Pressure level of pressure garments: Is tighter really better?

Yu-Li SUNG, Physical Therapist and Director

Medical Device Center, Sunshine Social Welfare Foundation

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As its name implies, pressure therapy uses the application of pressure to control scar proliferation. Many people will often assume that increasing pressure of pressure garments will necessarily improve outcomes. How to explain that this is a common misunderstanding and why higher pressure does not necessarily mean better outcomes?

This misunderstanding stems from the oversimplification of the relationship between pressure and scar control.

Pressure level of pressure garments: Literature versus clinical reality

Literature recommends that pressure should be 25 millimeters of mercury and exceed capillary pressure to provoke changes in scars [1]. Some research also points out that pressure between 25 and 35 millimeters of mercury can speed up scar maturation process.

In the reality of our clinical practice, we find that recommendations from literature sometimes can be hard to achieve. First, it’s difficult to achieve this recommended pressure evenly, everywhere. Pressure in areas with small circumference, like wrists, can achieve 20 to 25 millimeters of mercury, but pressure in areas like the trunk, buttocks and cheeks can barely reach 25 millimeters of mercury even with the help of inserts. Second, using a pressure mapping device daily in clinical practice to check every garment is impractical.

However, in 2016, we tracked over six months the effects of different pressure levels on scar redness, an indicator of scar vascularization and maturation. Patients were randomly assigned to a “high pressure” group (20-30 mmHg) or a “medium pressure” group (10-18 mmHg). While scar redness decreased in both groups, the high-pressure group showed more consistent improvement. However, this group also experienced more complications, such as friction wounds on joints and peripheral edema in hands and feet. Although these findings align with literature supporting 20-30 mmHg for scar maturation, they also highlight the need to balance pressure levels with potential side effects.

The potential side effects of too much pressure

Pressure must be “just right” to be effective. Too little pressure may not provide the necessary stimulus to remodel scar tissue, while too much pressure can harm the skin and underlying structures. Applying too much pressure can result in side effects that worsen the patient’s condition:

1. Peripheral edema in hands and feet (especially if the proximal pressure is higher than the distal pressure).

2. Numbness and cyanosis of the extremities.

3. Skin breakdown or ulcers from friction or over-compression. These wounds cannot heal easily because of repeated friction on the skin.

4. Restriction of joint mobility, leading to stiffness or contractures.

5. Breathing difficulties if chest movement is restricted in the case of pressure garment vest that is too tight.

6. Poor posture, such as rounded shoulders, can be caused by overly tight garments.

7. Skeletal or soft tissue growth limitation. This can be especially problematic in the case of children.

Too much pressure can also compromise patient comfort and compliance. We want patients to wear pressure garments for 23 hours every day, but excessive pressure can make garments uncomfortable or even painful to wear, which reduces patient compliance. A well-designed pressure garment should be tolerable for long durations, as consistent wear is crucial for effective scar management. If higher pressure leads to reduced wear time, the intended benefits of pressure garments end up being negated.

Other factors to consider regarding level of pressure

When determining the level of pressure of pressure garments, we must also consider these important factors:

1. Skin stability: The stability of the scar surface is crucial in determining the appropriate pressure. Unstable scars are more prone to breaking or blistering under pressure. For such scars, lower level of pressure should be applied to minimize friction. As the scar matures and becomes more stable, it can better tolerate friction, allowing for the gradual increase in pressure.

2. Patient tolerance to pressure: Pressure garments can be tight and uncomfortable, making it challenging for patients to wear them for the recommended 23 hours a day. Additionally, many patients find garments hot and stuffy, which can further reduce compliance. In the beginning, it’s important to apply lower pressure to help patients adjust to the garment. Over time, as they become accustomed to wearing it, the pressure can be gradually increased to maximize effectiveness while maintaining comfort.

Finding the balance between comfort and effectiveness

So, is higher pressure more effective? It’s not a straightforward answer. Some patients prefer higher pressure and frequently visit to adjust their garments to their desired tightness. While we can accommodate this request, we emphasize the importance of skin stability. We teach patients how to assess their skin's condition to ensure it can tolerate higher pressure without adverse effects.

On the other hand, some patients struggle with higher pressure and cannot tolerate it. In these cases, we work with the patient to find a pressure level that is both tolerable and effective. The goal is to avoid situations where patients stop using pressure garments because they are too tight or uncomfortable. As therapists, it's essential to proactively schedule regular follow-ups to check on compliance and assess whether the pressure is too low or too high.

In our clinical practice, we have found that even lower-pressure garments are still effective in promoting scar improvement when used consistently over time. Ultimately, the most ineffective pressure garment is one that the client refuses to wear due to discomfort. Therefore, the key is achieving a balance between comfort and pressure effectiveness. Pressure garments work best when they are used thoughtfully and with precision. It’s not about “more pressure,” but about the right pressure for the patient’s situation, applied consistently and in a way that supports the patient’s comfort and overall rehabilitation.

References:

1.     Ai, J. W., Liu, J. T., Pei, S. D., Liu, Y., Li, D. S., Lin, H. M., & Pei, B. (2017). The effectiveness of pressure therapy (15-25 mmHg) for hypertrophic burn scars: A systematic review and meta-analysis. Scientific reports, 7, 40185.