Representative charting of vital signs in an intensive care unit

An automatic vital signs charting system had been operational in the intensive care units of our hospital for over 10 years, but the system was susceptible to non-representative transients in the data. A median selection rule was implemented to make the system less susceptible to transients. After implementation of the median rule, we examined (1) the agreement of the resulting medians and the values that would have been reported using the previous "real-time" system and (2) the frequency of occurrence of "out-of-range" values for each system. The median value system was found to improve the representativeness of the recorded data. Improved representativeness will enhance the usefulness of reports, but more importantly will enable us to use the resulting data as inputs to computerized practice protocols and other computerized decision support applications.