Ultrasound Measurement of Reactive Hyperemia in Critical Care
| Status: | Recruiting |
|---|---|
| Conditions: | Hospital, Hematology |
| Therapuetic Areas: | Hematology, Other |
| Healthy: | No |
| Age Range: | 18 - Any |
| Updated: | 3/2/2019 |
| Start Date: | January 2013 |
| End Date: | July 2022 |
| Contact: | Amy MK Rovitelli, MS |
| Email: | Amy_Rovitelli@urmc.rochester.edu |
| Phone: | (585) 276-3144 |
Ultrasound Measurement of Reactive Hyperemia in Critical Care: Prognostic and Pathophysiologic Significance
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.
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.
Inclusion Criteria:
- Patients admitted to University of Rochester Medical Center ICU services with 2 of the
4 systemic inflammatory response syndrome (SIRS) criteria and acute organ dysfunction
will be considered for enrollment.
- Healthy control subjects >= 18 years of age will be recruited from the University and
Rochester region at large.
Exclusion Criteria
- Critically ill patients:
1. Refusal of patient or designated surrogate decision-maker to provide written
informed consent, or inability to obtain consent within 48 hours of diagnosis
2. Attending physician refusal
3. Hematocrit (Hct) < 21%
4. Acute bleeding requiring PRBC transfusion
5. History of chronic, dialysis dependent renal failure
6. End-stage liver disease and Child-Pugh Grade C
7. History of organ, bone marrow, or stem cell transplant
8. Pregnancy
9. Cardiac surgery (including ventricular assist device prior to first sample
collection)
10. Do not resuscitate at screening or plans for withdrawal of life support imminent
11. Suicide attempt or intentional drug overdose;
12. Jehovah's witness
- Healthy Control subjects:
1. Absent doppler signal in brachial or radial arteries.
2. Asymmetric cyanosis, poor capillary refill or cold temperature
3. Known venous thrombosis or there is asymmetric swelling (arm circumference > 2
inches larger than opposite side).
4. Evidence of inflammation or impaired skin integrity of the involved limb.
5. History of surgery involving the blood or lymphatic vessels of this limb,
including axillary lymph node dissection, will preclude this testing.
6. History of Anemia or G6PD deficiency
We found this trial at
1
site
601 Elmwood Avenue
Rochester, New York 14642
Rochester, New York 14642
(585) 275-2100
Phone: 585-276-3144
Univ of Rochester Medical Center One of the nation's top academic medical centers, the University...
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