Journal of Perinatology (2010) 30, 414–419
r 2010 Nature Publishing Group All rights reserved. 0743-8346/10
www.nature.com/jp
ORIGINAL ARTICLE
Effectiveness of No-Sting skin protectant and Aquaphor
on water loss and skin integrity in premature infants
DH Brandon1, K Coe2, D Hudson-Barr3, T Oliver4 and LR Landerman5
1
Department of Pediatrics, Duke University School of Nursing, Duke University Hospital, Durham, NC, USA; 2Special Care Nursery,
Durham Regional Hospital, Durham, NC, USA; 3Newborn Critical Care, North Carolina Children’s Hospital, Durham, NC, USA;
4
Division of Neonatology, Brenner Children’s Hospital, Durham, NC, USA and 5Office of Research Affairs, Duke University School of
Nursing, Durham, NC, USA
Objective: The purpose of this study was to evaluate the effects of No-Sting
skin protectant and Aquaphor, a water-based emollient, on skin integrity
measured by Neonatal Skin Condition Score (NSCS) and transepidermal
water loss (TEWL) in premature infants. In addition, with no data
regarding the use of No-Sting in the neonatal population and its desirability
because it requires less infant manipulation and less nursing time, it was
important to evaluate the use of this product.
Study Design: In all, 69 premature infants born at <33 weeks gestation
were randomly assigned to one of the two treatment groups: (1) No-Sting
or (2) Aquaphor for a total of 14 days.
Result: Gestational age and total fluid intake were related to NSCS
whereas gestational age, incubator humidity levels and total daily fluid
intake were significantly related to TEWL. Infants receiving Aquaphor had
significantly higher NSCS, but the mean scores in both groups over the 14day period were in the normal range (<4). There were no differences
between Aquaphor and No-Sting in the rate of TEWL over the 14-day period.
Conclusion: This study provides the first information regarding
the use of No-Sting in the neonatal population. This skin protectant
seems as effective as Aquaphor in decreasing TEWL and maintaining
skin integrity, and is less resource intensive.
Journal of Perinatology (2010) 30, 414–419; doi:10.1038/jp.2009.174;
published online 5 November 2009
Keywords: skin; transepidermal water loss; skin care; emollients
Introduction
Premature infants experience frequent complications related to
skin immaturity. Their underdeveloped epidermis and stratum
corneum inhibit the skin’s ability to regulate body temperature,
Correspondence: Dr DH Brandon, Department of Pediatrics, Duke University School of
Nursing, Duke University Hospital, BOX 3322, 307 Trent Drive, Durham, NC, 27710, USA.
E-mail: [email protected]
Received 27 April 2009; revised 26 September 2009; accepted 27 September 2009; published
online 5 November 2009
maintain water and electrolyte balance, prevent infection and
protect against absorption of toxic substances.1–8 In addition,
the thin premature infant skin is characterized by increased
insensible water loss and frequent skin breakdown.2,5,9–13
Premature skin is most fragile for 2 weeks after birth, especially
in very immature infants (23 to 25 weeks).5,6,12,14 This is
exacerbated by the use of skin probes and leads that can
damage the skin.4,5,8,13,15
A variety of skin care practices have been used to ameliorate
these problems, including increased humidity and the use of
emollients such as Aquaphor. The use of emollients has been
shown to protect premature infant skin and prevent it from tearing
or stripping,7,16–19 and has also been associated with an increased
risk of nosocomial sepsis.16,20 However, the acceptability of
emollients is low because of the difficulty in affixing leads and
temperature probes.
No-Sting is a hypoallergenic, non-cytotoxic liquid film
that will not sting even when applied to damaged or denuded
skin.21,22 It comprises water, plastic polymers and odorless
non-alcohol evaporating agents. Although the evaporating
agents are not felt to be harmful with contact to the skin,
care should be taken to cover the face to avoid inhalation
of the product during application. There are no data regarding
No-Sting’s use on premature infant skin and it is not currently
approved by the Food and Drug Administration for infants
<30 days of age; however, its nontoxic nature,22 effectiveness
in adult wound care21,23 and ease of application make this
product an appealing option for protecting fragile premature
skin.
The purpose of this study was to compare the effects of
No-Sting skin protectant and Aquaphor on transepidermal
water loss (TEWL) and skin integrity over the first 2 weeks of
life in premature infants (<33 weeks gestation). The following
research questions were addressed: (1) Are there any differences
in neonatal skin condition scores between skin treated with
No-Sting versus Aquaphor? and (2) Are there any differences
in TEWL between skin treated with No-Sting versus Aquaphor?
No-Sting protectant and Aquaphor
DH Brandon et al
415
Methods
Study design
Over 18 months, 69 infants born at <33 weeks gestation were
enrolled after parental consent at <48 h of age. Infants were
stratified according to gestation, <28 weeks or 29 to 33 weeks, and
randomly assigned using a computer-generated list to one of the
two treatment groups: No-Sting or Aquaphor. Infants were excluded
from study participation if they had a congenital skin disease, skin
rash, an initial Neonatal Skin Condition Score (NSCS)24 of X5
(poor skin condition) or known maternal HIV infection. This study
was conducted in the intensive care nurseries at Duke University
Hospital in Durham, North Carolina, and Brenner Children’s
Hospital in Winston-Salem, North Carolina. The study was
approved by the institutional review boards of both institutions. Out
of 69 infants, three (1 No-Sting and 2 Aquaphor) were withdrawn
from the study after 6 days because of severity of illness or transfer
to another institution.
Intervention
The intervention was initiated as soon as feasible after birth
with all treatments beginning by 48 h of age. Infants received the
skin care treatment for 2 weeks (No-Sting or Aquaphor) on the
trunk, arms and legs, excluding the perineal area. Infants assigned
to the No-Sting group had the front of the trunk, arms and legs
sprayed and allowed to dry for 30 s. The infant was then turned
and the back of the trunk, arms and legs were sprayed in a similar
manner. A second application was administered using the same
procedure at 7 days after the first application. During each
application, a cloth diaper placed over the infant’s face prevented
any vapor from potentially entering the infant’s airway and/or eyes.
Although daily applications of No-Sting are recommended to
protect skin from repeated exposure to urine or stool, it was
expected that one application weekly for the first 2 weeks of life
would be adequate to minimize water loss and maintain skin
integrity.
Infants in the Aquaphor group received an individual-use tube
for twice daily applications. Using sterile gloves, a 1-inch ribbon of
Aquaphor was applied over the infant’s trunk, arms and legs from
the neck distally. This application procedure was repeated twice
daily. Both treatments were administered without any infant
instability (for example, bradycardia) by nurses trained according
to the study protocol. The intervention protocol continued for
14 days, at which time skin care resumed according to the unit
guidelines.
Measures
Covariates. The medical record was reviewed and the following
data were collected: infant gestational age, fluid intake, phototherapy use, urine output and serum sodium and potassium.
Gestational age was based upon either the first day of the last
menstrual period or an obstetric ultrasound to calculate the
expected date of confinement.
The standard of care in both study sites was to provide
supplemental humidity for infants with birth weights p1000 g
for the first 2 weeks of life. Depending upon birth weight, 60 to
80% humidity level was provided for the first week of life and 40 to
60% humidity was provided for the second week of life (protocols
available upon request). Humidity levels were measured at each
assessment point with the DermaLab (Cortex Technology, Hadsund,
Denmark; see TEWL below).
Neonatal skin condition. The skin condition was assessed daily
for 14 days and the NSCS was recorded.24 The NSCS is a 9-point
scale that assesses the entire body in three domains: dryness,
erythema and skin breakdown. Each domain is ranked on a scale
of 1 to 3, with a total score of 3 being normal and 9 being the
worst score possible. The NSCS has good intrarater (k ¼ 0.687 to
0.854) and interrater (k ¼ 0.659 to 0.89) reliability. In addition,
infants with higher skin scores have a higher probability of having
a documented infection.24 Clinically scores of <4 are considered
normal, 4 to 6 at risk and >6 poor skin condition.
Transepidermal water loss (TEWL). Transepidermal water loss
was measured daily for 14 days using the DermaLab.25–27 The
Dermalab consists of an open probe with paired sensors placed at
different distances from the skin. Humidity and temperature are
measured in each sensor to calculate vapor pressure gradients. The
difference between the two vapor pressure gradient measures is
representative of TEWL at that point on the skin.26,27 The Dermalab
measures TEWL from 0 to 250 g m2 h1. TEWL measures were
taken at two sites daily; the right shoulder and left thigh. Two
different sites were chosen to measure TEWL because previous
research showed that TEWL varied with body location.28,29 The
thigh was chosen because the infant’s leg was usually easily
accessible regardless of the infant’s position and the right shoulder
was selected because it is not typically used as a site for any other
monitors or equipment and could also be easily reached with
minimal manipulation of the infant.6
Environmental humidity levels were measured using the
Dermalab with the paired sensors in the open probe before
obtaining the TEWL measures. The average of the humidity
readings from the two sensors was recorded as environmental
humidity. Of the 1088 observations of TEWL, most infants were
cared for in incubators (incubators, 93.0%; radiant warmers, 3.1;
open crib 3.9%) with mean humidity levels between 46 and 55%
(incubator, mean 55.1, s.d. 15.9; radiant warmer, mean 54.9, s.d.
15.8; open crib, mean, 46.5, s.d. 18.6. Humidity levels were also
used as a covariate in each analysis of TEWL to ensure that
observed treatment differences were not confounded with
environmental humidity levels.
Data analyses
Power analyses for regression models using repeated measures were
performed, allowing for correlational structures in addition to
Journal of Perinatology
No-Sting protectant and Aquaphor
DH Brandon et al
416
compound symmetry.30 A first-order autoregressive model
indicated that standardized mean differences of 0.42 with power
equal to 0.80 and a ¼ 0.05, two tailed were detectable. Effects of
this magnitude are considered ‘medium-sized’ in the statistical
literature.31
Statistical models, referred to as mixed models,32,33 hierarchical
linear models34 and multilevel models,35 were used to answer the
research questions. With this approach, each subject’s repeated
measures on a dependent variable are first parameterized as an
individual growth trajectory plus an error term. In a second stage,
the estimated trajectories are modeled as a function of the
differences between individuals on independent variables of interest.
For analysis of TEWL, SAS PROC MIXED (SAS Institute, Cary, NC,
USA)36 was used to estimate the mixed models. Because SAS does
not provide procedures to estimate multilevel ordinal logistic
models, the STATA-based procedure GLLAMM (University of
London, London, England)37 was used for the one ordinal outcome
(NSCS).
Results
In initial analyses, several variables were examined to determine
whether despite randomization, they were over-represented in a
treatment group. Study site, day of life entering the study,
gestational age at birth, birth weight, gender, race, type of birth
(vaginal vs cesarean), Apgar scores, admitting diagnosis and
incidence of sepsis were similar across the treatment groups.
Table 1 includes descriptive characteristics of each group.
Ten infants had a diagnosis of late-onset sepsis; defined as a
positive blood culture drawn after 3 days of life that was treated
with antibiotics for at least 5 days. Six infants (15.8%) in the
No-Sting and 4 infants (12.9%) in the Aquaphor had positive
cultures. Out of 10 infants, 7 were born at p28 weeks gestation,
and the other three infants were each born at 31 weeks gestation
and were in the Aquaphor treatment group. The study was not
powered to evaluate differences in the incidence of sepsis between
the two treatment groups.
Neonatal skin condition
The total NSCS for the three domains (dryness, erythema and skin
breakdown) ranged between 3 and 6. In all, 73% of the NSCS in
both groups were scored a normal value of 3, 22% scored 4, 4%
scored 5 and only 1% scored 6. Figure 1a presents observed means
over the 14 days of treatment. The results of significance tests,
based on the multilevel regression models described above, are in
Table 2. For NSCS, the exponentiated logistic odds ratio coefficients
indicate multiplicative change in the odds of an increase in the
NSCS per unit change in the predictor. The observed means
indicate that a decline in NSCS over time was slightly steeper in the
Aquaphor group. The regression results show a significant group by
time interaction effect with the effect of time on NSCS equal to odds
ratio ¼ 1.02 in the No-Sting group compared with 0.81 in the
Aquaphor group. Of the three NSCS domains (redness, dryness and
skin breakdown), the dryness scores of 2 contributed to the higher
skin condition scores in the No-Sting group. Among the covariates,
gestational age was negatively related to NSCS (odds ratio ¼ 0.66),
whereas total daily fluid intake was positively related to skin
condition (odds ratio ¼ 1.11; see Figure 1a).
Table 1 Infant characteristics (N ¼ 69)
Variable
Gestational age at birth (weeks)
Birth weight (g)
Day of life at enrollment
RDS
Sepsisa,b
Caucasian
Male gender
Apgar score 1 min
Apgar score 5 min
No-Sting, N ¼ 38
Aquaphor, N ¼ 31
Mean (s.d.)
Mean (s.d.)
28.6 (2.6)
1117 (412)
1.6 (0.75)
28.5 (3.0)
1215 (430)
1.7 (0.53)
Percentage (N)
Percentage (N)
100%
15.8%
42.1%
57.9%
(38)
(6)
(16)
(20)
100%
12.9%
45.3%
51.6%
(31)
(4)
(14)
(16)
Mode
Mode
7
6
8
8
Abbreviation: RDS, respiratory distress syndrome.
a
Diagnosed after 48 h of age and before day of life 28.
b
All positive cultures in infants <750 g were coagulase-negative staphylococcus
(Coag Negative Staph).
Journal of Perinatology
Transepidermal water loss (TEWL)
Transepidermal water loss was measured at two sites: the left thigh
and the right shoulder. TEWL data for the left thigh, observed
means and regression results are given in Figure 1b. The regression
coefficients are unstandardized regression b’s indicating additive
change in TEWL per unit change in a predictor (see Table 2). The
observed means indicate similar change over time (days of
intervention) by treatment group (Figure 1b), and the regression
results reflect this pattern, indicating significant decline over time
(P<0.02) but no significant group effect or group by time
interaction. Infants of older gestational ages (b ¼ 3.77) and
cared for in higher humidity (b ¼ 0.09) had lower TEWL,
but increases in total fluid intake (b ¼ 0.07) were related to
higher TEWL.
Figure 1c presents observed means for TEWL data for the right
shoulder. In general, both treatment groups show initial steep
decline, which begins to level off after day 10. Although overall
mean decline seems fairly similar across treatment groups, decline
is steeper in the No-Sting group from day 2 through day 4 (largely
because of higher initial values), whereas those in the Aquaphor
No-Sting protectant and Aquaphor
DH Brandon et al
417
Table 2 Results of multilevel regression models for ordinal (NSCS)a and
continuous (TEWL)b dependent variables
Dependent variable: Neonatal Skin Condition Score (NCNS)
Variable
ORa
Gestational age
% humidity
Total fluids
Aquaphor vs No-Sting
Time
Aquaphor * time
0.66
1.00
1.11
2.03
1.02
0.79
P-value
<0.001
0.98
0.05
0.39
0.74
0.04
Dependent variable: transepidermal water loss (TEWL), left thigh
Variable
Gestational age
% humidity
Total fluids
Aquaphor vs No-Sting
Time
Aquaphor * time
b
P-value
3.78
0.09
0.07
2.57
0.56
0.21
<0.001
0.005
0.002
0.36
0.02
0.52
Dependent variable: transepidermal water loss (TEWL), right shoulder
Variable
Gestational age
% humidity
Total fluids
Aquaphor vs No-Sting
Time
Time2
Aquaphor * time
Aquaphor * time2
b
P-value
1.98
0.02
0.01
7.12
2.63
0.11
1.55
0.07
<0.001
0.36
0.26
0.08
<0.001
<0.001
0.01
0.03
a
Coefficients are exponentiated logistic odds ratios (OR) from multilevel ordinal logistic
models.
b
Coefficients are unstandardized regression coefficients.
Figure 1 (a) Mean Neonatal Skin Condition Score (NSCS) over 14 days of
treatment. (b) Mean left thigh transepidermal water loss (TEWL) scores over
14 days of treatment. (c) Mean right shoulder TEWL scores over 14 days of
treatment.
group (but not those in the No-Sting group) increased TEWL
between days 10 and 13. These differences are reflected in the
significant group by time interactions (Table 2). For the No-Sting
group, initial decline is 2.63, whereas the average increase in the
rate of decline is 0.11 per day. For the Aquaphor group, the
comparable estimators are (2.63 þ 1.55 ¼ 1.08) and
(0.11–0.07 ¼ 0.04). Similar to the left thigh, gestational
age was negatively related to TEWL (b ¼ 198).
In additional analyses (available upon request), the group
by humidity and the group by total fluid interactions were tested.
The results were negative for total fluids and ambiguous for
humidity, with results dependent upon the residual covariance
used and whether the dependent variable was analyzed in logged
versus raw form. A high zero-order correlation between humidity
and gestational age (0.58) likely introduced collinearity into
the model and accounted, at least in part, for these unstable
results.
Journal of Perinatology
No-Sting protectant and Aquaphor
DH Brandon et al
418
Discussion
Previous research with premature infants has shown increased skin
integrity and decreased TEWL with use of emollients in the first few
days of life.7,17 The increased risk of infection associated with
emollients has limited their use;16,38 yet, care practices that
promote skin integrity are essential to prevent fluid and electrolyte
imbalance and minimize risk of nosocomial infections from
epidermal stripping. In this study, the neonatal skin condition
scores for infants receiving Aquaphor were statistically better
than those for infants receiving No-Sting, but infants in both
groups had normal skin scores, and few infants in either group
had any skin breakdown (breakdown domain scores of 2 or 3).
Of the three skin domains (redness, dryness and skin breakdown),
dryness scores of 2 contributed to the higher skin condition
scores in the No-Sting group. The loss of moisturization in skin
makes the skin at risk for cracking and skin breakdown.39,40.
The application of No-Sting creates a dry layer of skin protectant that makes normal skin look dry. In contrast, emollients
make the skin look slick and moist. It is likely that the product,
rather than the condition of the skin, contributed to the
observed differences in skin condition scores, and the underlying
health of the skin was similar.
Previous research has shown that emollients significantly
reduce TEWL.7,41 In this study, TEWL declined significantly
over time in both intervention groups, as would be expected.5,6,29,42.
In addition, infants at older gestational ages had significantly
less water loss.29 Given that there were no observed differences
in TEWL between infants receiving No-Sting and Aquaphor, this
would suggest that No-Sting is as effective as Aquaphor in
minimizing TEWL.
In this study, both Aquaphor and No-Sting were able to
maintain normal skin condition scores and decrease TEWL.
No-Sting’s ease of application (only twice in 2 weeks compared
with Aquaphor’s twice daily for 2 to 4 weeks) makes it more
favorable to nursing staff, and allows fragile neonates to be left
alone and minimally stimulated. However, given the concern
over the risk for nosocomial infections with emollients,16,20 future
research should analyze the risk of nosocomial infections with
No-Sting. This study was not adequately powered to address
this issue.
Similar to previous research, infants cared for in higher
humidity in this study had significantly less TEWL.28,29,42,43
The skin of a premature infant makes up about 13% of the
body weight and comprises 80 to 90% of water in infants of
<26 weeks gestation.44,45 For every 1 ml of water lost through a
premature infant’s skin, 560 calories of heat are produced.
Therefore, it is difficult to maintain temperature stability in infants
with high TEWL,1 and growth is compromised because of the
energy used in heat production. Although humidity decreases
TEWL, it has also been related to decreased skin maturation
Journal of Perinatology
at 4 weeks of age.42 As many infants in this study were cared for
in >50% of humidified environments during the first week of life,
it is possible that the long-term skin condition of these infants may
have been influenced by the humidity.
This study has provided preliminary evidence for the
effectiveness of No-Sting on premature infant skin to minimize
water loss and maintain skin integrity. Future research should
explore both the short- and long-term effects of No-Sting and
humidity on TEWL, skin condition and skin maturation.
Interventions designed to maintain skin integrity and minimizing
TEWL will promote growth, maintain fluid and electrolyte balance
and prevent infections.
Conflict of interest
The authors declare no conflict of interest.
Acknowledgments
The preparation of this paper was supported by the Duke University School of
Nursing, the Duke Neonatal Perinatal Research Institute and the Wake Forest
University Baptist Medical Center.
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