Tourniquet Application on Total Knee Arthroplasty

Study Overview
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Brief Summary
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This is a randomized controlled trial designed to research the effects of different tourniquet applications on postoperative pain in patients undergoing total knee arthroplasty, and to guide early postoperative recovery.

Detailed Description
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Sixty participants undergoing unilateral TKA would be recruited in this study. On one side, the tourniquet would be inflated immediately before incision and deflated after the use of the cement , and 10 minutes later(after the hardening of the cement) , reinflate the tourniquet and deflate at the end of the operation. On the other side the tourniquet would be inflated immediately before incision and deflated at the end of the operation.The total time of tourniquet inflation is controlled within 90 minutes. The postoperative pain, limb swelling , the score of surgical field, blood pressure during the operation, blood loss, operating time, transfusion rate, deep vein thrombosis (DVT) incidence and clinical outcomes would be monitored for comparison.

Official Title
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The Effect of Different Applications of Tourniquet on Total Knee Arthroplasty

Conditions
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Tourniquets, Total Knee Arthroplasty

Intervention / Treatment
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* Procedure: Reinflation after early deflation
* Procedure: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of anesthesiologists Grade 1-3 Patients Undergoing unilateral total knee arthroplasty under general anesthesia Should be treated with tourniquet Exclusion Criteria: Tourniquet inflation time is less than 1h, greater than 1.5h Abnormal coagulation function BMI < 20kg/m2 or > 35kg/m2 History of cerebral infarction History of Peripheral vascular disease Anemia (hemoglobin<90g/L) Systolic blood pressure (SBP) ≥ 170mmHg Pregnant blood glucose > 10mmol/L or HbA1c > 8.5% of diabetic patients History of chronic narcotic use Participate in other clinical trials at the same time Asked to withdraw from the trial

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 85 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Reinflation after early deflation<br>The tourniquet would be inflated immediately before incision and deflated after the use of the cement, and 10 minutes later (after the hardening of the cement) , reinflate the tourniquet and deflate at the end of the operation.The total time of tourniquet inflation is controlled within 90 minutes. | Procedure: Reinflation after early deflation<br>* the tourniquet would be inflated immediately before incision and deflated after the use of the cement , and 10 minutes later (after the hardening of the cement) , reinflate the tourniquet and deflate at the end of the operation. The total time of tourniquet inflation is controlled within 90 minutes.<br>|
| Placebo Comparator: Control<br>The tourniquet would be inflated immediately before incision and deflated at the end of the operation. The inflation of tourniquet should not last more than 90 minutes. | Procedure: Control<br>* The tourniquet would be inflated immediately before incision and deflated at the end of the operation. The inflation of tourniquet should not last more than 90 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain | tested by Visual Analogue Scale | 48 hours post surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The rate of postoperative limb swelling | test the perimeter of the surgary limb at four fingers under the inguen,then Calculate the rate by formula (postoperative perimeter-preoperative perimeter)/preoperative perimeter | 24 hours post surgery, 48 hours post surgery | 
| Endothelin-1 | tested by ELISA | one minute before tourniquet inflation, tourniquet inflation for an hour, one minute before tourniquet deflation, fifteen minutes after tourniquet deflation | 
| Nitric Oxide | tested by ELISA | one minute before tourniquet inflation, tourniquet inflation for an hour, one minute before tourniquet deflation, fifteen minutes after tourniquet deflation | 
| Lac | blood gas analysis mmol/L | one minute before tourniquet inflation, tourniquet inflation for an hour, one minute before tourniquet deflation, fifteen minutes after tourniquet deflation | 
| Hemoglobin | blood gas analysis g/L | one minute before tourniquet inflation, tourniquet inflation for an hour, one minute before tourniquet deflation, fifteen minutes after tourniquet deflation | 
| partial pressure of oxygen in artery | blood gas analysis mmHg | one minute before tourniquet inflation, tourniquet inflation for an hour, one minute before tourniquet deflation, fifteen minutes after tourniquet deflation |