The Science Journal of the American Association for Respiratory Care

2005 OPEN FORUM Abstracts

Automated Quality Control for blood gas instrumentation: Expectations and Experiences



--Tim Frymyer, BS, RRT, David Mussetter, BA, RRT, Michael Trevino, MS, RRT, Gary Weinstein, MD, FCCP, Presbyterian Hospital of Dallas, Dallas, Texas.

Background: Our 903-bed metropolitan hospital averages approximately 33,000 blood gas samples annually. We utilized Instrumentation Laboratoriesâ 1610ä bench top blood gas analyzers with manual quality control protocols for 8 years. On weekdays, the pulmonary lab staff would manually run quality control (QC) at 7:00 am and 2:30 pm. The clinical staff was responsible for QC at 11:00 pm, as well as all the weekend QC. We were concerned that our clinicians had to prioritize between reliably running QC at preset intervals or giving timely direct patient care. To achieve this balance, we replaced our instrumentation with Roche Laboratories AVL Omniâ series blood gas analyzers with AutoQCä. We theorized the automated process would reduce technician time, address our QC timeliness and compliance concerns and allow the clinicians to focus on bedside care.

Method: The new blood gas instruments were set up with appropriate clinically significant ranges for QC, calibration cycles and internal QC rules. The QC was set to be analyzed in precise eight hour intervals, repeating after one failure before deactivating the failed analyte(s). Our pulmonary lab technicians received advanced training. The remaining staff was trained in basic use and troubleshooting; for example, calibrating the instrument for ready or forcing a non-scheduled QC measurement. Our staff was then instructed to notify the pulmonary lab technician if an analyte was not "ready" for analysis after simple troubleshooting was performed.

Results: The QC material ran as programmed every eight hours. However, there were some unexpected challenges with the automated QC process. One of our 4 instruments had a QC failure rate > 5%, the rate deemed acceptable by Roche. In most cases, failed results were either recorded as dash (-) marks in the onboard data manager or were well outside the acceptable range. It remains difficult to ascertain why these occur without direct technician observation of the QC material during analysis. We surmised there could be any number of failures including how the ampule was seated, aspirated, measured, as well as the calibration status of the instrument at the time of analysis. Timely troubleshooting was also identified as a problem with automation. An analyte failure would often go unnoticed until an ABG analysis was needed. Our clinicians would either attempt troubleshooting before analysis or use another blood gas instrument located elsewhere. Additionally, notification delays often cause the troubleshooting to become more extensive, costly or time consuming. Frequently, our clinicians would begin troubleshooting by forcing an unscheduled repeat measurement, only to observe the same error or failure. As a result, we incurred depletion of QC material causing us to curb troubleshooting activities amongst the clinical staff.

Conclusion: Our experience with automated QC in this instrumentation was initially met with great enthusiasm but was quickly tempered by the realization of its limitations. Automated QC is not a panacea for blood gas lab managers. The associated direct and indirect costs of the material, troubleshooting, timely review and delays in patient care must all be weighed when making decisions on new instrumentation. We realized the technician must continue to be an integral part of the daily QC process. The change to the Roche Laboratories AVL Omniâ series blood gas analyzers with AutoQCä brought us mixed results. They did provide consistent and timely QC measurements, but overall technician time spent with the instruments and their associated costs were not reduced.

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