DIMENSION® CLINICAL CHEMISTRY SYSTEM

Additional Manufacturer Narrative

ANALYSIS OF THE INSTRUMENT AND INSTRUMENT DATA INDICATE THAT THE CAUSE FOR THE FALSELY ELEVATED TAC SAMPLE RESULT IS UNKNOWN. EVALUATION OF INSTRUMENT FILTER DATA BY SIEMENS HEADQUARTERS SUPPORT CENTER DATA REVEALED DIFFERENCES IN THE HEMOGLOBIN CONCENTRATION OF THE PATIENT SAMPLE BETWEEN INITIAL AND REPEAT RUNS. WHEN THE HEMOGLOBIN CONCENTRATION CHANGES THE TACROLIMUS VALUE CHANGES. THE MOST COMMON CAUSE FOR CHANGES IN HEMOGLOBIN CONCENTRATION BETWEEN REPLICATES IS SETTLING OF RED BLOOD CELLS CAUSED BY A DELAY IN ALIQUOTING THE SAMPLE AFTER MIXING OF THE PRIMARY SAMPLE CONTAINER HAS STOPPED. A SAMPLE HANDLING ISSUE SPECIFIC TO THE INDIVIDUAL PATIENT WHO HAD AN ELEVATED ERYTHROCYTE SEDIMENTATION RATE CANNOT BE EXCLUDED. NO SAMPLE WAS RETURNED TO SIEMENS FOR FURTHER EVALUATION OF THE INDIVIDUAL PATIENT'S SAMPLE. THE DEVICE IS PERFORMING WITHIN SPECIFICATIONS. NO FURTHER EVALUATION OF THE DEVICE IS REQUIRED.

Description of Event or Problem

A FALSELY ELEVATED TACROLIMUS (TAC) RESULT WAS OBTAINED ON A PATIENT SAMPLE ON THE DIMENSION EXL INSTRUMENT. THE PATIENT RESULT WAS REPORTED TO THE PHYSICIAN WHO QUESTIONED THE RESULT. THE SAMPLE WAS REPEATED ON AN ALTERNATE EXL INSTRUMENT AND A LOWER RESULT WAS OBTAINED. A CORRECTED REPORT WAS ISSUED. PATIENT TREATMENT WAS NOT ALTERED OR PRESCRIBED ON THE BASIS OF THE FALSELY ELEVATED TACROLIMUS (TAC) RESULT. THERE WAS NO REPORT OF ADVERSE HEALTH CONSEQUENCES TO THE PATIENT DUE TO THE FALSELY ELEVATED TACROLIMUS (TAC) RESULT..