Surgical dressing - Basics

1. SURGICAL DRESSING

2.  Treatment of wounds originally consisted of homemade
remedies and evolved very little for many years.
 In 1867, Lister introduced antiseptic dressings by
soaking lint and gauze in carbolic acid.
 The main purpose of wound dressings is to provide the
ideal environment for wound healing.
 The dressing should facilitate the major changes taking
place during healing to produce an optimally healed
wound.

3. Table 9-8 Desired Characteristics of Wound Dressings
Promote wound healing (maintain moist environment)
Comfortability
Pain control
Odour control
Non-allergenic and non-irritating
Permeability to gas
Safety
Non-traumatic removal
Cost-effectiveness
Convenience

4.  PRINCIPLES
 Covering a wound with a dressing mimics the barrier role of
epithelium and prevents further damage.
 In addition, application of compression provides hemostasis
and limits edema.
 Occlusion of a wound with dressing material helps healing
by controlling the level of hydration and oxygen tension
within the wound.
 It also allows transfer of gases and water vapour from the
wound surface to the atmosphere.

5.  Occlusion affects both the dermis and epidermis, and it
has been shown that exposed wounds are more
inflamed and develop more necrosis than covered
wounds.
 Occlusion also helps in dermal collagen synthesis and
epithelial cell migration and limits tissue desiccation.
 As it may enhance bacterial growth, occlusion is
contraindicated in infected and highly exudative wounds.

6.  Dressings can be classified as primary or secondary.
 A primary dressing is placed directly on the wound and may
provide absorption of fluids and prevent desiccation,
infection, and adhesion of a secondary dressing.
 A secondary dressing is one that is placed on the primary
dressing for further protection, absorption, compression, and
occlusion.
 Two concepts that are critical in selecting appropriate
dressings for wounds are occlusion and absorption.

7.  Winter and colleagues published a study demonstrating
that the rate of epithelialization under an occlusive
dressing was twice that of a wound that was left
uncovered and allowed to dry.
 Placement of an occlusive dressing over the wound
provides a mildly acidic pH and low oxygen tension on
the wound surface.
 The steep oxygen gradient is a good environment for
proliferation of fibroblasts and formation of granulation
tissue.

8.  absorption would be beneficial in wounds that have a
significant amount of exudate or wounds with high bacterial
counts.
 The skin surrounding the wound can become macerated
with large amounts of uncontrolled exudate.
 These wounds require a dressing that reduces the bacterial
load within the wound while removing the exudate produced.
 Placement of a pure occlusive dressing without bactericidal
properties will allow bacterial overgrowth and worsen the
infection.

9.  Wound dressings can be categorized into four classes:
 nonadherent fabrics
 absorptive dressings
 occlusive dressings
 creams, ointments, and solutions

10. 1 Non adherent fabric
 are generally fine-mesh gauze supplemented with a
substance to augment its occlusive properties or
antibacterial abilities.
2 Absorptive dressings
 used mainly for wounds that produce a significant
amount of exudate
 Wide-mesh gauze is the oldest of this type of
dressing and is very absorbent, but it loses its
effectiveness when saturated.

11. NON ADHERENT DRESSING

12. ABSORPTIVE DRESSING

13.  Newer materials such as foam dressings provide the
absorbent qualities to remove large quantities of
exudate and have a nonadherant quality to prevent
disruption of newly formed granulation tissue on
removal.
 Examples are :Lyofoam , Curafoam, Flexzan, and
VigiFOAM
 Wound healing beneath absorptive dressings
appears to be slower than under occlusive
dressings, possibly because of wicking of cytokines
from the wound bed or decreased keratinocyte
migration.

14. 3 Occlusive dressing
 provides moisture retention, mechanical protection,
and a barrier to bacteria.
 The occlusive class can be divided into biologic and
nonbiologic dressings.
 Examples of biologic dressings are allograft,
xenograft, amnion, and skin substitutes.
 Pigskin is the most commonly used xenograft.

15. OCCLUSIVE AND SEMI OCCLUSIVE DRESSING

16.  Homografts and xenografts are temporary dressings
in that both are rejected if left on a wound for an
extended period.
 Amnion is derived from human placentas. These
dressings are often used in the treatment of burn
wounds.
 newest type of wound dressings are skin substitutes
that can be used for structural support and
scaffolding for regeneration. Examples include :

17.  Integra -
 Integra is a bilayer membrane system for skin replacement.
 The first layer is made of a porous matrix of cross-linked
bovine tendon collagen and a GAG (chondroitin 6-sulfate).
 The second layer is made of synthetic polysiloxane polymer
(silicone) and functions to control moisture loss from the
wound.

18.  The first layer serves as a template for the infiltration of
fibroblasts, macrophages, lymphocytes, and capillaries from
the wound bed.
 During the healing process, a new collagen matrix is
deposited by fibroblasts and the dermal layer of the template
is degraded.
 Once vascularization of the dermal layer is complete, a thin
autograft can be applied after removal of the silicone layer.

19.  Alloderm
 is an acellular dermal matrix derived from donated human skin
tissue. It provides the matrix for revascularization and
incorporation into host tissue.
 Apligraf
 is a living, bilayered biologic dressing that has been designed
to simulate normal skin.
 Initially, neonatal-derived dermal fibroblasts are cultured in a
collagen matrix for 6 days. Human keratinocytes are then
cultured on top of this neodermis.
 The dressing contains matrix proteins and expresses
cytokines.It does not contain melanocytes, Langerhans cells,
macrophages, lymphocytes, or the adnexal structures normally
present in human skin.

20. 4. Creams, ointments, and solutions.
 This is a broad category that extends from traditional
materials, such as zinc oxide paste, to cutting-edge
preparations containing growth factors.
 The various categories include those with antibacterial
properties such as acetic acid, Dakin's solution, silver
nitrate, mafenide (Sulfamylon), silver sulfadiazine
(Silvadene), iodine-containing ointments (Iodosorb), and
bacitracin.
 They are indicated when clinical signs of infection, such
as an increase in exudate or cellulitis, are present or if
quantitative culture demonstrates greater than 105
organisms per gram of tissue.

21. Types of surgical dressing
A. POLYMERIC FILM
 Opsite
 Bioclusive
 Tegaderm
• They are transparent dressing for sutured wounds or
donor sites.
• Their advantages are:
 Barrier to bacteria including MRSA
 Reduce the risk of maceration
 Reduce the risk of blistering

22.  Reduce pain on removal
 Waterproof ,conformable and comfortable to wear
 Manage exudate through a highly absorbent pad and
breathable film
 Easy to apply and remove aseptically
 Allow constant monitoring on the wound and peri-wound
area
 are permeable to gases such as water vapour and
oxygen but impermeable to larger molecules including
proteins and bacteria.

23.  This property enables insensible water loss to
evaporate, traps wound fluid enzymes within the
dressing, and prevents bacterial invasion.
 Transparent film dressings were found to provide the
 fastest healing rates
 lowest infection rates
 most cost-effective method for dressing split-
thickness skin graft donor sites.

24. OPSITE

25. OPSITE TEGADERM

26. B FOAMS
 silastic foams can be shaped to fit deep cavities and
granulating wounds.
 It is absorbent and non adherent.
 They consist of two layers, a hydrophilic silicone or
polyurethane-based foam that lies against the wound
surface, and a hydrophobic, gas permeable backing
to prevent leakage and bacterial contamination.
 Some foams require a secondary adhesive dressing.

27. FOAM

28.  Advantages of foams include their high absorptive capacity
and the fact that they conform to the shape of the wound
and can be used to pack cavities.
 Minimize maceration of peri-wound edges (can be used in
areas of fragile skin)
 Can be used under compression .
 Disadvantages of foams include the opacity of the
dressings and the fact that they may need to be changed
each day.
 Foam dressings may not be appropriate on minimally
exudative wounds, as they may cause desiccation.

29. c. ALGINATES
 Natural complex polysaccharides from various types
of algae form the basis of alginate dressings.
 Their activity as dressings is unique because they
are insoluble in water, but in the sodium-rich wound
fluid environment these complexes exchange
calcium ions for sodium ions and form an amorphous
gel that packs and covers the wound.
 Alginates come in various forms including ribbons,
beads, and pads.
 these dressings are more appropriate for
moderately to heavily exudative wounds.

30. ALGINATES

31.  Advantages
 augmentation of hemostasis
 they can be used for wound packing
 most can be washed away with normal saline in
order to minimize pain during dressing changes
 they can stay in place for several days.
 Disadvantages
 they require a secondary dressing that must be
removed in order to monitor the wound
 they can be too drying on a minimally exudative
wound
 they have an unpleasant odor

32. D. HYDROCOLLOIDS
 consist of a gel or foam on a carrier of self-adhesive
polyurethane film.
 The colloid composition of this dressing traps
exudate and creates a moist environment.
 Bacteria and debris are also trapped, and washed
away with dressing changes in a gentle, painless
form of mechanical debridement.
 Another advantage of hydrocolloids is the ability to
use them for packing wounds

33.  Disadvantages
 Mal-odour
 Daily dressing change
 Allergic dermatitis.
 Cadexomer iodine is a type of hydrocolloid in which
iodine is dispersed and slowly released after it
comes in contact with wound fluid.
 The concentration of iodine released is low and does
not cause tissue damage
 Hydrocolloid products include DuoDERM, Tegasorb,
J and J Ulcer Dressing, and Comfeel.

34. E. HYDROGELS
 Hydrogels are a matrix of various types of synthetic
polymers with >95 percent water formed into sheets,
gels, or foams that are usually sandwiched between
two sheets of removable film.
 The inner layer is placed against the wound, and the
outer layer can be removed to make the dressing
permeable to fluid.
 These unique matrices can absorb or donate water
depending upon the hydration state of the tissue that
surrounds them.

35.  Hydrogel products include Intrasite Gel, Vigilon,
Carrington Gel, and Elastogel.
 Hydrogels are most useful for dry wounds.
 They initially lower the temperature of the wound
environment they cover, which provides cooling pain
relief for some patients.
 hydrogels have been found to selectively permit
gram-negative bacteria to proliferate .

36. HYDROCOLLOID AND HYDROGELS

37. F. HYDROACTIVE
 Hydroactive, the most recently developed synthetic
dressing, is a polyurethane matrix that combines the
properties of a gel and a foam.
 Hydroactive selectively absorbs excess water while
leaving growth factors and other proteins behind .

38. G. ENZYMATIC
 Enzymatic debridement involves applying
exogenous enzymatic agents to the wound.
 collagenase may promote endothelial cell and
keratinocyte migration, thereby stimulating
angiogenesis and epithelialization.
 Streptokinase/ streptodornase helps in fibrynolysis
and liquefy pus on chronic skin ulcer.

39. H. BIOLOGIC
 Maggot therapy can be used as a bridge between
debridement procedures, or for debridement of
chronic wounds when surgical debridement is not
available or cannot be performed.
 Maggot therapy may also reduce the duration of
antibiotic therapy in some patients.
 Maggot therapy has been used in the treatment of
pressure ulcers , chronic venous ulceration ,diabetic
ulcers and other acute and chronic wounds .

40.  maggot therapy has additional benefits, including
antimicrobial action and stimulation of wound
healing.
 Dressing changes include the application of a
perimeter dressing and a cover dressing of mesh
(chiffon) that helps direct the larvae into the wound
and limits their migration.
 Larvae are generally changed every 48 to 72 hours.
 The larvae can also be applied within a prefabricated
“biobag”

42. TOPICAL THERAPY
1. GROWTH FACTORS
 Platelet derived growth factor
 Becaplermin is a platelet-derived growth factor
(PDGF) gel preparation that promotes cellular
proliferation and angiogenesis.
 for the treatment of diabetic foot ulcers and chronic
wounds, it is the only pharmacological agent
approved.
 It is delivered in a topical aqueous-based
sodium carboxymethylcellulose gel.
 It is indicated for noninfected diabetic foot ulcers

43.  Epidermal growth factor
 topical application of human recombinant epidermal
growth factor was associated with a greater
reduction in ulcer size and higher ulcer healing rate.
 Granulocyte macrophage colony stimulating factor
 Intradermal injections of granulocyte-macrophage
colony stimulating factor (GM-CSF) promote healing
of chronic leg ulcers, including venous ulcers.

44. 2. ANTISEPTIC AND ANTIMICROBIALS
 Cadexomer iodine (eg, Iodosorb) is an antimicrobial
that reduces bacterial load within the wound and
stimulates healing by providing a moist wound
environment.
 Cadexomer iodine is bacteriocidal to all gram-positive
and gram-negative bacteria.
3. BETA BLOCKERS
 Keratinocytes have beta-adrenergic receptors, and
beta blockers may influence their activity and increase
the rate of maturation and migration.
 Timolol is a topically applied beta blocker with some
limited evidence

45. SKIN SUBSTITUTES
 Manufactured by tissue .
 they promote healing, either by stimulating host
cytokine generation or by providing cells that may also
produce growth factors locally.
 Their disadvantages include
 limited survival
 high cost
 need for multiple applications .

46. Desired Features of Tissue-Engineered Skin
Rapid re-establishment of functional skin (epidermis/dermis)
Receptive to body's own cells (e.g., rapid "take" and integration)
Graftable by a single, simple procedure
Graftable on chronic or acute wounds
Engraftment without use of extraordinary clinical intervention (i.e., immunosuppression)

47.  Cultured epithelial autografts (CEAs) represent
expanded autologous or homologous keratinocytes.
 CEAs are expanded from a biopsy of the patient's own
skin, will not be rejected, and can stimulate re-
epithelialization as well as the growth of underlying
connective tissue.
 Keratinocytes harvested from a biopsy roughly the size
of a postage stamp are cultured with fibroblasts and
growth factors and grown into sheets that can cover
large areas and give the appearance of normal skin
 CEAs are available from cadavers, unrelated adult
donors, or from neonatal foreskins

48.  fibroblasts can be grown on bio-absorbable or non-
bioabsorbable meshes to yield living dermal tissue that
can act as a scaffold for epidermal growth.
 Fibroblasts stimulated by growth factors can produce
type I collagen and glycosaminoglycans (e.g.,
chondroitin sulfates), which adhere to the wound
surface to permit epithelial cell migration, as well as
adhesive ligands (e.g., the matrix protein fibronectin),
which promote cell adhesion.
 Indicated for use with standard compression therapy in
the treatment of venous insufficiency ulcers and for the
treatment of neuropathic diabetic foot ulcers

49. References
 Sabiston test book of surgery
 Schwartz principles of surgery.
 Basic priniples of wound dressing-UPTODATE.

50. Thank you