wound management

Question 1

Wound management dressings

Answer 1

• Primary dressing: in direct contact with wound
• Secondary dressing: if required, to secure primary dressing, absorb exudate, etc.
• Traditionally dressings are classified by their generic description, which depends on their main ingredient rather than performance

Question 2

Alginate

Answer 2

• Produced from sodium and calcium salts of alginic acid, a natural polymer derived from seaweed
• Main purpose is absorption of exudate – very high absorbency per gram of material
• Flat sheets or packing for cavity wounds
• It has been suggested that alginates have pharmacological properties (?) due to healing rates achieved in one study

Question 3

Alginate Indications

Answer 3

• Sloughy or clean wounds producing moderate to heavy exudate
• Ribbon/rope for packing cavities
• Sheet for shallow wounds

Question 4

Alginate Contra-indications

Answer 4

• Dry wounds
• Diabetic foot ulcers if underlying infection

Question 5

Cadexomer-iodine

Answer 5

• Spherical starch microbeads that form a 3D lattice, iodine trapped in lattice at a concentration of 0.9%
• Starch has high absorption capacity – as it absorbs the pore size of the lattice increases (swells)
• Releases iodine for up to 3 days, which has an antimicrobial effect against Gram-positive and Gram-negative bacteria, fungi and yeasts, protozoa, and viruses
• Ointment or powder (Iodosorb®)
• Paste sandwiched in protective gauze backing (Iodoflex®)

Question 6

Cadexomer-iodine Indications

Answer 6

• Adsorption of high levels of exudate
• Infected wounds and prevention of infection

Question 7

Cadexomer-iodine Contra-indications

Answer 7

• Dry wounds
• Hx of thyroid dysfunction
• Severely impaired renal function
• Potential interaction with lithium
• Secreted into milk – avoid in breastfeeding

Question 8

Povidone-iodine

Answer 8

Knitted viscose fabric containing 10% povidone-iodine (equivalent to 1% iodine) in a PEG base

Question 9

Povidone-iodine Indications

Answer 9

Prophylaxis and treatment of wounds where likely bacterial, fungal, or protozoal infection

Question 10

Povidone-iodine Contra-indications

Answer 10

• Sensitivity to iodine
• Breastfeeding or pregnancy (risk of elevated serum iodide)

Question 11

Honey

Answer 11

• Honey has been used in wound healing for centuries
• Only honey that has been sterilised should be used on wounds
• Contains an enzyme that produces hydrogen peroxide
• Acts as a deodorizer
• Maintains a moist environment and it is claimed to stimulate tissue growth

Question 12

Honey Indications

Answer 12

• Malodorous wounds
• Dry or sloughy wounds
• Necrotic wounds

Question 13

Honey Contra-indications

Answer 13

• Allergy to bee venom
• Caution in diabetes – potential for absorption of glucose and fructose from the woun

Question 14

Hydrocolloid

Answer 14

• Micro-granular suspension of gelatin, pectin, and sodium carboxymethylcellulose in an adhesive matrix
• Granules are hydrophilic and capable of absorbing exudate – forms a gel
• Matrix is hydrophobic and prevents wound from desiccation
• Waterproof – patient can bath or shower with dressing in place

Question 15

Hydrocolloid Indications

Answer 15

• Dry to moderately exuding wounds
• Sloughy or necrotic wounds – prevents loss of water vapour and hydrates dead tissue encouraging autolysis

Question 16

Hydrocolloid Contra-Indications

Answer 16

• Contains gelatin
• Debate regarding use in diabetic foot ulcers

Question 17

Hydrocolloid-fibrous

Answer 17

• Many be used in similar situations to alginates, but greater capacity for retaining exudate
• Converts from a dry dressing to a soft coherent gel sheet

Question 18

Hydrocolloid-fibrous Indications

Answer 18

• Moderate to heavy exudate
• Infected wounds, but must be changed daily

Question 19

Hydrocolloid-fibrous contra-Indications

Answer 19

Dry wounds

Question 20

Semi-permeable film

Answer 20

• Thin, comfortable, hypoallergenic sheets of polyurethane coated with a layer of acrylic adhesive
• Permeable to water vapour and gases, but not to liquid water or microorganisms

Question 21

Semi-permeable film indications

Answer 21

• Can be applied as secondary dressing, to cover shallow wounds, or to protect the skin (e.g. protection against pressure ulcers)
• Securing venous catheters, surgical drains
• Suitable for showering as waterproof

Question 22

Semi-permeable film contra-indications

Answer 22

Fragile skin (trauma on removal)

Question 23

Silver

Answer 23

• Silver readily ionises in contact with body fluids to become reactive
• Antibacterial mechanisms of silver are poorly understood – can bind to and damage bacterial cells at different sites
• Used in caution in epithelialising wounds – silver potentialy toxic to the monolayer of epithelial cells resurfacing the wou

Question 24

Silver indications

Answer 24

Used to decrease bacterial count when critical colonisation suspected

Question 25

Silver contra-indications

Answer 25

• Pregnancy, breastfeeding
• Sensitivity to sulphonamides

Question 26

Topical negative pressure (TNP)

Answer 26

• Uses negative pressure applied directly to the wound bed to promote healing
• A vacuum unit capable of providing controlled levels of sub-atmospheric pressure is required
• Foam dressings or gauze are used with this system
• Works by continuous wound cleansing and stimulation of granulation tissue:
  -Fluid removal – bacteria, inflammatory mediators, cellular waste
  -Increased blood flow
  -Reduced oedema

Question 27

Larval therapy

Answer 27

• Common greenbottle maggots
• When applied to wound they produce proteolytic enzymes that degrade necrotic tissue
• 2-3 mm when applied, grow to 8 – 10 mm
• Also remove odour by ingesting bacteria in the wound
• Larval Debridement Therapy (LDT) is classified under the European Medicines Directive 2001/83/EC as a medicine

Question 28

3D-printed sensor dressings

Answer 28

• Can sense when bacteria are growing and change colour
• Based on the CO2 produced by respiring bacteria
• Xylenol blue dye changes from blue to green to yellow in the presence of CO2
• Can help to diagnose the onset of infection so antibiotic therapy can be started