P14: Wounds & Dressings Flashcards
what is a wound
any defect or damage in the skin caused by physical, chemicl or thermal factors; damage caused by an infectious disease
result of disruption of normal anatomical structure and function
what is an incision
regular wound caused by a clean sharp-edged object
what are lacerations
rough irregular wounds, caused by crushing or ripping forces
what are abrasions
grazes
superficial wound caused by a sliding fall onto a rough surface
what are puncture wounds
caused by a sharp-pointed object punching the skin; high risk of anaerobic infection, injury of big vessels and nerves
what are penetration wounds
caused by a knife entering the body
what are avulsion wounds
when the integrity of any tissue is compromised
what is a contusion
bruise
caused by blunt force trauma, damaged tissues under the skin
what is a hematoma
caused by damage to a blood vessel, blood accumulation under the skin
what are crushing injuries
caused by blunt force, pressure injury over a long period of time
what does the wound healing process involve
dynamic interactive process involving; parenchymal cells, extracellular matrix, blood cell and soluble mediators
what is homeostasis (vasoconstriction) during the inflammatory phase
first bleeding occurs at the site to remove toxic waste; then activation of homeostasis begins
how does the clotting mechanism work during the inflammatory phase
elicited by platelets resulting in coagulation and the formation of fibrin network; the inflammation causes vasodilation and hagocytosis -> release of histamine and serotonin
phagocytes enter the wound, engulf dead cells, platelets are liberated and form aggregates as part of the clotting mechanism
what happens during granulation in the proliferation phase
migrating cells travel about 3cm from the point of origin in all directions; process occurs 2 days - 3 weeks following injury; results in granulation tissue at the wound space
what is granulation
the effect of fibroblasts and macrophages provising a continuing source of growth factors for stimulating angiotensins and fibroplasia (production of fibrous tissue)
what happens during contraction and angiotensins during proliferative phase of wound healing
fibroplasia results in formation of a bed of collagen to fill the defect, so wound edges pull together
(contraction) and new capillaries are produces (angiotensins)
what happens during the remodelling phase of wound healing
involves formation of collagen to increase tensile strength
begins 3 weeks post-injury up to months; principle cells involved are fibroblasts, collagen molecules formation, further modification to form in a characteristic helical structure; collagen is released in extracellular space to form stable cross links, collagen matures more at the wound its resulting in intra and intrer-molecular cross links forming
cross linking provides strength and stability to collagen
the tissue will never regain the properties of uninjured skin
what do myofibroblasts do in normal tissue
microvasculature is stable and covered by pericytes and inactivated fibroblasts occupy the surrounding connective tissue
what do myofibroblasts do during wound healing
activated fibroblasts or pericytes may differentiate into myofibroblasts and enter the wound bed
signals and matrix from the wound microenvironment may cause pericytes to assume a more contractile and matrix depositing phenotype
what dressings are used in primary wound dressing
hydrogel dressing, hydrocolloids, gauze impregnated, gauze non-impregnated, composite dressings, wound fillers, alginate dressings, foam dressings
what dressings are used in secondary dressing
tape, elastic bandage, transparent film dressings, gauze dressing, carbon dressing
when are petroleum impregnated dressings used
for clean, healthy wounds with minimal granulation bed; for wounds with no need for debridement/granulation/contraction, used at early stage wound repair for shallow wounds, increases wound contraction but delays epithelialisation
what are non-adhering dressings used for
dry to highly exuding wounds where adherance of dressing and exudate is to be prevented, including first and second degree burns, abrasions, grafts, venuous ulcers, pressure ulcers, nail extractions, eczema, staples, surgical incisions, lacerations, reconstructive procedures and suture lines
what are hydrogel sheets used for
shallow wounds
like burns, fungating, lesions, low exuding wounds
