Wound Healing Flashcards
Why do we need to know about wound healing?
Common problems
Failure to treat will lead to morbidity, increased costs
Concepts relatively simple & can lead to good results
How to Understand Wounds
Phases of wound healing
Important factors in each phase
Understand factors that influence wound healing
4 Stages of Wound Healing
Hemostasis/Coagulation
Inflammation
Migration/Proliferation
Remodeling
Coagulation
Platelet aggregation
Degranulation of platelets
Fibrin clot formation
Inflammation
Attraction/activation of infiltrating cells
Neutrophils
Macrophages
Neutrophils in the Inflammation Process
Phagocytosis of bacteria & matrix
Macrophages in the Inflammation Process
Debridement/matrix turnover
Major source of stimulatory signals
Important for would healing
Define Angiogenesis
Formation of blood vessels
How does angiogenesis occur?
Begin as endothelial cell buds
Progress toward wound space (follows oxygen gradient)
Immature vessels differentiate into capillaries, arterioles, & venues
Macrophages & keratinocytes provide angiogenic stimuli
Describe Epithelization
Epidermal covering reconstituted from wound margin & hair follicle remnants
How does epithelization occur?
Keratinocytes migrate across wound
During & after migration, differentiation & stratification of neodermis occurs
Epithelization aided by moist environment
What happens to the fibroblasts in fibroplasia?
Migrate into wound site & replicate
Dominant cell type at wound edge
Synthesize & deposit collagen & proteoglycans
What is matrix deposition dependent on?
Oxygen & substrate availability
Growth factors
Define Remodeling
Changes in matrix composition over time
What is healing retarded by?
Ischemia Dry wound environment Infection Foreign bodies Anti-inflammatory therapy Nutritional deficiency
Local Factors Affecting Wound Healing
Mechanical injury Infection Edema Ischemia/necrotic tissue Topical agents Ionizing radiation Low oxygen tension Foreign bodies
Things to Know About Your Patient that will Affect Wound Healing
Age Nutritional status Circulation DM Smoking Steroids Support system
Essential Nutrients for Wound Healing
Calories Carbs Protein Fats Vitamin A Vitamin C Zinc Water
Halsted’s Principles of Wound Care
Gentle handling of tissues Careful hemostasis Aseptic technique Avoidance of tension Sharp dissection Obliteration of dead space
3 Types of Wound Healing
Primary intention
Secondary intention
Third intention
Primary Intention of Wound Healing
Wound closed with stitches or staples
Cover with sterile dressing
Keep protected from getting wet
Monitor for erythema, swelling, warmth, & drainage
Secondary Intention of Wound Healing
Epidermis & dermis not closed
Usually due to contamination, an infected wound, or peritonitis
Packed daily with saline moistened gauze or sponges
Covered with sterile dressing
Third Intention of Wound Healing
I&D
Observed 3-4 days
Closed
Types of Wound Closure
Staples
Sutures
Wound Vac
Purpose of the Wound Vac
Decreases edema
Enhances granulation & vascularity
Lower bacterial counts
Excellent results
Define Surgical Site Infection
Infection at the incision site
May extend to adjacent deeper tissues
Most Common Nosocomial Infection Among Surgical Patients
Surgical site infection
Patient Risk Factors for Surgical Site Infection
DM Obesity Cigarette smoking Systemic corticosteroids or other immunosuppressive drugs Malnutrition Pre-op nasal carriage or colonization with S. aureus Presence of remote focus of infection Duration of preoperative hospitalization Preoperative severity of illness
Most Important Factors for Prevention of Surgical Site Infections
General health of patient
Meticulous operative techniques
Timely administration of pre-op antibiotics
IV Antibiotic Prophylaxis Regimen for Colorectal Surgery
Cefoxitin or cefotetan
Cefazolin + metronidazole
Hair Removal and Surgical Site Infections
Due immediately prior to surgical incision
