System Analyzes Vital Signs to Diagnose Life-Threatening Bleeding
By monitoring patients in transit to trauma centers, an automated system that analyzes vital signs could significantly improve the ability to diagnose patients with life-threatening bleeding before they arrive at the hospital.
A research team from Massachusetts General Hospital, the U.S. Army, air ambulance service Boston MedFlight, and two other Boston trauma centers, field tested the Automated Processing of the Physiological Registry for Assessment of Injury Severity (APPRAISE) system, which analyzes blood pressure, heart rate, and breathing patterns during emergency transport.
The pattern-recognition capabilities provided by the APPRAISE system successfully identified 75 to 80 percent of patients with life-threatening bleeding, compared with 50 percent who were identified by standard clinical practice.
While the clinical information that ambulance crews call in to trauma centers was sufficient to determine the presence of a life-threatening hemorrhage in about half the patients we studied, many other patients were in a grey area and may or may not have been at risk of bleeding to death, said Andrew Reisner, M.D., from Massachusetts Generals Department of Emergency Medicine and senior author of a study published in the May issue of the journal Shock. Our study demonstrated that automated analysis of patients vital signs during pre-hospital transport was significantly better at discriminating between patients who did and did not have life-threatening hemorrhage. Receiving more reliable information before the patient arrives can help hospitals be ready for immediate surgery and replenishment of lost blood without wasting time and resources on false alarms.
Researchers developed software based on statistical techniques currently used in stock market trading and manufacturing to determine whether particular data points represent real problems and not random fluctuations. Consisting of an ultra-compact personal computer networked to a standard patient monitor, the system was installed in two MedFlight helicopters and collected data on more than 200 trauma patients transported to participating Boston hospitals. Researchers also analyzed vital signs data gathered manually by a Houston-based air ambulance system.
We are now working on a follow-up study to use this system in actual trauma care and will be measuring whether it truly leads to faster treatment of life-threatening hemorrhage and better patient outcomes, said Reisner, also an assistant professor of Emergency Medicine at Harvard Medical School. This approach could also be helpful for patients transported by ground ambulance and for hospitalized patients at risk of unexpected hemorrhage, such as during recovery from major surgery.