Clinical and Echocardiographic Predictors of Recovery of Moderate-to-severe Sepsis-associated Acute Kidney Injury in Critically Ill Patients

BACKGROUND: Acute kidney injury (AKI) is associated with significant short- and long-term morbidity and mortality. In critically ill patients with sepsis, AKI tends to be more severe, more likely to require kidney replacement therapy (KRT), with less chance of recovery. Consequently, critically ill patients with sepsis-associated AKI (SA-AKI) have extended intensive care unit (ICU) stays and higher mortality rates. This study evaluated the predictive value of clinical and transthoracic echocardiographic (TTE) parameters for recovery from moderate-to-severe SA-AKI in critically ill patients. METHODS: This single-center historical cohort study was conducted at a tertiary academic medical center. We analyzed the data of all adults (age ≥18 years) admitted to the ICU at Mayo Clinic, Rochester, MN, from June 1, 2018, to December 31, 2020. We included all patients who developed sepsis within the initial 24 h of their ICU stay. RESULTS: We identified 2919 eligible septic patients with available TTE, among which 1431 patients (49%) had moderate-to-severe SA-AKI. The mean age of the patients was 68 ± 15 years, and the male-to-female ratio was 1.3:1. The most common comorbidities were diabetes mellitus and chronic lung and kidney diseases. Clinical predictors associated with SA-AKI non-recovery were the presence of stage III AKI (HR 1.5, 95% CI 1.0–2.1, p = 0.03) and utilization of kidney replacement therapy (KRT) (HR 6.8, 95% CI 3.6–12.4, p = 0.01). On the other hand, higher TAPSE was the only TTE variable associated with SA-AKI recovery (HR 1.1; 95% CI 1.08–1.15; p = 0.01). CONCLUSION: Our data from a single-center provide new information on the clinical (AKI stage, utilization of KRT, BMI, and peak serum creatinine) and echocardiographic features (TAPSE) associated with improved recovery in SA-AKI. There is a definite knowledge gap in the current literature regarding optimizing recovery in moderate-to-severe SA-AKI. Larger, multi-center studies are required to confirm these findings.