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Patient 1
SIEMENS HEALTHCARE DIAGNOSTICS INC. (SIEMENS) ANALYSED THE DATA PROVIDED BY THE CUSTOMER TO DETERMINE THE CAUSE OF THE DIFFERENT APTT RESULTS OBTAINED ACROSS DIFFERENT SYSTEMS FOR SAMPLE(S) FROM THIS PATIENT. SIEMENS DETERMINED THAT THE KINETIC REACTIONS FROM THE DATA PRINTOUT ARE CONSISTENT WITH PATIENT SAMPLES ON ARGATROBAN THERAPY. THE INTERNAL QUALITY CONTROLS ON THE BCS XP SYSTEM AND SYSMEX CA-7000 SYSTEM RECOVERED WITHIN EXPECTED RANGE AT THE TIME OF THE EVENT AND THERE IS NO INDICATION THAT OTHER PATIENTS WERE IMPACTED. THE AFFECTED PATIENT IS ON ARGATROBAN, A DIRECT THROMBIN INHIBITOR (DTI), WHICH INFLUENCES APTT RESULTS FOR ALL MANUFACTURERS' REAGENTS AND SYSTEMS. THE REAGENT AND THERAPEUTIC RANGE FOR ARGATROBAN USED ON THE STAGO SYSTEM WAS NOT PROVIDED, THEREFORE DIFFERENCES OF SENSITIVITY INHERENT TO BOTH REAGENT AND SYSTEMS CANNOT BE DETERMINED. APTT VALUES OF THERAPEUTIC SAMPLES BETWEEN SYSTEMS MAY BE NUMERICALLY DIFFERENT, HOWEVER STILL ACCURATE FOR THE INDEPENDENT SYSTEM THE SAMPLE WAS TESTED ON. REAGENT SENSITIVITY CAN VARY BETWEEN REAGENT PRODUCTS ACROSS DIFFERENT MANUFACTURERS. A DIRECT COMPARISON OF THE APTT RESULTS IS NOT POSSIBLE. SIEMENS DETERMINED THAT THE CUSTOMER REPORTED A NON-REPORTABLE, FLAGGED RESULT FROM THE SYSMEX CA-7000 SYSTEM. BASED ON THE SYSMEX "CA SERIES CHECKING METHODS AND EVALUATION GUIDE", ERE 1 (EARLY REACTION ERROR: SLOW REACTION) OCCURS WHEN THE SLOPE OF THE COAGULATION CURVE AROUND THE DETECTION POINT IS TOO LOW. THIS ERROR MAY BE REPORTABLE AFTER VISUAL REVIEW OF THE MEASUREMENT CURVE TO ENSURE THE APTT VALUE DETERMINED AT THE 50% IS CONSISTENT WITH THE KINETICS. ATO (ANALYSIS TIME OVER) DETECTS WHETHER THE REACTION END POINT IS CORRECT. IF THE SAMPLE REACTION END ANGLE IS GREATER THAN THE PERMITTED ANGLE AT THE MAXIMUM DETECTION TIME, THE RESULT WILL BE FLAGGED WITH AN ANALYSIS TIME OVER ERROR. IF THIS ERROR PERSISTS, AND ALTERNATE PROTOCOL SHOULD BE FOLLOWED. SIEMENS DETERMINED THAT THE REACTION CURVE FROM THE SYSMEX CA-7000 SYSTEM DEMONSTRATES INCREASING ANGLE IN THE PLATEAU AREA OF THE CURVE, HOWEVER CLOTTING WAS OBSERVED EARLIER ON THE REACTION CURVE. BASED ON THE SYSMEX BULLETIN AND GUIDES, OPERATORS CAN REPORT RESULTS WITH THE ERE1 FLAG BUT CANNOT REPORT RESULTS WITH THE ATO FLAG. THE CUSTOMER HAS IMPLEMENTED THEIR OWN POLICY TO ACCEPT ATO ERRORS WHEN CLEAR CLOTTING IS DEMONSTRATED. SIEMENS OFFERED TO PROVIDE FLAG INTERPRETATION AND RESULTS EVALUATION BULLETINS FOR THE SYSMEX CA-7000 SYSTEM AND THE BCS XP SYSTEM TO THE CUSTOMER AND THE CUSTOMER REJECTED THE OFFER. THE CUSTOMER STATED THAT THE LAB HAS THESE BULLETINS BUT WILL NOT CHANGE THEIR LAB POLICY-EVEN IF THEIR POLICY CONFLICTS WITH SIEMENS GUIDELINES. SIEMENS ALSO REVIEWED THE KINETIC CURVE ON THE BCS XP SYSTEM AND DETERMINED THAT THE BCS XP KINETIC CURVE DEMONSTRATES A PATTERN THAT IS CONSISTENT WITH PATIENTS ON ARGATROBAN THERAPY. THE KINETIC PROVIDED IS NOT FOCUSED ON THE AREA OF CLOTTING PREFERRED FOR INTERPRETATION OF THE CURVE. THE APTT RESULT WAS FLAGGED APPROPRIATELY AND THE CUSTOMER NEEDED TO SELECT "AUTO" TO APPROPRIATELY EVALUATE THE CURVE. THE CAUSE OF THE MODIFICATION OF THE PATIENT'S TREATMENT IS DUE TO USER ERROR AS THE CUSTOMER REPORTED NON-REPORTABLE, FLAGGED RESULTS. THE INSTRUMENTS AND REAGENT ARE PERFORMING ACCORDING TO SPECIFICATIONS. NO FURTHER EVALUATION OF THIS DEVICE IS REQUIRED. MDR 9610806-2017-00091 WAS FILED FOR THE SAME EVENT.