Wounds Flashcards
What are the phases of wound healing?
INFLAMMATORY
PROLIFERATIVE
REMODELING
What occurs in a wound from day 0 to day 5?
HAEMOSTASIS & INFLAMMATION
1- clotting cascade initiated
2- platelet aggregation
3- release of cytokines & growth factors
4- chemotaxis of macrophages to help in phagocytosis & wound debridement
5- activation of fibroblasts & endothelial cells
what are the signs of the inflammatory phase in wound healing?
redness heat swelling pain loss of function at wound site
(phase is short if there’s no infection or contamination)
What are the characteristics of the proliferative phase?
- FIBROBLASTS from surrounding tissue secrete collagen I & III
- ENDOTHELIAL CELLS from intact venules form new capillary buds which will form granulation tissue with fibroblasts
- EPITHELIAL CELLS from wound edges migrate to close the epithelial defect
What occurs in the maturation phase?
deposition of collagen in the wound
- collagen III first then collagen I
- collagen fibers become thicker & arrange along the lines of stress to increase the tensile strength of the wound
How long does remodeling continue for?
1 year
When does wound contraction start?
starts immediately & continues for 2 - 3 weeks
MYOFIBROBLASTS help diminish the size of wound
What are the general factors that affect wound healing?
AGE
decreased protein turnover in elderly slows healing
DEBILITATING DISEASE
like uremia, jaundice, cirrhosis, malignancy, & diabetes
IRRADIATION
- inhibit wound contraction & granulation tissue formation
- prior irradiation causes ischemia due to end arteries obliterans
NUTRITION
- proteins: essential for collagen synthesis
- Vit C: maturation of protocollagen
- Vit. A: epithelialization
- calcium, zinc, manganese & copper
DRUG INTAKE
steroids inhibit inflammatory response & fibroblast formation
What are the local factors affecting wound healing?
VASCULARITY
- good blood supply in face & scalp help rapid healing
- bad blood supply below the knees delay healing
IMMOBILIZATION
wounds over joints or weight bearing have smaller healing powers
TENSION
cause ischemia & delayed healing
INFECTION
bacteria competes with fibroblasts for oxygen & nutrition
- they secrete collagenolytic enzymes
FOREIGN BODIES & NECROTIC TISSUE impair healing
ADHESION TO A BONY SURFACE
prevents wound contraction
What are the types of wound healing?
PRIMARY INTENSION
- clean wounds immediately closed by sutures or clips
- minimal scar
SECONDARY INTENSION
- edges not approximated or gaping due to hematoma or infection
- filled with granulation tissue
- ugly scar
TERTIARY INTENSION
- contaminated wounds left open for 5 days
- if there are no signs of infection delayed primary sutures could be done
surgical incision & wounds caused by sharp objects are classified as? How should they be treated?
Tidy wounds
- primary sutures
- healed by primary intention
crushing, tearing, avulsion, devitalised injury, vascular injury, multiple irregular wounds & burns are classified as? What complications could they cause?
Untidy wounds
Could cause: - wound dehiscence
- infection
- delayed healing
What are the 2 types of wounds?
CLOSED
- contusions
- hematoma
OPEN
- abrasions
- incised
- lacerated
- penetrating
- bites
a blow with a blunt object causing extravasation from the injured blood capillaries, the area is painful & swollen & is bluish then brownish then green. What is this called & what is its treatment?
CONTUSION
elevation & anti-inflammatory ointment
excessive bleeding that is cystic in the beginning then after hours begins to clot and later liquifies is called? What are the complications caused?
HEMATOMA
- absorption
- organization by fibrosis
- abscess
- liquifaction & cyst formation
- calcification (myositis ossificans)
- abscess
- false aneurysm
What are abrasions & why do they hurt? How should they be managed?
- scraping of superficial layer of skin due to friction with hard rough surface
- sensitive nerve endings are exposed
- clean with anti-septic
- nonadherent dressing
how is an incised wound caused?
- sharp cutting instruments
- long than it is deep
- edges are clean cut
- tendons & nerves are liable to be cut
severe violence with a blunt object will cause?
LACERATED wound
- irregular in shape & severely traumatized
- devascularized & contaminated
could cause DEGLOVING INJURY
- in skin & subcutaneous tissue from deep fascia
- skin devascularization becomes apparent in a few days
How are penetrating wounds caused?
penetration by a pointed object that could injure deep structures
- small external opening
- has poor drainage so it encourages infection
What type of wounds do bites cause?
Lacerated wounds with bone, joint, tendon, vessel, & nerve involvement
Puncture wounds with high risk of infection (difficult to irrigate & decontaminate
A superficial wound involves?
the epidermis alone
a partial thickness wound involves?
- epidermis
- dermis
a full thickness wound involves?
- epidermis
- dermis
- fat
- fascia
- exposes bone
How should any open wound be managed?
1- direct local compression to stop BLEEDING
2- splint & arrange for x-ray if there is a suspected fracture
3- saline irrigation & removal of foreign bodies THEN antiseptic
4- inspection of all structures within wound
5- repair large veins or arteries & ligated small veins or arteries
6- repair nerves or tendons
7- repair muscles by mattress sutures if incised cleanly
excise ischemic or necrotic muscle
8- if there is a possibility of infection, external bone fixation
9- leave deep fascia open if wound is contaminated or there is extensive tissue destruction
What are the complications of WOUND HEALING?
HEMORRHAGE
- slipped suture
- erosion of blood vessels
- infection
- dislodged clot
INFECTION
- due to purulent material draining from wound
- its greater when wounds contain necrotic tissue, foreign
bodies, or blood supply & local tissue defense is reduced
- bacteria inhibits wound healing
EVISCERATION
- visceral organs protrude through wound opening due to total separation of wound
DEHISCENCE
- partial or total separation of wound layers
- BURST ABDOMEN
STRETCHING
CONTRACTURE
- usually in burns
What are the signs & symptoms of an infected wound?
- contaminated or traumatic 2 - 3 days
- post-op surgical wound 4 - 5 days
- fever, tenderness & pain at wound site & inflamed edges
- odorous & purulent drainage (yellow, green, or brown)
- elevated WBC
What are the complications of wounds?
GENERAL
- shock
- crush syndrome
- compartment syndrome
LOCAL
- infection: pyogenic or specific
- gangrene: vascular or infective
- complications of healing
a closed injury causing hematoma leading to increased pressure will cause?
COMPARTMENT SYNDROME
- usually associated with a bone fracture aggravating ischemia
What are the signs of compartment syndrome?
- Pallor
- pulslessness
- pain
- paresthesia
- diffuse swelling
- cold limb
IF IT PROGRESSES
- gangrene
- chronic ischemic contracture leading to a deformed limb
What are the problems associated with compartment syndrome?
- renal failure
- gangrene of limb
- chronic ischemic contracture
- disabled limb
How should compartment syndrome be treated?
pressure will be more than 30mmHg
1- FASCIOTOMY should be done until muscle bulges out
2- antibiotics
3- catheterisation
4- mannitol or diuretics to flush the kidney
5- fresh blood transfusion
6- hyperbaric oxygen
What are the dreaded problems of crush injury?
- renal failure
- hypovolemic shock
- sepsis
What does crush syndrome lead to?
extravasation of blood & release of myohaemoglobin into the circulation leading to acute tubular necrosis & acute renal failure
What are the causes of crush syndrome?
- earthquakes
- mining & industrial accidents
- air crash
- tourniquet
What is the pathogenesis of crush injury?
1- tension increases in the muscle compartment
2- circulation impeded & ischemic damage increases
3- urine becomes discolored & scanty in 3 days
4- patient becomes restless, apathic, & delirious with onset of uremia
INJURY IS WORST THAN INITIAL LOOK (life threatening)
What are the effects of crush syndrome?
- renal failure
- toxaemia
- septicemia
- disability with extensive tissue loss
- gas gangrene
How is crush syndrome treated?
- relieve tension by multiple parallel deep incisions
Keloid is more common in?
- black people
- women
What are the predisposing factors for keloid?
- genetic (familial)
- defect in maturation & stabilization of collagen fibrils
What is the commonest site for Keloid formation?
over sternum
Whats the pathology of keloid?
- continues to grow even after 6 months
- extends into adjacent normal skin
- brownish?pinkish black in color (vascular)
- painful, tender, & hyperaesthic
proliferating immature fibroblasts & blood vessels & type III collagen
What diseases may be associated with Keloid?
Ehlers Danlos syndrome
Scleroderma
How should Keloid be treated?
- excision & skin grafting
- irradiation
- excision & irradiation
- steroid injection
- silicone gel sheeting
- laser therapy
- vitamin E/palm oil massage
- intralesional excision
What are the different characters of a hypertrophic scar? (compared with keloid)
- not genetic or familial
- occurs anywhere in the body
- growth limits up to 6 months
- limited to scar tissue only
- pale brown in color
- not tender or painful
- self-limiting
- responds to steroid injection
What are the common sites for a hypertrophic scar?
- wound crossing tension lines
- deep dermal burns
- wounds healed by secondary intension
What are the complications of a hypertrophic scar?
- breaks repeatedly & causes infection & pain
- may turn into Marjolin’s ulcer (SSC) after repeated breakdown
