What is the gap?

The gap is the space between the wound bed and the dressing. It’s also called the ‘dead space’.^{1, 2} However, the space between the wound bed and the dressing is far from ‘dead’.

Let’s see why that is.

All wounds have unique, irregular topographies, or shapes.^{3, 4} Some wounds have steep angles between the edge of the wound and the wound bed. This can create cavities where fluid – or exudate – can accumulate. To find out how this might affect wound healing, we need to take a closer look at exudate.

What is exudate?

Perhaps you know it as ‘ooze’, ‘wound fluid’, ‘wound drainage’, ‘pus’ or ‘secretion’. All of these names refer to the fluid a wound creates when it’s healing. In this section, we use the term, exudate.

All wounds have exudate. This fluid is usually clear. It has a pale amber colour and a watery consistency. Wound exudate plays an essential role in the healing process.⁶

Why exudate can stop wound healing

While exudate is essential to the healing process, it can also stop a wound from healing.

This can happen if:

• the wound has the wrong amount of exudate (either too much, or too little);
• the exudate is the wrong composition; or
• the exudate is in the wrong place.^{8, 7}

As a wound begins to heal, the amount of exudate it produces usually decreases. However, many chronic wounds can get stuck in the inflammatory healing stage where harmful bacteria might develop.

In such cases, exudate can:

• obstruct healing;
• slow down or prevent cell growth;
• interfere with growth factor availability; and
• contain elevated levels of inflammatory mediators; e.g. platelets, neutrophils, monocytes /macrophages and mast cells.⁷

This brings us back to ‘the gap’, and why managing the gap is so important for wound healing.