Elsevier

Resuscitation

Volume 82, Issue 11, November 2011, Pages 1387-1392
Resuscitation

Clinical paper
Longitudinal analysis of one million vital signs in patients in an academic medical center

https://doi.org/10.1016/j.resuscitation.2011.06.033Get rights and content

Abstract

Background

Recognition of critically abnormal vital signs has been used to identify critically ill patients for activation of rapid response teams. Most studies have only analyzed vital signs obtained at the time of admission. The intent of this study was to examine the association of critical vital signs occurring at any time during the hospitalization with mortality.

Methods

All vital sign measurements were obtained for hospitalizations from January 1, 2008 to June 30, 2009 at a large academic medical center.

Results

There were 1.15 million individual vital sign determinations obtained in 42,430 admissions on 27,722 patients. Critical vital signs were defined as a systolic blood pressure <85 mm Hg, heart rate >120 bpm, temperature < 35 °C or >38.9 °C, oxygen saturation <91%, respiratory rate ≤12 or ≥24, and level of consciousness recorded as anything but “alert”. The presence of a solitary critically abnormal vital sign was associated with a mortality of 0.92% vs. a mortality of 23.6% for three simultaneous critical vital signs. Of those experiencing three simultaneous critical vital signs, only 25% did so within 24 h of admission. The Modified Early Warning Score (MEWS) and VitalPAC Early Warning Score (VIEWS) were validated as good predictors of mortality at any time point during the hospitalization.

Conclusions

The simultaneous presence of three critically abnormal vital signs can occur at any time during the hospital admission and is associated with very high mortality. Early recognition of these events presents an opportunity for decreasing mortality.

Introduction

Rapid response teams have been implemented in a number of hospitals for assistance with the care of critically ill patients. The designation of particular vital signs as “triggers” for alerting rapid response teams have been derived from landmark studies in this field that were limited by relatively small datasets and often included only one measurement of vital signs1, 2 or measurement of vital signs only early in the hospital admission.3, 4, 5 Studying vital signs throughout the entire hospital stay is important because rapid response teams are called not only at admission, but at any time throughout the hospitalization.

The purpose of this study was to determine the prevalence and time of occurrence of critical vital signs throughout the hospital stay and examine their associated mortality. It was our intent to determine if the simultaneous occurrence of more than one critical vital sign at any time during the hospitalization was associated with in-hospital mortality and to validate prior scores.3, 6

In order to accomplish this, we were able to take advantage of the fact that vital signs at the medical center under study are entered electronically into a computer database. We were therefore able to analyze a very large amount of data (>1 million vital sign sets) in a large number of admissions (42,430). In addition, code status could be determined in individuals with the highest morbidity.

Section snippets

Methods

This was a retrospective study approved by the Wake Forest University School of Medicine Institutional Review Board.

Results

There were 1.15 million individual vital sign determinations obtained in 42,430 admissions on 27,722 patients between January 1, 2008 and June 30, 2009. A complete set of vital signs (level of consciousness, pulse oximetry reading, blood pressure, temperature, respiratory rate, and pulse) was present in 71.9% of measurements, and there was one missing vital sign out of 6 in 12.2%, 2/6 missing in 4.3%, 3–5/6 missing in 11.6%. The most common missing vital signs were temperature (17.8%) and pulse

Discussion

The simultaneous occurrence of three or more critical vital signs was more likely to occur early in the hospital admission (38% occurring within 48 h of admission), but could occur at any time, with 40% occurring greater than 5 days after admission. We found that a simple summation score of critical vital signs was highly predictive of in-hospital mortality. We were able to validate the MEWS and VIEWS as well, and show that these scores are predictive not only at the time of admission but also

Conflict of interest statement

There are no financial and/or personal relationships with other people or organizations that could inappropriately influence this work.

Acknowledgements

Funds were provided by Wake Forest University School of Medicine for statistical analysis of the data. The study sponsors did not participate in study design, data collection, analysis, interpretation of data or in the writing of the manuscript or the decision to submit the manuscript for publication. Work complies with the principles laid down in the Declaration of Helsinki.

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A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2011.06.033.

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