| Abstract | Automated physiologic event detection and alerting is a challenging task in the ICU. Ideally
care providers should be alerted only when events are clinically significant and there is
opportunity for corrective action. However, the concepts of clinical significance and
opportunity are difficult to define in automated systems, and effectiveness of alerting algorithms
is difficult to measure. This paper describes recent efforts on the Simon project to capture
information from ICU care providers about patient state and therapy in response to alerts, in
order to assess the value of event definitions and progressively refine alerting algorithms. Event
definitions for intracranial pressure and cerebral perfusion pressure were studied by
implementing a reliable system to automatically deliver alerts to clinical users alphanumeric
pagers, and to capture associated documentation about patient state and therapy when the
alerts occurred. During a 6-month test period in the trauma ICU at Vanderbilt University
Medical Center, 530 alerts were detected in 2280 hours of data spanning 14 patients. Clinical
users electronically documented 81% of these alerts as they occurred. Retrospectively
classifying documentation based on therapeutic actions taken, or reasons why actions were not
taken, provided useful information about ways to potentially improve event definitions and
enhance system utility. |