Wound Healing: General Principles Mansour Dib MD
Normal Wound Healing
Chronic Wounds: Stuck Where does it get stuck? Mostly Proliferation Sometimes Remodeling Why? Systemic factors Local factors
How do you get a wound to heal? Fix the underlying cause!!!!!! Pressure: Relieve Diabetes: Control Arterial: Restore flow Venous: Compress Help the wound milieu being as optimal as possible to build new tissue
Control pressure Pressure relieving surfaces Frequent turning Elevating Avoid shear forces
Restore flow! CP996219-65
Manage the edema!
Control: Glycemia Pressure Blood flow CP996219-63
CP996219-80
What can we do locally?
FISHBONE root cause analysis Necrosis (tissue) Bacteria Impaired Healing Moisture ph MMPs
Necrotic Tissue: Debridement Debridement Methods Surgical (OR) Sharp (Blade) Mechanical Enzymatic Autolytic
Sharp debridement
Mechanical Debridement: Wet to Dry dressing
Moisture Balance Moist wound healing principle Add moisture if too dry Hydrogel Absorb exudates if too wet Foam, Alginates
Bacterial overgrowth Chronic wounds are all contaminated some get even severely infected Patients with chronic wounds often have a compromised immune system
Different levels of bacteria presence Contamination Bacteria present on surface Colonization Bacteria attach to tissue and multiply Infection Bacteria invade healthy tissue and overwhelm immune defenses
Bacterial load control Systemic antibiotics if declared infection: Cellulitis Osteomyelitis Septicemia Get cultures! Local antibiotics (creams/ointments) Risk of resistance is high Less toxic on healing tissue
Bacterial load control Local antiseptics, heavy metals Chlorhexidine, Ag, Iodine More efficient than antibiotics More toxic on tissues Use in slow release forms!!!
25 ph and Chronic Wounds Natural skin has an acidic mantle of ph5.5 Acute wounds Chronic wounds Lars et al, 2006
ph and Chronic Wound Surface wounds develop respiratory alkalosis as CO 2 escapes from the wound surface to the air (Leveen et al, 1973) Escape of CO 2 reduces buildup of carbonic acid Bacterial production of ammonia further increases the ph Alkaline milieu: bacterial growth, MMP activity, wound hypoxia
Controlling wound ph Acidifying the wound helps healing Control bacterial load Provide acidity Acetic Acid/Boric Acid Honey Ringer Lactate
High proteases activity (Matrix MetalloProteases)
Effect of proteases on growth factors
MMP control Trap the enzymes or inhibit their action Collagen/ORC SAP Mechanically remove them Frequent dressing changes Negative pressure therapy Control ph
Growth Factors Lacking in chronic wounds Inhibit their destroyers Provide them externally: Platelet Rich Plasma Recombinant Growth Factors Honey?
How do you get a wound to heal? Local factors: Dead tissue: Debride Too dry/ Too wet: Moisture Balance Bacterial infection: control ph: acidify Matrix Metallo Proteinases (MMPs): Inhibit MMPs, provide GF Dressing choice will be dictated by wound characteristics
Dressings are confusing!
Dressing choice No magic dressing that works for everything However newer dressings are getting close: combining multiple functions
Products Silver Foam Elevate d MMP Bacterial Infection but with cytotoxic consequenc es Elevated ph Necrotic Tissue Moisture Balance Silver Foam Alginates Silver Alginates Hydrogel TenderWet
Dressing choice Understand principles of wound healing Properly evaluate wound conditions Wounds evolve with time!! First, do no harm
Dressing choice Availability (of dressing, and nursing staff) Ease of use Cheap/Cost-effective
Granulation tissue Healthy healing tissue Well vascularized Small bumps Protect!!!!
Epithelialisation Keep moist Protect from environmental factors (trauma, temperature etc.)