Dermal fillers General

What is a capillary refill test?

Capillary refill test (CRT) is used across many healthcare sectors, regularly within aesthetics. It is a quick visual assessment to check blood can flow correctly without any obstruction in the treatment area.

In relation to the lip filler procedure the Capillary refill test (CRT) is carried out by holding and applying pressure to the lip, often by pinching. When you pinch the area it while whiten, which is called blanching. The pressure should be maintained for 5-10 seconds. If it takes 3 seconds or more for the colour to return it is a warning sign that there may be a blockage (Fleming et al., 2015).

Observing the speed of the Capillary refill is essential in identifying any potential risks of injectable treatments. It is important to consider several different aspects to determine whether it is normal capillary refill or not. The age of the client and their level of hydration effects the refill time, it can take up to 4.5 seconds in people over 60 years of age. It is also important to apply the same amount of pressure each time the test is carried out. The temperature of the room can alter the results, as the lower the temperature the longer it may take. There are also other considerations, such as the lighting conditions in the room and the knowledge and experience of the person carrying out the test. It is imperative to carry out a capillary refill test before completing any injections, so that the ‘normal’ refill is identified.

If it is identified that the capillary refill is too slow, as mentioned before, it can indicate a blockage in a blood vessel. This can be incredibly risky if not dealt with quickly and correctly. Depending on how ‘sluggish’ the refill is would affect the reaction. If the refill is slowed and but still returning a warm compression can be applied to the area of concern and a firm massage to aid the blood in flowing around the area. As the lack of blood flow may also be caused by some compression on to a vein or artery, massaging may resolve the concern.  If this does not facilitate blood in flowing, then the practitioner may decide to dissolve the dermal filler to stop the blockage. A blockage within a blood vessel stops the circulation of blood in the body, it is known as a vascular occlusion. The occlusion can be very dangerous as it stops oxygen and nutrients getting to cells in our bodies. When oxygen cannot reach our cells, they can die and become necrotic.

Pain is usually associate with vascular occlusion. There have been cases reported that occurred 12-24 hours after being injected but almost always it occurs immediately. The area will feel very hot and painful the appearance of skin with be discoloured, mottled, blanch, or mottled. A recent study (Alam et al., 2021) with 370 participants, found that the risk of vascular occlusion is exceedingly low in fact only 1 in 6410 syringes via needle and 1 in 40 882 via cannula result in occlusions. Within this study all injecting practitioners were medics, the risks were increased significantly when the injector is not medically qualified.

The idea of this is understandably very scary but choosing to have your treatments with a medically trained injector lessens the likelihood of these risks happening! It also increases the speed in which they will identify anything that might have gone wrong and be able to act on it. Nurses are taught to assess their environment continually and monitor the patient throughout all treatments and procedures. There is no denying that choosing to have your treatments with a medically trained professional ensures your safety!