Download Microclimate Impact of Prophylactic Dressings Using

Original research
TE
Microclimate Impact of Prophylactic
Dressings Using In Vitro Body Analog
Method
D
D
O
N
O
T
Address correspondence to:
Evan Call, MS
Department of Microbiology
Science Lab Building Floor 3M
Weber State University
2506 University Circle
Ogden, UT 84408
[email protected]
U
From the 1Weber State University,
Ogden, UT; 2University of Utah, Salt
Lake City, UT; 3University of Alberta,
Edmonton, Canada
Abstract: Wound dressings have been successfully explored for use in
prevention of pressure ulcers in individuals who are at clinical high-risk
for developing ulcers. Methods. In this study, application of a recently
described body analog test fixture and method is used to evaluate performance features of 8 clinically available dressings for prophylaxis.
Documenting dressing performance is essential to defining the proper
use and limits to application of dressings for ulcer prevention. These in
vitro studies were undertaken to characterize the impact on the microclimate generated by the application of a dressing to the surface of the
skin. Results. The measurement of moisture trapped next to the skin,
moisture escaped from the dressing, and heat trapped by the dressing
show that some dressings are more suited for skin protection. Conclusion. It is evident that an optimal performance band for microclimate
management exists in the application of dressings for prophylaxis, and
that dressings should be evaluated for proper performance prior to implementation in a pressure ulcer prevention program.
PL
WOUNDS 2013;25(4):94–103
IC
A
Evan Call, MS;1 Justin Pedersen2; Brian Bill;1
Craig Oberg PhD;1 Martin Ferguson-Pell, PhD3
94
WOUNDS® www.woundsresearch.com
F
or 3 decades, pressure ulcer research has focused on pressure and ischemia to develop models for prevention and treatment of pressure ulcers.1,2 Current evidence indicates these efforts have not generated noticeable reductions in incidence.3-5 It was recently demonstrated by multiple
authors that a dressing placed on skin at risk for ulceration can significantly
reduce the rate of ulceration.6-8 While sacral pressure ulcer dressings have not
typically been applied preventively, it seems intuitive that a dressing that redistributes forces or mitigates the microclimate could provide some preventive benefit. Recognizing the impact of moisture on the generation of friction,
which results in shear forces delivered to the skin, suggest that microclimate
requires investigation.
Ohura et al’s9 demonstration of the reduction of both shear and axial
pressure forces by a dressing on the surface of porcine skin,9 combined
with the impact of moisture on friction,10 suggests the need to examine
microclimate in dressing-based prevention.11 Microclimate is defined as the
temperature and humidity found in the interface between the body and the
support surface.12 Its proper management will maintain a favorable tem-
Call et al
Keypoints
IC
A
TE
•T
wo methods have been developed for measuring
the heat and water vapor characteristics of support
surfaces in the laboratory.
•The Nicholson method yields engineering values for
heat transfer in watts/m2 and gm H2O/m2, units unrecognized by clinicians, and tests a small portion
of the surface without typical body loading.
•The Body Analog method was selected for its recognizable temperature and humidity report under
typical use conditions.
the indenter as though it were covering the sacrum of a
patient.
The moisture-dependent viscosity, elasticity, and resilience of skin, particularly in the aging individual, make
shear the most significant of ulcerating mechanical forces.15 This concept is supported by Wildnauer et al16 who
demonstrated significant changes in skin properties based
on skin moisture content. Knowing the protective effect
of dressings raises the following questions:6,20,21 how do
prophylactic dressings impact the forces reaching the underlying tissue and what characteristics of prophylactic
dressings impart the observed protective effect?22 This
research was undertaken to characterize these impacts
using bench tests for microclimate properties of 8 commercially available dressings.
Materials and Methods
A sweating thermodynamic rigid cushion loading
indenter (TRCLI) as described by Ferguson-Pell et al23
was employed for prophylactic dressing testing. Dress-
D
O
N
O
T
D
U
PL
perature and moisture level at the skin surface.11 Skin
moisture levels govern elasticity, tensile, and yield properties,16 and thus, resistance to injury. Limited testing of
the impact of pressure and shear of dressings8,13 leaves
the effect of dressings on microclimate unresolved.
Brienza and Geyer14 outlined tissue damage due to temperature exposure, heat flux, specific heat, perspiration,
incontinence, skin pH changes, and the moisture vapor
transmission rate. Dressings add the need to characterize moisture vapor transmission and the trapping of
moisture next to the skin.
The classic thermodynamic model considers the body
a heat source, and each layer on it a resistor to the escape
of heat or moisture.17 This model predicts the addition
of a dressing to the skin will raise the temperature. Making characterization of dressing prophylaxis important,
especially in consideration of these in deep tissue injury
prophylaxis.18 Given that moisture-accentuated shear
forces may contribute to deep tissue injury, and force
applied to the skin results in internal loads that are as
much as 2 times greater in the deep tissues,19 further
examination is required.
Two methods have been developed for measuring the
heat and water vapor characteristics of support surfaces
in the laboratory: the method proposed by Nicholson et
al22 and the Body Analog Method (US ANSI RESNA draft
standards), which is based on the method published by
Ferguson-Pell et al.23 The Nicholson method yields engineering values for heat transfer in watts/m2 and gm H2O/
m2, units unrecognized by clinicians, and tests a small
portion of the surface without typical body loading. The
Body Analog method was selected for its recognizable
temperature and humidity report under typical use conditions.
The body analog method utilizes the L5 to Femoral
Epicondyles (approximate) segment of a model of a 50th
percentile male human. An inner tank is filled with circulating water held at 37°C. An outer shell of the rig is filled
with water that escapes through a “sweating membrane,”
so that only water vapor is delivered to the test surface
mimicking the moisture vapor delivered by a human subject. This assembly is placed on a support surface such
as a mattress and weight is applied until the load on the
surface is the same as a 50th percentile human male.
The test rig is allowed to deliver heat and humidity
at the same rate as that of a 50th percentile male for 3
hours while the temperature and humidity are monitored
at the interface. For the purposes of this study, the authors placed the dressing being tested on the surface of
Figure 1. TRCLI with dressing applied.
Vol. 25, No. 4 April 2013
95
Call et al
Table 1. Description of dressings.
Thickness (cm)
Number of layers
(includes backing,
absorbent material,
adhesive)
Adhesive
Absorbent Layer
1
18 x 18
0.3175
5
silicone
2
23 x 23
0.3175
5
silicone
3
24.7 x 20.7
0.2184
4
acrylic
4
22 x 22
0.3988
3
acrylic
hydrocellular foam
5
17 x 17
0.4013
3
acrylic
hydrocellular foam
6
17 x 17
0.5867
3
acrylic
hydrocellular foam
7
15.2 x 16.5
0.2591
2
acrylic
foam
8
15.2 x 16.5
0.4166
3
acrylic
foam
TE
Size (cm)
foam
foam
IC
A
gelling foam
N
O
T
D
U
PL
Dressing #
O
Figure 2. Moisture trapped in the dressing vs escaped through the dressing
D
ings were tested by applying them to the approximasacral location of the TRCLI, and placement was done
to reflect typical application and functional anatomy
for dressings applied to the body while supine in bed
(Figure 1).
Each dressing was centered on the TRCLI and positioned to cover the typical sacral location. The TRCLI is
intended to test a larger surface area than the dressings
covered, so each dressing was placed as previously de96
WOUNDS® www.woundsresearch.com
scribed, and the remaining TRCLI test surface was left
unmodified. This arrangement was also selected to provide a microclimate comparable to that created by the
body when lying supine on a support surface. A photograph of the dressing placement is shown in Figure 1.
Eight commercially available dressings (Table 1) were
tested in triplicate. Dressings as close to the same size
as possible were obtained, however, due to differences
in dressing design, intended function, and manufacturer
Call et al
Table 2. Temperature difference across dressing
(inside to outside).
Confidence
Level*
0.43
< ± 0.02
Dressing 2
0.50
< ± 0.02
Dressing 3
0.47
< ± 0.02
Dressing 4
0.30
Dressing 5
0.27
Dressing 6
0.33
Dressing 7
0.20
Dressing 8
0.57
< ± 0.02
D
< ± 0.02
< ± 0.02
< ± 0.02
T
< ± 0.02
N
O
*a= 0.05
TE
A
• A sweating thermodynamic rigid cushion loading indenter (TRCLI) as described by Ferguson-Pell et al23
was employed for prophylactic dressing testing.
•Dressings were tested by applying them to the approximate sacral location of the TRCLI, and placement was done to reflect typical application and
functional anatomy for dressings applied to the
body while supine in bed (Figure 1).
•Temperature and humidity data were logged using a
Sensirion EK-H3 system (Sensirion Inc, Westlake
Village, CA) with 11 combined thermistor-based
temperature and silicone wafer humidity sensors
from the same company. Sensors were calibrated
prior to use with the saturated salts method.25
U
Dressing 1
Keypoints
PL
Average
TRCLI was brought to set point and held for 60 minutes
to allow for equilibration prior to each trial. The sweat
chamber of the TRCLI was charged with deionized water and recharged following each test to ensure that the
starting sweat volume was identical for each trial. The
charged, dressed, and equilibrated TRCLI was loaded onto
a mattress surrogate consisting of a water-impermeable
mattress cover over a high resilience-45 (firm) foam mattress analog.
Temperature and humidity data were logged using a
Sensirion EK-H3 system (Sensirion Inc, Westlake Village,
CA) with 11 combined thermistor-based temperature
and silicone wafer humidity sensors from the same company. Sensors were calibrated prior to use with the saturated salts method.25 Duplicate sensors were placed at
IC
offerings, there were significant differences in size of
the dressings.
All trials were conducted in a temperature and humidity controlled laboratory maintained at 23°C +/- 2°C and
50% RH +/- 5% as per International Organization for Standardization 554-1976(E).24 The TRCLI was charged with
a 50/50 ethylene glycol/water solution and a circulating
water bath (Forma Scientific Model 2095) maintained circulation through the indenter at a constant temperature
of 37°C +/- 0.1°C.
The TRCLI has been shown to deliver 3.6 grams of insensible water vapor per 3-hour trial, and the resolution
of the system is 1% relative humidity and 0.1°C.23 The
Table 3. Moisture trapped in or escaped from dressing.
Confidence Level*
Average Moisture
Escaped Dressing
(grams)
Confidence Level*
Dressing 1
1.02
± 0.13
2.58
± 0.13
Dressing 2
0.89
± 0.59
2.53
± 0.68
Dressing 3
3.32
± 0.54
-0.23
± 1.06
Dressing 4
0.72
± 0.19
2.88
± 0.19
Dressing 5
1.56
± 0.36
2.04
± 0.36
Dressing 6
1.31
± 0.50
1.93
± 0.83
Dressing 7
1.94
± 0.59
1.66
± 0.59
Dressing 8
3.60
---
-2.48
± 1.76
D
O
Average Moisture
Trapped in Dressing
(grams)
*a= 0.05
Vol. 25, No. 4 April 2013
97
Call et al
Table 4. P-values for differences in moisture trapped inside dressings (grams). Significant differences highlighted yellow.*
2
3
4
5
6
1
--
0.9827
0.0033
0.5667
0.1243
0.3391
2
0.9827
--
0.0042
0.6228
0.1491
0.3585
3
0.0033
0.0042
--
0.0061
0.0089
0.0060
4
0.5667
0.6228
0.0061
--
0.0277
0.1364
5
0.1243
0.1491
0.0089
0.0277
--
6
0.3391
0.3585
0.0060
0.1364
0.4774
7
0.0627
0.0702
0.0283
0.0449
8
0.0097
0.0122
0.4226
0.0011
8
0.0627
0.0097
0.0702
0.0122
0.0283
0.4226
0.0449
0.0011
0.4774
0.3504
0.0082
--
0.1861
0.0123
IC
0.3504
0.1861
--
0.0315
0.0082
0.0123
0.0315
--
PL
*a= 0.05
7
TE
1
A
Dressing
Dressing
1
2
3
5
6
7
8
1
--
0.7235
0.0180
0.5667
0.1243
0.2135
0.0624
0.0215
2
0.7235
--
0.0182
0.4174
0.3038
0.3376
0.1322
0.0198
3
0.0180
0.0182
--
0.0261
0.0411
0.0380
0.0532
0.1131
4
0.5667
0.4174
0.0261
--
0.0277
0.1473
0.0448
0.0258
5
0.1243
0.3038
0.0411
0.0277
--
0.8236
0.3480
0.0328
6
0.2135
0.3376
0.0380
0.1473
0.8236
--
0.6298
0.0237
7
0.0624
0.1322
0.0532
0.0448
0.3480
0.6298
--
0.0335
8
0.0215
0.0198
0.1131
0.0258
0.0328
0.0237
0.0335
--
N
O
T
D
4
U
Table 5. P-values for differences in moisture escaped the dressings (grams). Significant differences highlighted
yellow.*
*a= 0.05
D
O
each of the following 5 locations, one inside and one outside the dressing; right and left ischial tuberosities, the
perineum and the right and left thigh. When dressing
size limited the number of sensors that could be placed
under the dressing, the compliment of sensors was reduced to 3 locations, the right and left ischial tuberosities
and the perineum.
Each test consisted of a 60-minute equilibration period, a 180-minute test period, then a 45-second raising of
the indenter intended to represent the repositioning of
the patient, followed by a 15-minute replacement in the
test position. The apex of the TRCLI was placed 13 cm
from the edge of the support surface surrogate so that no
edge effect would confound the test data.
The 11 sensors were continuously sampled with data
98
WOUNDS® www.woundsresearch.com
logged at a rate of 0.5 Hz throughout the test period. Data
was stored in a comma-delimited format that allowed it
to be imported into a spreadsheet for analysis. The average temperature, average relative humidity, difference
between pairs of sensors both inside and outside the
dressing, and the difference between the dressing and the
support surface surrogate were calculated.
Results
Tests utilizing the dressings showed a significant difference in the amount of heat and moisture transpired
through or being trapped in a particular dressing (Tables
2 and 3). Table 2 shows the average temperature difference from inside the dressing to outside the dressing. It
should be noted that the tight range in the confidence
Call et al
Table 6. Percent relative humidity at TRCLI/dressing
and dressing/support surface interfaces.
Average % Relative Average % Relative
Humidity on Patient Humidity on Outside
Side of Dressing
of Dressing
Discussion
Dressing 1
59.00
56.00
Dressing 2
58.33
Dressing 3
67.33
45.33
Dressing 4
63.00
60.00
Dressing 5
70.33
60.00
Dressing 6
64.33
58.00
Dressing 7
77.50
62.00
Dressing 8
60.00
43.33
IC
A
55.67
Moisture. In 1981, Reuler and Cooney29 indicated the
presence of moisture from either incontinence or perspiration resulted in a 5-fold increase in risk of ulceration. In
measuring the validity and reliability of the Braden scale,
it was shown that the presence of excess moisture on
the skin is 1 of 4 risk factors predictive of ulceration.30,31
Clark32 found that the relative humidity between the
body and support surface was higher for subjects who
developed ulcers.
In the examination of blister formation, results showed
that wet skin is less susceptible to friction and shear-based
damage; however, moist skin has a greater risk due to the
increase in friction caused by the presence of moisture
in quantities too low to be lubricious, but high enough
to increase the surface tension between the skin and the
contacting surface.33
D
O
N
O
T
D
U
Heat. When lying on a support surface the insulated
nature of the surface traps body heat at the interface.17
This trapped heat generates the following physiologic responses; increased transpiration, increased perspiration,
increased metabolic stress on cells (due to the Arrhenius
Effect), increased friction, and thus, shear due to the increased moisture present, and heat-accelerated moisture
softening of the hyaluronic acid intracellular bonds increasing the potential for skin failure.
Kokate et al26 showed that elevation of skin temperature under identical loading conditions increases the rate
of ulceration in swine. The average temperature differences observed are just under 0.4°C (Table 2). According to the Arrhenius Effect, temperature over time begins
to have a significant impact on tissue at approximately
1.0°C - 2.0°C.17, 27
While the authors anticipated this effect with the application of dressings to the skin, the heat-trapping effect of the dressing is low enough that it does not have a
significant negative impact on the skin (Table 3). Therefore the authors conclude that the use of a dressing does
not elevate the tissue temperature to the point of injury.
It is important to observe that typical interventions
to reduce pressure risk to the tissue also tend to mitigate heat accumulation, such as turning and offloading,
both of which produce an inrush of air that washes the
heat from the region at risk, as well as improved exposure to room temperature air (21°C - 23°C). The mechanism of the beneficial effect of reducing skin temperature supports this discussion as described by Tzen and
colleagues.28
TE
Dressing
PL
intervals of the means is due to the very large data sets
that were generated by logging temperature at 0.5 Hz
throughout the 3-hour and 15-minute test period. Note
that there is not a direct correlation between thickness
and temperature.
In addition, as moisture built up in the moisture management bed, some dressings lost the ability to transpire
as the moisture level in the dressing increased (see dressings 3 and 8 in Table 3.) Dressings 3 and 8 also demonstrate negative moisture escape values, indicating that
the moisture management of these 2 dressings absorbed
more moisture than was delivered by the test fixture, presumably from the ambient laboratory conditions. P-values
are shown in Table 4 and Table 5 for the moisture that
escaped the dressing, and moisture trapped inside the
dressing, respectively.
Keypoints
• An aggressive moisture-trapping bed can draw too
much moisture from the skin in the early phase of
use, while dressings that do not breathe adequately
will trap moisture and compromise skin viability due
to overhydration. In the extreme, these changes will
result in undesirable changes in skin properties.16,35
•Managing these changes by retaining adequate
moisture in the skin to optimize elasticity and minimize maceration, excoriation, and cell stripping is
an essential function of a prophylactic dressing.
This suggests that the optimal performing dressings are those found in the midrange of the results
shown in Table 3.
Vol. 25, No. 4 April 2013
99
Call et al
Table 7. Dressing related hydration of the skin.
Optimal Hydration
(moderate)
Under Hydration
TE
Over Hydration
Increased risk of shear damage
Increased risk of pressure damage
Increased maceration and risk of
excoriation
Increased risk of skin tears
Maximized elasticity
Maximized strength
Maximized resilience under
compression
Maximized response to shear
Chemical,
adhesive, irritant
exposure
Increased transdermal diffusion
Increased sensitivity
Reduced irritation and
sensitization
Balanced transepidermal water
loss
Reduced transdermal diffusion
Compromised barrier
properties
Absorption of chemicals or
irritants
Water activity level
and protease
Supports microbial growth
Favors pathogenic and invasive
species (dermatophytes)
Protease activity enhanced by
increased solvent and subsequent
diffusion
Supports normal flora
Provides normal osmotic
pressure (isotonic surface)
Supports normal immune
function at skin surface
Limits microbial growth, both
normal flora and pathogens
Inhibits protease function
IC
PL
moisture should not drop below prescribed levels in order to preserve the skin’s elasticity and protective barrier
properties.36
The moisture management demonstrated by dressings
in the lower midrange of test results appear to support
the observation that moisture in the skin environment
not be allowed to fall below 40% relative humidity,36 thus
protecting the skin from both dehydration and overhydration. The authors theorize that overhydration exhibited by dressing 3 and dressing 8 will amplify the issues
identified by Breuls et al,37 Ceelen et al,38 and Gawlitta
et al.39 Overly hydrated cells are more sensitive to compression and shear loading due to reaching the distortion
limit at lower forces.37,38,39
This becomes the argument that there is an “optimal
band” of moisture for prevention of pressure ulcers using dressings prophylactically (Table 7). Confirming the
estimate of the upper limit of this band now becomes
the focus in dressing-related prophylaxis. Overhydration
of the skin is also responsible for increasing sensitivity to
irritants.40
Use of a dressing on the surface of the TRCLI raises
the temperature at the interface of the dressing and
the TRCLI, as predicted by the Interface Model, except
where the dressing’s moisture management bed is saturated. When this occurs, the heat conduction increases
and the thermal resistance of the dressing is overcome.
At least 3 of the tested dressings maintained a moisture
D
O
N
O
T
D
U
Moisture management by dressings has been examined and the role of moisture wicking, storage, and evaporation in relation to dressing design described.34 Wildnauer et al16 demonstrated that, as moisture in the skin
increases, skin strength decreases. Results in the author’s
laboratory indicate all of these conditions are changed
when a dressing is applied to the skin. An aggressive
moisture-trapping bed can draw too much moisture from
the skin in the early phase of use, while dressings that do
not breathe adequately will trap moisture and compromise skin viability due to overhydration.
In the extreme, these changes will result in undesirable
changes in skin properties.16,35 Managing these changes
by retaining adequate moisture in the skin to optimize
elasticity and minimize maceration, excoriation, and cell
stripping is an essential function of a prophylactic dressing. This suggests that the optimal performing dressings
are those found in the midrange of the results shown in
Table 3.
In the case of dressing 3 and dressing 8, both the moisture transmission and the thermal resistance characteristics altered significantly after 90 minutes of exposure
to test conditions (Table 6). Grams of moisture trapped
in the dressing verses grams of moisture escaping the
dressing provides strong evidence of a dressing’s ability
to moderate the skin/dressing microclimate and to potentially provide a prophylactic benefit.
It should be noted that some references suggest skin
100
WOUNDS® www.woundsresearch.com
Loss of elasticity
Cracking and fissures
Increased risk of skin tears
A
Physical damage
Call et al
TE
Employing the TRCLI to characterize dressing performance yields a sensitive test method for temperature
and humidity and moisture escape from the body analog. Historically, the average differences in temperature
and humidity are small yet the test system provides adequate resolution to observe significant differences between the dressings tested in this system.
The use of a dressing prophylactically alters the skin
surface microenvironment for both temperature and humidity. For temperature, the increase is less than half of
the estimated threshold for potential heat stress-related
ulceration risk. For humidity, the impact can be either
negative or positive based on the nature of the dressing
and the performance of the fluid handling bed.
Two of the dressings tested create environments that
are thought to be in the range of risk to the tissue. This
was due to high relative humidity where the ultimate
relative humidity under the dressing reaches ≥ 70% as
seen with dressing 5 and dressing 7.
Another area of potential concern is where a dressing’s performance changes due to fluid loading in the
dressing’s moisture-management bed; this is a potential
risk for dressing 3 and dressing 8. The materials of each
dressing’s construction were found to have a significant influence on the temperature of the TRCLI (body
analog) under the dressing, particularly when foam was
present. These temperature differences did not reach
the point of inducing temperature-related injury, which
has been a point of potential concern based on the classic thermodynamic model.
The significance of the microclimate challenge represented by this study is seen in the heat and relative
humidity data where the support surface is a dramatically larger resistor to heat and moisture loss; yet, in this
study, it did not obscure the observed results.This is due
to the fact that temperatures were measured both inside
and outside the dressing, and thus were able to treat
the dressing as one of the resistors to heat loss in the
system. These measurements were independent of the
largest resistor, the support surface.
Because there is no direct relationship between
dressing thickness and resistance to heat flow through
N
O
T
D
U
PL
environment comparable with other work that defines a
minimum relative humidity in the skin environment that
ensures adequate elasticity and strength to respond to
typical loading and shear that skin is exposed to in the
bed-bound patient.15,35
At least 2 of the dressings (Table 6) retained moisture
at a level that will challenge the integrity of the skin exposed to observed moisture levels based on the characterization of skin strength and elasticity shown by Wildnauer16 and Wilkes.35 The ability of a dressing to handle
the transdermal water vapor loss of the skin under the
dressing appears to play a pivotal role in managing the
microclimate of the protected skin.
The dressings tested did not follow the classical thermodynamic model for resistance to heat flow based on
the thickness of the resistor, which indicates that the
specific heat and thermal conduction of each dressing is
unique and dependent upon the material of construction;
the number of layers; the presence of perforations or micropores in the films used; the concentration of thermally
dense polymers; air entrapment in foams; and changes in
all of these factors based on the accumulation of moisture
in the moisture management bed.
Conclusions
A
• The dressings tested did not follow the classical
thermodynamic model for resistance to heat flow
based on the thickness of the resistor, which indicates that the specific heat and thermal conduction of each dressing is unique and dependent upon
the following factors: material of construction; the
number of layers; the presence of perforations or
micropores in the films used; the concentration of
thermally dense polymers; air entrapment in foams;
and changes in all of these factors based on the
accumulation of moisture in the moisture management bed.
load over the responding area of the dressing. Since it was
not possible to match the various manufacturers’ dressings to the same size, it seems appropriate to explore the
proper methods of standardizing for size and repeating
these tests.
IC
Keypoints
O
Limitations
D
Test data shows a continuing moisture trapped/escaped curve suggesting that the test period should be
lengthened to allow the time/moisture escaped curve to
approach equilibrium, or to reach the point that would
be considered a typical use period for a dressing, for example, 24 hours.
It is believed that the size of the dressing does play a
role in the outcome of these tests. This belief is based on
the test forces being applied to a dressing structure that
reacts to the loading as a cohesive unit, dispersing the test
Vol. 25, No. 4 April 2013
101
Call et al
2.
3.
D
5.
T
6.
N
O
7.
8.
D
O
9.
13.
14.
15.
16.
17.
U
4.
Brienza DM, Karg PE, Geyer MJ, Kelsey S, Trefler E. The relationship between pressure ulcer incidence and buttockseat cushion interface pressure in at-risk elderly wheelchair users. Arch of Phys Med Rehab. 2001;82(4):529-533.
Geyer MJ, Brienza DM, Karg P, Trefler E, Kelsey S. A randomized control trial to evaluate pressure-reducing seat
cushions for elderly wheelchair users. Adv Skin Wound
Care. 2001;14(3):120-132.
Reger SI, Ranganathan VK, Sahgal V. Support surface interface pressure, microenvironment, and the prevalence
of pressure ulcers: an analysis of the literature. Ostomy
Wound Manage. 2007;53(10):50-58.
Schue RM, Langemo DK. Prevalence, incidence, and
prediction of pressure ulcers on a rehabilitation unit. J
Wound Ostomy Continence Nurs. 1999;26(3):121-129.
Bates-Jensen BM, McCreathe HE, Pongquan V. Subepidermal moisture is associated with early pressure ulcer damage in nursing home residents with dark skin
tones: pilot findings. J Wound Ostomy Continence Nurs.
2009;36(3):277-284.
Bots TC, Apotheker BF. The prevention of heel pressure
ulcers using a hydropolymer dressing in surgical patients.
J Wound Care. 2004;13(9):375-378.
Brindle CT. Outliers to the Braden Scale: Identifying highrisk ICU patients and the results of prophylactic dressing
use. WCET J. 2010;30(1):11-18.
Ohura N, Ichioka S, Nakatsuka T, Shibata M. Evaluating dressing materials for the prevention of shear force
in the treatment of pressure ulcers. J Wound Care.
2005;14(9):401-404.
Ohura T, Takahashi M, Ohura N Jr. Influence of external
forces (pressure and shear force) on superficial layer and
subcutis of porcine skin and effects of dressing materials: are dressing materials beneficial for reducing pressure and shear force in tissues? Wound Repair Regen.
2008;16(1):102-107.
Sperling L. Skin Diseases Associated With Excessive Heat,
Humidity, and Sunlight. In: James WD, ed. Military Dermatology:Textbook of Military Medicine. Part III. Disease and
the Environment. 1st ed. Washington DC: Office of the
Surgeon General, US Department of the Army; 1994:39-54.
International Review. Pressure ulcer prevention: pressure,
PL
1.
10.
11.
102
TE
References
A
12.
shear, friction and microclimate in context. A consensus
document. London: Wounds Int. 2010.
National Pressure Ulcer Advisory Panel and European
Pressure Ulcer Advisory Panel. Prevention and treatment
of pressure ulcers: clinical practice guideline. Washington
DC: National Pressure Ulcer Advisory Panel, 2009. www.
npuap.org/online-store/product.php?productid=17585&
cat=0&besteller=Y
Ashford RL, Freear ND, Shippen JM. An in-vitro study of
the pressure-relieving properties of four wound dressings
for foot ulcers. J Wound Care. 2001;10(2):34-38.
Brienza DM, Geyer MJ. Understanding support surface
technologies. Adv Skin Wound Care. 2000;13(5):237-244.
Gerhardt LC, Lenz A, Spencer ND, Münzer T, Derler S. Skintextile friction and skin elasticity in young and aged persons. Skin Res Technol. 2009;15(3):288-298.
Wildnauer RH, Bothwell JW, Douglass AB. Stratum and
corneum biomechanical properties. I. Influence of relative humidity on normal and extracted human stratum
corneum. J Invest Dermatol. 1971;56:72-78.
Call E, Levy B, Jones R, Oberg B. Classical thermodynamics
of wheelchair cushions and Otto Bock comfort temperature intervention. Paper presented at: Nineteenth International Seating Symposium. February 27-March 3, 2003;
Orlando, FL.
Sanders JE, Goldstein BS, Leotta DF. Skin response to mechanical stress: adaptation rather than breakdown--areview of the literature. J Rehabil Res Dev. 1995;32(3):214226.
Solis LR, Liggins AB, Seres P, et al. Distribution of Internal
Strains Around Bony Prominences in Pigs. Ann Biomed
Eng. 2012; 40(8):1721-1739.
Hall P. Prophylactic use of Op-Site on pressure areas. Nurs
Focus. 1983;4(5):16.
Nakagami G, Sanada H, Konya C, Kitagawa A, Tadaka E, Tabata K. Comparison of two pressure ulcer preventative
dressings for reducing shear force on the heel. J Wound
Ostomy Continence Nurs. 2006;33(3):267-272.
Nicholson GP, Scales JT, Clark RP, de Calcina-Goff ML. A
method for determining the heat and water vapour permeability of patient support systems. Med Eng Phys.
1999;21(10):701-712.
Ferguson-Pell M, Hirose H, Nicholson G, Call E.Thermodynamic rigid cushion loading indenter: a buttock-shaped
temperature and humidity measurement system for cushioning surfaces under anatomical compression conditions. J Rehabil Res Dev. 2009;46(7):945-956.
International Standards Organization. Standard atmospheres for conditioning and/or testing—specifica-
IC
the dressing, it is not possible to use marketing literature
or dressing specifications to determine the ability of a
dressing to support prophylaxis without testing. The
authors recommend dressings be characterized prior to
use in a pressure ulcer prevention program.
WOUNDS® www.woundsresearch.com
18.
19.
20.
21.
22.
23.
24.
Call et al
IC
A
TE
Policy and Research, United States Department of Health
and Human Services; 1992.
37. Breuls RG, Bouten CV, Oomens CW, Bader DL, Baaijens FP.
Compression induced cell damage in engineered muscle
tissue: an in vitro model to study pressure ulcer aetiology.
Ann Biomed Eng. 2003;31(11):1357-1364.
38. Ceelen KK, Stekelenburg A, Loerakker S, et al. Compression-induced damage and internal tissue strains are related. J Biomech. 2008;41(16):3399-3404.
39. Gawlitta D, Li W, Oomens CW, Baaijens FP, Bader DL,
Bouten CV.The relative contributions of compression and
hypoxia to development of muscle tissue damage: an in
vitro study. Ann Biomed Eng. 2007;35(2):273-284.
40. Basketter D, Gilpin G, Kuhn M, Lawrence D, Reynolds F,
Whittle E. Patch tests versus use tests in skin irritation risk
assessment. Contact Dermatitis. 1998;39(5):252-256.
D
O
N
O
T
D
U
PL
tions. ISO 554:1976 http://www.iso.org/iso/catalogue_
detail?csnumber=4635 Accessed March 26, 2013.
25. American Society for Testing and Materials. ASTME 10485 (Reapproved 1996)--Standard practice for maintaining
constant relative humidity by means of aqueous solutions.
1985;33-34,637
26. Kokate JY, Leland KJ, Held AM, et al. Temperature-modulated pressure ulcers: a porcine model. Arch Phys Med
Rehabil. 1995;76(7):666-673.
27. Lachenbruch, C. Skin cooling surfaces: estimating the importance of limiting skin temperature. Ostomy Wound
Manage. 2005;51(2):70-79.
28. Tzen Y, Brienza DM, Karg PE, Loughlin PJ, Geyer MJ. Effectiveness of local fast and slow cooling on pressure
induced reactive hyperemia (RH) in adult human participants. Rehabilitation Engineering and Assistive Technology Society of North America Annual Conference; June
26-20, 2010: Las Vegas, NV.
29. Reuler JB, Cooney TG. The pressure sore: pathophysiology and principles of management. Ann Inter Med.
1981;94(5):661-666.
30. Vanderwee K, Clark M, Dealey C, Gunningberg L, Defloor
T. Pressure ulcer prevalence in Europe: a pilot study. J
Eval Clin Pract. 2007;13(2):227-235.
31. Halfens RJ, Van Achterberg T, Bal RM. Validity and reliability of the Braden scale and the influence of other risk
factors: A multi-centre prospective study. Int J Nurs Stud.
2000;37(4):313-319.
32. Clark M. The etiology of superficial sacral pressure sores.
In: Leaper D, Wound Management Association, eds. Proceedings of the 6th European Conference on Advances
in Wound Management. Amsterdam: McMillian Magazines;
1997:167-170.
33. Mulvaney M, Harrington A. Cutaneous trauma and its treatment. In James WD, ed. Military Dermatology:Textbook of
Military Medicine. Part III. Disease and the Environment.
1st ed. Washington DC: Office of the Surgeon General, US
Department of the Army; 1994:145.
34. Thomas S. The Role of dressings in the treatment of
moisture-related skin damage. World Wide Wounds. 2008.
http://www.worldwidewounds.com/2008/march/Thomas/Maceration-and-the-role-of-dressings.htmlmarch/
Thomas Accessed March 28, 2013.
35. Wilkes GL, Brown IA, Wildnauer RH. The biomechanical
properties of skin. CRC Crit Rev Bioeng. 1973;1(4):453495.
36. Pressure Ulcers in Adults: Prediction and Prevention:
Clinical Practice Guideline Number 3. (AHCPR Publication NO 92-0047). Rockville, MD: Agency for Health Care
Vol. 25, No. 4 April 2013
103