The Pneumatic Tourniquet Technique for Endoscopic Radial Artery Harvest; Does it Affect Patient Hemodynamics?

Study Overview
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Brief Summary
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This study aims to investigate the effect of the pneumatic tourniquet technique on the patients' hemodynamics; heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Detailed Description
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Coronary artery bypass graft surgery (CABG) is the most common cardiac surgical procedure. Radial artery of the non-dominant hand with better ulnar collaterals is preferred over the saphenous vein because of long term patency of the radial artery. Radial artery is the preferred second or third arterial conduits for vessels with sub occlusive stenosis. There are two techniques of radial artery harvesting; open and endoscopic techniques. Endoscopic radial artery harvesting (ERAH) is increasing and it is possible but the evidence regarding its safety is scarce. ERAH is cosmetically better than the open technique. ERAH technique is performed after applying a tourniquet over the distal arm proximally to the elbow. Allen test will be done first and if the hand has a good blood supply through the ulnar artery, the tourniquet pressure is increased 75-100 mmHg over the systolic pressure and the tourniquet time is kept under one hour and the left radial artery will be endoscopically harvested. During the time of tourniquet inflation, there is ischemia of the forearm with subsequent cellular ischemic changes like; cellular acidosis, cellular edema, and activation of cellular apoptosis. On deflating the tourniquet, there is reperfusion of the limb and development of ischemic / reperfusion injury with a subsequent increase of inflammatory mediators and reactive oxygen species (ROS). These changes may be associated with some hemodynamic instability that might be dangerous, especially in patients with ischemic heart disease (IHD).

Official Title
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The Pneumatic Tourniquet Technique for Endoscopic Radial Artery Harvest; Does it Affect Patient Hemodynamics?

Conditions
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Ischemic Heart Disease, Coronary Artery Bypass Graft

Intervention / Treatment
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* Procedure: Pneumatic tourniquet, endoscopic left radial artery harvesting


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Listed for CABG surgery with the use of ERAH technique. Exclusion Criteria: Emergency CABG surgery. CABG plus any other cardiac surgery. The use of inopressor drugs before ERAH

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| endoscopic left radial artery harvesting<br>single group of 32 patients listed for coronary artery bypass surgery with endoscopic radial artery harvesting. | Procedure: Pneumatic tourniquet, endoscopic left radial artery harvesting<br>* Endoscopic radial artery harvesting technique is performed after applying a tourniquet over the distal arm proximally to the elbow. The tourniquet pressure is increased 90 mmHg over the systolic pressure and the tourniquet time will be monitored. he changes in Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) will be assessed before and after deflating the tourniquet every 5 minutes for 30 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| heart rate | HR will be recorded at inflating the tourniquet and every five minutes for thirty minutes. HR will be recorded at tourniquet deflation and every five minutes for total of thirty minutes. | the changes in HR are being assessed at baseline for 30 minutes and for 30 minutes of deflating the tourniquet. | 
| systolic blood pressure | SBP will be recorded at inflating the tourniquet and every five minutes for thirty minutes. SBP will be recorded at tourniquet deflation and every five minutes for total of thirty minutes. | the changes in SBP are being assessed at baseline for 30 minutes and for 30 minutes of deflating the tourniquet. | 
| diastolic blood pressure | DBP will be recorded at inflating the tourniquet and every five minutes for thirty minutes. DBP will be recorded at tourniquet deflation and every five minutes for total of thirty minutes. | the changes in DBP are being assessed at baseline for 30 minutes and for 30 minutes of deflating the tourniquet. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phenylephrine use | 0 microgram of phenylephrine will be used after deflating the tourniquet if systolic blood pressure is lower than 100mmHg. | The phenylephrine use ( for SBP less than 100 mmHg) will be recorded for one hour |