Aesthetic Medicine
Aesthetic Medicine


CPR of complications

When completing training in facial aesthetics more than 20 years ago, I recall that there was no mention of complications, let alone how to manage them. Now, avoiding and managing complications should be at the forefront of education in this sector. In recent years, there has been a rise in the number of complications due to: 1

• More procedures being performed

• Better reporting of complications

• More aesthetic practitioners (both medical and non-medical)

• More choice of products

• Unrealistic expectations from both the patient and practitioner.

With complications rising, it is of course safer to avoid them, rather than simply manage them. I recommend following the five Ps to reduce the chances of a complication occurring:

• Patient: are you happy to see this patient? Have you built rapport with them, and do they have realistic expectations of the treatment outcome?

• Practitioner: only treat the patient if you have the right experience and can achieve their desired expectations

• Product: make sure that the correct product, with the properties required to deliver the result in a safe manner, is used

• Plane: ensure that you are injecting in the right plane, whether this is superficial, medium or deep

• Precision: are you confident enough to know when to use a needle or cannula and competent enough to use either?

In regard to managing complications, there are an array of articles, protocols and templates available within the medical aesthetics sector, however, there is no standardised agreement. In this article, the author will focus on two aspects of managing complications: capillary refill time (CRT) and patch testing.


CRT is the time taken for a distal capillary bed to regain its colour after pressure has been applied to cause blanching. It was first introduced by Beecher et al. 2, using the categories of normal, definite slowing and very sluggish. 3In a suspected vascular occlusion or vascular compromise, slow capillary refill is one of the signs and symptoms. However, this alone should not be used to diagnose; the practitioner would need to consider the other possible immediate signs and symptoms, such as pain, blanching and/or discolouration of the skin and a livedo pattern.

Medical practitioners need a baseline to refer to for complications. My preferred option is to perform the CRT before treating the area you intend to inject. This can be performed with no stress, and on several occasions. It should then be recorded in the patient’s notes.

When a vascular occlusion is suspected, perform the CRT and compare it to the previous noted reading. The second alternative is, if the pre-procedure CRT is forgotten, to do one on the opposite side of the face to where the suspected vascular occlusion is. Be aware, however, if this is done during a highly stressful time, it may not be as accurate. The upper limit of normal for CRT is two seconds. 4

In a suspected vascular occlusion, it is hypothesised that alterations in distal capillary bed perfusion will affect the measurement of CRT by altering the time for the distal capillaries to become refilled with blood. 3

In a suspected vascular occlusion, it is hypothesised that alterations in distal capillary bed perfusion will affect the measurement of CRT by altering the time for the distal capillaries to become refilled with blood. 3It is important to note that there are no current publications directly supporting this theory, however, there are many factors that affect CRT, including:

• Age: studies have found a wider variation of CRT, with an average increase of CRT of 3.3% per decade of age 5

• Temperature: CRT decreased by 1.2% per degree Celsius increase in ambient temperature 5

• Ambient light: poor light conditions make it difficult to assess CRT. In daylight conditions (partly cloudy day, approximately 4000 lux), CRT was reported as normal in 94.2% of healthy participants, compared with only 31.7% of the same participants in dark conditions (moonlight or streetlamp, approximately three lux) 6

• Pressure application: there is no universal agreement on the optimal duration and amount of pressure or site used when assessing CRT. It has been suggested that moderate pressure should be applied for three seconds 7, five seconds 8, or until the capillary bed blanches. 9


There is big debate regarding the validity and usefulness of patch tests when administering hyaluronidase for treatment complications. Hyaluronidase is a protein that breaks down hyaluronic acid and has an immediate action. 10When using hyaluronidase, a number of factors need to be considered, including:

• Dose

• Frequency of administration

• Depth of injection

• Drug interactions 11

• Patch test

A patch test is a diagnostic method used to determine which specific substances cause allergic inflammation of a patient’s skin. It helps to identify which substances may be causing a delayed-type allergic reaction in a patient and may identify allergens not identified by blood testing or skin-prick testing. However, even though the term ‘patch test’ is generally used in the aesthetics sector, it is not actually a patch test that is being performed: it is an intradermal test.

Intradermal test with hyaluronidase While studies have reported hypersensitivity reactions to either hyaluronidase or sodium chloride (benzyl alcohol) 12, the incidence of localised reactions to hyaluronidase is extremely low, with reports of 0.05% to 0.69%. 13

Nevertheless, all of the variables associated with this intradermal test need to be considered, including how much hyaluronidase to inject and how long to wait for a reaction. Generally, a reaction could occur immediately to within 72 hours. 14

My preferred protocol is as follows: 1500IU of hyaluronidase diluted in an 8-10ml saline solution, with each ml containing up to 150iu. Then, 0.1ml of this dilution is injected subcutaneously into the forearm. The patient is kept in the clinic for an average of 60 minutes. Any reaction (for example, itching, swelling and/or redness) at the injection point signifies that the patient should not receive treatment.


When performing an intradermal test, there are two possible hypersensitivity outcomes:

Type 1 hypersensitivity Immediate reactions are particularly marked by oedema, rash, itching, pain, respiratory distress, nausea, vomiting and hypotension. These reactions require immediate medical treatment. Immediate reactions, such as anaphylactic shock, general urticaria and respiratory distress, usually appear after intravascular injection and have been described during hyaluronidasechemotherapeutic agent injections for cancer. 15Clinical symptoms of the allergic reaction are efficiently treated with adrenaline and antihistamine.

Type 4 or delayed-type hypersensitivity Type 4 hypersensitivity typically occurs at least 48 hours after exposure to an antigen. It involves activated T cells, which release cytokines and chemokines, as well as macrophages and cytotoxic CD8+ T.


Medical practitioners must be able to confidently and quickly assess the seriousness of any complication and be able to adequately treat and manage it without hesitation. It is recommended that, where necessary, practitioners should refer to or seek the assistance of experts in a suspected vascular occlusion. Furthermore, be aware of and have on display the details of any emergency department that the patient will be accompanied to in a potential vascular occlusion case (once hyaluronidase has been administered).

Both CRT and intradermal tests are not 100% foolproof, as false positive and negative outcomes are both possible and should not be relied upon soley. A number of diagnostic tools should be used before deciding on the best course of action.

To access free resources regarding complications visit https://complications. treatwithhyalase

Dr Harry Singh has been carrying out facial aesthetics for more than 20 years and has treated over 10,000 cases. He is a trainer for Medfx and Galderma and was awarded the Fellowship of The-International Academy for Dental Facial aesthetics. He has published numerous articles on the clinical and non-clinical aspects of facial aesthetics and runs clinical and non-clinical workshops for his training company –


1. Is the NHS equipped to manage complications? A. Adatia & A. Boscarino. British Dental Journal volume 231, p.205 (2021)

2. Beecher HK, Simeone FA, Burnett CH, Shapiro SL, Sullivan ER, Mallory TB. The internal state of the severely wounded man on entry to the most forward hospital. Surgery. 1947; 22(4):672–711

3. Pickard A, Karlen W, Ansermino JM. Capillary refill time: is it still a useful clinical sign? Anesthes Analg. 2011; 113(1):120–123. 4. Baraff LJ. Capillary refill: is it a useful clinical sign? Pediatrics. 1993; 92(5):723–724

5. Anderson B, Kelly AM, Kerr D, Clooney M, Jolley D. Impact of patient and environmental factors on capillary refill time in adults. Am J Emerg Med. 2008; 26(1):62–65. https://

6. Brown LH, Prasad NH, Whitley TW. Adverse lighting condition effects on the assessment of capillary refill. Am J Emerg Med. 1994; 12(1):46–47. 6757(94)90196-1

7. World Health Organization. Management of the child with a serious infection or severe malnutrition: guidelines for care at the first referral level in developing countries. 2000. (accessed 1 December 2021)

8. Schriger DL, Baraff L. Defining normal capillary refill: variation with age, sex, and temperature. Ann Emerg Med. 1988; 17(9):932–935. 0644(88)80675-9

9. Steiner MJ, DeWalt DA, Byerley JS. Is this child dehydrated? JAMA. 2004; 291(22):2746–2754. 10. Almeida A, Saliba A. Hyaluronidase in cosmiatry: what should we know? Surg Cosmet Dermatol. 2015; 7(3):197–203.

11. Dunn A, Heavner JE, Racz G, Day M. Hyaluronidase: a review of approved formulations, indications and off-label use in chronic pain management. Expert Opinion Biol Ther. 2010; 10(1):127–131.

12. Schnuch A, Uter W, Geier J, Lessmann H, Frosch P. Sensitization to 26 fragrances to be labelled according to current European regulation. Results of the IVDK and review of the literature. Contact Dermatitis. 2007; 57(1):1–10.

13. Jung H. Hyaluronidase: an overview of its properties, applications, and side effects. Arch Plast Surg. 2020; 47(4):297–300.

14. (The Role of Hyaluronidase in the Treatment of Complications From Hyaluronic Acid Dermal Fillers Maurizio Cavallini, Riccardo Gazzola, Marco Metalla, Luca Vaienti, Aesthetic Surgery Journal, Volume 33, Issue 8, November 2013, Pages 1167–1174

15. Szepfalusi Z Nentwich I Dobner M Pillwein K Urbanek R. IgE-mediated allergic reaction to hyaluronidase in paediatric oncological patients. Eur J Pediatr. 1997; 156(3):199– 203.

This article appears in the June 2022 Issue of Aesthetic Medicine

Click here to view the article in the magazine.
To view other articles in this issue Click here.
If you would like to view other issues of Aesthetic Medicine, you can see the full archive here.

This article appears in the June 2022 Issue of Aesthetic Medicine