Efficacy of Lower Tourniquet Pressure During Total Knee Arthroplasty

Study Overview
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Brief Summary
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This study aims to determine whether the lower tourniquet pressure, which is set by adding 120mmHg (millimeter of mercury) on the systolic blood pressure just before tourniquet inflation, are efficient and safe during total knee arthroplasty, compared with the conventional tourniquet pressure: 150mmHg above the systolic blood pressure before tourniquet inflation.

Detailed Description
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We will compare the two groups of patients undergoing total knee arthroplasty, which the tourniquet pressure will be set differently: systolic blood pressure plus 120mmHg vs. systolic blood pressure plus 150mmHg, the conventional method, in terms of efficacy and safety.

Official Title
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The Efficacy of Using Lower Tourniquet Pressure During Total Knee Arthroplasty: Comparison With Conventional Tourniquet Pressure Group

Conditions
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Osteoarthritis

Intervention / Treatment
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* Procedure: Low tourniquet pressure
* Procedure: Conventional tourniquet pressure


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patients undergoing total knee arthroplasty Exclusion Criteria: Systolic blood pressure measured at ward > 200mmHg Thigh circumference > 78cm Anesthesia other than spinal anesthesia Simultaneous bilateral total knee arthroplasty The patients who disagreed the enrollment of this study

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 90 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional tourniquet pressure<br>The patients in this group will undertake total knee arthroplasty under conventional tourniquet pressure, which will be set as the pressure added by 150mmHg on the last systolic blood pressure just before tourniquet inflation. | Procedure: Conventional tourniquet pressure<br>* Tourniquet pressure set as 150mmHg above the systolic blood pressure just before tourniquet inflation<br>|
| Experimental: Low tourniquet pressure<br>The patients in this group will undertake total knee arthroplasty under low tourniquet pressure, which will be set as the pressure added by 120mmHg on the last systolic blood pressure just before tourniquet inflation. | Procedure: Low tourniquet pressure<br>* Tourniquet pressure set as 120mmHg above the systolic blood pressure just before tourniquet inflation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acquisition of bloodless surgical field just after skin incision | Dichotomous variable determined during operation by operator (Yes or No) | just after skin incision during operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Failure of acquiring bloodless surgical field during operation |  | after skin incision through the point of tourniquet deflation | 
| Increasement of tourniquet pressure to acquire bloodless surgical field | We will increase the tourniquet pressure by 30mmHg from the initial tourniquet pressure, if we will fail to achieve bloodless surgical field during operation. The increasement of tourniquet pressure will be recorded if it will be needed during operation. | after skin incision though the point of tourniquet deflation | 
| Thigh pain on the site of tourniquet application | measured by 11-point numerical visual analog scale (VAS)and 5-Likert scale | postoperative 2nd day | 
| Knee pain | measured by 11-point numerical visual analog scale (VAS)and 5-Likert scale | postoperative 2nd day | 
| Skin problem on the site of tourniquet application | It includes ecchymosis, bullae formation and skin necrosis. | posteoperative 2nd day | 
| Nerve palsy |  | within 7 days after surgery | 
| symptomatic venous-thromboembolism | It includes deep vein thrombosis and pulmonary embolism which are symptomatic and diagnosed by confirmative test, such as CT angiogram. | within 7 days after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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tourniquet pressure, total knee arthroplasty