Regional Prophylactic Vancomycin With Restricted Tourniquet Time in Primary Total Knee Replacement

Study Overview
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Brief Summary
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The purpose of this study is to determine whether or not giving a lower dose of antibiotics (Vancomycin) in the area where it is needed (the knee joint) is more effective at obtaining adequate tissue levels of the antibiotic than the current standard dose which is given intravenously (IV) through a wrist vein. The use of intraosseous regional administration (IORA) of vancomycin requires the use of a tourniquet for the duration of the procedure. Many surgeons prefer to perform the surgery with tourniquet use minimised or without a tourniquet at all. The aim of this study is to evaluate whether IORA vancomycin can achieve effective tissue concentrations with tourniquet use minimised.

Detailed Description
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Patients are assigned to one of two groups by chance (like a coin toss): GROUP A - Will receive 15mg/kg based on actual body weight (maximum of 2g) of vancomycin via the systemic route at a rate of 15mg/kg as per hospital guidelines. Systemic IV vancomycin is given via a forearm vein, given over an infusion timed to finish immediately prior to surgery. GROUP B - Will have the limb exsanguinated and an above knee tourniquet inflated to 300 mmHg. Immediately following tourniquet inflation, Group B will receive 500mg of vancomycin, via an EZ-IO intraosseous cannula. The vancomycin would be administered in 150ml of saline solution. The intraosseous cannula would be placed into the epiphysis of the proximal tibia. The tourniquet will be left inflated for 10 minutes following completion of the IORA injection then deflated. Both Groups will receive weight-based dose of systemic cefazolin ( or alternative antibiotic if allergic to cefazolin 15 minutes prior to inflation of tourniquet. This ensures all patients in the study receive effective antibiotic prophylaxis regardless of randomization. Both groups of patients would then undergo routine prep and draping For both groups, Total knee replacement would then be carried out as normal and the tourniquet will be inflated for cementation of the implants. TISSUE SAMPLES Ten (10) tissue samples will be taken from each patient, 6 'fat' samples and 4 'bone' samples. Each sample is very small, around the size of a pinhead. Bone samples will be taken from the femur only to ensure no direct contamination from the site of injection (tibia) In addition, drain samples will be taken from the intra-articular drain site to measure vancomycin concentration the morning following surgery. Three blood samples will be taken in both groups, intraoperatively, in recovery, and the following morning. These samples are frozen and sent to a lab for analysis.

Official Title
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Regional Prophylactic Vancomycin With Restricted Tourniquet Time in Primary Total Knee Replacement

Conditions
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Arthropathy of Knee Joint

Intervention / Treatment
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* Drug: Vancomycin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria Primary Total Knee Arthroplasty for osteoarthritis Informed consent given Exclusion Criteria Current or treatment with IV Vancomycin within preceding 7 days Previous hypersensitivity to vancomycin Significant cardiac or respiratory abnormality Patient has contraindications to IO vascular access using the EZ-IO

Ages Eligible for Study
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Minimum Age: 18 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Vancomycin 15mg/kg IV<br>Will receive 15mg/kg based on actual body weight (maximum of 2g) of vancomycin via the systemic route at a rate of 15mg/kg as per hospital guidelines. Systemic IV vancomycin is given via a forearm vein, given over an infusion timed to finish immediately prior to surgery. | Drug: Vancomycin<br>* Antibiotic<br>* Other names: Vancocin;|
| Experimental: Vancomycin 500mg Intraosseous<br>Will have the limb exsanguinated and an above knee tourniquet inflated to 300 mmHg. Immediately following tourniquet inflation, Group B will receive 500mg of vancomycin, via an EZ-IO intraosseous cannula. The vancomycin would be administered in 150ml of saline solution. The intraosseous cannula would be placed into the epiphysis of the proximal tibia. The tourniquet will be left inflated for 10 minutes following completion of the IORA injection then deflated. | Drug: Vancomycin<br>* Antibiotic<br>* Other names: Vancocin;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vancomycin Concentration in Fat | Mean vancomycin concentration in fat measured in ug/g at surgical closure | Approximately 60 minutes post surgical incision | 
| Vancomycin Concentration in Bone | Mean vancomycin concentration in bone measured in ug/g at surgical closure | Approximately 60 minutes post surgical incision |