ONLINE TDM VALPROIC ACID

Additional Manufacturer Narrative

THE INVESTIGATION DETERMINED THE ISSUE WAS CONSISTENT WITH A PRE-ANALYTICAL HANDLING ISSUE.THE INVESTIGATION DID NOT IDENTIFY A SPECIFIC CAUSE OF THE EVENT.

Description of Event or Problem

THERE WAS AN ALLEGATION OF QUESTIONABLE ONLINE TDM VALPROIC ACID RESULTS FOR 1 PATIENT SAMPLE ON A COBAS 8000 COBAS C 502 MODULE. THE INITIAL RESULT WAS 4.2 G/ML. THE RESULT WAS QUESTIONED BY THE PHYSICIAN, AND THE SAMPLE WAS REPEATED. THE REPEATED RESULTS WERE 184.3 G/ML AND 109.5 G/ML. A DILUTION WAS PERFORMED, AND THE RESULT WAS 219 G/ML. THIS RESULT WAS BELIEVED TO BE CORRECT. THE CUSTOMER INDICATED THAT THE SAMPLE QUALITY WAS IN QUESTION.

Additional Manufacturer Narrative

THE ANALYZER'S SERIAL NUMBER IS (B)(6). THE CUSTOMER DECLINED A SERVICE VISIT BECAUSE REPEATED RESULTS FOR ALL OTHER VALPROIC ACID SAMPLES, WHICH WERE TESTED THE PREVIOUS WEEK, WERE ACCEPTABLE AND MATCHED THE ORIGINAL RESULTS. A SAMPLE QUALITY ISSUE IS SUSPECTED. THE INVESTIGATION IS ONGOING.