Skin IQTM
Microclimate
Manager
PRODUCTS FOR PRACTICE
made
easy
Volume 2 | Issue 2 | May 2011 www.woundsinternational.com
Box 1 What is microclimate? (adapted from2,4)
Introduction
This article describes the importance of
microclimate control in pressure ulcer prevention
and treatment. It focuses on the structure and
mode of action of a new cover system — the
Skin IQTM Microclimate Manager (KCI). For many
years, the use of support surfaces in pressure
ulcer prevention has concentrated on reducing
the mechanical load on the skin. However,
when selecting products, there is now a need
for clinicians to also consider how well a support
surface manages conditions at the interface
between the skin and the support surface
(the microclimate).
Microclimate =
{
Skin surface or tissue temperature
or
Humidity and/or skin surface moisture
Skin surface temperature can be measured at the skin/support surface
interface with the patient still in contact with the surface or after moving out of
contact with the surface
Relative humidity (often abbreviated to humidity) relates the amount of water
vapour in the air at a specific air temperature to the maximum amount of water
vapour that body of air would hold at that temperature. Relative humidity can
be measured using a hygrometer5,6. Methods that examine the ability of skin
to conduct electricity can measure the water content of the stratum corneum7.
In clinical practice, assessment of skin moisture may be more subjective, eg by
using the moisture subscale of the Braden scale8
Why is microclimate important?
What is a microclimate?
Successful pressure ulcer prevention depends upon a complex
balance between two sets of parameters — the external loads
applied to the skin and soft tissues, and the intrinsic ability of the
skin and soft tissues to withstand prolonged or excessive loading.
If loading increases, and/or the intrinsic resilience of the skin
and soft tissues deteriorates, the balance is tipped and pressure
damage is more likely to occur (Figure 1).
In relation to pressure ulcer development, microclimate was
initially a term used to describe three aspects of the interface
between the skin and a support surface — skin temperature,
humidity and air movement1. In early pressure ulcer
publications, the maintenance of a favourable microclimate was
seen to be a key modifier of the ability of skin and underlying
soft tissue to withstand prolonged stress (eg pressure and
shear). However, the concept has been largely overlooked since
the 1970s2.
This concept is also illustrated in Figure 2. This is a modification of
the Reswick-Rogers curve that describes the relationship between
pressure and time4. The area above the blue line indicates pressure
and the duration of application that is likely to induce pressure
damage. When the resilience of skin and soft tissue is compromised,
however, the curve shifts to the left and down (the red line),
demonstrating that in these cases lower pressure of a shorter
duration can also cause damage.
Authors: Clark M, Black J. Full author details are
on page 6.
In recent years, microclimate has again been
attracting attention, but is now associated with
two parameters — temperature (of the skin or the
soft tissues) and humidity or skin surface moisture
at the interface between the skin and the support
surface3,4. Air movement has been omitted from the
more recent definition as the movement of air can
itself affect skin temperature and local humidity
or moisture.
Further clarification of the elements of microclimate
is needed to aid clinicians in judging the condition of
patients who are using support surfaces2. Objective
measurement of skin temperature and humidity
presents practical problems and may require
equipment not readily available in clinical settings.
Box 1 outlines recently proposed definitions of
microclimate, with suggestions for measurement of
the parameters involved.
Figure 1 Pressure damage and the balance between intrinsic and extrinsic factors
No pressure damage
— the skin and tissues
are able to withstand the
external loads
Damage
No Damage
Pressure damage — when loads increase and/or
the ability of the skin to withstand them decreases,
the balance changes (from left to right below) so
that damage is more likely to occur
Damage
Extrinsic: loading on
tissues (pressure/shear/
friction)
No Damage
Damage
No Damage
Intrinsic: resilience of the
skin and soft tissues
(tissue tolerance)
1
As explained below, changes in the
microclimate at the skin/support surface
interface can affect the body’s ability to
withstand the effects of external factors,
such as pressure. As a result, changes to
microclimate may alter tissue tolerance
and make pressure ulcers more or less
likely to develop, depending on the
temperature and humidity changes that
have occurred.
Focus on temperature
Raised skin temperature may be related to
pressure ulceration as higher temperatures
increases metabolic demand, which raises
the tissue’s susceptibility to the ischaemic
effects of pressure and shear (Figure 3). As
body temperature rises, tissue demand for
oxygen and energy also increases. It has
been estimated that a 1oC increase in body
temperature increases metabolic demand
by approximately 10%9. Where skin,
subcutaneous tissue and muscle perfusion
are already compromised, any increased
metabolic activity may give rise to
ischaemia and subsequent tissue damage
faster and at lower levels of pressure/shear
than if the body temperature was normal10.
While the rise in metabolic activity results
from increased body temperature, it has
been suggested that elevations in skin
temperature may also lead to skin and
soft tissue damage, perhaps through
weakening of the epidermis2. In addition,
raised body/skin temperature often
induces sweating, which as explained
below, may further increase risk of
pressure damage.
made
easy
high relative humidity may mean that
the skin can become ‘boggy’ or even
macerated. This will reduce the skin’s
smoothness, thereby raising the friction
coefficient and increasing the likelihood of
damage from shear and friction2 (Figure 3).
Causes of excessive moisture
In hospital it is common for clinicians
to ‘turn’ patients and find that the skin
and bed linen are damp. This sweat is
produced in an attempt to cool the back,
buttocks and legs due to the heat that
accumulates where the body is in contact
with the support surface. Excessive skin
moisture can arise from a wide variety of
causes. Patients at particular risk include
those who are incontinent, febrile, have
major injuries to the central nervous
system, are in sympathetic nervous
system overload, or who are extremely
obese and have skin folds that are
difficult to keep dry.
Febrile patients perspire to cool the
body. If these patients can be regularly
repositioned, or move themselves,
while in bed, excessive moisture may
not become a problem. However, if the
patient is immobile, the skin in contact
with the bed may become very wet.
Excessive moisture
Patients with central nervous system
injuries may experience over activity
of the sympathetic nervous system.
The sympathetic nervous system
is responsible for the ‘fight or flight’
response and the reflexes involved induce
excessive sweating. Patients in critical care
units may also experience sympathetic
nervous system overstimulation, as do
dyspnoeic patients who sweat profusely
in response to the stress of finding it
difficult to breathe.
Excessive moisture on the skin’s surface
is believed to elevate the risk of pressure
ulcer development by weakening the
skin. Moisture weakens the linkages
between the collagen fibres in the dermis
and also softens the stratum corneum11.
As a result, excessive skin moisture and
Extremely obese (bariatric) patients often
sweat profusely as the body attempts
to control temperature. When these
patients fill the width of a bed, turning
or moving becomes very difficult and
moisture may build up.
Focus on humidity
Figure 2 Adaptation of the Reswick-Rogers curve
to show the effect of reduced tissue tolerance
(adapted from4)
Pressure ulcers develop
Pressure
Skin IQTM
Microclimate
Manager
PRODUCTS FOR PRACTICE
Key
Time
Above the line, the magnitude and duration of
pressure is likely to cause pressure damage. Below
the line, pressure damage is unlikely to occur
Pressure-time curve shifts to left and down
when skin and tissue tolerance is reduced,
lowering the pressures and durations required to
induce pressure damage
Excessive dryness
Excessive dryness of the skin also causes
challenges for tissue integrity. Dry skin has
reduced lipid levels, water content, tensile
strength, flexibility, and junctional integrity
between the dermis and the epidermis2.
Dry skin is therefore weakened and more
vulnerable to damage by pressure, shear
and friction (Figure 3).
Microclimate management in pressure
ulcer prevention would, therefore,
appear to necessitate avoidance of
raised skin temperature (or even a slight
reduction in skin temperature) and
maintenance of levels of moisture or
humidity that avoid excess wetness or
drying of the skin.
Microclimate management
The initial approach to the management
of extremes of microclimate should
involve addressing the cause of excess
temperature or altered skin moisture,
eg by treating pyrexia or managing
incontinence effectively2. Fans may help
2
to cool the skin and will evaporate excess moisture. Patients
who are dyspnoeic may find the air movement produced
by a fan provides a sense of improved breathing12.
Additional approaches to managing the accumulation
of excessive heat and moisture on the skin include
encouraging the patient to move in the bed or through
turning regimens. Movement will allow moisture to
evaporate from areas previously in contact with the
support surface. Control of skin moisture may be assisted
by regular changing of gowns and bed linen. Bariatric
patients in particular may benefit from frequent washing
and changing of clothes.
Figure 3 Microclimate and the risk of pressure damage
Humidity/skin moisture
Metabolic demand
Sweating — pyrexia/critical illness/
obesity/sympathetic nervous
system stimulation/dyspnoea
Incontinence
High environmental humidity
Pyrexia
Sympathetic nervous system
stimlulation (critical illness/CNS
injuries/dyspnoea)
Dry skin
Weakened skin
Incontinent patients require particularly careful
management of the skin, which needs to be protected
from future exposure to urine and faeces with products
that repel these fluids. Where skin is dry, the use of
emollients may be helpful4.
Recently, the application of large absorbent dressings
to the sacrum in patients at high risk of pressure ulcers
has been found to reduce pressure ulcer occurrence13.
This may be because of the absorption of skin moisture.
However, it should be noted that the dressings also
reduced pressure and that the study included an aggressive
patient-turning schedule.
Support surfaces and microclimate management
Many of the mattress covers and support systems in use today
are designed to reduce cross-contamination between serial users
and are fluid resistant and easy to wipe down. Such surfaces
may contribute to the accumulation of heat and moisture at the
patient/support surface interface.
Low air loss (LAL) overlays/mattresses and air-fluidised support
surfaces both act in ways that may draw moisture and heat away
from patients. LAL systems blow air into a series of inflatable
cylindrical cushions that support the patient. The cushions allow
air to escape through small pores and to flow along the inside of
a vapour permeable cover. This draws moisture and heat through
the cover into the air in the surface and away from the skin.
Air can penetrate the cover in the reverse direction, out of the
mattress and over the skin.
Air-fluidised support surfaces pump air out through small holes
in the support surface cover that also let fluids (eg sweat and
urine) pass through. The temperature of the air can also be
controlled. However, one issue with both LAL and air-fluidised
support surfaces is that, by default, patients may block the holes
of the covers as they lie on them.
Coefficient of friction
of skin
Ischaemia
Vulnerability of skin and soft tissues to the effects of pressure, shear and friction
Risk of pressure damage
A new cover system, the Skin IQTM Microclimate Manager, is
designed to overcome this issue and assist with the management
of microclimate to prevent pressure ulcers when used in
conjunction with a pressure redistribution surface.
Little information is currently available to clearly guide choice
of a surface for the management of microclimate2. The choice
of a support surface will be guided by clinical judgement and
numerous other factors (Box 2).
What is the Skin IQTM Microclimate
Manager?
The Skin IQTM Microclimate Manager (Skin IQTM MCM) is a
mattress cover system designed to aid in the management
of the microclimate of the skin when fitted over a pressure
redistribution surface (Figure 4).
The Skin IQTM MCM has three layers (Figure 5):
n a woven nylon fabric top layer that is vapour permeable
but fluid-resistant and coated with an antimicrobial
treatment. The cover helps to reduce shear and friction,
and acts as a bacterial and viral barrier
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PRODUCTS FOR PRACTICE
Box 2 Factors influencing choice of surface for
management of microclimate2
Figure 5 Structure of the Skin IQTM MCM
Requirement for pressure
redistribution
n Patient size
n Patient mobility
n Body temperature
n Incontinence
n Ease of use
n Availability
n Cost and reimbursement
n
a middle layer of open cells allows
air to pass through the Skin IQTM
MCM, without the layers collapsing
n a non-woven fluid-resistant
vapour permeable bottom layer
that is intended to prevent
movement of the Skin IQTM
MCM over the top surface
of the underlying pressure
redistribution mattress.
Top layer: fluid-resistant vapour
permeable layer
Middle layer: foam layer
Bottom layer: fluid-resistant vapour
permeable layer
n
A small negative airflow device attached
to the ‘foot’ end of the Skin IQTM MCM pulls
air through the foam layer.
How does the Skin IQTM
MCM work?
The objective of the Skin IQTM MCM is to
help reduce or maintain skin temperature
while preventing excess moisture or
humidity building up on the skin’s
surface. The Skin IQTM MCM is similar in
some respects to a LAL therapy mattress/
Figure 4 The Skin IQTM MCM
system in situ
overlay. However, it does not blow
warm air into the surface, but in contrast
uses a fan that pulls moisture and heat
away from the patient (negative airflow
technology) (Figure 6).
The pump pulls room temperature air
and moisture vapour through the outer
layer and into the foam spacer layer
towards the foot of the bed. Air entry
sites are located at the head of the
bed, but air and water vapour can also
enter the cover system via the vapour
permeable cover.
The negative airflow provided also
means that moisture and air are pulled
away from areas where the skin is directly
in contact with the support surface,
meaning that the system may be better
able than LAL and air-fluidised systems to
manage skin moisture levels.
The moisture vapour transfer rate
(MVTR) of the Skin IQTM MCM top layer
is reported to be 130g/m2/hr14, which is
higher than the rate measured for LAL
surfaces (average MVTR 97.7g/m2/hr)15.
The MVTR measures the ‘breathability’
of a material in terms of how well
moisture vapour will pass through the
cover material.
A cover with a low MVTR allows moisture
to quickly build up on the skin’s surface.
Pressure redistribution is provided by the
underlying mattress with the additional
benefits of negative airflow technology
provided by the Skin IQTM MCM — skin
surface cooling, prevention of excessive
moisture, and reduced friction.
What are the special features of
the Skin IQTM MCM?
The Skin IQTM MCM allows clinicians to
Figure 6 Mode of action of the Skin IQTM MCM
Moisture
Air
Water vapour
Mattress
Airflow entry (head of bed)
Negative airflow —
device
Airflow exit (foot of bed)
4
Figure 7 The system connects to the power supply and can be plugged in or disconnected
In an earlier study, Lachenbruch has
argued that a 5oC reduction in skin/
support surface interface temperature
would confer tissue-protective effects
similar in magnitude to the interface
pressure reductions afforded by the
most expensive support surfaces17. This
hypothesis remains untested.
Clark reported that the humidity above
the sacral skin of elderly hospital patients
who subsequently developed Category
II pressure ulcers was higher than the
humidity above the sacrum of patients
who did not5.
manage skin temperature and moisture/
humidity while using existing pressure
redistributing mattresses. The Skin IQTM
MCM can be stored in a nursing unit,
allowing immediate application to a bed
when indicated.
interface layer and bottom layer — are
all coated with a bactericidal treatment.
The reduction of temperature and
moisture on the skin also reduces the
potential for bacterial growth.
The Skin IQTM MCM can be applied
without needing to move the patient
from the bed. Its low height (6.35mm)
only slightly increases the total height
of the support surface, and so does not
significantly affect ease of patient transfer
from bed to standing, or the probability of
falls from the bed.
What is the evidence
supporting use of the Skin
IQTM MCM?
The single patient, 30-day use of each Skin
IQTM MCM is designed to prevent crosscontamination between successive patients.
Bench studies have shown that
negative airflow technology reduced
Staphylococcus aureus growth by
2.24 logs over a 24-hour period when
compared to a hospital bed sheet. They
have also shown that negative airflow
technology significantly reduced odour
at the patient/surface interface when
compared to the same surface without
airflow14. The product acts as a bacterial
and viral barrier (like human skin), plus
the three components — top layer,
Following the recent introduction of the
Skin IQTM MCM, work is now underway to
gather a body of clinical evidence of its
effect in reducing pressure ulcer incidence.
There is a small body of indirect evidence
supporting control of local microclimate
in pressure ulcer prevention. This was
reviewed in the international consensus
document on pressure, shear, friction and
microclimate2.
In an animal study, pressure of
100mmHg was applied for five hours
with indentors heated to 25, 35, 40
or 45oC16. Cutaneous and deep tissue
damage was observed at 40oC and 45oC,
with moderate muscle damage seen at
35oC. No cutaneous or muscle damage
was observed where a load was applied
at 25oC, suggesting that local cooling
may have a protective effect.
While there may be few direct
studies that implicate either changes
in temperature or humidity as
predisposing factors in pressure
ulcer development, clinical judgment
has long associated microclimate
changes with increasing vulnerability
to pressure ulcers in the presence of
pressure and shear4.
When should the Skin IQTM
MCM be used?
The Skin IQTM MCM is intended for use in
all care settings in the care of individuals
who are perceived to be at risk of
pressure ulcer development, who have
been allocated a pressure redistributing
mattress, and whose pressure ulcer
vulnerability includes either prolonged
exposure to moisture or high skin
temperatures, eg patients who are
incontinent or febrile18. It is also intended
for overall pressure ulcer prevention and
patient comfort.
How should the Skin IQTM
MCM be used?
The Skin IQTM MCM is intended for single
patient use only. It should not be used
for longer than 30 days and should be
disposed of following the manufacturer’s
instructions after patient use18.
5
The complete Skin IQTM MCM package
incorporates the cover system, a power
supply and a power cord to connect
to an electrical supply (Figure 7). The
cover system and power unit can also be
obtained separately.
While the cover system and negative
airflow device are only to be used in the
care of a single patient for 30 days, the
power supply and cord can be reused
and should be cleaned in accordance
with local guidelines on the cleaning of
electrical units between patients.
Contraindications and
precautions
The Skin IQTM MCM should not be used in
the care of people with an unstable spinal
cord injury and those undergoing cervical
traction. The Skin IQTM MCM is designed to
fit pressure redistribution surfaces that are
2.03–2.13m (80–84 inches) long and 88.9–
91.44cm (35–36 inches) wide. It may be
used in the care of people weighing up to
227kg (500lb)18. However, clinicians should
check that the pressure redistributing
mattress and bed frame can support these
weights before use. The Skin IQTM MCM
may have different surface characteristics
(ie reduced friction between the patient
and the pressure redistributing mattress).
When should use of the Skin
IQTM MCM be discontinued?
Use of the Skin IQ MCM should stop
and the coverlet be replaced at the end
of the 30-day warranty period. Skin IQ
is also recommended for its comfort,
TM
meaning that patients can benefit even if
microclimate is no longer the issue.
Useful links
Definitions of the different support surfaces
used in the prevention and treatment of
pressure ulcers can be found at: http://www.
npuap.org/NPUAP_S3I_TD.pdf
References
1. Roaf R. The causation and prevention of bed sores. J
Tissue Viability 2006; 16(2): 6–8.
2. International review. Pressure ulcer prevention:
pressure, shear, friction and microclimate in context. A
consensus document. London: Wounds International,
2010. Available at: www.woundsinternational.com
3. National Pressure Ulcer Advisory Panel (NPUAP).
Support Surface Standards Initiative. NPUAP, 2007.
Available at: http://www.npuap.org/NPUAP_S3I_
TD.pdf
4. NPUAP and European Pressure Ulcer Advisory Panel
(EPUAP). Prevention and Treatment of Pressure Ulcers:
clinical practice guideline. 2009; NPUAP; Washington
DC, USA.
5. Clark M. The aetiology of superficial sacral pressure
sores. In: Leaper D, Cherry G, Dealey C, Lawrence
J, Turner T (eds). Proceedings of the 6th European
Conference on Advances in Wound Management.
1996; McMillan Press, Amsterdam: 167-70.
6. Schäfer P, Bewick-Sonntag C, Capri MG, Berardesca
E. Physiological changes in skin barrier function
in relation to occlusion level, exposure time and
climatic conditions. Skin Pharmacol Appl Skin Physiol
2002; 15: 7–19.
7. Egawa M, Oguri M, Kuwahara T, Takahashi M. Effect
of exposure of human skin to a dry envirnoment.
Skin Res Technol 2002; 8(4): 212–18.
8. Bergstrom N, Braden B, Laguzza A, Holman V. The
Braden scale for predicting pressure sore risk. Nurs
Res 1987; 36(4): 205–10.
9. Fisher SV, Szymke TE, Apte SY, Kosiak M. Wheelchair
cushion effect on skin temperature. Arch Phys Med
Rehabil 1978; 59(2): 68–72.
10. Brienza DM, Geyer MJ. Using support surfaces to
manage tissue integrity. Adv Skin Wound Care 2005;
18: 151–57.
11. Mayoritz HN, Sims N. Biophysical effects of water
and synthetic urine on skin. Adv Skin Wound Care
2001; 14(6): 302–8.
12. Galbraith S, Fagan P, Perkins P, Lynch A, Booth S.
Does the use of a handheld fan improve chronic
dyspnea? A randomized, controlled, crossover trial. J
Pain Symptom Manage 2010; 39(5): 831–38.
13. Brindle CT. Outliers to the Braden Scale: Identifying
high risk ICU patients and the results of prophylactic
dressing use. World Council of Enterostomal
Therapists J 2009; 30(1): 11–18.
14. Data on file — please contact KCI for further details.
15. Reger SI, Adams TC, Maklebust JA, Sahgai V.
Validation test for climate control on air-loss
supports. Arch Phys Med Rehabil 2001; 82(5):
597–603.
16. Kokate JY, Leland KJ, Held AM, et al. Temperaturemodulated pressure ulcers: a porcine model. Arch
Phys Med Rehabil 1995; 76(7): 666–73.
17. Lachenbruch C. Skin cooling surfaces: estimating
the importance of limiting skin temperature. Ostomy
Wound Manage 2005; 51(2): 70–79.
18. KCI Skin IQTM Microclimate Manager. Instructions
for use. 2010; Data on file — please contact KCI for
further details.
Supported by an educational grant from
KCI. The views expressed in this ‘Made
Easy’ section do not necessarily reflect
those of KCI.
Author details
Clark M1, Black J2.
1. Independent Consultant, Cardiff, UK.
2. Associate Professor, University of Nebraska
Medical Center, College of Nursing,
Omaha, Nebraska, USA
USA disclaimer
Skin IQtm Microclimate Manager units have specific
indications, contraindications, safety information and
instructions for use. Please consult product labelling and
instructions before use. For instructions, compatibility,
and safety information specific to the bed mattress/
frame, please consult product labelling provided by the
manufacturer. CAUTION: Federal law restricts the device to
sale by or on the order of a physician.
Summary
Further research is needed to fully define the optimal skin support surface microclimate,
but existing evidence indicates that preventing accumulation of excess moisture and
increases in skin temperature have a role to play in preventing pressure damage. The Skin
IQTM MCM is a new type of cover system that enables management of microclimate even
where the skin is touching the support surface by drawing away moisture and heat. The
system is easy to apply to beds, does not affect the pressure redistributing characteristics
of the underlying surface, and does not significantly add to support surface height.
To cite this publication
Clark M, Black J Skin IQTM Microclimate Made Easy. Wounds International 2011; 2(2).
Available from http://www.woundsinternational.com
DSL#11-0152.US (4/11)
© Wounds International 2011
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