Point-of-care creatinine testing in patients receiving contrast-enhanced computed tomography scan

Background: The aim of this study was to evaluate the creatinine assay on the ABL800 FLEX© blood gas analyzer for the screening of pre-existing renal impairment before radiographic contrast administration in the emergency department (ED), by comparing it with standard practice using central laboratory blood testing.

Methods: The evaluation comprised two elements. The first, conducted in the central laboratory, focused on the analytical performance of the ABL800 creatinine assay. This included assessment of imprecision and accuracy by comparison with central laboratory standard creatinine assay. We also compared ABL 800 estimated glomerular filtration rate (eGFR) and ^99mTc-DTPA measured GFR (mGFR). The second part, conducted in ED sought to determine the impact that implementation of the creatinine at the point-of-care (POC) has on the timeframe in which ED patients are submitted for computed tomography scan (CT).

Results: The ABL800 enzymatic creatinine assay met the National Kidney Disease Education Program acceptance criteria for imprecision and showed good agreement with the isotope dilution mass spectrometry-traceable Roche enzymatic assay used in the central laboratory. Furthermore, ABL800 eGFR was in total agreement with mGFR by a reference method. The implementation of POC testing creatinine in the ED significantly reduced patient waiting times for contrast enhanced CT (1.73[0.75-3.01] vs 2.57 [1.53-3.48] hours, for period with and without ABL800 respectively, p=0.04).

Conclusion: The ABL800 assay is comparable with central laboratory reference method in terms of analytical performance and superior in terms of turnaround time. Implementation of creatinine at POC reduces delay results, potentially allowing ED clinical staff to make more rapid clinical decisions and reduce patient waiting time.