ELECSYS PROBNP II

Additional Manufacturer Narrative

BASED ON FURTHER INVESTIGATIONS OF THE SAMPLE, IT WAS ASSUMED THAT THERE ARE NO SUBSTANCES IN THE COMPLAINED SAMPLE THAT EXCLUSIVELY INTERFERE WITH THE PROBNP ASSAY. SPIKING THE PATIENT SAMPLE WITH RECOMBINANT PROBNP PROVIDED NO CLEAR INDICATION OF POSSIBLE INTERFERENCE WITH THE PROBNP ASSAY. IT IS ASSUMED THAT THE PROBNP VALUES THAT THE CUSTOMER OBTAINED ARE CORRECT.

Additional Manufacturer Narrative

THIS EVENT OCCURRED IN (B)(6).

Description of Event or Problem

THE CUSTOMER INITIALLY QUESTIONED A LOW RESULT FOR ONE SAMPLE FROM A PATIENT TESTED FOR N-TERMINAL PRO B-TYPE NATRIURETIC PEPTIDE (PROBNP). IT WAS DETERMINED THIS SAMPLE WAS COLLECTED IN A CAPILLARY TUBE, WHICH IS NOT SPECIFIED FOR USE WITH THE PROBNP ASSAY. THE CUSTOMER ALSO NOTED THAT THEY NEEDED TO USE VASELINE WHEN PUNCTURING THE SKIN OF THE PATIENT AND IT MAY HAVE BEEN POSSIBLE THAT SOME OF IT WAS TRANSFERRED TO THE TUBE, WHICH MAY HAVE AFFECTED THE RESULT. THE CUSTOMER LATER STATED ON (B)(6) 2016 THAT THEY HAD TWO MORE SAMPLES COLLECTED FROM THE PATIENT ON TWO CONSECUTIVE DAYS AND EACH OF THESE SAMPLES HAD LOW PROBNP RESULTS. THE FIRST SAMPLE WAS COLLECTED WITH A CAPILLARY TUBE AND THE SECOND SAMPLE WAS COLLECTED IN A NORMAL SAMPLE COLLECTION TUBE. MEASUREMENT DATES AND SPECIFIC RESULT DATA WERE NOT PROVIDED. ON (B)(6) 2016, THE CUSTOMER COLLECTED TWO ADDITIONAL SAMPLES FROM THE PATIENT. BOTH SAMPLES WERE COLLECTED VIA CANNULA AND WERE TESTED FOR PROBNP ON AN E411 ANALYZER. THESE SAMPLES HAD ERRONEOUS LOW PROBNP RESULTS THAT WERE REPORTED OUTSIDE OF THE LABORATORY. THE LOW RESULTS WERE SAID TO NOT BE CLINICALLY PLAUSIBLE FOR THIS PATIENT COMPARED TO PRIOR RESULTS. THE FIRST SAMPLE, FROM A PLASMA TUBE, RESULTED AS 55.63 NG/L WHEN TESTED WITH AN OLDER PROBNP REAGENT PACK. THE SECOND SAMPLE, FROM A SERUM TUBE, RESULTED AS 57.25 NG/L WHEN TESTED WITH A NEW PROBNP REAGENT PACK. NO ADVERSE EVENTS WERE ALLEGED. THE E411 ANALYZER SERIAL NUMBER WAS (B)(4). THE TWO SAMPLES FROM (B)(6) 2016 WERE PROVIDED FOR INVESTIGATION. INVESTIGATIONS OF THE SAMPLES CONFIRMED THE CUSTOMER'S RESULTS. FURTHER CLARIFICATION IS NOT POSSIBLE WITH THE AVAILABLE INFORMATION AND MEASURED RESULTS.