As per the siemens investigation data, although, there is evidence of benzalkonium interference routinely throughout the use life this measurement cartridge, this particular sample was affected by a clot just prior to the suspect sample being run.This material caused perturbances on multiple sensors resulting in calibration drifts just after the suspect sample being run.Investigation: data from rp500 34960 was examined.The measurement cartridge in use, sn (b)(4), had been installed on (b)(4) 2014.There are numerous occurrences of benzalkonium interference at various points during use life of this cartridge; however, there is no evidence of contamination around the time of event.At 17:04 on (b)(6) 2014, a sample had been attempted which resulted in a d39 clot detected error.The suspect sample was run at 17:08 resulting in a na+ result of 160.5 mmol/l.The data suggests that the d39 clot detected error resulted in an obstruction in the sample path which caused perturbances on multiple sensors.The results indicate several sensors had different results suggesting a systemic issue, most likely related to the obstruction in the sample path over multiple sensors.At 17:19, a 1 point calibration occurred resulting in d2 drift errors on ph, na+, k+, and cl- sensors.The calibration repeated with all the same sensors failing calibration.A third 1 point calibration occurred and all sensors except for cl- passed calibration and were enabled.The sample was then repeated again with an na+ result of 138.9.
|