The healing process

Local and systemic factors.

Tissue regeneration or scar formation

Primary intention - close approximation of all layers of the wound.

greater chance of infection

Secondary intention - healing by filling the open area from the bottom.

healing is a slow process

scar formation usual

Tertiary intention - or delayed primary closure.

for contaminated wounds

Factors adversely affecting healing

i. Systemic factors

Bacterial contamination

Poor hygiene Poor or delayed treatment

Prolonged treatment procedures Systemic infection

Impaired immune response

Poor circulation

Immobility Peripheral vascular disease

Hypotension Untreated cardiovascular disease

Poor wound oxygenation

Hypoxia Anaemia

Smoking Respiratory disease

Nutritional factors

Poor nutrition Gastrointestinal disease

Pharmocology

Steroid therapy NASIDs

Psychosocial factors

Poor family support Stress

General systemic factors

Diabetes Hyperthermia

Hypothermia Old age

Carcinoma Cytotoxic drugs

Radiotherapy

ii. Local factors

Infection Foreign material

Necrotic material Ischaemia

Anaerobic conditions Presence of local allergens

Wound Infections

Caused by aerobic bacterial, eg. Staphylococcus aureus

Caused by anaerobic bacteria, eg. Bacteroides fragilis

Clinical features of local infection

Redness, swelling, tenderness Red streaks

Pus or other discharge Tender lymph nodes

Smell Chills or fever

Pyrexia with tachycardia

Factors effecting extent of infection

Nature of infectious agent Presence of dead or foreign tissue

Location and nature of wound Amount of dead space or haematoma

Individual immunity Ischaemia

Systemic condition

Factors in treatment of an infected wound

Culture Irrigation

Drainage Antibiotics

Wound care Correct dressing

Systemic improvement

Purpose of a wound dressing

Protect from contamination and subsequent infection.

Protect from friction damaging granulation tissue.

Immobilize.

Provide pressure, eg haematoma prevention.

Prevent dissemination of bacteria from an already infected area.

Wound infections are responsible for 5.7% of nosocomial infection.

Factors which may delay wound healing

Factor Rationale

Local

Infection

Foreign material

Nature of the wound

Cooling of the wound

Systemic

Insufficient Diet/Malnutrition

Old age

Delayed inflammatory response

Hyperthermia

Hypothermia

Immobility

Psychological Stress

Hypoxia

Ischaemia

Smoking

Poor immunity

Hypotension

Untreated diabetes mellitus

Poor hygiene

External

Delay in seeking health care

Prolonged treatment procedures

No family support/poor patient compliance

Poor nursing care

Contact with some chemicals

Primary healing

1. Cut surface becomes inflamed. Blood clot and cell debris fill up the gap

2. Migration of phagocytes and fibroblasts. Collagen. Spread of dermal and epidermal cells through clot. Clot above becomes scab

3. Clot between cut surfaces is removed and scab separates

4. Epidermis grows upwards to restore thickness

5. Fibrous tissue growth continues to give strength

6. Inflammation resolves but scar tissue remains vascular

7. Wound gets stronger for 2 - 4 weeks. Fibrous tissue is removed by fibrolytic enzymes. Scar tissue vascularity is reduced

Forms of healing

Primary healing

Secondary healing

Delayed primary

Priorities

Cleaning

Haemostasis

Analgesia

Exploration

Closure/pack/cover

Physiology

Macrophages

Phagocytosis

Mitosis

Fibroblasts

Collagen

Fibrous tissue

Angioneogenesis

Fibrinogen

Stages of healing

Inflammation

Migration and destruction

Granulation

Maturation

Problems

Local

Systemic