Date of Award

January 2012

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

David G. Silverman

Subject Area(s)

Medicine, Health care management


Measuring individual patient outcomes in the intensive care unit (ICU) has been a difficult task at best. Multiple ICU scoring systems have been developed which are best used for assessing overall ICU performance. Recently the APGAR score, a simple metric based on worst cardiovascular parameters in operating room, has been designed to determine morbidity and mortality in post-surgical ICU patients. Cardiovascular instability is very likely an important key to assessing and predicting poor outcomes. Beat-to-beat variability and blood pressure variability have been well characterized. The hypothesis for this study was that cardiovascular instability, as measured by lability in heart rate and blood pressure during the ICU stay, yields information that is different than the current ICU and APGAR scoring systems. This study captured ICU data on 10 post-operative patients at 5 minute intervals. Fluctuations over ICU stay in blood pressure and heart rate were measured as range, interquartile range, and coefficient of variation. These measures were analyzed to determine if they correlated with ICU and APGAR scores. Our results show that range, interquartile range, and coefficient of variation for heart rate, arterial systolic blood pressure, and diastolic blood pressure do not correlate with the scores and so provide different information that may better reflect a patient's instability and thus outcomes. From this work, we hope to develop more studies especially focused on morbidity and mortality outcomes.