Effect of radiant warmer on transepidermal water loss (TEWL) and skin hydration in preterm infants

Case Report: Anesthesia for a Neonate With Cutis Aplasia

Cutis aplasia is a rare condition characterized by skin and subcutaneous tissue defects. Researchers have previously described both conservative and surgical management methods. We report herein the case of a neonate with extensive cutis aplasia involving 37% of the total body surface area. Due to the risk of meningitis and catastrophic hemorrhage associated with scalp defects, she underwent staged surgical procedures with skin harvesting and synthetic skin application, followed by the application of cultured epithelial autografts. This report highlights the challenges in temperature and fluid management as well as intraoperative positioning in a neonate with cutis aplasia.

Differences in Temperature Changes in Premature Infants During Invasive Procedures in Incubators and Radiant Warmers

Premature infants tend to lose heat quickly. This loss can be aggravated when they have received an invasive procedure involving a venous puncture. This research uses crossover design by conducting 2 intervention tests to compare 2 different treatments on the same sample. This research involved 2 groups with 18 premature infants in each. The process of data analysis used a statistical independent t test. Interventions conducted in an open incubator showed a p value of .001 which statistically related to heat loss in premature infants. In contrast, the radiant warmer p value of .001 statistically referred to a different range of heat gain before and after the venous puncture was given. The radiant warmer saved the premature infant from hypothermia during the invasive procedure. However, it is inadvisable for routine care of newborn infants since it can increase insensible water loss.

Transepidermal Water Loss in Neonates: Baseline Values Using a Closed-Chamber System

BACKGROUND

Transepidermal water loss (TEWL) is the normal, constitutive loss of water vapor from the skin in the absence of sweat gland activity. It is regarded as one of the most important parameters for characterizing skin barrier function, and the values are dependent on multiple variables. The objective of this study was to evaluate TEWL in neonates using a closed- chamber system, and determine if there is a variation of TEWL with the mode of delivery, pre-term birth, low birthweight or phototherapy.

METHODS

This prospective study was conducted in 104 healthy neonates, 30 neonates in the Neonatal Intensive Care Unit (NICU) and 40 adults using a noninvasive, closed- chamber system (VapoMeter™).

RESULTS

A statistically significant difference in TEWL was noted between newborns and adults. No remarkable difference in TEWL was seen between boys or men and girls or women or those born via normal vaginal birth and caesarean section, but TEWL was significantly higher in preterm and low birthweight neonates. Significantly higher TEWL was noted from the antecubital fossa of the neonates who received phototherapy when compared with six other sites.

CONCLUSIONS

The closed- chamber system is an acceptable alternative to the more widely used open-chamber system. The higher mean TEWL in neonates suggests that the epidermal barrier is still adapting to extrauterine life, making newborn skin more sensitive and requiring appropriate, age adapted care.

The effect of convective heating on evaporative heat loss in anesthetized children

BACKGROUND

Convective warming is effective in maintaining core temperature under anesthesia. It may increase evaporative water loss (EWL). If significant, further investigation of warming modifications to minimize this impact would be warranted.

OBJECTIVES

To quantify EWL in two groups of children (warmed and nonwarmed) having surgical procedures under anesthesia.

METHODS

We performed an observational study of well children having general anesthesia for elective surgical procedures lasting ≥60 min. They were recruited sequentially to each of three age groups: 1-12 months, 13 months-5 years, and 5-12 years--with each age group divided into convectively warmed (43°C) and nonwarmed (21°C) subgroups. Evaporative heat loss (EHL) was calculated from accurate measurement of net EWL during the surgical period.

RESULTS

Sixty children were studied. As a percentage of body mass, mean EWLs were 0.29 (warmed) and 0.09 (nonwarmed). Using an ancova model, only procedure duration had a significant impact and explained why the extended procedural time in some convectively warmed children led to higher mean EWLs for that group. For the nonwarmed group, the mean Tcore drop was 1.27°C with a contribution from EWL of 0.6°C over ~70 min.

CONCLUSIONS

Within the age range 1 month-12 years, EHL is not significantly influenced by convective heating under anesthesia. There is no thermal advantage in exploring technique modifications such as humidifying the warming air. Previous estimates of the contribution of EHL to total heat loss in anesthetized children may require revision.

Postnatal maturation of skin barrier function in premature infants

BACKGROUND

In preterm infants, skin barrier maturation entails regional variability.

OBJECTIVES

To characterize postnatal skin barrier development in covered, uncovered and diapered regions in healthy premature infants over a longitudinal observation period.

METHODS

Transepidermal water loss (TEWL), stratum corneum hydration (SCH), pH and sebum were measured at postnatal ages of 1-7 days and 2-7 weeks on the forehead, abdomen, thigh and buttock of preterm infants (gestational age 30-37 weeks; n = 48) under monitored ambient conditions. A standard minimal skin care regimen was practised.

RESULTS

TEWL increased significantly on the buttock (p = 0.007), while remaining stable on the forehead, abdomen and thigh. SCH and sebum remained stable in all studied body regions with increasing age. On the buttock, pH increased (p = 0.049), while other body regions exhibited a significant decrease (p ≤ 0.019). TEWL (p < 0.001) and SCH (p ≤ 0.002) revealed significantly higher values on the buttock, compared to other body regions.

CONCLUSIONS

Stable TEWL, SCH and sebum values may indicate a lack of skin barrier maturation. Postnatal decrease in skin pH suggests an adaptation process with acid mantle formation. Differences in skin barrier development were observed between anatomical regions. SCH, TEWL and pH values demonstrated a distinct course in the diaper area, indicating an impaired skin barrier function in this region.

Functional skin adaptation in infancy - almost complete but not fully competent

Early postnatal life is a period of active functional reorganization and cutaneous physiological adaptation to the extrauterine environment. Skin as the outermost organ of mammalians is endowed of multiple functions such as protection, secretion, absorption and thermoregulation. Birth stimulates the epidermal barrier maturation and the skin surface acidification especially in premature infants. In full-term infants the developed stratum corneum accomplishes competent barrier function, in contrast to prematures. Complete barrier maturation in preterm infants is fulfilled by 2-4 weeks of the postnatal life. However, in preterms with 23-25 weeks gestational age this process takes longer. Versatile regulatory mechanisms, namely skin surface acidity, calcium ion gradient and nuclear hormone receptors/ligands are interrelated in the complex postnatal newborn adaptation. The skin of newborns is adjusting quickly to the challenging environmental conditions of the postpartum. However, certain functions, for example, microcirculation, continue to develop even beyond the neonatal period, that is, up to the age of 14-17 weeks. Different environmental factors (for instance, dry and cold climate, diapers and cosmetic care procedures) influence the postnatal development of skin functional parameters such as stratum corneum hydration and the permeability barrier especially in premature infants. The aim of this article is to summarize the current knowledge on skin physiology in newborn and infants with a practical approach and to discuss the possible clinical consequences. This review offers the readership a critical and practical overview of skin physiology in newborns and infants. It emphasizes possible new research fields in neonatal and infantile skin physiology.