed academic medical center in South Carolina, USA assessed trauma patients admitted to the ICU between January 2022 and December 2023 who received either intermittent boluses or continuous infusion of 3% sodium chloride for suspected elevated intracranial pressure (ICP). Primary outcomes included the combined incidence of acute kidney injury (AKI), hyperchloremia, and metabolic acidosis within 7 days, while secondary outcomes focused on individual complications, time to serum sodium goals, and major renal events. Data were collected through chart review and stored in REDCap, with approval from the institution’s IRB.


Results: A total of 88 patients were included (61 continuous infusion, 27 bolus). Continuous infusion patients were younger and had longer ICU stays (6.8 vs 4.8 days, p=0.02), though hospital stays were similar. Hypertonic saline exposure was higher in the continuous group, particularly on days 2–3 (p<0.001). The combined incidence of acute kidney injury, hyperchloremia, and metabolic acidosis was significantly higher in the continuous group (91.8% vs 66.7%, p=0.009), mainly due to hyperchloremia (p=0.002). Multivariate analysis confirmed infusion method as a significant predictor (aOR 0.19, p=0.03). Switching to sodium acetate occurred in 38 patients, more commonly in the infusion group but not statistically significant. Those who switched had higher hyperchloremia incidence after day 4 (p=0.0009). No differences were found in secondary outcomes.


Conclusion: Bolus therapy achieved similar time to target sodium levels while resulting in fewer electrolyte-related complications—particularly hyperchloremia—and a lower combined incidence of kidney injury, hyperchloremia, and metabolic acidosis compared to continuous infusion. These findings suggest that bolus therapy may be a safer and more favorable strategy for hypertonic saline administration.