30 - IMPACT OF FLUID BALANCE ON INTENSIVE CARE UNIT LENGTH OF STAY IN CRITICALLY ILL TRAUMA PATIENTS

Objectives: There is significant data in the medical and surgical literature supporting the correlations between positive volume balance and negative outcomes such as AKI, prolonged mechanical ventilation, ICU and hospital length of stay (LOS), and increased mortality. The purpose of this study is to determine the impact of positive volume balance at 72 hours in critically ill trauma patients on total days spent in the ICU.

Methods: This single-center, retrospective chart review included adult patients identified from a Trauma Registry database who survived more than forty-eight hours from hospital presentation, and were admitted to the ICU under the trauma service from 2019 through 2021. The primary outcome was the total ICU LOS. Secondary outcomes include hospital LOS, ventilator-free days, incidence of compartment syndrome, acute respiratory distress syndrome, renal replacement therapy (RRT), and days of vasopressor therapy. The Mann-Whitney U Test was used for continuous non-parametric variables, which were reported as median and 25%-75% interquartile range (IQR). Median reporting was used to decrease bias. For nominal variables, the chi-squared and Fisher’s exact test were used. A p-value of < 0.05 was considered to be statistically significant. Multivariate linear regression modeling was utilized to analyze the relationship between volume balance and total ICU days.

Results: Among the 716 patients screened for inclusion, 250 were analyzed, 121 in the even fluid balance group, 50 in the negative fluid balance group, and 79 in the positive fluid balance group. In general baseline characteristics were similar between groups with the exception of mechanism of injury, FAST exam, and disposition from the emergency department. The ICU LOS was shortest in the negative fluid balance, and longest in the positive fluid balance group (4 days vs. 6 days, p = 0.001). Hospital LOS was also shorter in the negative fluid balance compared to the positive fluid balance group (7 days vs. 12 days, p < 0.001). More patients in the positive fluid balance group experienced ARDS compared to the negative fluid balance group (6.3% vs. 0%, p = 0.004). There was no significant difference in the incidence or RRT, days of vasopressor therapy, or ventilator free days.

Conclusion: A negative fluid balance at 72 hours was associated with a shorter ICU and hospital LOS in critically ill trauma patients. Our observed correlation between positive volume balance and total ICU days merits further exploration with prospective, comparative studies of lower volume resuscitation to key physiologic endpoints compared with routine standard of care.