Wound Healing and Asepsis Flashcards
1
Q
The breakdown of living tissue by the action of microorganisms and is usually accompanied by inflammation
A
Sepsis
2
Q
The attempt to keep patients, personnel, objects, surgical wounds free of microbial contamination
A
Asepsis
3
Q
Substance applied to living tissue to prevent multiplication of micro-flora
A
Antiseptic
4
Q
Substance applied to inanimate object to prevent multiplication of micro-flora
A
Disinfectant
5
Q
- Surgeon’s hand/arm surgical scrub procedure
- Surgical field prep with betadine or chlorhexidine
- Sterlie drape/gown/gloves
A
Sterile technique for operating room
6
Q
When is the clean technique used
A
Intraoral office based procedure
7
Q
- heat
- mechanical dislodgement
- Radiation
A
Physical methods of general sterilization/disinfection
8
Q
- Antiseptics
- Disinfectants
- Ethylene oxide gas
A
Chemical methods of general sterilization/disinfection
9
Q
- Hair back
- Eye protection
- Mask
- Scrub of white coat
- Wash hands
- Open instruments
- Glove
A
Surgical staff prep
10
Q
Under Rule#1 what are the only surfaces the gloved hands can touch
A
- Opened instruments
2. Covered operatory
11
Q
What is Rule #2
A
Glove can’t touch anything else besides the patient’s mouth or anything in Rule #1
12
Q
What is Rule #3
A
When gloves touch anything else they are considered contaminated and have to be changed
13
Q
- Compromised blood flow
- Crushing
- Desiccation
- Incision
- Irradiation
- Overcooling
- Overheating
A
Physical causes of tissue damage
14
Q
- Agents w/ unphysiologic pH
- Agents w/unphysiologic tonicity
- Proteases
- Vasoconstrictors
- Thrombogenic agents
A
Chemical causes of tissue damage
15
Q
Stage 1 of Wound Healing
A
Inflammatory Stage
16
Q
Stage 1a of Wound Healing
A
Vascular Phase
17
Q
Stage 1b of Wound Healing
A
Cellular Phse
18
Q
Stage 2 of Wound Healing
A
Fibroplastic Stage
19
Q
Stage 2a of Wound healing
A
Migratory Phase
20
Q
Stage 2b of Wound Healing
A
Proliferative Phase
21
Q
Stage 3 of Wound Healing
A
Remodeling
22
Q
Stage 3a of Wound healing
A
Wound maturation
23
Q
Starts at injury and lasts 3-5 days
A
Inflammatory stage
24
Q
- Vasoconstriction/Coagulation
- Vasodilation
- Fibrin causes lymphatic obstruction
A
Vascular phase of the inflammation stage
25
1. Histamine/Prostaglandins cause leukocyte to migrate and plasma leaks into interstitial tissues
2. Results in edema
Vasodilation during Vascular Phase of Inflammation Stage of Wound Healing
26
1. Fibrin does not improve wound strength
| 2. Results in EDEMA
Fibrin causing lymphatic obstruction during Vascular Phase of Inflammation Stage of Wound Healing
27
1. Tissue trauma produces C3a and C5a
2. C3a/C5a are chemotactic for Neutrophils
3. Neutrophils release lysosomal enzymes (Degranulation)
4. Macrophages phagocytize foreign and necrotic material
5. B Cells produce antibodies
6. T cells Help/Kill/Suppress
Cellular Phase of Inflammatory Stage
28
C3a and C5a are chemotactic for
Neutrophils
29
When neutrophils stick to blood vessel walls
Margination
30
When neutrophils migrate through vessel walls
Diapedesis
31
These destroy bacteria, foreign material, and digest necrotic tissue
Proteases, which are the lysosomal enzymes released by neutrophils
32
1. Erythema/Redness
2. Edema/Swelling
3. Warmth
4. Pain
5. Loss of function
Signs of Inflammation
33
1. Proliferation/Migration
| 2. Contact inhibition
Steps of Epithelialization
34
1. Edge of epithelium advances over wound bed until contact with other epithelial cells
2. Cell w/o cell-to-cell contact release chemical mediators that regulate cell growth
Proliferation/Migration stage of Epithelialization
35
1. Chemical mediator release stops
| 2. Cell proliferation stops
Contact inhibition of epithelialization
36
1. Wound fills with clotted blood, inflammatory cells, and plasma
2. Epithelium migrates into wound
3. Mesenchymal cells transform into fibroblasts
Beginning of wound healing during inflammatory stage
37
1. Starts 3-4 days after injury
2. Epithelial Migration continues
3. Leukocytes remove necrotic material
4. Capillary in-growth
5. Fibroblasts migrate into wound
6. If wound is placed under early tension (no suture) the edges pull apart and increase scarring
Migratory Phase of the Fibroplastic Stage of Wound healing
38
1. Epithelial thickness increases
2. Collagen fibers are laid down in a haphazard pattern
3. Capillaries connect to increase vascularity
4. 2-3 week long; increases wound to 75% of uninjured tissue
Proliferative Phase of Fibroplastic Stage
39
Mucopolysaccharides
Ground substance present in the proliferative phase of fibroplastic stage
40
Tropocollagen
Forms crosslinks to make collagen....this process is found in the proliferative phase of the fibroplastic stage of wound healing
41
1. Epithelial Stratification
2. Collagen remodeling
3. Fibroblasts disappear
4. Vascular integrity
5. No new elastin in tissue = loss of flexibility
6. Wound contraction
Remodeling Stage
42
1. Foreign Material
2. Necrotic Tissue
3. Ischemia
4. Tension (meaning anything holding wound edges apart)
Factors that Impair Wound healing
43
1. Bacteria (Infection)
| 2. Debris (Shelters bacteria from host response
Foreign Material as a factor of impaired wound healing
44
1. Barrier to in-growth of reparative cells
2. Shelters bacteria from host defenses
3. Frequently includes blood (hematoma) which is a nutrient source for bactera
Necrotic tissue
45
1. Leads to further necrosis
2. Decreases delivery of antibodies, WBCs, antibiotics (increased risk of infection)
3. Decreases delivery of oxygen and nutrients
Ischemia
46
1. Tight/incorrect sutures
2. Improperly designed flaps (small base to height ratio)
3. Excessive external pressure to the wound
4. Excessive internal pressure (hematoma)
5. Systemic hypotension
6. Peripheral vascular disease
7. Anemia
Causes of Ischemia
47
1. Tight sutures --> strangulation --> Ischemia
2. Early suture removal
3. Sutures left in place too long
Sources of tension
48
1. Edges of wound placed together in pre-injury anatomic position
2. Minimal re-epithelialization, collagen deposition, contracture
3. Associated with????_________
Healing by primary intention
Laceration/Incision
Reduced & Stablilized bone fracture
Anatomic nerve anastomoses
49
1. Gap between tissue edges, bone fractures, nerve endings
2. Epithelial migration, collagen deposition, increased contracture
3. Associated with???__________
Healing by secondary intention
Extraction socket
Unreduced bone fractures
Ulcer
Avulsive injury
50
1. Corical bone
2. Periodontal Ligament
3. Rim of gingival epithelium
4. Blood clot
Contents of the extraction socket
51
1. WBCs remove bacteria and debris/bone fragments
2. Fibroplasia (Fibroblasts & Capillaries)
3. Epithelium migrates down walls until contact inhibition
4. Osteoclasts accumulate along crestal bone
First week after extraction
52
1. Osteoid deposition along alveolar bone lining
2. Cortical bone lining resorbed (in 4-6 months)
3. Trabecular bone fills socket
4. Epithelium displaced on top of socket as bone fills
2nd, 3rd, 4th Weeks of Healing after extraction
53
1. Osteoclasts
2. Osteoblasts
3. Primary Intention
4. Secondary Intention
5. Factors
Factors in Bone Healing
54
Come from a Monocyte precursor cell
Resorb necrotic bone and bone to be remodeled
Osteoclasts
55
Circulating multipotent mesenchymal cells
Lay down osteoid
Periosteum
Endosteum
Osteoblasts
56
1. Greenstick fracture
2. Anatomically reduced fracture
3. Ossification
Bone Healing via Primary Intention
57
This primary intention fracture is not completely seperated
Green stick
58
This primary intention fracture has been stabilized by surgery
Anatomically reduced fracture
59
This occurs across the fracture site with minimal fibrous tissue
Ossification
60
Free ends of bone more than 1 mm apart
Fibroplastic stage:
Excess collagen formation around free ends
Results in a callus
Secondary Intention
61
1. Osteoclasts remove old bone
2. Osteoblasts lay down new bone
3. Cortical bone laid down along blood vessels
Remodeling stage of bone healing
62
1. Vascularity
| 2. Immobility
Factors affecting bone healing
63
1. Supplies oxygen for proper healing
| 2. Compromised: low oxygen levels
Consequences of good and bad vascularity on bone healing
64
1. Cartilage formation
| 2. Fibrous tissue formation
Results of poor vascularity on bone healing
65
1. Bone forms perpendicular to lines of tension: functional matrix theory
2. Excess mobility form excess tension results in decreased vascularity
Consequences of movement v. immobility on bone healing
66
An INERT FOREIGN MATERIAL placed through an EPITHELIAL BARRIER develops a BIOLOGIC BOND to surrounding bone, which resists EPITHELIAL MIGRATION along the surface of the material
Implant Osseointegration
67
1. Bone heals to implant
2. Tissue reaction
3. Alveolar soft tissue heals to implant
4. Guided-Tissue Regeneration
Process of Implant Osseointegration
68
1. Short distance between bone/implant
2. Viable bone
3. No movement
4. Implant Surface
Factors that would help bone to heal to implants
69
how can distance from bone to implant be minimized?
Through excellent site preparation
70
How can you maximize the viable bone retained?
limit heat production when drilling hole
71
What is it important that you keep the implant surface free from
Bacteria
Oil
Glove powder
72
1. Surrounding damaged bone remodeled by osteoclast/osteoblast activity
2. Osteocytes secrete glycosaminoglycans to coat the titanium oxide implant surface
3. Osteoblasts deposit OSTEOID over the proteoglycan layer
Tissue reaction between bone and titanium oxide implant
73
1. Woven membrane placed around implant
| 2. Pore Size
Factors in Guided-Tissue Regeneration
74
How does a woven membrane help osseointegration
It inhibits fibrous tissue ingrowth
75
How does the right pore size help guided tissue regeneration?
1. Allows oxygen and nutrients in but keeps fibroblasts out
76
1. Epithelium secretes ground substance to coat implant
| 2. Hemidesmosomal-Basal Lamina system forms
How alveolar soft tissue heals to the implant
77
1. Neuropraxia
2. Axonotmesis
3. Neurotmesis
Seddon Classification of Nerve Injury
78
1. Contusion from trauma
2. Inflammation
3. Ischemia
4. Spontaneous recovery within a few days/weeks
Neurapraxia
79
What is neurapraxia?
Epineural sheath and axons maintain continuity after injury
80
1. Crushing injury
2. Excess traction
3. Axonal regeneration within 2-6 months possible
Axonotmesis
81
What is Axonotmesis
When the epineurial sheath is intact but the axons are disrupted
82
1. Fractures
2. Iatrogenic transection
3. Poor prognosis unless re-anastomosed/reapproximated
Neurotmesis
83
What is a neurotmesis
A nerve injury where the nerve has been completely severed
84
1. Degeneration phase
| 2. Regeneration phase
Phases of Nerve Healing
85
Altered sensation
Paresthesia
86
Dysesthesia
Painful sensation
87
Hyperesthesia
Excessive sensation
88
Hypoesthesia
Decreased sensation
89
When does segmental demyelination occur typically?
After a neuropraxia injury
90
Myelin sheath dissolved into segments
segmental demyelination
91
1. Segmental Demyelination
| 2. Wallerian Demyelination
Results of the degeneration phase of nerve healing
92
What type of demyelination results in the myelin sheath/axon distal from injury disintegrating?
Wallerian
93
1. Begins immediately after injury
2. New growth cone down Schwann cell tube
3. 1 mm-1.5 mm per day
4. New myelin sheath forms
5. Continues until area of innervation reached OR FIBROUS TISSUE OBSTRUCTS GROWTH
6. PARESTHESIA/DYSESTHESIA before normal feeling returns
7. If obstructed, a TRAUMATIC NEUROMA may form (painful)
Regeneration Phase of Nerve Healing
