OPTIMAL AMOUNT The best tourniquet systems are designed to use the minimum pressure needed to stop blood flow, thereby reducing the risk of injury.

Pneumatic tourniquets provide orthopedic surgeons with a bloodless field, but the devices can cause a host of pressure-related complications, such as skin breakdown, nerve injuries, intraoperative bleeding, toxic reactions, thrombosis, digital necrosis and pronounced and sometimes prolonged post-op swelling. When it comes to tourniquet safety, less is more: The less pressure you can apply, the better.

1. Achieve optimal pressure
Optimal pressure depends on several variables, including a patient's age and blood pressure and the shape and size of the extremity in question. But your goal should be to achieve optimal limb occlusion pressure (LOP), defined as the minimum pressure needed to stop the flow of arterial blood into the limb distal to the cuff, at a specific time, with a specific cuff. Some advanced tourniquet systems measure LOP automatically, but it can also be measured manually by detecting the presence of arterial pulsations in the limb, which indicate arterial blood flow past the cuff into the distal limb.

Current guidelines for setting tourniquet pressure based on LOP call for an additional safety margin of pressure to account for physiologic variations and other changes that occur normally during surgical procedures. (For more on LOP, go to tourniquets.org/lop.php)

2. Use personalized cuffs
Research has also led to the creation of personalized cuffs, which are safer and more effective than traditional straight cuffs because they match patient limb size and shape, letting you use lower pressures. They fit better, because unlike straight cuffs, which are designed to accommodate cylindrical limb shapes, they can be adapted to a wide range of non-cylindrical (or tapered) limb shapes. Recently created cuff designs for pediatric and bariatric limb sizes and shapes have also been shown to be effective.

3. Reduce soft tissue injuries
Along with the wide variety of potential internal injuries posed by tourniquets, high pressures, high-pressure gradients and shear forces can also injure skin and soft tissue. Your best bet: limb protection sleeves consisting of double-layer material specifically matched to the limb size and cuff size. Studies show they protect skin and tissue better than various alternatives, including underlying padding, underlying stockinette, single-layer sleeves or no protective material at all.

BEST PRACTICES
AORN Updates Tourniquet Guidelines

ON TIME Administer antibiotics 20 minutes before inflating the tourniquet, says AORN

On June 15, AORN published a major update of its recommended practices on pneumatic tourniquet-assisted procedures. Here are 4 key areas addressed:

1. Preconditioning. Several studies suggest that preconditioning, either through anesthesia or via a series of cycles of brief inflation and deflation of the tourniquet cuff, can prepare skeletal muscles for ischemia and reperfusion and thereby decrease inflammatory responses.

2. Timing of antibiotics. Recent studies, though inconclusive, suggest that the ideal flow of antibiotics into the blood supply going back to the limb can be achieved by administering antibiotics at the time of deflation. Previously, the recommended practice was to infuse antibiotics 20 minutes before inflating the tourniquet.

3. Nurse's role. The new guidelines encourage nurses to collaborate with the surgeon and the anesthesia provider to determine an appropriate cuff pressure, based on limb occlusion pressure or systolic blood pressure, and to then add a safety margin. There's evidence that surgeons tend to use standard tourniquet pressures for all patients, rather than basing pressure on individual factors. Establish policies that explain how to determine minimal pressure settings and that empower nurses to speak up.

4. Are tourniquets necessary? Shorter procedures, such as routine knee arthroscopies, can be performed adequately without tourniquets. We also found 4 meta-analyses that explore the efficacy of tourniquets in foot-and-ankle, total knee replacement, and upper limb surgeries. Our new recommendations encourage nurses to confirm whether pneumatic tourniquets will be used, rather than assuming they will be, and to participate in the discussion about the patient's care.

— Bonnie Denholm, MS, BSN, RN, CNOR

Ms. Denholm ([email protected]) is a perioperative nursing specialist for AORN.

4. Reprocess with care
You may be able to save money by reprocessing and reusing tourniquet cuffs, but be careful. An appropriate and adequate tourniquet cuff-testing program can be complex and expensive, so it's important to consider the pros and cons. Manufacturers of "reusable" cuffs usually provide straightforward instructions on how to clean, inspect and test cuffs between uses. But no such instructions accompany "disposable" or "single-use" cuffs.

If you're considering reprocessing and reusing single-use cuffs:

• establish a cuff-testing program, so each cuff is thoroughly tested according to a written protocol between uses, and the results are thoroughly documented;
• use a unique identifier for each cuff, so you can record the number of reuse cycles; and
• replace each cuff after you've reached a pre-established number of uses.

Your cuff-testing protocol should follow the manufacturer's recommendations and, at a minimum, should include:

• a leak test, including inflating the cuff to a maximum pressure recommended by the manufacturer, with the cuff wrapped around a test mandrel or laid flat;
• a fastener integrity test, to ensure the fasteners aren't degraded to the point of being unsafe at the maximum pressure specified by the manufacturer;
• a physical inspection, to detect blockages of the pneumatic passageway in any portion of the inflatable bladder or tubing due to reprocessing damage or fluid entry;
• a visual inspection to detect damage or deterioration, including any warping of the stiffener due to inappropriate reprocessing, discoloration or contamination of the cuff surface, damage or deterioration of the cuff connector or inflatable portion; and
• written documentation and an evaluation of the test results, before you decide whether the cuff can be reused.