Virtual Intensive Care Can See You Now

Clinical warning system cuts wires of a traditional ICU

(RxWiki News) In addition to being costly, hospital intensive care units are constrictive for patients. Hoping to remedy that, one medical facility is testing the notion of a virtual intensive care unit where patients are free of wires and beeping machines.

A clinical warning system, capable of taking blood oxygen and heart rate readings up to twice a minute for at-risk patients, is currently being tried out at Barnes-Jewish Hospital in St. Louis.

"Ask your physician about wireless hospital monitoring."

Chenyang Lu, a computer scientist at Washington University in St. Louis and principal investigator for the prototype-network trial, said the goal is to create a virtual ICU that allows patients to move around freely. Lu said his newly designed system is part of a new field called body sensor networks or wireless health that could change the future of medicine.

The warning system is currently being tested in the hospital's cardiac step-down unit, an intermediate level of care for those who no longer need to remain in ICU, but need more oversight than ordinary patients.

Patients in the unit wear a telemetry pouch around their necks and a pulse oximeter on their finger to measure blood oxygen and heart rate. Sensors then send the data to a base station, where it is saved in a database. Data can then be compared with other information in a patient's electronic medical record such as lab tests.

Vital signs and other information sent from patient readings are continually studied by a machine that is capable of spotting signs of clinical deterioration. If it finds such indications, the system automatically calls a nurse by cell phone, requesting that they check on the patient.

Dr. Thomas C. Bailey, a professor in the School of Medicine, who is working with Lu on the system, said clinical deterioration is a major concern for every hospital. He said that between 4 percent and 17 percent of all hospitalized patients suffer an adverse event such as a heart attack. Often vital signs change up to six hours before such an event, allowing a clinical warning system to alert medical staff.

Data from the clinical warning system was found to be accurate more than 99 percent of the time. Sensing reliability was lower with an 81 percent success rate. Patient gesturing could cause short failures, and oximeters sometimes fell off or were removed by patients. It was also found that nail polish could block readings. To better deal with disconnections, an alarm would be sent if data failed to arrive for 10 to 15 minutes.

A next generation network is currently being developed and tested at the hospital. The new system will alert nursing staff when new clinical data is added to an electronic medical record. It also will identify clinical deterioration based on both real-time data collected by wireless sensors and clinical data already in medical records.

Before actual implantation, a prototype network was installed at the hospital from June 2009 through January 2010. That network did not alert nurses. Instead reports and vital signs were later reviewed to see if it could correctly identify patient deterioration. The current feasibility study will be presented at the American Medical Informatics Association Annual Symposium in October.

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Review Date: 
August 9, 2011