The investigation determined that multiple non-reproducible, lower than expected vitros phyt results were obtained from multiple patient samples on two vitros 5600 integrated systems.A likely assignable cause for the lower than expected vitros phyt results could not be determined, however, an unexpected instrument, a reagent issue, or user error due to inappropriate pre-analytical sample handling cannot be ruled out as contributing factors.The within run phyt precision testing was unacceptable, indicating the instrument was not performing as intended, however repeat within run phyt testing was acceptable without changing the state of the analyzer.Therefore the vitros 5600 system contribution to the event could not be ruled out or confirmed.Based on review of historical quality control, there was no indication the vitros phyt microslide reagent lot 2614-0158-8794 malfunctioned.No quality control results were provided for the alternate reagent lot 2614-0158-8775, used on the vitros j2 system, therefore, although there is no evidence the reagent lot malfunctioned, it cannot be ruled out as a contributing factor to the event.Pre-analytical sample processing could not be ruled out as a contributing factor, as the customer was unable to provide information regarding the specific centrifugation conditions used to pre-analytically handle the patient sample in question, therefore it is unknown if they are following the sample device manufacturer's recommended guidelines for sample centrifugation.Cellular debris, due to poor sample preparation, may have been present in the affected sample, although this could not be confirmed.
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A customer obtained multiple non-reproducible, lower than expected vitros phenytoin (phyt) results from multiple patient samples processed using vitros chemistry products phyt slides on two vitros 5600 integrated systems (j1 and j2).J1: vitros phyt reagent lot 2615-0158-8794.Patient a: vitros result 3.4 and 4.6 ug/ml vs.The expected result of 10.9 ug/ml.Patient c: vitros result 6.1 ug/ml vs.The expected result of 12.9ug/ml.Patient 2: vitros result 11.0 ug/ml vs.The expected result of 16.3 ug/ml.Patient 6: vitros result 3.3 and 8.2ug/ml vs.The expected result of 10.9 ug/ml.Patient 7: vitros result 16.2 and 23.4 ug/ml vs.The expected result of 35.7ug/ml.Patient 8: vitros result 3.0 and 3.0 ug/ml vs.The expected result of 24.7ug/ml.Patient 9: vitros result 12.5 ug/ml vs.The expected result of 16.3ug/ml.Patient 13: vitros result 3.0 ug/ml vs.The expected result of 7.5ug/ml.Patient 14: vitros result 3.0 ug/ml vs.The expected result of 7.5ug/ml.Patient 15: vitros result 9.4ug/ml vs.The expected result of 25.2 ug/ml.J2: vitros phyt reagent lot 2615-0158-8775 patient 7: vitros result 27.7 ug/ml vs.The expected result of 35.7ug/ml.Patient 8: vitros result 3.0 and 3.0 ug/ml vs.The expected result of 24.7ug/ml.Patient 9: vitros result 11.3 ug/ml vs.The expected result of 16.3ug/ml.Patient 13: vitros result 3.0 ug/ml vs.The expected result of 7.5ug/ml.Patient 15: vitros result 5.3 ug/ml vs.The expected result of 25.2 ug/ml.The customer reported the result for patient a (3.4 ug/ml) to the clinician; however, the higher than expected result was questioned by the clinician and the corrected report was released.No additional results were reported from the laboratory, as the additional patient samples were tested for investigation purposes only.Ortho has not been made aware of any allegations of actual patient harm occurring as a result of the events.This report is number sixteen of twenty mdr's for this event.Twenty 3500a forms are being submitted for this event as twenty devices were involved.(b)(4).
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