Navigating an unexpected creatinine result during a pre-intravenous contrast renal function workup

• Published in: Clinical biochemistry Vol. 139; p. 110979
• Main Authors: Narasimhan, Madhusudhanan, Smith, Kibibi, Muthukumar, Alagarraju
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2025
• Subjects: Creatinine; Index of individuality; IV contrast; Patient-centered metrics; Reference change value; Renal assessment; Subject-based reference interval; eGFR; SBRI; Creatinine; FDA; IOI; IDMS; RCV; POC; Reference change value; Index of individuality; Subject-based reference interval; Renal assessment; PBRI; IV; Cr; IV contrast; CT; BV; AV; Patient-centered metrics; RI; CLIA
• ISSN: 0009-9120; 1873-2933; 1873-2933
• DOI: 10.1016/j.clinbiochem.2025.110979

•Unexpected POC Cr increase delays IV contrast plans and cause patient anxiety.•Accurate renal assessment requires more than lab-based Cr results and PBRI.•Patient-centered IOI, RCV, SBRI metrics with TEa guide result interpretation.•Holistic method with TEa conformity eased renal concerns and enabled imaging. Increasing chronic disease incidence drives intravenous (IV) contrast-based diagnostic imaging. While IV procedure is largely safe, contrast-induced neuropathy risk in patients with predisposing factors demand pre-IV renal assessment. Although common, point-of-care creatinine (POC) tests are prone to generating ambiguous results. This frequently result in time-consuming retests, rescheduled appointments, patient distress, and healthcare burdens. A diabetic, hypertensive, and chronic kidney diseased Caucasian male, aged 61, presented for a scheduled intravenous contrast-enhanced computed tomography scan. His initial POC-based creatinine result of 1.20 mg/dL (106.1 μmol/L) narrowly exceeded the reference interval (0.67–––1.17 mg/dL [59.2 – 103.5 μmol/L]). Given the patient’s pre-existing conditions, laboratory-based creatinine test was performed to reassure his renal function. The new result was found to be 0.95 mg/dL (84 μmol/L), which fell within the normal reference interval. This substantial disparity of 0.25 mg/dL (22.1 μmol/L; 20.8 %) between creatinine tests while delaying the intravenous procedure prompted the clinicians to request an in-depth laboratory investigation. Comprehensive analysis using patient-centered metrics such as index of individuality, reference change value, and subject-based reference interval alleviated the concerns on his renal health and disparity in assay results (<0.3 mg/dL≡ <26.5 μmol/L) total allowable error limit), thus allowing intravenous contrast imaging.