Wound Bioburden

Question 1

What are the roles of skin, microflora, and immune cells in preventing wound infection?

Answer 1

• Skin acts as a mechanical barrier; oils and sweat chemically prevent bacterial entry.
• Microflora on skin and in the digestive tract protect against pathogens.
• Immune cells and an acidic pH also contribute to defense.

Question 2

What local factors and host characteristics increase the risk of wound infection?

Answer 2

• Local factors include ischemia, necrotic tissue, wound debris, and chronic wounds.
• Host factors include breaks in skin integrity, diabetes, malnutrition, obesity, steroid use, immunocompromise, and advanced age.

Question 3

What are the adverse effects of high microbe concentrations in wounds?

Answer 3

• They compete with host cells for oxygen/nutrients, release exotoxins (cytotoxic) and endotoxins (activate inflammation), delaying/preventing wound healing.

Question 4

How do the cardinal signs of inflammation differ in inflamed vs. infected wounds?

Answer 4

- Rubor:

• Inflamed – defined border
• Infected – poorly defined, streaking possible.

- Calor:

• Inflamed – localized
• Infected – large area, potential fever.

- Tumor:

• Inflamed – proportionate
• Infected – disproportionate, indurated periwound.

- Dolor:

• Inflamed – proportionate
• Infected – new-onset or disproportionate pain.

- Function Loss:

• Inflamed – temporary
• Infected – systemic signs (maliase, tachycardia, hypotension, altered mental status, altered function of affected area)

Question 5

How does wound drainage differ in inflamed vs. infected wounds?

Answer 5

• Inflamed: Thin, serous or serosanguinous, proportionate to wound size.
• Infected: Thick, purulent (creamy white/green/blue), distinctive odor, disproportionate.

Question 6

What indicates a decline in wound status, differentiating infection from normal healing?

Answer 6

• Infected wounds show a plateau/increase in size, reduced/friable granulation tissue, color change to dusky, and increased necrosis.
• Healthy wounds follow 3 phases of healing, showing a steady decline in non-viable tissue.

Question 7

What are planktonic organisms, and how do they impact wound healing?

Answer 7

Planktonic organisms are free-floating single cells that contaminate wound surfaces and can be neutralized by antibiotics.

Question 8

Define biofilm and its impact on wound healing.

Answer 8

• Biofilm is a layer of microorganisms on wound surfaces protected by an extracellular matrix.
• It’s found in 60% of chronic wounds, resists antibiotics, reduces bacterial metabolism, and stalls healing by evading immune responses.

Question 9

What do the acronyms NERDS and STONEES indicate in chronic wounds?

Answer 9

• NERDS: Critical colonization (e.g., Non-healing, Exudate, Red friable tissue, Debris, Smell).
• STONEES: Infection (e.g., Size increase, Temperature increase, Osseous exposed, New breakdown, Erythema/Edema, Exudate, Smell).

Question 10

What are silent infections, and which patients are at risk?

Answer 10

• Silent infections occur in immunocompromised patients or those with inadequate perfusion.
• They may present without obvious signs; systemic signs (e.g., fever) should be checked.

Question 11

What methods are used for wound cultures, and how do they help in managing infections?

Answer 11

• Biopsy: Gold standard, identifies infection/disease processes.
• Swab: Quantifies bacteria type/number.
• Aspiration: Samples tissue fluid. They confirm infection and guide treatment choice.

Question 12

How are aerobic and anaerobic cultures collected in wound assessment?

Answer 12

• Aerobic: Swab rotated over 1 cm² of wound for 5 seconds. add enough pressure to express tissue fluid
• Anaerobic: Swab moved in a 10-point pattern within wound bed.

Question 13

What staining methods differentiate gram-positive and gram-negative bacteria?

Answer 13

• Gram-positive: Stained by crystal violet.
• Gram-negative: Stained by safranin.

Question 14

How does bacterial fluorescence imaging assist in wound assessment?

Answer 14

• It identifies bacteria by their metabolic byproducts.
• Collagen fluoresces green; porphyrins fluoresce red (Staph aureus); pyoverdines fluoresce cyan (Pseudomonas).

Question 15

What are the strategies for treating wound bioburden and biofilm?

Answer 15

• maximize host resistance (e.g., diabetes control, nutrition),
• minimize bioburden (e.g., antimicrobials)
• disrupt biofilm (e.g., sharp debridement)
• eliminate invasive organisms

Question 16

What agents are used for antimicrobial and antibacterial treatments in wounds?

Answer 16

• Antimicrobials: Include antibiotics, antivirals, antifungals, antiparasitics.
• Antibacterials: Target large bacteria, not other organisms.

Question 17

How do wound cleansers affect healing, and which are effective?

Answer 17

• Saline/water do not kill organisms or enhance healing.
• Polyhexanide and povidone-iodine improve healing rates against contaminants.

Question 18

What defines resistant vs. sensitive bacteria in wounds?

Answer 18

• Resistant: Bacteria continue to multiply in drug presence (e.g., MRSA, VRE).
• Sensitive: Bacteria cannot grow in presence of certain antimicrobials.

Question 19

What are the characteristics of MRSA, and how is it treated?

Answer 19

• MRSA spreads via environmental/person contact, can cause cellulitis/abscesses, and lives on surfaces for hours to days.
• Treatment: mupirocin.

Question 20

What is Vancomycin-Resistant Enterococci (VRE), and where is it found?

Answer 20

VRE is common in surgical wounds/UTIs and treated with ampicillin-amoxicillin.

Question 21

What causes resistant bacteria, and how can it be prevented?

Answer 21

• Causes: Misuse of antimicrobials, improper prescriptions, incorrect usage, agricultural overuse.
• Prevention: Proper prescription, full course completion, limited antibacterial use.

Question 22

What are the advantages and disadvantages of topical antimicrobial therapy?

Answer 22

• Advantages: Lower cost, reduces bacteria, effective in compromised circulation.
• Disadvantages: Higher cost than non-antimicrobials, frequent application, potential resistance.

Question 23

What topical agents are commonly used for wound infections?

Answer 23

Acetic acid, chlorhexidine, honey, iodine, methylene blue-gentian violet, mupirocin, PHMB, potassium permanganate, silver.

Question 24

When should topical antimicrobial therapy be used, and when should it stop?

Answer 24

• Use when infected and stop when infection signs resolve.
• Exceptions: prophylactic use in high-risk wounds, two-week trial on non-healing pressure ulcers.

Question 25

What are antiseptic agents, and what are their proper uses?

Answer 25

• They prevent infection by killing microorganisms, used for surgical scrubs, hand washing, and cleansing intact skin.

Question 26

How does systemic antimicrobial therapy differ from topical therapy?

Answer 26

• Systemic therapy is physician-prescribed, used for sepsis/advancing infection, and may be combined with topical treatment.

Question 27

What are the disadvantages of systemic antimicrobial therapy?

Answer 27

Higher cost, adverse reactions, resistance risk, missed doses.

Question 28

What are the main steps to minimize bioburden and disrupt biofilm in wounds?

Answer 28

Sharp debridement is most effective for biofilm disruption; antimicrobials target bioburden.

Question 29

How should wound bioburden be managed in diabetic patients?

Answer 29

• control blood glucose
• promote tissue perfusion
• manage comorbidities to maximize host resistance

Question 30

What are the benefits and risks of using antiseptic agents on wounds?

Answer 30

They prevent infection but can be cytotoxic, potentially slowing healing depending on microbial load.