EP1080372A1

EP1080372A1 - Method and apparatus for background surveillance and detection of unsuspected aberrant clinical information

Info

Publication number: EP1080372A1
Application number: EP99918224A
Authority: EP
Inventors: Stephen E. Kellett
Original assignee: Bayer AG; Bayer Corp
Current assignee: Bayer AG; Bayer Corp
Priority date: 1998-05-21
Filing date: 1999-05-19
Publication date: 2001-03-07
Also published as: JP2002520684A; WO1999060410A1; CA2332773A1; AU3623799A

Abstract

A method and apparatus for providing background surveillance and detection of unsuspected aberrant clinical information. The capability of selecting to receive test results for a patient from one or more tests of a plurality of tests is provided, as well as the ability to receive test results that were originally not desired, but only on the condition that the undesired test results meet a predetermined threshold value, thus indicating an aberrant condition with the patient which must be addressed. As such, the amount of extraneous information which must be considered by the physician is minimized, resulting in a savings of time and money which would have been spent unnecessarily. The method and apparatus applies to a single test or to continuous testing of a patient. The method and apparatus are further useful as a quality control measurement tool.

Description

TITLE OF THE INVENTION

Method and Apparatus for Background Surveillance and Detection of Unsuspected Aberrant Clinical Information

CROSS REFERENCE TO RELATED APPLICATIONS Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR

DEVELOPMENT Not Applicable

BACKGROUND OF THE INVENTION

In the complex and cost conscious medical environment of the present day, physicians are often required to make decisions regarding the tradeoff between the cost and the benefit of the diagnostic information they obtain to assist them in making medical decisions. Broad screening approaches or batteries of tests which are not clinically warranted increase the cost of the health care provided, while rarely providing additional medical value. Much of the costs associated with the tests is the physician's time in interpreting the test results, while the cost of the actual test itself is minimal in comparison. Further, individual results in the barrage of information provided by a battery of tests can be easily overlooked by a physician during a stressful moment in the critical care environment, only to be later identified as indicative of a certain condition and denoting a certain course of action. Such actions may even lead to claims of malpractice, which further serves to increase the cost of providing adequate medical care. It would be desirable to provide a method for background surveillance and detection of unsuspected aberrant clinical information in which the physician is only notified of certain test results if the results indicate a condition which may have clinical benefits once identified. BRIEF SUMMARY OF THE INVENTION A method and apparatus for performing background surveillance and detection of unsuspected aberrant clinical information is presented. The capability of selecting to receive test results from one or more tests of a plurality of tests is provided, as well as the ability to receive test results that were originally not desired, but only on the condition that the undesired test results exceed a predetermined threshold value, thus indicating an aberrant condition with the patient which must be addressed. As such, the amount of extraneous information which must be considered by the physician is minimized, resulting in a savings of time and money as well as providing a higher quality of health care. The method and apparatus includes the performance of a single test or the performance of continuous testing and monitoring of a patient. The method and apparatus are further useful as a quality control measurement tool.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: Fig. 1 is a flow chart of the method of the present invention; Fig. 2 is a flow chart of an additional embodiment of the method of the present invention;

Fig. 3 is a print out of a first display screen showing the test selection portion of a particular embodiment of the present invention;

Fig. 4 is a print out of a second display screen directing that aspiration of the sample be started; Fig. 5 is a print out of a third display screen showing the aspiration time for taking the sample;

Fig. 6 is a print out of a fourth display screen directing that the aspiration of the sample be halted;

Fig. 7 is a print out of a fifth display screen showing the entry of patient/sample data;

Fig. 8 is a print out of a sixth display screen showing the results of the testing as the testing of the sample is being run; Fig. 9 is a print out of a seventh display screen showing that an alarm limit has been exceeded and asking whether this information should be displayed;

Fig. 10 is a print out of an eighth display screen showing the results being displayed including the results for the unselected test; Fig. 11 is a print out of a ninth display screen showing the test results for all the selected tests; and

Fig. 12 is a flow chart of a quality control method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION An analyzer or other sample testing device can provide a plurality of tests of a sample, for example a blood analyzer can provide tests for the tHb, pO2, pH etc., of a blood sample taken from a patient. Typically, a physician while require only a subset of the available tests. While only a subset of tests are determined to be of particular relevance by the physician, there may be other tests which would show a condition not originally thought to be existing in the sample being tested. The presently disclosed method and apparatus allows for a physician to select the tests thought to be most relevant and further provides the ability to monitor the output of other unselected tests should the results of these unselected tests meet a predetermined threshold, thus indicating an aberrant condition which typically requires immediate attention. This could be a single test, such as a blood test, or continuous testing such as the monitoring of a patient's blood while the patient is being mechanically ventilated.

Referring to Fig. 1, a flow chart of a first embodiment 1 of the presently disclosed method is shown. In a particular example, the presently disclosed method is useful for the detection of unsuspected carbon monoxide poisoning caused by an improperly functioning heating system or other combustion source. In this scenario, a patient presents himself to an emergency room of a hospital complaining of fatigue and headaches. These symptoms in this instance are rather non-specific and are associated with a wide variety of disorders.

At the first step 100, alarm thresholds are defined for at least one of the plurality of available tests the analyzer can perform. The defined alarm thresholds, when exceeded, indicate that that an aberrant condition exists which requires immediate attention. As shown in the next step 110 a selection is made by the physician as to which test results are to be reported. These test results will be reported to the physician irregardless of whether the selected tests have had alarm thresholds defined or if these alarm thresholds have been exceeded. The attending physician in this example may order a general blood screen in an attempt to identify the underlying cause of the symptoms experienced by the patient. The blood sample taken from the patient is then tested on the analyzer utilizing the method of the present invention.

The following step, step 120, recites that the selected tests are run on the sample, and the tests which were not selected but have had threshold limits defined are also run on the sample, although these tests which were not selected but have had threshold limits defined are run in the background. In this instance the physician has not elected to test for hemoglobin fractions as part of the testing operations selected, however an alarm threshold has been defined earlier for the different hemoglobin parameters. This alarm threshold may be a pre-established generic threshold, or a threshold specifically defined by the physician. At step 130, a determination is made as to whether any alarm thresholds of the unselected tests have been exceeded by the measurement of the sample. If any of the alarm thresholds of the unselected tests have been exceeded, then the test results for the selected tests and for the tests that have had their alarm thresholds exceeded are reported to the physician, even though these tests were not originally selected by the physician, as shown in step 140. If no alarm thresholds were exceeded on the unselected tests, then the results of the selected tests are reported, as shown in step 150. After the reporting of the selected tests results and any tests results that were not selected but exceeded their predetermined threshold, the testing of the sample is finished, as shown in step 160. In this instance the alarm threshold for carboxyhemoglobin level has been exceeded and is reported to the physician who is alerted to what could be or may be a life threatening situation if left undiscovered. The new information, which would not have been available without the presently disclosed method, can lead the attending physician to a rapid and accurate diagnosis and treatment of the carbon monoxide poisoning, and resolution of the underlying cause of the patient's condition. An additional example of where the presently disclosed method is particularly useful relates to the titration of Positive End Expiratory Pressure (PEEP) therapy on mechanically ventilated patients. Progressive increases in the level of PEEP can produce competing effects on the heart and lungs. At higher levels, the positive benefit of PEEP on lung performance and gas exchange can come at the expense of decreased cardiac function. Diminished cardiac function can produce poor perfusion and result in the generation of lactate, an indicator of inadequate tissue oxygenation. Lactate production can occur in the presence of acceptable blood gases or oxygen saturation, the normal tools for managing ventilation. Background surveillance and detection of elevated lactate levels are an indication for aborting any subsequent increases in PEEP, thus resulting in higher quality level of treatment for the mechanically ventilated patient.

A second embodiment 200 of the presently disclosed invention is shown generally in Fig. 2 and more particularly in Figs. 3-11. The method 200 is similar to the method 100 of Fig. 1 but allows the physician to consciously elect not to view parameters for which the results were not originally desired, but which the alarm threshold limit is exceeded. This may be useful in certain clinical procedures where the value is expected to be abnormal, such as in the period following administration of cardioplegic solutions. At the first step 100', alarm thresholds are defined for at least one of the plurality of available tests the analyzer can perform. The alarm thresholds, when exceeded, indicate that that an aberrant condition exists which requires immediate attention.

The next step 110' shows that a selection is made by the physician as to which test results are to be reported. Shown in Fig. 3 is a printout of a first display screen 400. This screen shows that a sample is going to be tested. The screen further shows that the testing of the sample for pH, pC0₂, p0₂, Na⁺, K⁺, Ca⁺⁺, GLU and HCT are selected. The testing for the level of Cl^" has not been selected. An alarm limit has previously been defined for a level of Cl^". Fig. 4 shows a second display screen 410 which directs the clinician to insert the syringe containing the sample material into the analyzer to begin aspiration of the sample. Fig. 5 shows the display screen 420 where the aspiration of the sample material from the syringe is timed. Fig. 6 show the display screen 430 which directs the clinician to remove the syringe from the analyzer thereby ending the aspiration of the sample. Fig. 7 shows the display screen 440 where the patient and sample information is entered. The following step, step 120', recites that the selected tests are run on the sample, and that the tests which were not selected but have had threshold limits assigned are also run on the sample. Fig. 8 shows the display screen 450 which shows the testing being performed on the sample. The ongoing results for the testing of Cl^" level are not shown since that test was not selected, however the testing for Cl^" level is actually occurring in the background.

At step 130' a determination is made as to whether any alarm thresholds have been exceeded by the testing of the sample. If any of the alarm thresholds of the unselected tests have been exceeded, then the physician is queried as to whether the results of the unselected tests are to be reported, as shown in step 135. Referring now to Fig. 9 a display screen 460 is shown. This screen indicates that a safety alarm limit (also known as SAFETY NET ™) has been exceeded and questions the clinician as to whether this information, even though originally not selected, should be displayed to the clinician. If the clinician desires to see the unselected test results than the YES box is selected; if the clinician does not desire to see the unselected test results the NO box is selected. If the results are desired, then as shown in step 140' the results of the selected tests and the results of the unselected tests that exceeded the alarm threshold limit are reported. Selection of the YES box shows the test results as shown in Fig. 10. The results of the Cl^" testing are shown along with the other selected tests results. If the results are not desired, or if none of the alarm thresholds have been exceeded, then as shown in step 150, the selected test results are reported without reporting any of the unselected tests results. Selection of the NO box shows the results as shown in Fig. 11. Here the display screen 480 shows only the test results for the selected tests and does not show the results for the unselected test even though the alarm limit for that test had been exceeded. The testing is then finished, as shown in step 160'.

The present invention may additionally be utilized as part of a quality control measurement system. A set of counters are provided which keep track of the number of times different tests which were unselected by the physician as part of the diagnosis of a patient's condition had their alarm threshold exceeded. If a high rate of this situation occurs for a particular physician, then the physician can be notified and a determination made as to why this is occurring. For example if a certain physician is constantly having results reported which are not requested, it may indicate that the physician needs to be aware of checking for a broader range of causes related to certain symptoms or that the physician is lacking in proper clinical knowledge with respect to testing for certain conditions given a particular set of symptoms. Further, an overall count can be maintained and observed on a timely basis to ensure that proper testing is being requested at appropriate times by comparing results month to month. If too small a number of thresholds alarm are being reported, than the doctors may be ordering too many tests. On the other hand, if a larger than usual number occurs, then the physician may need to prescribe more tests. As such, a level of quality control can be monitored and maintained. Referring now to Fig. 12, the counters utilized for quality control are initialized as shown in step 310. At the next step 100, alarm thresholds are defined for at least one of the plurality of available tests the analyzer can perform. The defined alarm thresholds, when exceeded, indicate that that an aberrant condition exists which requires immediate attention. As shown in the next step 110 a selection is made by the physician as to which test results are to be reported. These test results will be reported to the physician irregardless of whether the selected tests have had alarm thresholds defined or if these alarm thresholds have been exceeded.

The following step, step 120, recites that the selected tests are run on the sample, and the tests which were not selected but have had threshold limits defined are also run on the sample. The selected tests are run on the sample in the foreground, while the unselected tests which include a respective predefined threshold limit are executed in the background.

At step 130, a determination is made as to whether any alarm thresholds of the unselected tests have been exceeded by the testing of the sample. If any of the alarm thresholds of the unselected tests have been exceeded, then the counter(s) for the respective test(s) are updated as shown in step 320. Further, the test results for the selected tests and for the tests that have had their alarm thresholds exceeded are reported to the physician, even though these tests were not originally selected by the physician, as shown in step 140. If no alarm thresholds were exceeded on the unselected tests, then the results of the selected tests are reported, as shown in step 150. Periodically, each counter value is compared to an expected counter value as shown in step 155. After the reporting of the selected tests results and any tests results that were not selected but exceeded their predetermined threshold, the testing of the sample is finished, as shown in step 160. An automated analyzer is typically utilized to perform testing of a sample to determine characteristics of the sample. The automated analyzer is under control of a programmable processor which is coupled to a memory and to a user interface. The analyzer is capable of performing a plurality of tests on the sample. A user of the analyzer selects a first group of tests from the available tests to be run on the sample. Previous to this, certain ones of the plurality of tests may have had threshold limits defined. The selected tests are run on the sample under the control of the analyzer. While the selected tests are being run in the foreground, the analyzer is additionally running the unselected tests which have had threshold limits defined in the background. The user interface does not make the user aware that the unselected tests which have had threshold limits exceeded are in fact being run. When the analyzer has completed the testing of the sample, the user is provided with the tests results via the user interface. Additionally, the analyzer reports via the user interface the results of any of the unselected tests which were run in the background if the respective threshold limit was exceeded.

In a further embodiment the analyzer, instead of reporting the results of any of the unselected tests which had an alarm threshold exceeded for a respective test, questions the user as to whether the user desires to view the results of any unselected tests which have had an alarm threshold exceeded. The user responds either yes or no via the user interface. If the user indicated that the results were desired, the analyzer provides the results to the user. If the results are not desired, the analyzer then does not report the unselected test results.

Having described preferred embodiments of the invention it will now become apparent to those of ordinary skill in the art that various modifications could be made to the presently disclosed invention. Therefore, it is submitted that the invention should not be limited to the described embodiments but only by the spirit and scope of the appended claims.

Claims

CLAIMSI claim:

1. A method for background monitoring and detecting of aberrant clinical information using an automated analyzer comprising the steps of: performing a first group of tests in said automated analyzer comprising the steps of: defining a second group of at least one test from a plurality of tests, each test of said second group of at least one test having a respective threshold alarm limit; defining a third group of at least one test to be performed from said plurality of tests; and running said first group of tests wherein said first group of tests comprises said second group of at least one test and said third group of at least one test; reporting results, to a user, of said third group of at least one test; reporting results, to a user, of any test of said second group of at least one test that had an alarm threshold limit for the respective test exceeded; and failing to report, to a user, results of any test of said second group of at least one test that did not have an alarm threshold limit for the respective test exceeded.

2. The method of claim 1 wherein said step of performing a first group of tests comprises monitoring physiological parameters of a patient sample under test.

3. The method of claim 1 wherein said step of performing a first group of tests comprises analyzing a patient sample on an analyzer.

4. The method of claim 1 wherein said step of reporting results of any test of said second group of at least one test comprises the steps of: before reporting the results of any test of said second group of at least one test, querying, of a user, whether to report results of any test of said second group of at least one test that had the alarm threshold limit of the respective test exceeded; reporting, to a user, the results of any test of said second group of at least one test that had its respective alarm threshold limit exceeded if said results are requested; and failing to report, to a user, said results of any test of said second group of at least one test that had its respective alarm threshold limit exceeded if said results are not requested.

5. A method of monitoring the quality of care provided to a plurality of patients comprising the steps of: background monitoring and detecting of aberrant clinical information using an automated analyzer comprising the steps of: performing a first group of tests in said automated analyzer comprising the steps of: defining a second group of at least one test from a plurality of tests, each test of said second group of at least one test having a respective threshold alarm limit; defining a third group of at least one test to be performed from said plurality of tests; and running said first group of tests wherein said first group of tests comprises said second group of at least one test and said third group of at least one test; reporting results, to a user, of said third group of at least one test; reporting results, to a user, of any test of said second group of at least one test that had an alarm threshold limit for the respective test exceeded; and failing to report results, to a user, of any test of said second group of at least one test that did not have an alarm threshold limit for the respective test exceeded; maintaining, by said automated analyzer, a count of the number of times the results from said second group of at least one test were reported during a time period; and comparing, by said automated analyzer, said count to an expected count.

6. The method of claim 5 wherein said step of performing a first group of tests comprises monitoring physiological parameters of a patient under test.

7. The method of claim 5 wherein said step of performing a first group of tests comprises analyzing a patient sample on an analyzer.

8. The method of claim 5 wherein said step of reporting results of any test of said second group of at least one test comprises the steps of: before reporting the results of any test of said second group of at least one test, querying, of a user, whether to report results of any test of said second group of at least one test that had the alarm threshold limit of the respective test exceeded; reporting, to a user, the results of any test of said second group of at least one test that had an alarm threshold limit of the respective test exceeded if said results are requested; and failing to report, to a user, said results of any test of said second group of at least one test that had an alarm threshold limit of the respective test exceeded if said results are not requested.

9. An analyzer for analyzing a sample and for background monitoring and detecting of aberrant clinical information comprising: a processor; a memory coupled to said processor; a user interface coupled to said processor; wherein said analyzer, under control of said processor, is operative to perform a plurality of tests upon a sample, wherein said user interface is operative to allow a user to define alarm thresholds for a first group of tests from said plurality of tests and wherein said user interface is further operative to allow a user to select a second group of tests from said plurality of tests to be performed by said analyzer under control of said processor, wherein said analyzer is further operative to perform said first group of tests and said second group of tests under control of said processor, and wherein said user interface is further operative to report the test results of said second group of tests and to report the test results of said first group of tests which had the threshold limit of a respective test exceeded, and wherein said user interface is operative to not report the results of any test of said first group of tests that did not have a respective threshold limit exceeded and is not one of said second group of tests.

10. The analyzer of claim 9 wherein said plurality of tests performed by said analyzer under control of said processor comprise monitoring physiological parameters of a patient sample under test.

11. An analyzer for analyzing a sample and for background monitoring and detecting of aberrant clinical information comprising: a processor; a memory coupled to said processor; a user interface coupled to said processor; wherein said analyzer, under control of said processor, is operative to perform a plurality of tests upon a sample, wherein said user interface is operative to allow a user to define a threshold limit for each of a first group of tests from said plurality of tests, wherein said user interface is further operative to allow a user to select a second group of tests from said plurality of tests to be performed by said analyzer under control of said processor, wherein said analyzer is further operative to perform said first group of tests and said second group of tests under control of said processor, wherein said user interface is further operative to report the test results of said second group of tests and to query the user as to whether to report the test results of said first group of tests which had the threshold limit of a respective test exceeded, wherein said user interface is operative to report the results of any test of said first group of tests that had a respective threshold limit exceeded if the results are requested by the user, and wherein said user interface is operative to not report the results of any test of said first group of tests that did not have a respective threshold limit exceeded if the results are not requested by the user.

12. An analyzer for analyzing a sample and for background monitoring and detecting of aberrant clinical information comprising: a processor; a memory coupled to said processor; a user interface coupled to said processor; wherein said analyzer, under control of said processor, is operative to perform a plurality of tests upon a sample, wherein said user interface is operative to allow a user to define a threshold limit for each of a first group of tests from said plurality of tests and wherein said user interface is further operative to allow a user to select a second group of tests from said plurality of tests to be performed by said analyzer under control of said processor, wherein said analyzer is further operative to perform said first group of tests and said second group of tests under control of said processor, wherein said user interface is further operative to report the test results of said second group of tests and to report the test results of said first group of tests which had the threshold limit of a respective test exceeded, wherein said user interface is operative to not report the results of any test of said first group of tests that did not have a respective threshold limit exceeded, and wherein said processor is operative to maintain in said memory a count of the number of times the results from a respective one of said first group of at least one test exceeded a respective threshold during a time period and to compare said count to an expected count stored in said memory.

13. The analyzer of claim 12 wherein said plurality of tests performed by said analyzer under control of said processor comprise monitoring physiological parameters of a patient sample under test.