Choice of Reference Creatinine for Post-Traumatic Acute Kidney Injury Diagnosis

Area of Science:

• Nephrology
• Trauma Surgery
• Critical Care Medicine

Background:

• Acute kidney injury (AKI) following trauma is linked to adverse patient outcomes.
• Current AKI diagnosis relies on serum creatinine increase from a reference value, often unavailable in trauma cases.
• Establishing an optimal reference creatinine estimate is crucial for accurate post-traumatic AKI diagnosis and staging.

Purpose of the Study:

• To identify the best reference creatinine estimate for diagnosing and staging AKI in adult trauma patients.
• To evaluate reference estimates based on incidence, prognostic ability, and stage-specific mortality risk correlation.

Main Methods:

• A cohort study included 8,026 adult trauma ICU patients (2009-2018).
• AKI was assessed using four creatinine estimates: MDRD, Trauma MDRD, admission creatinine, and first-day nadir.
• Prognostic ability was determined via multivariable modified Poisson regression; incrementality by correlating mortality risk across AKI stages.

Main Results:

• AKI incidence varied widely (21% with admission creatinine to 76% with Trauma MDRD).
• The MDRD estimate yielded 41% AKI incidence, demonstrating prognostic value and incrementality.
• Other estimates lacked prognostic or incremental value for AKI staging.

Conclusions:

• The choice of reference creatinine estimate significantly impacts the clinical significance of AKI diagnoses.
• The MDRD reference creatinine estimate provides the most optimal and clinically relevant AKI diagnosis in trauma patients.