The Influence of a Warmed Surgical Bandage System on Subcutaneous Tissue Oxygen Tension After Cardiac Surgery

Study Overview
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Brief Summary
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Warmed Surgical Bandage may improve tissue oxygenation and thus on the long run reduce wound infections

Detailed Description
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Wound infections are common and serious complications of anesthesia and surgery. The morbidity associated with surgical infections is considerable and includes substantial prolongation of hospitalization. The wound infection risk in patients undergoing cardiac surgery ranges from 0.8 to 17.7% including both superficial and deep sternal infections. Major factors influencing the incidence of surgical wound infection other than site and complexity of surgery, underlying illness, timely administration of prophylactic antibiotics, intraoperative patient temperature, hypovolemia and tissue oxygen tension. The primary determinant of tissue oxygen availability is local perfusion. Thermoregulatory status is one of the major factors influencing tissue perfusion. Local warming induces pre- capillary vasodilation and improves tissue oxygenation. Local warming of surgical wounds may provide a simple and inexpensive way to reduce perioperative wound complications. Specifically, we will test the hypothesis that Warm- Up therapy increases postoperative tissue oxygen tension in patients undergoing cardiopulmonary bypass.

Official Title
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The Influence of a Warmed Surgical Bandage System on Subcutaneous Tiisue Oxygen Tension After Cardiac Surgery

Conditions
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Cardiac Surgery

Intervention / Treatment
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* Device: conventional bandage
* Device: warming bandage


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients ≥18 years of age scheduled for elective cardiac surgery on normothermic cardio-pulmonary bypass will be invited to participate Exclusion Criteria: Emergency surgery Pre - or postoperative on intraaortic balloon pump Preoperative mechanical ventilation Postoperative respiratory failure Postoperative extracorporal membrane oxygenation Left ventricular function < 40% Fever (core temperature > 38 °C) or current infection No anticipated or no definitive primary closure of surgical wound.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: conventional bandage<br>conventional bandage on sternal wound after skin closure after cardiac surgery. conventional gauze covered with elastic adhesive (Medipore™ Dress-it) The designated bandage will be positioned in the operating room by the surgeons after the skin will be closed. The conventional elastic bandage consists of several layers of gauze covered with a special adhesive bandage | Device: conventional bandage<br> <br> |
| Active Comparator: warming bandage<br>The Warm-Up bandage consists of an adhesive shell and a foam frame that supports a clear window about one cm above the surface of the wound. A battery-powered heating card can then be inserted into the window to provide gentle warming of the wound. The surface temperature of heating card is fixed at 38°C, and heat is usually provided for two hours at a time. That is, the experimental bandage will be continuously applied to the wound and heated to 38°C using a two-hour on/off cycle. | Device: warming bandage<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tissue Oxygenation Levels |  | 2 years | 
| Tissue Oxygen Tension in the Sternal Wound | Tissue oxygen tension in the wound Tissue oxygen tension will be measured with a polarographic electrode system (Licox CMP, GMS Germany), the oxygen electrode will be calibrated with room air (154 mmHg) and then positioned within the silastic tonometer that will be inserted 2 3 cm lateral to the surgical incision. | 8 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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wound infection, tissue oxygen tension, local warming