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Abstract: SA-PO718

From Baseline Serum Creatinine to Creatinine-Based AKI: Different Definitions for Different Results

Session Information

Category: Pathology and Lab Medicine

  • 1602 Pathology and Lab Medicine: Clinical


  • Samoni, Sara, IRRIV - San Bortolo Hospital, Vicenza, Italy
  • Lorenzin, Anna, IRRIV - San Bortolo Hospital, Vicenza, Italy
  • De Rosa, Silvia, IRRIV - San Bortolo Hospital, Vicenza, Italy
  • Marchionna, Nicola, IRRIV - San Bortolo Hospital, Vicenza, Italy
  • de Cal, Massimo, IRRIV - San Bortolo Hospital, Vicenza, Italy
  • Bonilla, Luis Ignacio, IRRIV, Vicenza, Italy
  • Villa, Gianluca, University of Florence, Florence, Italy
  • Zanella, Monica, San Bortolo Hospital, Vicenza, Italy
  • Brendolan, Alessandra, San Bortolo Hospital, Vicenza, Italy
  • Ronco, Claudio, University of Padova, IRRIV, San Bortolo Hospital, Vicenza, Italy

The lack of consensus on the definition of baseline serum creatinine(bsCr) influences the creatinine-based acute kidney injury(AKI) diagnosis, leading to problems relating to both research and clinical purpose. Pre-admission bsCr, measured in a time-period of a maximum of 365 days and minimum of 7 days from hospitalization, is considered the gold standard, but is rarely available in unscheduled patients. Our study aims at evaluating sensitivity and specificity of different bsCr.


We retrospectively enrolled patients admitted to our intensive care unit(ICU) over 6-month period. Inclusion criteria were:(i)availability of pre-admission bsCr;(ii)length of ICU stay≧72hrs.
According to the bsCr definitions derived from literature, we recorded:(i)sCr measured at ICU admission(admission bsCr);(ii)the lowest sCr achieved during the first 3 days of ICU stay(nadir bsCr);(iii)sCr calculated using the MDRD equation(back-estimation formula)(estimated bsCr), thus resulting 4 different bsCr for each patient. The occurrence of AKI was evaluated according to KDIGO criteria considering each of the 4 bsCr.


Of 490 patients,195 had pre-admission bsCr. 14 patients were excluded because daily sCr was not available. Using pre-admission bsCr, we identified 79 patients who developed AKI(43.6%). Results are summarized in table 1.


Admission bsCr, frequently used in ICU, has the lowest sensitivity for AKI, missing almost entirely the diagnosis of community-acquired AKI. In previous studies, estimated bsCr has been demonstrated to overestimate the incidence of AKI in patients with pre-existent chronic kidney disease. In the absence of pre-admission bsCr, nadir bsCr seems to be the most accurate bsCr for diagnosis of AKI. Future efforts should focus on identifying a shared definition of bsCr.

 pre-admission bsCradmission bsCrnadir bsCrestimated bsCr
no AKI(pts)102968691
sensitivity(%) 46.887.379.7
specificity(%) 94.184.389.2