Use of antimicrobial Dialkyl Carbamoyl Chloride (DACC) surface dressings for the treatment of infected post-surgical complications in neonates with low risk of adverse reactions: case series in the AOU Meyer NICU
From Firenze University Press Journal: Infermieristica Journal
Biagio Nicolosi, AOU Meyer IRCCS
Eustachio Parente, AOU Meyer IRCCS
From the 3rd trimester of pregnancy onwards, the skin presents a structure similar to the de!nitive one. The maturing process continues until birth and continues rapidly until 2–3 weeks later, unless the skin is exposed to a high-humidity environment or is covered by occlusive materials, which can slow down its maturation. The stratum corneum reaches functional maturity around the 33rd gestational week. The first skin cells are formed from the ectoderm, from which those of the nervous system also derive, in fact because of this relationship, the peripheral sensory function of the skin is understood. The ectodermal cells reach the intermediate cell stage before finally maturing into keratinocytes. Around the 7th week a cell layer (periderm) is present, which disappears around the 24th week, with the formation of scales. The specialised skin cells, melanocytes, Merkel cells and Langerhans cells, also begin to differentiate early, and from the 24th to 25th week, they start their activity.At the 24th week of gestation, newborns have a reduced stratum corneum. The skin is red, wrinkled, translucent, and apparently gelatinous. The subcutaneous tissue is absent, so the dermis lies directly in contact with the bone. Consequently, removal of an adhesive dressing or patch, with removal of the skin, may result in loss of full thickness tissue.Between the 26th and 29th weeks of gestation, fat begins to be deposited at the subcutaneous level and wrinkles tend to diminish. However, the barrier function of the skin remains poor; in fact, around the 26th week of gestation, up to 110 ml of water can be lost in 24 hours.
The main function of the foetal sebaceous glands is the excretion of sebum, a complex mixture of relatively non-polar lipids. In infants, the sebaceous glands are well formed, hyperplastic and macroscopically visible on certain areas of the body, such as the nose. The surge in their activity during the last trimester of pregnancy leads to the production of a dense, lipid-rich hydrophobic film called caseous varnish. This film is present in varying amounts on the infant’s skin surface, both in utero, where it protects the skin from maceration by exposure to the amnion, and at birth. After birth, a proportion of caseous varnish is physiologically reabsorbed, while it is necessary to remove the remaining part with oily substances, otherwise the lipids could go rancid and cause damage to the skin. Its removal must be partial, as it plays an important role in preventing water loss, thermoregulation and innate immunity. The latter is indispensable in protecting the infant from sudden exposure to micro-organisms, toxins, oxidative stress, “uctuating temperatures and humidity, and is made possible by its content of LL-37 peptide and lysozyme, i.e. two antimicrobial substances that act synergistically, lactoferrin, alpha-defensin and other antimicrobial peptides.
The caseous varnish, therefore, acts as a natural moisturiser and protects the outer layers of the skin to allow normal adaptation in the new aerobic environment. After removal, the skin is reddened and slightly cyanotic at the extremities. Capillary dilatation is frequently present at the eyelids, forehead and nape of the neck, but these regress spontaneously. The combination of an evolutionarily and functionally immature barrier, the absence or reduced production of caseous varnish, the large body surface area in relation to mass and a still-deficient immune system exposes newborns to a significant risk of infections and skin lesions, particularly those born with a gestational age of less than 33 weeks. A further consideration resulting from the skin characteristics of the preterm infant is the increased risk of percutaneous toxicity from topical drugs, cleansers and even emollients.At 30 weeks, the subcutaneous tissue is evident and the stratum corneum has 2–3 thick cell layers, compared to 40 weeks, when it is 30 layers thick. Functional maturation of the skin occurs at 33 weeks, with the epidermis completely keratinised and the dermo-epidermal junction more resistant, although it remains fragile and easily damaged.
DOI: https://doi.org/10.36253/if-2105
Read Full Text: https://riviste.fupress.net/index.php/if/article/view/2105
