Kapitel 76 - Open wounds

Question 1

What are the 4 steps of wound healing?

Answer 1

1) formation of a fibrin-platelet clot at the site of injury
2) recruitment of white blood cells to protect the site from infection
3) neovascularization and cellular proliferation, and
4) tissue remodeling.

Question 2

List the different types of wounds.

Answer 2

1) Abrasion
2) Puncture wounds
3) Laceration
4) Degloving injury
5) Thermal burn
6) Decubital Ulcer

Question 3

Describe the difference between anatomic degloving injure and physiologic degloving injury

Answer 3

1) With an anatomic degloving injury, the skin and various levels of underlying tissue are torn off the body.

2) With a physiologic degloving injury, the skin surface is intact but separated or avulsed from the underlying subcutaneous tissues and blood supply, resulting in delayed necrosis of the skin.

Question 4

What is considered the threshold of bacterial burden for development of infection?

Answer 4

A burden of 105 colony-forming units (CFU) per gram of tissue.
(with a time frame for this to occur being 6 h or more)

Question 5

What are the different types of wound managements?

Answer 5

1) Primary closure – appositional closure and first intension healing

2) Delayed primary closure - describes appositional closure within 3 to 5 days after wounding but before granulation tissue is evident in the wound bed.
3) Secondary wound closure describes appositional closure of a wound more than 3 to 5 days after wounding, by which time granulation tissue has formed in the wound bed (also called third intension healing)

4) Second intension healing – healing by epithelialization and contraction

Question 6

Give examples of topical antimicrobial agents used for immediate wound management?

Answer 6

1) Antimicrobial ointments
2) Silver based dressings
3) Hyperosmotic dressings (20% hypertonic saline, honey, sugar)

(Hypertonic saline dressings are profoundly antimicrobial, naturally debriding, and more cost effective than silver in the immediate wound management period.)

Question 7

What concentration of antiseptic solution and be used for irrigation of the wound?

Answer 7

1) A 0.05% to 0.1% solution of chlorhexidine (1 : 40 dilution of stock 2% solution) or

a 0.1% to 0.01% solution of povidone-iodine (1 : 100 to 1 : 1000 dilution of 10% stock solution)

(Although addition of antiseptics to irrigation solution is unnecessary because the primary goal of irrigation is mechanical removal of contamination.)

Question 8

How does honey work as a nonenzymatic debridement dressing?

Answer 8

1) It is hyperosmotic and dehydrated microorganism and inhibit their growth

2) It produced hydrogen peroxide that are oxidized to oxygen-derived free radicals that are damaging to microorganism (but in a low concentration not to be cytotoxic)

3) It has phytochemicals (complex nonperoxide antibacterial substances made up of phenols and organic acids) and a low pH –> antimicrobial
4) It reduced inflammation because of antioxidant content and facilitation of wound healing by stimulation of B- and T-lymphocyte proliferation, phagocytic activity, and cytokine release from monocytes

Question 9

What pressures are used in NPWT in small animals?

Answer 9

Pressures of −80 mm Hg for gauze-based systems to −125 mm Hg for foam-based systems

Question 9

What are some beneficial effects of negative pressure wound therapy?

Answer 9

1) Improve would perfusion
2) Reduce edema
3) Stimulate granulation tissue
4) Decrease bacterial colonization
5) Remove exudate from the wound.

Question 10

What pressure should be used in NPWT used over skin grafts?

Answer 10

• 65 to -75 mmHg