Bone Fractures Multiple Clinical Trial
Official title:
Non-invasive Assessment of Perfusion and the Risk of Wound Complication in High Risk Surgical Incisions
This is a prospective cohort pilot study. The primary purpose is to report the perfusion status of the surgical field in at risk surgical incisions. The secondary purposes are to describe the relationship between perfusion status and wound healing status and complications, and to describe the relationship between infrared digital thermography perfusion readings and the timing of propofol infusion. The research intervention will be photographs taken of the wound on the injured extremity, with a Forward-Looking Infrared (FLIR) camera, for the purpose of assessing perfusion status and skin temperature at the surgical site.
Patients with qualifying injuries will be identified at the time of injury. There will be no
deviation from standard of care for these patients outside of the acquisition of the FLIR
image. Standard emergent management of these injuries including but not limited to reduction,
immobilization, and acquisition of advanced imaging will take place. Pre-operative discussion
of the risks and benefits of surgical management will occur and informed consent obtained.
Propofol is a commonly used anesthetic agent. However, propofol is also a vasodilating agent,
which acts by blocking sympathetic tone. Limited worked has been done to evaluate the effects
of propofol administration on the FLIR imaging data acquisition. A single study used FLIR to
look at tissue perfusion after propofol infusion in children. In this study, the primary
concern was whether infrared imaging could replace or augment, serial blood pressure and
heart rate measurements, or other invasive monitoring measurements in patients undergoing
general anesthesia with the use of vasodilatory agents, such as propofol. The authors' goal
was to "assess the ability of the thermal imager to trend heat loss that registers as skin
temperature from propofol-mediated vasodilation and study reversibility as propofol levels
drop and vascular tone returns." This leaves a void regarding surgeons' understanding of the
optimal timing of FLIR perfusion assessment and the reliability of measurements obtained pre
and post propofol infusion.
In order to better understand the effects of propofol and determine the optimal time for
determining perfusion with the FLIR camera, the investigators will take a first reading in
the pre-operative holding area, prior to the administration of any propofol or other
vaso-active agent (as described below). Once in the operating room, after the induction of
anesthesia but prior to application of any topical cleansing or cooling products to the skin,
the participant will be transferred to the operating room table and placed on a clean, white
sheet and blankets will be removed from both lower extremities. The planned surgical
incision(s) to be used will be drawn on the skin by the most senior surgeon. Next, a clinical
photo and a FLIR image will be obtained at 90 degrees to the skin, and 1 meter from the
surface of the skin at the site of each planned incision. One researcher has successfully
used a protocol of taking images at perpendicular to the skin and 1 meter distance and
demonstrated that deviation of as much as 20 degrees from the perpendicular and 0.5m of
distance has negligible effect on readings. A set of control photos, identical to the ones
obtained on the injured extremity will be obtained on the contralateral, non-injured
extremity. A physician who is part of the surgical team who is trained in the use of the FLIR
camera will obtain the images. At the time of image acquisition, results of the wrinkle test
at each incision, patient body temperature, room temperature and humidity will be recorded.
Analysis of the FLIR images will involve averaging the tissue perfusion in a box drawn with 1
cm borders around the planned incision site as well as the entire area imaged. This will be
compared to the control, the contralateral uninjured extremity.
Participants will receive standard operative management of these injuries with standard of
care post-operative management.
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