MO324: Serum Potassium Trajectory During AKI and Mortality Risk

Abstract

Abstract BACKGROUND AND AIMS Kidneys play a primary role in potassium homeostasis. The association between potassium (sK+) level and mortality or the need for kidney replacement therapy (KRT) during acute kidney injury (AKI) has not been adequately explored. METHOD In this prospective cohort study, AKI patients admitted to the Hospital Civil de Guadalajara were enrolled from August 2017 to June 2021 with AKI. We divided patients into eight groups based on the serum potassium level trajectories up to 10 days following hospitalization: (1) normokalemia (normoK), defined as sK + values between 3.5 and 5.5 mEq/L; (2) corrected hyperkalemia (hyperK), sK+ > 5.5 mEq/L on hospital admission and decreased to normoK; (3) corrected hypokalemia (hypoK), sK+ < 3.5 mEq/L on hospital admission and increased to normoK; (4) fluctuating potassium, sK + increased/decreased in and out of normoK parameters; (5) uncorrected hypoK, sK+ < 3.5 mEq/L; (6) normoK to hypoK, sK + that were normal on hospital admission and decreased to hypoK and never went back to normal; (7) normoK to hyperK, sK + that were normal on hospital admission and increased to hyperK and never went back to normal; and (8) uncorrected hyperK, sK+ > 5.5 mEq/L. We assessed the association of serum potassium trajectories with mortality and the need for KRT (secondary objective). RESULTS A total of 311 AKI patients were included. The mean age was 52.6 years, and 182 (58.6%) were male. AKI stage 3 was present in 199 (63.9%). KRT started in 112 (36%) patients, and 66 patients (21.2%) were died. After adjusting for confounders, 10-day hospital mortality was significantly higher in group 7 and 8 (OR 1.37 and 1.63; P = < .05 for both, respectively), and KRT initiation was higher only in group 8 (OR 1.40; P = < .05) compared with group 1. Mortality in different subgroups of patients in group 8 did not change the primary results. CONCLUSION In our prospective cohort, most patients with AKI had alterations in sK + . NormoK to hyperK and uncorrected hyperK were associated with death, while only uncorrected hyperK was correlated with the need for KRT.