wound care
TRANSCRIPT
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Wound Care
The basic function of the wound care materials is providing protection against an infection,
blood and exudates absorption, to promote healing and possibly apply a medication to the
wound [1]. The today available materials range from simple cotton gauzes and lint to
sophisticated multifunctional systems made from natural or synthetic materials [2].
In the history, the development of wound dressings was managed in accordance to personal
experience or historical knowledge. Recently, the development is guided by clinical studies
and evidence based medicine. There have been recognized two wound care systems, these
being traditional and advanced dressing. Their classification includes 10 dressing classes [3].
Gauzes Bio-dressing
Antiseptics Skin derivates
Proteolytic Enzymes Semipermeable Dressings
Absorbents Occlusive Dressing
Granulation Promoters Hydrogels
The materials and designs of wound dressings are derived from the application condition.
These are for the traditional and advanced dressing summarized in Table 1 [3]. It was already
known in the Arabian period that the healing conditions are critical for successful healing
process. The moist wound healing philosophy was scientifically explained in 1960’s in
magazine Nature by George Winter. On the basis of this theory, a new wound care treatment
methods have been developed promoting and respecting the physiological healing process.
Table 1: The functionality of traditional and advanced wound dressings. Traditional dressing Advanced dressing
Exudate absorption and drying of the wound Keep a moist environment
Haemostatis Remove exudates and necrotic tissue
Antisepsis Keep temperature constant
Protection from infection Oxygen permeable
Wound covering Protection from exogeous infection
Easy to handle
Non-traumatic at the dressing change
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The wound dressing materials belonging to the traditional and advanced wound dressings are
designed according to their functionality. They are presented in Table 2 [3].
Table 2: The categories of traditional and advanced wound dressings according to their design
or a material. Traditional dressing Advanced dressing
Gauze Alginates
Lint Hydrogel
Wadding Hydrocolloids
Plasters Foam dressing
Film dressing
The Figure 1 shows the different classes of products; we can highlight that alginates are
positioned in the middle of the two wound care philosophies, because they keep the
microenvironment moist and do not occlude the wound and promote granulation. We can now
analyse the conditions, which advanced dressings produce in comparison to traditional
dressings [3].
Figure 1: Different categories of wound dressings according to use.
Epithelial Cells Migration Under Advanced And Traditional Dressing
The ability to keep a moist microenvironment is important because human cells can only live
in water. The only tissue that can live in the air is that of the skin (keratinised dead cells). The
wound has a superficial loss of tissue and so the structures that need water to live are exposed.
It is obvious then, we need to promote a moist environment to support the healing process.
The second most important condition is that of the length of healing time. Epithelialization
starts from the edge of the wound due to cell migration: keratinocytes need a moist
microenvironment. In a dry wound they will migrate under the dry dermis, but in a moist
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wound they will migrate on the surface, as shown in Figure 2. We can easily understand that a
water mass movement is quicker than that of the removal of dry tissues [3].
Figure 2: Cell migration in a dry and moist wound environment.
Mitosis stops at 32°/33°C and this is the temperature on the wound surface when it is exposed
to air. Dressings made from a fabric cannot isolate the wound but this can be achieved by
using synthetic films because they have a lower thermal conductivity and can be worn over a
longer period of time. This helps to restore the thermal stability lost by the skin.
Prevention of Infection - Comparison Between Traditional & Advanced Dressings
(Hutchinson, mod.)
It’s commonly believed that a moist wound is frequently infected. Hutchinson demonstrated
in a very large number of studies that advanced dressings can reduce the incidence of
infection by more than 50% in comparison with traditional dressings.
The advanced dressings do not adhere to the lesion and so avoid further damage to the wound
or it’s surrounding tissues. The comfort during dressing changes is immediately noticeable
and the creation of a moist, warm environment can reduce pain.
Everyone knows that dressings represent 5% of the management costs of a chronic wound,
whilst 70% of the cost is absorbed by nursing time. It is evident that if dressings worn over a
longer period are used, nursing time can be reduced. This represents a gain, both
economically and in clinical resources [3].
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Traditional Wound Dressings
Examples of available wound dressings according to their origin, functions and applications
are presented in Table 3 [2].
Table 3: Traditional wound dressings. Types Examples Function Form of Application
Traditional
dressings
Cotton
wool
gauze & lint
Allow strike through, shed fibres and
adhere to the wound + dehydrate the
wound
Used on clean, dry wound or as
secondary dressing
Low
adherent
dressing
Cutilin
Melolin
Release
Setoprime
Suitable for dry wounds or lightly
exuding wounds.
Need to be secured with bandage or
adhesive tape.
Some structures of gauze and lint materials are shown in Figure 3. A gauze material is an
open weave, absorbent fabric. When coated with parafin wax, it is used for burns and scalds
treatment.
Figure 3: Examples of gauze and lint structures: A –structure of plain weave, B – real gauze
plain weave, C – structure of leno weave, D – real fabric of leno weave.
A gauze serves as an absorbent material in a pad form (swab) in surgical applications. If yarns
are barium sulphate coated and incorporated into a swab, the material is X-ray detectable [1].
Lint is a plain weave cotton fabric that is used as a protective dressing for first aid and mild
burn applications [1].
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Wadding materials are also used for wound care applications. They are a high absorbent
materials sometimes covered with a nonwoven fabric to prevent wound adhesion or fibre loss
as shown in Figure 4 [1]. The absorbent layer can be made of cellulose pulp, wood pulp, wet
laid cotton or viscose fabrics, etc. Recently the absorbent core can also obtain superabsorbent
polymer powder.
Figure 4: Structure of a wadding material.
More complex wound dressings are composite materials consisting of an absorbent layer
placed between a wound contact layer and a flexible base material, as shown in Figure 5 [1].
The wound contact layer should prevent the adherence of the dressing to a wound and be
easily removed without disturbing the tissue growth. The function of absorbent layer is to
absorb blood or other exudate liquids and provide cushioning effect to protect a wound.
Figure 5: A wound dressing functionality.
The basic textile structures of a wound contact layer are the same as gauze and lint materials
shown in Figure 3. They can be also made of a soft nonwoven spunlaced fabric shown in
Figure 6 [4]. All the fabrics are mostly made of the natural fibres. The recent use of a
collagen, alginate or chitin fibres contribute to the healing process [4].
Some of these articles can be coated by pressure sensitive adhesives which contribute to
wound dressing performance by being stick to the skin around the wound and preventing the
abrasion of wound by the material, therefore damaging of new grown tissue [2].
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Figure 6: E – structure of spunlaced fabric, F – spunlaced fabric.
The absorbent layers are much more the same as those described for wadding materials shown
in Figure 4..
The flexible base materials should protect the surrounding of a wound from leaking of blood
or other exudates leaking. It can be made from a polymer film or porous membranes
permeable to air but not to a liquid.
Examples of a commercially available gauze, lint and wadding pads
ES gauze swabs are the classic swabs made of absorbent cotton
threads [5]. They are highly absorbent, soft, conformable and
permeable to air. They are also available with interwoven Telatrast
X-ray detectable thread under the brand name of "Telacomp ".
They are used for general wound treatment, especially in primary
treatment of dirty, infected or highly exudative wounds, as swabs
and sponges in minor surgery actions.
ES umbilical pads are elastic pads made of absorbent cotton threads. They are soft and
absorbent, used for sterile care of the cord stump in new born babies [5].
PehaSlit Dressing is gauze dressing with the Y slit made of
absorbent cotton threads. A pre-cut, so-called Y slit makes them
suitable for use around rains, in tracheotomies and extensions [5].
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Mulpa is a general purpose gauze swab made of absorbent
cotton specially designed to meet criteria for generally treatment,
especially for larger wounds. They are high absorbent, air
permeable, soft and conformable [5].
Medicomp is a non-woven swab used as an alternative to the
traditional gauze in the ward and in outpatient treatment [5]. It is
made of 70% viscose and 30% polyester fibres. It has an open
gauze-like structure. They are very absorbent, soft and permeable
to air. The non-woven fabric is bonded mechanically and does
not contain binding agents or optical brighteners.
Medicomp® Drain is a non-woven, gauze-structured slit dressings
made of 70% viscose and 30% polyester fibres; free of binding
agents and optical brightening agents, two additional layers for
extra high absorbency, with Y slit [5]. Medicomp Drain non-
woven swabs with Y slits are recommended for use around drains,
in tracheotomies and extensions as well as to offer protection
when cannulae und probes are employed. It is used for the general treatment of wounds; as
swabs and sponges during outpatient and inpatients interventions.
Examples of commercially available wadding pads and wound dressing composites
Eycopad is and eye pad made of absorbent cotton wool with pure
cotton gauze covering. The use of high-quality absorbent cotton
wool and absorbent gauze made of pure cotton makes the
Eycopad eye pad particularly soft and absorbent [5]. The gauze
covering is closed at the narrow sides of the dressing, which
considerably improves cohesion. Eycopad is lint-free and has a
long-lasting, good cushioning effect.
Comprigel is an impregnated, non-adhering gel dressing with an
integrated absorbent core made of a non-woven fabric [5]. This
favourable combination of materials allows both simple and
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effective management of many different kinds of wounds. The wound side of the dressing is
layered with a gel of natural polysaccarides, which is well tolerated by the skin and permeable
to air and secretions. Wound secretions can freely pass through into the absorbent core. The
highly absorbent core is made of a non-woven fabric and possesses a high retention capacity.
Comprigel does not adhere to the wound surface and it keeps wound edges supple. The
gelatinous mass is firmly bonded to the supporting layer made of open-weave cotton tulle,
ensuring that the wound remains clean and the risks of drying out or sticking are reduced.
Comprigel can therefore also be removed painlessly even if the dressing is left in place for
long periods of time. The cooling effect of the gel when applied eases patient discomfort.
The gel layer gives Comprigel slight adhesive properties. It remains in place without any
additional fixation, making its application considerably easier. Comprigel is used for the
general treatment of wounds of diverse origins, on the ward, in general practice and in first
aid.
Fil-Zellin is non-iritant universal dressing for particularly
economical use. It consists a wound compatable nonwoven layer
applied directly to the wound, and several layers of highly bleached
cellulose as the absorbent layer. The dressings are quilted several
times over the entire width to connect the two material layers [5].
The soft, nonwowen wound-contact layer rapidly guides secretions into the absorbent core.
The absorbent core made of highly bleached, creped cellulose layers provides Fil-Zellin its
good absorption capacity. The quilting gives both materials good cohesion, which guarantees
a constantly smooth surface at the wound dressing with no creases.
It may be used universally for wound-compatible treatment of dry or secreting wounds or as
carrier material for ointment and moist dressings.
Zetuvit was specially developed for the treatment of highly
exudative wounds. It consists of four layers of different materials,
which complement each other perfectly to give the dressing pad
its outstanding properties [5].
The covering layer consists of a two-ply non-woven material: The
surface in contact with the wound is made of hydrophobic
polyamide fibres and does not absorb any liquids, thus preventing it from sticking to the
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wound. The inner surface of the non-woven material consists of hydrophilic cellulose fibres
with high capillary activity through which wound exudates can pass quickly to be retained in
the absorbent core. Bleached cellulose tissue disperses the exudates, thereby making full use
of the high retention capacity of the absorbent core. The absorbent core made of soft cellulose
fluff has a high absorption capacity and exerts a good cushioning effect. The backing consists
of a layer of cellulose, which although permeable to air, is hydrophobic and prevents the
exudates from striking through it. Thus the wound is protected against contamination.
It is used for the treatment of highly exudative wounds in all fields of medicine; for
cushioning and protecting wounds.
Grassolind is made of an open weave cotton cloth impregnated
with a non-medicated ointment, which is neutral. It is therefore
especially suitable for the treatment of wounds in dermatology,
for patients with sensitive skin or those who are sensitive to
certain medication and for long-term treatment of wounds with
delayed healing [5].
During all stages of wound healing Grassolind keeps the edges of the wound supple and
protects the wound from drying out. It promotes granulation and re-epithelialization and
effectively prevents undesirable scar tissue contraction. The impregnated dressing does not
adhere to the wound. It can be changed painlessly, granulation tissue and new epithelium are
not irritated. The open weave cotton cloth allows free access of oxygen to the wound and
provides good ventilation. Secretions can drain easily and maceration is avoided.
Grassolind has no sensitizing or allergenic effects even when applied for long periods.
Where necessary, specific topical medication can be added to the non-medicated ointment
base.
It is used for the gentle treatment of large surface lesions, e.g. abrasions, contusions, burns,
scalds, acid burns, radiation damage, etc. In plastic and cosmetic surgery, nail removal,
circumcisions, etc. As a dressing for the donor site in skin grafts and for fixing split-skin
grafts. It is also ideal for the treatment of wounds in dermatology, for patients sensitive to
certain medication and for long-term treatment of wounds with delayed healing, where there
is often the risk of sensitization.
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Atrauman is an ointment dressing that effectively supports all
phases of wound healing. The properties of the cloth used and the
composition of the ointment applied ensure atraumatic wound
care. The thin, soft, open-weave tulle of hydrophobic polyester
fibres with its smooth surface structure counteracts the tendency
of adhesion to the wound by preventing new tissue from
penetrating the dressing [5]. Atrauman's non-adhering properties are enhanced further by the
ointment present in the dressing, thus permitting removal without tissue injury.
Atrauman keeps wound surfaces and edges soft and supple and prevents the wound from
drying out. Undesired contraction of scar tissue is avoided.
The ointment itself is permeable to air and does not inhibit passage of secretions. In this way ,
the wound has sufficient contact with the air and the rapid transfer of excess secretions is
assured. Secretions are absorbed into a secondary dressing applied on top of the Atrauman
dressing. The ointment does not contain added vaseline or other paraffins. No ointment
residues, which are difficult to remove, are produced. The condition of the wound may be
assessed and cleaning of the wound is simplified. The ointment is non-medicated and does not
lead to sensitization. Therapeutically active substances can be applied topically at the
discretion of the physician.
It is used for a traumatic wound treatment in all phases of healing, e.g. for cuts, lacerations,
abrasions, leg ulcers, pressure sores, burns, scalds, acid burns, radiation burns, abscesses,
boils, carbuncles, panaritia; for covering donor and recipient sites in skin grafting, following
plastic and cosmetic surgery, nail extraction, phimosiectomy, etc. The non-medicated
ointment base makes Atrauman also suitable in dermatology and in the treatment of patients
with sensitive skin.
Modern materials are presented by several producers of the wound contact layers [6].
In US patent [7] is described a special wound covering allowing air circulation around a
wound suitable particularly for burns. This function is ensured by a loop (12), shown in
Figure 7, made from a flexible material (foamed elastomeric, or bulky cotton material). A
screen (26), made from air flexible (cotton) in a form of mesh, is attached to the loop and
extends across the opening (24) of the loop.
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Figure 7: Cross section of a wound cover allowing air circulation around a wound.
The screen mesh is fine enough to allow air past through but blocks particles, such as dust. A
panel (28) made from a flexible material is attached to peripheral wall (14) of the loop and
extends along, but does not extend over the opening (24). An adhesive covers the lower
surface (32) of the panel. When applied to a wound, the loop keeps the screen away from the
wound and this prevents the rubbing of the screen on the wound and ensures air circulation
across the wound.
Multi-layer absorbent wound dressing has been developed by 3M [8]. It is designed from
several layers of different functions as shown in Figure 8. A backing layer (20), an adhesive
layer (22), a porous or non-continuous wound contact layer (28) and a pressure sensitive
adhesive (30) are extended along the whole dressing therefore forming a perimeter of non-
absorbent material. Only the first (24) and second (26) absorbent layers are positioned within
the interior of the dressing. These layers are prepared by photo-initiated bulk polymerisation.
The firs absorbent layer is 25 mm thick and comprises of an absorbent composite capable
rapidly absorb moderate to heavy amount of exudates while retaining structural integrity and
transparency. The layer may include: 0-40 parts by weight of an acrylic or methacrylic acid
ester or a non-tertiary alcohol having 4-14 carbon atoms; 30-100 parts by weight of
hydrophilic, ethylenically unsaturated monomer (acrylate and metacrylate esters prepared
from mono-hydroxil-terminated poly lower alkylene oxides, such a PE-, PP-glycols); 0-40
parts by weight of a polar, ethylenically unsaturated monomer (partially neutraliyed acrylc
acid and N-vinyl acetamid), different from the hydrophilic ehylenicaly monomer.
The second absorbent layer is only 3 mm thick and less absorbent than the first one. It may
contain the same componenets but will generally have higher concentration of the acrylic or
metharylic ester monomer. Also one or more multifunctional cross-linking monomers can be
included into absorbent layers.
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Figure 8: Multi-layered absorbent wound dressing article.
An adhesive bandage, with antimacrobial and haemostatic
properties, has been disclosed by Kimberly-Clark [9]. It is
composed from layer an elastomeric layer for covering the
wound and surrounding area (70), as shown in Figure 9,
an adhesive layer (77) for adhering the adhesive bandage
to wound site, an absorbent pad (80) for absorbing
exudates made of a cellulose wadding or a nonwoven,
non-stick perforated cover (85) such as PE film for
allowing limited flow of exudates to the absorbent layer, a
layer of an antibacterial agent and haemostatic agent or a
single wound healing with haemostatic and antimicrobial
functionality (90) coming into contact with the wound.
Figure 9: An adhesive bandage
with antimicrobial and heamostatic
properties.
Cosmopor steril is a self-adhesive wound dressing, which differs
from traditional wound dressings in its novel combination of
materials. It is ideal for postoperative wound management [5].
The main beneficial feature of Cosmopor steril is the water-
repellent microgrid wound contact layer. This allows exudate to pass
quickly into the absorbent pad behind it whilst itself remaining absolutely dry. This prevents
the dressing from sticking to the wound. The dressing can be changed painlessly. The
absorbent pad is made of 100% pure cotton wool, conforms well to the body contours and has
excellent absorbent and cushioning properties. The soft, non-woven support is permeable to
both air and water vapour, thereby ensuring that Cosmopor steril does not interfere with the
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skin's natural functions. The non-woven support has rounded edges which prevent the
dressing from becoming detached even when the dressing remains in place for a long period.
The wide, continuous adhesive border ensures good closure. This, together with the water-
repellent, non-woven covering layer give reliable protection against contamination. Cosmopor
steril is coated with a hypoallergenic polyacrylate adhesive which is very well tolerated by
the skin.
It serves for postoperative wound management and sterile dressing of minor injuries, e.g. in
first aid.
Advanced Wound Dressings
There is a large variability of the materials classified as advanced wound dressing summarised
in Table 4 according to their origin, functional ability and form of applications. The
description of the functionalities of most common dressings from Table 4 [2] are described in
[3] and presented below.
Film Dressings
Film dressings are non-absorbent, permeable to moisture
vapour and oxygen and impermeable to bacteria and
viruses. They are typically made of a thin, transparent
polymer membrane, which is coated with a layer of acrylic
adhesive. Film dressings can be also combined with other dressing materials.
Hydrogel Dressings
Hydrogels maintain balanced hydration through controlled
evaporation. Exudates are absorbed into the gel, moisture
evaporates through semi-permeable film backing or a
secondary dressing.
Hydrocolloid Dressings
Hydrocolloid dressings are backed by either a waterproof polyurethane foam or a thin film. In
some cases, the backing extends beyond the margin of the hydrocolloid to form a border. The
totally sealed hydrocolloid at the wound area keeps the moisture in while keeping the bacteria
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and fluids out. This limits any gas exchange between a
wound and the environment. Fluid absorption is slow
primary trough swelling of particles in the dressing. This
swelling allows a soft, non-adherent gel formation over the
wound.
Calcium Alginate Dressings
The calcium alginates provide a moist healing environment
by converting the exudates into a gel. Reaction between the
calcium in the dressing and the sodium in a wound exudates
results in a chemical ion exchange, which forms a gel-like
substance. The gel conforms to the wound, providing a soft,
moist healing environment. Due to its dehydration effect, this
dressing should not be used with dry wounds.
Foam Dressings
Foam dressings are indicated for a partial thickness or
superficial wounds. The open pore structure of a foam
dressing gives it relatively high moisture vapour
transmission rate. Absorptive ability varies by a
manufacturer. The pore size, texture and absorbency are
controlled by the agents impregnated in the dressing. The degree of occlusion depends on a
presence of a film backing.
Silicon Dressings
A soft silicone dressing is a dressing coated with a soft silicone as an adhesive or a wound
contact layer. The intrinsic properties of soft silicone are such that these dressings may be
removed without causing trauma to the wound or to the surrounding skin [10].
There are different types of soft silicone dressings including a traumatic wound contact layers,
absorbent dressings for exuding wounds and also a dressing for the treatment of hypertrophic
scars and keloids. The soft silicone cannot enter the circulatory system. It is insoluble in
wound exudate and the silicone molecules are too big to penetrate through cell membranes or
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pass through the skin into blood vessels. They therefore cannot be transported around the
body to produce any systemic effects. Soft silicone is not intrinsically absorbent, but it can be
applied as a facing layer to dressings containing absorbent components that are used for the
management of exuding wounds.
Collagen Dressings
Collagen is the fibre forming protein of mammalian connective tissues. It is the major
component of the extracellular matrix forming an organized structure bridging the basal cells
to epidermis. At least 10 different types of collagen have been identified. In the wound
dressing applications, the collagen has haemostatic and absorbent functions [14].
Table 4a: Summary of available advanced wound dressings according to their origin,
functions and applications. Types Examples Function Form of Application
Films Bioclusive
C-View
OpSite Plus
Tegaderm
Vapour-permeable adhesive films,
thin, very flexible, easy to mold
around difficult shapes. They cool the
surface of the wound. Excessive
exudate may accumulate.
Suitable for shallow wounds,. Used to
prevent pressure ulcers and retention
dressing.
Hydrogels Agaflo
GrauGel
Intrsite Gel
Nu-Gek
Sterigel
Hydrophilic polymers, partially cross-
linked to form 3D network. Can
absorb up to 100% if their weight.
Promote moist healing, non-adherent,
by cooling of the wounds surface they
can reduce pain. Amorphous
hydrogels are particularly useful for
treating cavity wounds.
Most require covering with a secondary
dressing, suitable for dry “sloughy”
wounds and lightly exuding wounds.
They are not good for infected or
heavily-exuding wounds. They are also
good for drug delivery such a placental
growth factors and antibiotics.
Hydrocolloids Aquacel
Comfeel
Granuflex R.
Ultec Pro
More complicated than hydrogels,
contain constituets such as
methylcellulose, pectin, gelatin and
polyisobutylene, promote formation of
granulation tissue and provide pain
relief. Suitable for treatments of acurte
and chronic wounds, for desloughung;
light to heavily exuding wounds.
Not suitable for infected wounds,
usually require no secondary dressing,
hence patients can bath and shower.
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Table 4b: Summary of available advanced wound dressings according to their origin,
functions and applications. Alginate
dressing
Algisite M
Comfeel Plus
Kaltostat
SeaSorb
Sorbsan
Natural polysaccharides extracted
from brown seaweed. At
wound/dressing surface sodium-
calcium exchange takes place between
the dressing and the exudates
respectively hence swelling and
formation of gel.
Suitable for use of medium to heavily
exuding wounds and cavity. They are
more used on infected wounds. Most
alginates require secondary dressing.
Foams Avance
Cavi-Care
Flexipre
Tielle
Lyofoam
Polyurethane based, with or without
adhesive borders, main applications
are to absorb large volumes of
exudates reducing the need for
dressing changes
Suitable for use on light to medium
exuding wounds
Silicon
dressing
Cica-Care
Mepiform
N-A Ultra
Silgel
Consists of silicon gel, used to reduce
hypertrophic and keloid scarring,
cosmetically acceptable scars.
Gel sheet can be sterilized and are re-
usable.
Collagens Oasis
Opraskin
Promogan
Suabsorb C
Fibre-forming protein of mammalian
connective tissue. It contributes to
differ of wound healing by attracting
granulocytes and fibreblasts into
wounds and reduces wound
contraction, etc.
Collagen is used as haemostat, an
absorbable suture material, artificial
skin, bone filling and wound dressing
De-odoriser
dressing
Actisorb
Silver
220
Carboflex
Denidor
Metrotop Gel
Contain activate charcoal responsible
for reduction of offensive odours.
Suitable for discharging, purulent and
contaminated wounds complicated by
bacteria infection. Can contain silver
to inhibit bacterial growth.
They are used once or twice daily as
necessary.
Non-adherent
dressing
Available non-impregnated or
impregnated and discourage foreign
matter from becoming lodged in the
wound bed. They can be used on skin
tears, donor site and skin grafts.
Most non-adherent dressings require a
cover bandage or tape to hold them in a
place.
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Examples of film wound dressings
Hydrofilm is a self-adhesive, transparent film dressing that is
indispensable in modern wound management [5]. It gives excellent
protection against secondary infection and offers a number of
additional benefits. Although waterproof and impermeable to
micro-organisms, Hydrofilm does not prevent the passage of
oxygen and water vapour. Thus, it provides an effective barrier for bacteria and germs, but at
the same time does not inhibit cutaneous respiration.This helps to avoid skin irritation in the
area around the wound.
Hydrofilm’s skin compatibility is further enhanced by the use of a
hypoallergenic adhesive which makes it well tolerated even by
patients with extremely sensitive skin. Although it possesses
excellent adhesive properties, the dressing can be removed
painlessly without damaging new epithelium. Hydrofilm is
extremely thin and elastic and adapts perfectly to the body contours. The support material
consists of a resistant protective foil, which makes it easy to apply, even when wearing
gloves. As Hydrofilm is completely transparent, the wound and the sourrounding skin can be
inspected at any time without having to remove the dressing. The same applies when
Hydrofilm is used to secure catheters or cannulae. Hydrofilm is waterproof, enabling the
patient to shower while the dressing is in place. Hydrofilm is particularly useful as a
protective cover against secondary infection or physical damage on dry wounds healing by
first intention and nearly healed epithelial wounds. It may also be used to secure catheters or
cannulae and is ideal as a secondary dressing to cover gel-forming calcium alginate dressings,
e.g. Sorbalgon. It should not be used as a primary dressing on clinically infected, bleeding or
heavily secreting wounds.
Hydrofilm Plus is a self-adhesive transparent wound dressing with
an absorbant pad, which does not stick to the wound. It provides
safe protection of the wound and high degree of comfort for the
patient [5]. The absorbent pad of Hydrofilm Plus has good
absorbent and cushioning properties and is covered with a soft
polyethylene wound contact layer which reliably prevents adherence
to the wound. Although waterproof and impermeable to micro-organisms, the transparent,
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extremely thin Hydrofilm Plus does not prevent the passage of oxygen and water vapour.
Thus, the wound dressing provides an effective barrier for bacteria but at the same time it
does not inhibit cutaneous respiration. The skin compatibility of Hydrofilm Plus is further
enhanced by the use of a hypoallergenic adhesive which makes it well tolerated even by
patients with extremely sensitive skin. Due to the transparency of Hydrofilm Plus, the skin
surrounding the wound and the secretion absorbed by the wound pad can be inspected at any
time without having to remove the dressing. Due to the elasticity of the film, Hydrofilm Plus
adapts perfectly to the body contours thereby guaranteeing a reliable fit.
It is used for postoperative care of slightly secretory wounds, as protection against secondary
infection, as well as for sterile dressing of minor injuries.
Both, Hydrofilm and Hydrofilm Plus are waterproof, enabling the patient to shower while
the dressing is in place.
Examples of hydrogels wound dressing
Hydrosorb is a transparent, hydrocellular gel dressing made of
absorbent polyurethane polymers covered with a semi-permeable
polyurethane film, which prevents penetration of water and
microorganisms. The three-dimensional gel structure of
Hydrosorb has water content of 60 %. Thus, from the very
beginning, Hydrosorb represents a moist dressing with
outstanding biocompatibility [5].
Hydrosorb immediately creates a moist environment and is thus particularly suitable for
treating chronic wounds. It promotes the formation of new tissue during the granulation phase
and maintains a moist wound environment. This is achieved without any risk of wound
exudate accumulating, even during prolonged application. Granulation tissue is prevented
from drying out. During the epithelialization phase, the moist environment created by
Hydrosorb enhances the division and migration of epithelial cells. It also does not stick to
the wound, therefore the dressing may be changed without damaging the new tissue.
As Hydrosorb is transparent, the wound may be inspected at any time without having to
remove the dressing. This considerably reduces the frequency of dressing changes. It is not
dissolved by absorbed wound exudate. Thus it can be removed from the wound in one piece.
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No residues are left on the wound and assessment may be made without prior, time-
consuming rinsing being necessary; unpleasant odours do not occur. The soft elastic
properties of the gel also give Hydrosorb a good cushioning effect.
Hydrosorb has a slight self-adhesive effect. However, for fixation over a longer period of
time, it should be secured additionally with a hypoallergenic strapping tape or a dressing
retention bandage.
Hydrosorb is especially suitable for the treatment of chronic, slow-healing wounds where the
granulation process is not functioning satisfactorily, e.g. in leg ulcers, pressure sores, etc. It is
also used to treat second-degree burns, and to promote re-epithelialization at split-skin graft
donor sites after bleeding has stopped.
Waikatolink presents a honey based wound dressing [11]. The antibacterial nature of honey s
the reason for its potential use as a wound dressing. Honey is modified with a viscosity
increasing agent and is used in pliable or flexible sheets. The incorporation of modified honey
into a gels applied to moist wound dressing is designed to provide antibacterial and anti
inflammatory properties and the promotion of wound tissue growth. The dressing includes
water absorbing, trapping or removing components to assist in the removal of exudates, which
slowly dissolve in body fluids. The article is shown in Figure 10, where suitable material is
embedded with modified honey gel (2l), which is covered by a sheet of gauze (23) and
bonded to a backing sheet (25). The modified honey as ointments or self-adhesive gels are
used on mouth ulcers.
Figure 10: The wound dressing with incorporated modified honey component.
TenderWet 24 is a wound dressing pad, which produces a
"rinsing effect" continuously for up to 24 hours within the wound
[5]. This action exceeds the cleansing mechanisms of other
dressing systems used in moist wound treatment. TenderWet 24
facilitates interactive wet treatment, effectively supporting the
20
spontaneous cleansing mechanisms of the wound, and encouraging the formation of
granulation tissue. TenderWet 24 is a multilayer wound dressing pad containing a
superabsorbent core with irrigating properties as its central component. TenderWet 24
dressings are activated before use with an appropriate volume of Ringer's solution, which is
then delivered continuously to the wound for up to 24 hours. This constant supply of Ringer's
solution actively softens and detaches necrotic tissue. At the same time, the absorbent core
also reliably takes up and retains germ-laden wound exudate. This exchange is possible
because the superabsorbent core has a greater affinity for protein-containing solutions than for
salt-containing solutions. The wound exudate therefore displaces the Ringer's solution from
the dressing pad. Thus, TenderWet 24 continuously renews the film of Ringer's solution in
the wound bed over several hours, and simultaneously absorbs micro-organisms, released
detritus and toxins. Hence, the wound is rinsed and rapidly cleansed.
Furthermore, the physical properties of the superabsorbent compound, combined with the
covering of knitted fabric, give TenderWet 24 a high degree of plasticity. This ensures direct
contact with the wound bed, which is required for fluid exchange to occur.
Moisture and the electrolytes of the Ringer's solution such as sodium, potassium and calcium,
contribute to the stimulation of cell proliferation during the granulation phase. Wet therapy
with TenderWet 24 is indicated especially when wound conditions require active wound
cleansing and supportive treatment, for example in poorly-healing wounds with profuse
exudation; in clinically infected wounds; or in chronic wounds of the most diverse aetiology,
such as diabetic gangrene, pressure sores and leg ulcers. TenderWet standard is indicated for
packing deep wounds. The isotonic TenderWet Solution is available for activation of the
wound pads.
Examples of hydrocolloid wound dressing
Cotoplast Group presents a range of hydrocolloid based wound contact layers that do not stick
to a wound bed [12]. Physiotulle nd Physiotulle Ag are non-adherent, non-occlusive
polyethylene nets with significant absorbency for contact layers, which is a secret to
maintaining the moist environment around a wound.
21
Figure 11: Hydrocolloid based contact layers of Cotoplast Goup.
The netting is coated with Vaseline containing carboxymethylcellulose (CMC). The CMC
absorbs exudates achieving the gelling effect known from using hydrocolloid dressing.
Physiotulle provides faster healing by helping to prevent local infection, the coating ensures
a moist wound healing environment, and the dressing is removable without damaging newly
formed tissue. Physiotulle Ag contains Silver sulphadiazine in addition, which is
homogenously dispersed in Vaseline and provides sustained and controlled silver release. In
contact with a wound, the hydrocolloid particles absorb exudates and silver is released to into
the wound bed and provides faster wound healing by helping to prevent local infection.
Hydrocoll is a self-adhesive, absorbent hydrocolloid wound
dressing covered with a semi-permeable polyurethane layer that
prevents bacterial and moisture penetration. Upon absorption of
exudates from the wound the hydrocolloidal particles swell to
form a gel that expands into the wound and maintains a moist
wound environment. The gel remains absorbent until the
hydrocolloids are saturated [5].
Hydrocoll has a high absorbency due to the presence of
hydroactive colloids. Contaminated exudates are quickly taken
up and securely held in the structure during the swelling process.
During the granulation phase, Hydrocoll enhances the
formation of new tissue by stimulating the activity of fibroblasts,
which are mainly responsible for initiating the process of tissue
regeneration.
Hydrocoll maintains the moist wound environment thus
preventing the granulation tissue from drying out - without the
risk of exudate accumulating in the wound, even during
prolonged application.
22
The division and migration of epithelial cells are supported by the moist environment during
the epithelialization phase. If there are no complications, Hydrocoll can remain on the
wound during this phase for several days until the epithelialization process is completed.
The gel-forming layer prevents Hydrocoll from adhering to the wound. The dressing can be
removed painlessly from the wound without damaging the granulation and epithelial tissue.
Hydrocoll has the ability to adhere immediately, it is flexible and conformable and can thus
be moulded easily onto the body's contours. The bevelled edges help to keep the dressing
securely in place even in difficult areas. The top layer serves as a reliable barrier against
bacteria and protects the wound from contamination and penetration of moisture. Ambulant
patients can shower with the dressing in place.
Hydrocoll is suitable for light to medium exudating wounds, especially in cases of chronic,
slow-healing wounds where healing is delayed and where the granulation process is not
functioning satisfactorily, as is seen with varicose leg ulcers or pressure sores. It is also
indicated for the management of second degree burns.
Hydrocoll sacral is indicated for the specific treatment of pressure sores within the sacral
region; Hydrocoll concave is specially designed for treatment of wounds on the heel and
elbow. Hydrocoll thin, having a lower absorption capacity, should preferably be used during
the epithelialization phase.
Examples of calcium alginate wound dressing
Sorbalgon® is a conformable, non-medicated dressings made of
calcium alginate fibres which form a hydrophilic non-adherent gel
in contact with the sodium salts contained in blood and wound
exudate; the gel fills the wound cavity and creates a favourable
healing condition, drawing bacteria from the wound and keeping
them inside the gel treatment of external wounds of any type;
especially suitable for the treatment of bleeding or secreting wounds, since the gel-forming
properties promote the wound healing process, e.g. venous leg ulcers, pressulre sores,
abscesses, furuncles, burns, difficult wounds following accident or tumour surgery [5].
23
Examples of foam wound dressing
Smit&Nephew produce the range of wound contact layers Proguide
WCL based on Trilaminate Hydrocellular Foam Technology [6].
The dressing is a centrally located highly absorbent hydrocellular
pad, which absorbs and retains liquid in its microscopic structure,
preventing leakage and reducing the risk of maceration of the
surrounding skin. The pad is sandwiched between two perforated non-adherent polyurethane
wound contact layers, which allow even viscous exudate to pass into the dressing. It is
indicated for exudate absorption and the management of partial to full-thickness wounds, can
effectively manage exudate under compression for up to 7 days. It also helps in the creation
and maintenance of a moist wound environment. Moist wound environments have been
established as optimal environments for the management of the wound. It also provides
physical separation between the wound and external environments to assist in preventing
bacterial contamination of the wound.
Syspur-derm is a non-medicated dressing made of two layers of
soft polyurethane foam. Its mode of action and therapeutic
characteristics arise from the different physical structures of the
two foam layers. The open-pored lower layer and the dense, fine-
pored top layer are thermally bonded together without adhesives or
other agents [5].
The open-pored lower layer, which rests on the wound surface, together with the capillary
action of the dense top layer produce a high absorption capacity for exudates. Syspur-derm
thus ensures rapid and intensive cleansing of infected wounds. Necrotic material, cell debris,
pus and micro-organisms are eliminated with the dressing when it is removed.
During the granulation phase, Syspur-derm's open-pored foam layer serves as a matrix for the
development of new tissue und physically stimulates the granulation process. Within a short
time a clean, well-vascularized granulation bed forms as a precondition for spontaneous
epithelialization or successful skin grafts.
The dense, fine-pored, top layer of Syspur-derm has a microporous labyrinth structure which
assumes important physiological properties of the natural skin. It acts as a barrier against
secondary infections, restricts fluid losses and, due to its permeability to gas, ensures the
necessary ventilation of the wound.
24
Syspur-derm is used for the cleansing of all mechanical and thermal surface wounds, e.g.
infected abrasions, second and third degree burns, open fractures etc. It supports the formation
of a well-vascularized granulation bed on cleaned or primarily clean deep and superficial
wounds, e.g. on extensive mechanical lesions, open fractures, following vertical necrectomy,
extensive surgical excisions, etc. It is also suitable for the cleansing of wounds and the
promotion of granulation in cases where natural healing is compromised, e.g. leg ulcers,
pressure sores, radiation ulcers; for the undisturbed re-epithelialization of clean abrasions, for
covering skin graft donor sites, or following tangential necrectomy.
Examples of silicon wound dressing
Cica-Care Gel Sheet is a technically advanced silicone gel sheet for
scar care widely used by dermatologist and surgeons for management of
hypertrophic and keloid scars [13]. It is soft, comfortable and simple to
apply. The skin contact side is self-adhesive while the upper side is
strengthening non-adhesive silicone membrane. The siliscone membrane
and gel comnation akes the Cica-Care durable and less crumble than other silicon sheets.
Examples of collagen wound dressing
PROMOGRAN Matrix combines oxidized regenerated cellulose
(ORC) and collagen [15]. The combination has proved to promote
an optimal healing environment, which is conductive to granulation
tissue formation, epithelialization and rapid wound healing.
PROMOGRAN is used for treatment of diabetic, venous and
pressure ulcers, bleeding surface wounds, traumatic wounds by a
secondary intention, dehisced surgical wounds. The
PROMOGRAN is applied directly on a low exudate wound after
infection treatment. The matrix forms a gel in contact with exudate
or through saline hydration. The matrix is covered with a secondary dressing (type depends on
level and exudates) to maintain a moist wound healing environment.
References
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[1] Horrocks, A.R., Anand, S.C., Handbook of Technical Textiles, The Textile Institute,
2004.
[2] Miraftab, M.: Woundcare Materials: An Overview, Medical Textiles and Biomedical
Healthcare, Woodhead Publishing Limited, Cambridge 2006, ISBN-13: 978-1-85573-683-2,
p. 273.
[3]http://www.tycohealth-ece.com/index.php?folder=65
[4] Medical Textiles, S. Anand, International Conference 1999
[5] http://products.hartmann.info/main.asperl
[6] http://wound.smith-nephew.com/us/Product.asp?NodeId=2847
[7] US Patent 6940000
[8] US Patent 6942628
[9] US Patent 6932785
[10]http://www.worldwidewounds.com/2003/october/Thomas/Soft-Silicone-FAQ.html [11] Medical Textiles, March 2006, pp. 1-3.
[12] http://www.coloplast.com/ECompany/CorpMed/Homepage.nsf/
[13] http://www.nextag.com/SMITH-NEPHEW-Cica-Care-65268260/prices-html
[14] http://www.pjonline.com/pdf/hp/200210/hp_200210_wounds_dressings.pdf
[15]http://www.jnjgateway.com/home.jhtml?loc=USENG&page=viewContent&contentId=09
008b9880edadf1&parentId=09008b9880edadf1