Description of Event or Problem · 1
IN 2005, A PT WITH METHICILLIN RESISTANT STAPHAUREIS WAS TESTED FOR VANCOMYCIN ON AN ADVIA CENTAUR BY THE HOSPITAL LABORATORY, THE INITIAL RESULT WAS >90 UG/ML. BASED ON THIS RESULT FURTHER PT TREATMENT WITH THE ANTIBIOTIC VANCOMYCIN WAS WITHHELD. THE HOSPITAL CONTINUED TO OBSERVE THE PT AND TO MONITOR VANCOMYCIN LEVELS, A RETEST THE NEXT DAY GAVE A RESULT OF 70.2 UG/ML. ALL QUALITY CONTROL WAS IN RANGE AND ALL INDICATIONS WERE THAT THE SYSTEM WAS PERFORMING AS EXPECTED. BECAUSE THE VANCOMYCIN LEVELS HAD NOT GONE DOWN AS EXPECTED. THE HOSPITAL LABORATORY SENT THE SAMPLES TO A REFERENCE LABORATORY FOR TESTING WITH AN ALTERNATIVE METHOD. THE ALTERNATIVE METHOD AT THE REFERENCE LABORATORY RESULTED IN A 5.7 UG/ML FOR THE SAMPLE DRAWN ON FIRST. IN ADDITION, THE HOSPITAL LABORATORY RAN DILUTIONS AT 1:5 AND 1:3 WHICH GAVE RESULTS OF 19.85 UG/ML AND 25.77 UG/ML RESPECTIVELY. AT THIS TIME THE LABORATORY PATHOLOGIST SUSPECTED HETEROPHILIC ANTIBODY INTERFERENCE AND THE INITIAL SAMPLES WERE SENT TO BAYER'S LABORATORIES FOR FURTHER ANALYSIS. FURTHER TESTING AT BAYER'S LABORATORIES CONFIRMED THE OBSERVATIONS AT THE HOSPITAL LABORATORY AND A POSSIBLE PRESENCE OF A HETEROPHILIC ANTIBODY INTEFERENT. THE INSTRUCTIONS FOR USE FOR THE VANCOMYCIN ASSAY ON THE ADVIA CENTAUR INDICATE HETEROPHILIC ANTIBODY INTERFERENCE AS A LIMITATION OF THE ASSAY. FOR MEDICAL DEVICE REPORTING PURPOSES THIS EVENT IS CONSIDERED CLOSED.