Surgery: Exam 2 Flashcards
How does primary intention heal?
By the process of epithelialization
What layers of skin are involved in primary intention?
Epidermis and dermis, w/o total penetration of dermis
How do most sx wounds heal?
By primary intention
What are used to close wounds which are closing via primary intention?
Sutures, staples, or adhesive tape
What are some examples when you would want a wound to heal by primary intention?
Well-repaired lacerations; healing after flap sx; sx incisions
What type of wound healing would you want to pack gauze or use a drainage system?
Secondary intention
In what type of wound healing is the wound allowed to granulate?
Secondary intention
What type of wound heals slower, primary or secondary intention? Why?
Secondary intention bc there is drainage from infection
Does secondary intention allow for minimal or broader scarring? Why?
Broader bc it is allowed to granulate
What type of wound healing requires daily wound care?
Secondary intention=encourages wound debris removal to allow for granulation tissue formation
What are some examples when you would want a wound to heal by secondary intention?
Skin tears; foot ulcerations
What are some other names for tertiary intention?
- Delayed primary closure (DPC on OR orders)
- Secondary suture
What is unique about tertiary intention wound healing?
The wound is purposely left open
When would a surgeon want a wound to heal by tertiary intention?
When a wound is contaminated=it’s able to be cleaned, debrided, and observed (typically 4-5d prior to closure)
What are some examples when you would want a wound to heal by tertiary intention?
- Healing of wounds by tissue grafts
- Wounds that result from incision and drainage of an abscess or other infection
Use tissue GRAFTS instead of tissue substitutes
Use tissue GRAFTS instead of tissue substitutes
What WBCs migrate to the wound in the first 24h in a wound healing via primary intention?
Neutrophils
What processes/cells are occuring during days 3-7 in a wound healing via primary intention?
- Mitosis
- Granulation tissue formation
- Macrophage and fibroblast migration
- Angiogenesis
What factors/hormones are increased in tissue response to injury? Decreased?
Increased -ACTH -Cortisol -Aldosterone -Renin -Epi and NE -GH -Glucagon Decreased -TSH
What occurs in the Early Phase of the metabolic response to injury?
- Decr body cell mass
- Vasoconstriction=so you don’t bleed out
- Change in energy source
What occurs in the Second Phase of the metabolic response to injury?
- Water and salt diuresis
- Incr appetite
- Regain strength
What occurs in the Third Phase of the metabolic response to injury?
- Normal appetite
- Incr in physical activity, strength, and weight
What occurs in the Fourth Phase of the metabolic response to injury?
-FAT GAIN PHASE
What is the “newer view” of how skin/tissue heals (compared to the “traditional” inflammatory, repair, and remodeling stages)?
- Vascular and inflammatory stage
- Re-epithelialization
- Granulation tissue formation
- Fibroplasia and matrix formation
- Wound contraction
- Neovascularization
- Matrix and collagen remodeling
What is the role of fibronectin?
- Crosslinks w/ fibrin to provide matrix for cell adhesion and migration
- Early component of ECM
- Binds collagen and interacts w/ GAGs
- Chemotactant for MACs, fibroblasts, endothelial, and epidermal cells
- Promotes phagocytosis
- Forms a component of the fibronexus
- Forms scaffolding for collagen deposition
What is wound contraction?
Centripetal movement of the edges of a full thickness wound in order to facilitate closure of the defect
Wound is wound healing at its max?
~15d after wound creation–>important when removing sutures=removed at day 14 bc that’s when healing is at its max
What makes the fibronexus?
Intimate association btwn the membranes of the myofibroblasts, intracellular actin microfilaments, and extracellular fibronectin fibers
What is the most common cause(s) for prolonged wound healing?
- Prolonged inflam phase
- Incr toxins and damaging proteases in wound compete for O2 and nutrients
What is the #1 rule about wounds?
Make sure it’s CLEAN!
What are some local factors that affect wound healing?
-Vascularity
-Infection
-Pressure-
Hematoma formation
-Sx technique
-Foreign body rxn
-Topical meds
-Dresings
What’s imp regarding sx technique and wound healing?
You want to sew, NOT strengulate (suture technique)
Why is hematoma formation bad in wound healing?
- Means there’s excess bleeding=media for bacteria to grow
- Can incr tension on the incision
- *Manage your deadspace!**
T or F, you can use ANY suture technique on ANY patient?
FALSE! Suture choice matters and differs from pt to pt bc each pt will respond differently to foreign bodies (like sutures)
What causes tissue ischemia in wound healing?
- Foreign bodies
- Infection
- Strangulation of tissue (from sutures)
Why is local ischemia BAD news?
- Decreases cell proliferation
- Decr resistance to infection
- Decr collagen production
- *RESPECT BLOOD FLOW**
What are the ideal types of dressings used for wound healing?
Dressings that are semi-occlusive to occlusive=optimize humidity and cell migration
It’s really MORE than just a dressing
Deficiency in Vit A does what to wound healing?
Slows re-epithelialization, decr collagen synthesis, and ultimately incr infection
What “trace elements” are important for particular enzymes needed for wound healing?
- Zinc=DNA, RNA polymerases…deficiency=impaired immune response, decr protein and collagen synthesis, and interference w/ Vit A transport
- Copper
- Iron
- Manganese
What two classes of drugs are esp important factors that affect wound healing?
- Glucocorticoids=directly inhibit wound healing
- Anticoags=Incr chance of hematoma formation
Catgut is an example of what type of suture?
Natural, absorbable suture
Polyglactin (vicryl) is what type of suture?
Synthetic, absorbable suture
Polyglycolic acid (dexon) is what type of suture?
Synthetic, absorbable suture
Polyglyconate is what type of suture?
Synthetic absorbable suture
Silk linen is what type of suture?
Natural, NON-absorbable suture
Polyamide (nylon) is what type of suture?
Synthetic, NON-absorbable suture
Polyester (dacron) is what type of suture?
Synthetic, NON-abosrbable suture
Polypropylene (prolene) is what type of suture?
Synthetic, NON-abosrbable suture
What synthetic, non-absorbable suture accommodates swelling?
Polyamide or nylon
What synthetic, non-absorbable suture has an antimicrobial component?
Polypropylene or prolene
When would you use vicryl sutures?
When closing up SQ and deep tissues
After 2 weeks, how strong is the surgical wound compared to normal skin?
3-5% of the original strength
After 3 weeks, how strong is the surgical wound compared to normal skin?
20% of ultimate strength achieved
After 4 weeks, how strong is the surgical wound compared to normal skin?
50% of ultimate strength attained
What are some general uses of absorbable sutures?
- Used in SQ tissues
- Eliminates dead space
- Minimizes tension on wound edges
- May “spit” if placed too superficially
If using Surgical Gut sutures, what is the strength of the wound after 1 week? 2 weeks?
- 60% lost
- 100% lost
How are Surgical Gut sutures absorbed?
Proteolytic enzymatic degradation
How are Polyglycolic acid (Dexon) sutures absorbed?
Hydrolysis
If using Polyglycolic acid (Dexon) sutures, what is the strength of the wound after 2 week?
65% of tensile strength remains
What factors are important in deciding on a type of suture?
- Location of wound
- Static and dynamic tension on the wound
- Presence of infection
- Potential for edema
- Cost of suture material
What is the smallest suture?
7-0. Podiatric surgeons typically use 4.0-2.0 sutures
How long are plantar sutures left in?
At least 3 weeks
What is important when performing simple interrupted sutures?
Making sure you EVERT the skin edges
When would you use the horizontal mattress suture technique?
In longer wounds or calcaneal/ankle fractures
When would you use the vertical mattress suture technique?
When a pt has a deep wound; many variations and forms a straight line (far-far, near-near throw)
What is the goal of retention sutures?
Take tension off skin edges and provide deeper and wider support to the healing incision
What type of suture technique:
- is technically demanding
- leaves relatively no scar if done correctly
- has a high rate of dehiscence if done correctly
- is good foe elective surgeries
Subcuticular suturing
What are the pro’s to using staples?
- Fast and easy
- Allow for swelling
- Easy to evert skin edges
What are the con’s to using staples?
- Leave track marks
- Painful to remove
What is a keloid scar?
Overabundance of scar tissue formation due to collagen deposition that extends BEYOND original incision site
What is a hypertrophic scar?
Overabundance of scar tissue formation due to collagen deposition that DOES NOT extend beyond original incision site
What are the treatments for keloid/hypertrophic scars?
- Cortisone injections
- Scar revision
In regards to cortisone injections, what is the preferred drug?
Kenalog 40mg=injected directly into scar and away from healthy tissue–>decreases the level of collagenase inhibitors and increases collagen deposition
What is important in scar revision?
The length of the scar MUST BE 3X the width so you can bring the skin back together
In what stage of skin graft healing will you see a fibrin layer between the graft and host?
Plasmatic stage
In what stage of skin graft healing will you see revascularization of the graft?
Inosculation stage
In what stage of skin graft healing will you see a pinkish hue?
Inosculation stage
In what stage of skin graft healing will you see CT reorganize and regulate vascular and lymphatic flow?
Re-organization stage
What stage occur simultaneously w/ the re-organization stage of skin graft healing?
Re-innervation stage (may req 1-2 years to complete)
What are some post-op complications of skin grafting?
- Seroma formation (transudative fluid)
- Hematoma formation (blood pooling)
- Graft does not incorporate
- Graft necrosis
What is the most common cause for graft failure? Second most common?
- Seroma or hematoma formation
- Infection
What are the 6 foot and ankle angiosomes?
- Medial calcaneal artery
- Lateral plantar artery
- Medial plantar artery
- Lateral calcaneal artery
- Anterior tibial artery
- Dorsalis pedis
What type of skin flap gets its blood supply from the cutaneous dermal-subdermal plexus?
Cutaneous flaps
What type of skin flap gets its blood supply from a cutaneous artery?
Arterial flaps
A Limberg flap is used when the defect is of what shape?
Rhomboidal shape
What is the primary indication of a Z-plasty skin flap?
When you want to lengthen an existing structure (i.e., skin on a rigidly contracted hammer toe)
In a Z-plasty skin flap, the greater the angle the…
Greater the length gained (and vice versa)
What is a V-Y plasty used?
When you want to lengthen
In a V-Y skin plasty, the apex is proximal or distal?
Proximal
What is the primary source of blood supply to the skin?
Fasciocutaneous arteries
What arteries provide a blood supply to the skin?
Cutaneous, musculocutaneous, and fasciocutaneous arteries
What determines the success of a local cutaneous flap?
The presence of an artery at the base of the flap
Intrinsic muscle flaps of the foot are what type?
Type II- dominant vascular pedicle and minor vascular pedicle
A dorsalis pedis flap is an example of what type of flap?
Fasciocutaneous Flap
What is the degree of difficulty of skin flaps/restoration, from simple to complex?
Direct closure–>Grafts–>Local flaps–>Distant flaps–>Tissue transfer
What causes a neuropraxia?
Severe contusion to a nerve
With a neuropraxia, what happens to conductivity?
Transmission along the nerve is altered by DECREASED conductivity
What causes axontmesis?
Crushing injury to a nerve–>Wallerian degeneration
What is the worse nerve injury and what characterizes it?
Neurotmesis–>complete severence of a nerve which leads to irreversible damage (i.e., the nerve will NOT recover, but the pt might)
Relative to the site of injury to a nerve, where do you see swelling occur?
DISTAL to the injury
What are the functions of a Schwann cell?
- Promote nerve repair
- Proliferation
- Secretion of trophic factors and cytokines
- Phagocytose myelin debris
- Support of regeneration only lasts for 1-2 months
In a nerve injury, what cells are first to the site?
Neutrophils=phagocytose debris, modulate recruitment, activate other lymphocytes, and apoptose
In a nerve injury, what cells appear after ~1 week?
Macrophages=remove myelin debris; stay in axon for days to moths and return to circulation or die by apoptosis
In a nerve injury, what cells peak around 14-28 days?
T lymphocytes=help by supporting cellular and humoral immunity
Tapping along a nerve and producing “distal coursing pain” is what?
Tinnel’s sign
Tapping along a nerve and producing “proximal coursing pain” is what?
Valleaux’s sign
What is the specific plasma marker for skeletal muscle damage?
Skeletal troponin I
How to blood vessels respond to injury?
Stimulation of smooth muscle cell growth and associated matrix synthesis that thickens the TUNICA INTIMA forming a neointima
What are the stages of blood vessel healing?
- Inflammation
- Fibroblastic
- Remodeling
- *Essentially the same as all other tissues
What occurs when blood vessels are in a state of hypoxia?
Local ischemia–>increase in VEGF which binds to cognate receptor tyrosine kinases–>new blood vessels are created (angiogenesis)
What are the signs (“6 P’s”) of vascular injury?
- Paleness
- Palor
- Pokliothermia
- Polar
- Pulseless
- Pain
What is Buerger’s test?
It’s a special maneuver to test vascularity in the LE. It’s the angle at which the leg is raised before it becomes pale…if a pt has infection, redness will NOT go away; if they have vascular problems, redness WILL go away
What’s the name of “special maneuver(s)” to test the vascularity of the LE?
- Buerger’s test
- The Brodie-Trendelenberg test
How is the Brodie-Trendelenberg test carried out?
- Elevate leg to 90 degrees
- TQ around high thigh to occlude great saphenous v
- Have pt stand
- Evaluate the filling of the veins
A difference in ___ mmHg indicates pathology of the immediate PROXIMAL segment
> 30 mmHg
What is the Gold Standard for diagnosing a DVT?
Venogram=direct visualization of the veins
What are the major differences btwn an arterial and venous hemorrhage?
Arterial -Pulsatile flow -Bright red blood Venous -Oozing -Red to dark red blood
What type of transfusion product is good for massive hemorrhages?
Whole blood
What does whole blood NOT have in it?
No platelets, nor Factors V, VIII, or XI
What is significant about Packed RBCs (PRBC)?
It gives you oxygen-carrying capacity w/o the added issue of more volume
What is the disadvantage to using Packed RBCs?
Anticoagulation (no platelets)
What is the minimum acceptable platelet level for elective surgery?
50,000 cells/microliter (ideally you want >100,000)
What is the typical dose for platelets during a transfusion?
6-10 units=300-400mls
1 unit of PRBCs=how many mls?
300 (+/- 50mls)
1 unit of whole blood=how many mls?
450 (+/- 50mls)
What are the advantages to using plasma + soluble detergent?
- Inactivates lipid coated viruses
- Relatively inert
- Consistent coagulation factors
When is plasma + soluble detergent indicated?
- Coumadin reversal
- Coagulation factor deficiency
- Multiple coagulation defects
When is cryoprecipitate indicated?
- Factor VIII/XIII deficiency
- Von Willebrand disease
What are the most common complications to all blood transfusions?
- Infection (viral»bacterial)=Hep C&B, HIV, CMV/EBV
2. Transfusion reaction
What are the most common complications a/w RBC transfusions
- Hypocalcemia/citrate toxicity
- Hyperkalemia/acidosis
- Hypokalemia/alkalosis
- Hypothermia
- Hemosiderosis
- Pulmonary dysfunction
- Hemorrhage
What is a way to avoid bacterial infections related to blood transfusions?
NOT leaving the transfusion pack outside of the refrigerator for >30mins
What blood type is the “universal donor”?
Type O (40%)
What blood type is the “universal recipient”?
Type AB
What is the most common acute hemolytic transfusion reaction? How is it characterized?
- Category 1
- Characterized by pruritis
How is a Category 2 hemolytic transfusion reaction characterized?
Agitation, palpitation, HA, increased HR, DOE
What are the examples of delayed hemolytic transfusion reactions?
- Graft vs. Host disease (IC pts)
- Alloimmunization (pregnancy, multiparity, h/o prior transfusions)
- Anaphylactoid reactions (IgA deficiency)
What meds/fluid will be given to a pt experiencing delayed hemolytic transfusion reaction?
- IVF w/ NS/LR
- Epi (0.05-0.1ml to prevent bronchospasm)
- Antihistamine
- Corticosteroids
- HCO3 prn
How would you minimize the risk of non-hemolytic transfusion reactions?
- Slow the rate of transfusion
- Use minimal volume expanding products
- Diurese between each unit (i.e., Furosemide)
