Ultrasound Measurement of Reactive Hyperemia in Critical Care (URHC)
The investigators hypothesize that doctors and nurses can undergo a brief period of training and then use ultrasound to accurately measure blood flow in a forearm artery after a brief period when this flow is interrupted with a blood pressure cuff, a measurement the investigators call reactive hyperemia. Reactive hyperemia indicates whether the small blood vessels in the body are healthy -- lower reactive hyperemia indicates worse small blood vessel function. When measured by experienced ultrasound experts, low reactive hyperemia strongly predicts death in critically ill patients with infection (severe sepsis).
The investigators are conducting this study to determine if doctors and nurses, without specific pre-existing expertise in ultrasound, can be trained to make these measurements accurately. If so, the investigators will prove that these measurements can be applied reliably in real-world practice.
The investigators also hypothesize that reactive hyperemia predict the outcomes of illness not just in patients with severe infection, but in other critically ill patients as well.
Finally, the investigators hypothesize that reduced blood flow after blood pressure cuff occlusion is linked with other abnormalities of blood, previously identified in critically ill patients. For example, red blood cells from patients with severe sepsis have been shown to be stiffer than normal, so they are less able to flow along the small blood vessel passages of the body. Red blood cells become stiffer when there is a certain type of stress in the body known as "oxidative stress."
If the investigators show that low reactive hyperemia, stiff red blood cells, and oxidative stress are linked, the investigators hope to develop new treatments that reduce oxidative stress, reduce the stiffness of red blood cells, and in turn improve reactive hyperemia. Improvements in reactive hyperemia indicate improvements in small blood vessel function. Better small blood vessel function means better delivery of oxygen throughout the body. The investigators believe that this will improve outcomes for critically ill patients.
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Ultrasound Measurement of Reactive Hyperemia in Critical Care: Prognostic and Pathophysiologic Significance|
- hospital mortality [ Time Frame: vital status at hospital discharge, an expected average of 3 weeks ] [ Designated as safety issue: No ]
Biospecimen Retention: Samples With DNA
Blood and urine specimens will be obtained within 48 hours of diagnosis of severe sepsis or severe non-infectious systemic inflammatory response syndrome. Subsequent blood and urine samples will be obtained 3-5 days after the first set of samples, within 48 hours of ICU discharge, and within 48 hours of hospital discharge. Samples will analyzed immediately or stored at -80 degrees celsius until use.
|Study Start Date:||January 2013|
|Estimated Study Completion Date:||January 2017|
|Estimated Primary Completion Date:||January 2016 (Final data collection date for primary outcome measure)|
Patients with severe sepsis or septic shock
non-infected critically ill
Patients with severe non-infectious systemic inflammatory response syndrome
|Contact: Kathleen L. Falkner, R.N., B.S.N.||(585) 276-3144||Kathleen_Falkner@urmc.rochester.edu|
|United States, New York|
|University of Rochester Medical Center||Not yet recruiting|
|Rochester, New York, United States, 14642|
|Contact: Kathleen L. Falkner, R.N., B.S.N. 585-276-3144 Kathleen_Falkner@urmc.rochester.edu|
|Sub-Investigator: Orren Wexler, M.D.|
|Sub-Investigator: Rodel Banal, M.D.|
|Principal Investigator:||Anthony P. Pietropaoli, M.D., M.P.H.||University of Rochester|