Resolution of Sepsis-Associated Acute Kidney Injury: Association with Emergency Department Fluid Management Patterns

Background: Sepsis is the most common cause of acute kidney injury (AKI). AKI is associated with poor outcomes including progression to chronic kidney disease, increased intensive care unit and hospital length of stay, and mortality. Recent evidence suggests that trajectory of AKI (duration and resolution/persistence), rather than KDIGO stage, is associated with these poor outcomes. Fluid management decisions made during early resuscitation have the potential to improve AKI trajectory in patients with sepsis. Objective: To examine the association between emergency department (ED) fluid management patterns and AKI resolution in a cohort of ED patients with septic shock. Methods: Retrospective cohort study of 292 patients with septic shock identified in the ED at an academic county hospital in Seattle, WA from 2009 -2015. Multivariable relative risk regression was used to examine the association between two exposures; 1) total resuscitation volume administered in the ED and 2) total volume of Lactated Ringer’s solution administered in the ED, and the outcome of unresolved AKI at the earliest of death, discharge, or hospital day 5. Measurements and Main Results: Two-hundred six patients (71%) had sepsis-associated AKI and 83 (28%) had unresolved AKI. Patients with unresolved AKI were older, had more comorbidities, and were more severely ill. Mortality during the first 5 hospital days was more common among patients with unresolved AKI (34%) than those with resolved AKI (<1%) or no AKI (<1%). There was a trend toward decreased risk of unresolved AKI in patients receiving larger total ED resuscitation volumes. Each liter of Lactated Ringer’s solution administered in the ED was associated with a 24% decreased relative risk of unresolved AKI (95%CI 5%-39%, P=0.02). Conclusions: In this cohort, increased volume of Lactated Ringer’s solution in the ED was independently associated with decreased risk of unresolved AKI. This result supports the need for randomized trials comparing ED resuscitation with 0.9% saline to balanced crystalloid in patients with septic shock.