Serum Potassium Trajectory during Acute Kidney Injury and Mortality Risk

Nephron. 2023;147(9):521-530. doi: 10.1159/000529588. Epub 2023 Feb 17.

Abstract

Background: The association between potassium (sK) level trajectory and mortality or the need for kidney replacement therapy (KRT) during acute kidney injury (AKI) has not been adequately explored.

Methods: In this prospective cohort, AKI patients admitted to the Hospital Civil de Guadalajara were enrolled. Eight groups based on the sK (mEq/L) level trajectories during 10 days of hospitalization were created (1) normokalemia (normoK), defined as sK between 3.5-5.5; (2) hyperkalemia to normoK; (3) hypokalemia to normoK; (4) fluctuating potassium; (5) persistent hypoK; (6) normoK to hypoK; (7) normoK to hyperK; (8) persistent hyperK. We assessed the association of sK trajectories with mortality and the need for KRT.

Results: A total of 311 AKI patients were included. The mean age was 52.6 years, and 58.6% were male. AKI stage 3 was present in 63.9%. KRT started in 36% patients, and 21.2% died. After adjusting for confounders, 10-day hospital mortality was significantly higher in groups 7 and 8 (OR, 1.35 and 1.61, p < 0.05, for both, respectively), and KRT initiation was higher only in group 8 (OR 1.38, p < 0.05) 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 persistent hyperK were associated with death, while only persistent hyperK was correlated with the need for KRT.

Keywords: Acute kidney injury; Dialysis; Mortality; Potassium.

MeSH terms

  • Acute Kidney Injury* / complications
  • Female
  • Humans
  • Hyperkalemia* / complications
  • Hypokalemia* / complications
  • Male
  • Middle Aged
  • Potassium
  • Prospective Studies

Substances

  • Potassium