A Comparison Between an Individual Low Tourniquet Pressure Versus a Standard Pressure During Total Knee Arthroplasty

Charlotta Olivecrona

Status: Completed

Conditions: Complications; Arthroplasty

Treatments: Procedure: Limb occlusion pressure (LOP); Procedure: conventional measurement method

Study type: Interventional

Funder types: Other

Identifiers

NCT01442298

2007/757-31/1-4

Details and patient eligibility

About

The use of bloodless field is a helpful and important method in orthopedic surgery. The surgery can be done without interrupting bleedings, while keeping an exact overlook of the anatomy. However the method is not without risks, and complications of various kind may occur. One of the most important factors to minimise the risk of complications, is to keep the lowest possible cuff pressure. Previous electromyography (EMG) studies have indicated neuromuscular abnormalities after bloodless field among many patients which may lead to a prolonged rehabilitation period since they cause a postoperative weakness in the muscles. Although in these studies an unnecessary high tourniquet pressures were used and the EMG tests were made 6 weeks and 6 months after the surgery.

With today's demand for fast rehabilitation, there is a need for better knowledge if lower tourniquet pressure in bloodless field surgery may lead to less neuromuscular abnormalities.

Limb Occlusion Pressure (LOP) is the tourniquet cuff pressure required to occlude the blood flow. It accounts for a patients limb and vessel characteristics and the type and fit of the tourniquet cuff. The method has developed and is now simplified, by using an automatic (plethysmographic) sensor placed on the second toe on the involved limb, and after administration of anaesthesia, and immediately before limb preparation and draping it measures the limb occlusion pressure.

When surgery starts, the cuff is inflated again; plus a safety margin based on the LOP pressure measured. The LOP method is still rarely used it has been seen as difficult and time consuming.

The primary aim of this study is to investigate whether you can reduce the used tourniquet pressure with the new LOP measurement technique and still have a adequate bloodless field; and if this will lead to any clinical difference regarding postoperative pain. The secondary aim is to investigate the difference between the test groups concerning muscle function and wound healing and if these are remaining and of clinical importance. The third aim is to study how common neuromuscular abnormalities are after the use of bloodless field with lower cuff pressures and if there are any differences between the standard method and the LOP method.

Enrollment: 164 patients

Sex: All

Ages: Under 75 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Planned for total knee arthroplasty in bloodless field
• 75 year or younger

Exclusion criteria

• Patients unable to read and understand Swedish
• Systolic blood pressure over 200 mmHg and a girth of the thigh over 78 cm was excluded.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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164 participants in 2 patient groups

conventional treatment

Active Comparator group

Description:

the Standard method;tourniquet pressure based on systolic blood pressure, plus a safety margin.

Treatment:

Procedure: conventional measurement method

limb occlusion pressure(LOP)

Experimental group

Description:

cuff pressure is based on limb occlusion pressure measurement

Treatment:

Procedure: Limb occlusion pressure (LOP)