Biosurgical Wound healing

Question 1

What is the prevalence of diabetic foot ulcers in diabetic patients

Answer 1

5-7%

Question 2

What are pressure sores

Answer 2

Damaged skin by staying in one position for too long

Question 3

How do you normally treat chronic wounds

Answer 3

1. Debridement by surgical/deep, mechanical, enzymatic or autolytic removal of dead tissue
2. Traditional gauze dressings and antiseptics
3. Modern dressings: promotion of autolytic wound debridement and prevent infections
   Example: hydrogel, hydrocolloid, alginate

Question 4

How does maggot based therapy work

Answer 4

1. Debride (clean) wounds by dissolving dead infected tissues
2. 200 maggots, consume 15g of necrotic tissue per day
3. Disinfection: Maggots are more effective than antibiotics at killing gram positive bacteria (not gram negative)
4. Maggots prevent further infection of wounds and promote wound healing (granulation tissue forming)

Question 5

What are the factors that maggots release to break down dead flesh

Answer 5

1. Serine proteases (trypsin, chymotrypsin) - new antibiotic developed called Seraticin
2. Amino peptidases
3. Allantoin and urea (thin, soften and moisturises skin)

Question 6

What is the time frame of using maggots when first received and duration they last

Answer 6

8 hours after first receiving

5 days after packaging since they stop feeding

Question 7

What are the two methods to apply maggots?

Answer 7

1. Free range- applied directly to wound using hydrocolloid barrier for 3 to 4 days
2. Biobag: foam in pouch protects maggots and soaks up secretions

Question 8

What may you develop after maggot therapy?

Answer 8

1. Red or pink secretions from infected skin
2. Rash development
3. Fever development

Question 9

Which wounds are excluded from maggot treatment

Answer 9

Dry wounds- moist gauze swab is sufficient enough

WOUND IN BODY CAVITIES

Question 10

What factors do not influence treatment outcomes

Answer 10

Sex
Diabetes
SMOKING
Locations of wound
Wound size
Duration of wound

Question 11

What factors influence treatment outcomes

Answer 11

Age (patient is 60 years or older)

Type of wound: less effective on non traumatic wound or deeper wounds

Less effective in chronic limb ischaemia

Question 12

How are leeches used in medicine

Answer 12

1. Plastic and reconstructive surgeries- perfect for skin grafts and redrafting amputated appendages
2. Useful in cases of impaired venous circulation, not insufficient arterial inflow

Question 13

What is the mechanism of action of leeches

Answer 13

1. Produces small wound that mimics venous circulation in compromised tissue
2. Small anticoagulant made that is a local vasodilator and anaesthetic

Question 14

What are the benefits of leeches in microsurgery

Answer 14

Drainage of blood from congested sites

Relieves pressure build up

Prevention of blood clotting in small veins in graft

Question 15

What are the substances in leech saliva that provide it with its working properties

Answer 15

Hirudin- potent anticoagulant
Factor Xa inhibitor
Carboxypeptidase A inhibitor
Acetylcholine
Histamine like factors

Question 16

What is Bivalirudin

Answer 16

1. Drug that is used for anticoagulation in patients undergoing percutaneous coronary intervention
2. Reversible binding to thrombin

Question 17

What is Lepirudin

Answer 17

1. Recombinant hirudin
2. Indications: anticoagulation therapy in heparin induced thrombocytopenia
3. Side effect: bleeding

Question 18

How do you get rid of used leeches

Answer 18

Sedated with 8% alcohol, killed with 70% alcohol for 5 minutes