Exam 1 Flashcards
What are the 4 characteristics of a good surgeon?
Honesty
Diligence
Wisdom/humility
Compassion
What does the suffix “-centesis” mean?
To pierce
What does the suffix “-desis” mean?
A binding
What does the suffix “-ectomy” mean?
To excise
What does the suffix “-ostomy” mean?
Stoma, mouth
What does the suffix “-otomy” mean?
To incise
What does the suffix “-pexy” mean?
Fixation
What does the suffix “-plasty” mean?
Formed or shaped
What does the suffix “-orrhaphy” mean?
Suture
What is the least traumatic method for incising tissue?
Scalpel
What are the two scalpel handle grips and what are they used for?
Fingertip grip - large incision
Pencil grip- small incisions
What are the advantages and disadvantages of using scissors?
Disadvantages- increased tissue trauma due to shearing force
Advantages- ease of cutting, improved visibility and control
What type of scissor tip improves control and visibility?
Curved
What is the purpose of tissue forceps and what grip should you hold them with?
Purpose - tissue manipulation with non-dominant hand
Use pencil grip!
What does needle holder size depend on?
Needle size, not surgeon size
Moving your hand closer to the tip of an instrument decreases _____ but increases ____.
Leverage; control
What are the 3 grips used to hold needle holders?
Thumb-third finger or “tripod” grip
Palm grip
Thenar-eminence grip
What are the two classifications of retractors?
Self-retaining
Hand-held
What is the purpose of using suction tips?
To remove blood or fluid from operative site
To avoid corrosion, what should you do to instruments before cleaning?
Hinged instruments- open them Rinse under distilled or tap water (NOT saline) Hand scrub remaining soil Use instrument milk Separate delicate instruments
What are Halsted’s Principles?
Gentle handling of tissue Meticulous hemostasis Preservation of blood supply Strict aseptic technique Minimum tension on tissues Accurate tissue apposition Obliteration of deadspace
What are the shock fluid doses for dogs and cats?
Dogs- 90ml/kg
Cats- 60ml/kg
What will a 25% decrease in blood volume result in? 40%?
25%- tachycardia, decreased BP
40%- severe shock, death
What is primary hemostasis?
Platelet plug
vWB factor
Fibrin plug
What is secondary hemostasis?
Coagulation cascade (extrinsic, intrinsic, and common pathways)
What does PTT and PT test?
PTT- extrinsic and common pathways
PT- intrinsic and common pathways
What might influence an animals ability to coagulate?
Drugs (aspirin, rodenticide toxicity) Acquired conditions (liver disease, DIC) hereditary conditions (vWB deficiency)
What should be done first in hemostasis?
Apply pressure
Use pressure pads for 1-5 minutes
What do hemostatic forceps do?
Crush vessel
Injured vessel activates native coagulation mechanism
What sized vessels would you use ligation for hemostasis?
Vessels >2mm
What is the most secure form of hemostasis?
Vascular ligation
What do vascular forceps do?
They are atruamatic and are used when vessel needs to be preserved
What topical agents are used in hemostasis?
Gelfoam
Surgicell
Bone wax
Epinephrine
What is electrosurgery?
High frequency AC current applied to tissue
Tissue resistance generates heat which causes cut, coagulation, dessication, etc.
What type of electrosurgery requires a grounding unit?
Monopolar
What are the disadvantages of monopolar electrosurgery?
Peripheral tissue injury
Improper grounding may result in thermal burns
Cannot us in wet field
Cannot use near heart, spinal cord, etc.
What are the advantages of bipolar electrosurgery?
More precise
Can use in wet field
No risk of distant injury
What is Ligasure?
Bipolar vessel-sealing device
Senses tissue impedance and automatically adjusts energy and output
Can seal vessels up to 7mm
What is the infection rate for clean procedures?
<5%
What are the two methods of sterilization?
Physical and chemical
What are the most common methods of physical sterilization? Chemical sterilization?
Physical- heat (dry and wet), radiation, filtration
Chemical - ethylene oxide, gluteraldehyde, H2O2 plasma
In steam sterilization, what is pressure used for?
To achieve high temperatures
What are the standard temp/pressure/time settings for steam sterilization?
250 F, 15 psi, for 15 minutes
262 F, 20 psi for 5 minutes
What has the longest shelf life for wrapping sterilized instruments?
Polypropylene peel pouches (12 months)
What should you not autoclave?
Plastics Suture material Electronics Powders Glassware Liquids
What is ethylene oxide?`
Colorless, odorless, toxic gas used in chemical sterilization
Must aerate objects for hours to days
Temperature range 84-150 F
Can manipulate concentration, humidity, and temperature
What is cold sterilization?
Sterilization by immersing items in gluteraldehyde
What is sterilization by radiation?
Sterilization using lethal ionization (gamma radiation most popular)
Used in commercially sterile products
What are the different types of indicators?
Physical
Chemical
Biological
Preparation of the surgical site prior to surgery includes what?
Wide clip
Antiseptic scrub
What is the difference between antiseptic and disinfectant?
Disinfectant is for inanimate objects
Antiseptic is for person/animal
What are the most common types of antiseptics?
Chlorhexidine
Iodophors (betadine)
Alcohols
What are some advantages and disadvantages of chlorhexidine solution?
Advantages: Non-irritating Good residual activity Not affected by organic matter Effective against a wide array of microbes
Disadvantages:
Allergies/irritation from chronic exposure
Ototoxicity
Corneal toxicity
What are some advantages and disadvantages of iodophores?
Advantages:
Cheap
Effective against a wide array of microbes
Disadvantages: Can cause dermal irritation Decreased activity in organic matter Unreliable residual activity Stains
What are some advantages and disadvantages of alcohols?
Advantages:
Very rapidly acting
Cheap
Disadvantages: Decreased activity in organic matter Poor residual activity Drying effects on skin Rapid heat dissipation
To minimize trauma to tissue, what needle point is typically used?
Tapered point or diamond point
When would you use a straight needle vs. curved needle?
Straight: external procedures
Curved: tighter, smaller areas
What is the difference between simple continuous and running suture patterns?
Simple continuous- only advances with new bite
Running- advancement with new bit AND across tissue
What is the difference between a cushing and connell suture pattern?
Connell penetrates into lumen, cushing does not.
Connell has “L” for lumen
What does the strength of a surgical knot depend on?
Material used
Length of cut ends
Configuration of knot
Pulling ____ rather than ___ will minimize suture friction
horizontally; vertically
The ideal suture material is what?
Bioinert
Easily sterilizable without consequences
Handles well and produces secure knots
Cheap
How is suture classified?
Absorbable vs non-absorbable
Multifilament vs monofilament
Natural vs synthetic
Coated or impregnated
Sutures are absorbed through what two methods?
Enzymatic degradation or hydrolysis
What is the difference between multifilament and monofilament?
Multi- flexible, handles well, has capillary action, superior knot security
Mono- stiff, has memory, non-capillary, poorer knot security, more easily damaged
What is the difference in absorption rates for natural vs synthetic sutures?
Absorption rate is more variable with natural sutures
You would expect moderate to marked tissue reaction with what kind of suture?
Natural
What is cat gut?
Absorbable, natural,”twisted”
Made from sheep intestinal mucosa and bovine intestinal serosa
Formaldehyde-treated collagen
50-100% loss of tensile strength within 2-3 weeks
What is monocryl?
Synthetic, absorbable, monofilament
Strong but rapidly loses strength - 50% loss of tensile strength in 1-2 weeks
Used for bladder, SQ tissues, vessel ligation
What is biosyn?
Synthetic, absorbable, monofilament
Complete absorption is rapid - 50% of tensile strength within 2-3 weeks
What is vicryl?
Synthetic, absorbable, multifilament
Used for intradermal, small vessel ligation, oral surgery
50% loss of tensile strength within ~2 weeks
What is dexon?
Like vicryl but with slightly greater knot security
What is PDS II?
Synthetic, absorbable, monofilament
Most popular suture in vet med
Slowly absorbed- 50% loss of tensile strength in 5-6 weeks
What is Maxon?
Like PDS with greater memory
What are the absorbable sutures?
Cat gut Monocryl Biosyn Vicryl Dexon PDS II Maxon
What are the non-absorbable sutures?
Silk
Nylon
Prolene
Stainless steel
What is silk?
From silkworm cocoon
Natural, non-absorbable, multifilament
Vessel ligation (PDA, portosystemic shunt)
What are braided synthetic non-absorbable sutures?
Very strong
Cheap
Some not even sterile
Tissue trauma
What is nylon?
Synthetic, non-absorbable, monofilament
Memory/stiffness/knot security is not the best
Skin is most common use
What is prolene?
Synthetic, non-absorbable, monofilament
Strong with good handling
Least likely of non0absorbable sutures to potentiate infection or induce thrombi
Skin, tendon, ligament, herniorrhaphy
What is stainless steel suture?
Cheap, autoclave, strong
Poor handling
Cycle to failure
What are the functions of skin?
Maintain hydration and thermoregulation Defense against pathogens and chemicals Vitamin D synthesis Sensory Storage Insulation
What are the 3 layers of skin?
Epidermis
Dermis
Hypodermis
Why is the benefit of the parallel vascular supply in the hypodermis of animals?
Better for wound healing
What is the timeline of wound healing?
- Coagulation (<5 minutes)
- Inflammation (0-24 hours)
- Debridement (2-5 days)
- Proliferation (4-21 days)
- Maturation (21 days - 2 years)
What are some markers of inflammation?
Vasodilation (redness, heat) Leukocytes and serum (swelling) Platelets Neutrophils Macrophages
What are some markers of debridement?
Removal of necrotic tissue and debris by macrophages (“lag phase”)
What are some markers of proliferation?
Fibroblast influx Macrophages Agiogenesis (VEGF)- Granulation tissue formation Epithelialization Contraction (myofibroblast)
What are some markers of maturation?
Collagen remodeling
What dose the wound healing curve look like?
Lag phase- debridement (macrophages)
Log phase- fibroblasts
Tissue tensile strength inverse to suture tensile strength
What are examples of intrinsic wound factors?
Hypoporteinemia Anemia Malnutrition Uremia DM
What are examples of extrinsic wound factors?
Mechanism
Foreign material
Irradiation
Antiseptics
What are the different types of wound classifications?
- Based on time and contamination
2. Based on surgical factors
What is the clinical significance of wound classifications?
Let’s you know how to close the wound and when
Wound classification based on time and contamination
Class 1: 0-6 hours, minimal contamination, primary closure
Class 2: 6-12 hours, moderate contamination, probably shouldn’t do a primary closure
Class 3: >12 hours, gross contamination, never close!
Wound classification based on surgical factors
Clean (SSI 5%)
Clean-contaminated (SSI 10%)
Contaminated (SSI 30%)
Dirty (Already infected)
In what type of wound classification warrants antibiotic use?
Anything besides class 1, clean wounds
What do you use to lavage a wound?
0.9% saline
Pressure cuff 300 mmHg
16-22 ga needle
Liberal volume
What should you use to wet a wet-to-dry bandage?
Hypertonic saline
What are the two types of drains?
Active - vacuum
Passive - gravity
How long should a drain stay in?
3-5 days
Longer than this indicates something is wrong, wound is infected, etc.
What are the types of wound closure?
Primary (<6 hours) Delayed primary (after 6 hours but before granulation) Late secondary (after granulation) Second intention (no surgical closure, dependent on wound healing)
What are the layers incised to perform a celiotomy?
Skin SQ tissue Linea Alba Retroperitoneal fat Peritoneum
What are the holding layers in celiotomy closure?
Linea Alba
External Rectus Abdominus Fascia
Why should you avoid large bites of muscle when closing celiotomy?
Muscle necrosis loosens closure
What type of suture would you want to use to close fascia?
Absorbable, monofilament, long retention of tensile strength PDS, Maxon, Vicryl Non-absorbable used when slow healing is anticipated Stainless Steel, Nylon Size: <5kgs - 3-0 5-15kgs - 2-0 20-40kgs - 1 Horse - 3
What are some general guidelines to follow during skin closure?
Keep tissues hydrated
Avoid undermining
Avoid excess manipulation
Closing the subcutaneous layer functions to what?
Minimize deadspace
What type of suture would you want to close SQ layer?
Monofilament, absorbable, small diameter (1-2 sizes smaller than linea)
PDS, Vicryl, Maxon, Monocryl
Does not require prolonged retention of tensile strength
What type of suture would you use for cutaneous layer?
Monofilament, non-absorbable or absorbable
Reverse cutting needle
Nylon, prolene, fluorofil
Cut ends 8-10mm for ease of removal
What are some indications for intradermal patterns in skin closure?
Clean wound
Healthy patient
Minimal to no tension
Mass removal or elective spay/neuter
What type of suture would you use for intradermal sutures?
Absorbable, monofilament
Vicryl, PDS, Monocryl
Small diameter
Reverse cutting needle
What are some pros and cons of using staples?
Pros - decreased operative time
Cons- increased cost, not suited for wounds under tension or thin skin
What is included in pre-operative care?
Signalment/presenting complaint/history
Physical exam
Diagnostics (BW, imaging, etc)
Treatment/stabilization (IV access, fluids, oxygen)
What are the classifications of surgical risk?
Minimal
Moderate
High
Extreme
What are the ASA classifications?
I - normal, healthy patient
II- non-clinical systemic disease
III - systemic disease with clinical signs
IV - severe, potentially life-threatening disease
V - moribund, not expected to survive 24 hours
What are the indications for a blood transfusion?
PCV < 20-25%
>30% blood loss
What are some examples of blood products?
Fresh whole blood Packed red cells Fresh frozen plasma Frozen plasma Cryoprecipitate
When should peri-operative prophylactic antibiotics be given?
<60 minutes but >30 minutes from start of Sx
What are some advantages of laparotomy?
Full thickness intestinal biopsies
Organ biopsy/excision
Ability to address/obtain hemostasis
Option for therapeutic intervention
?What are some disadvantages of laparotomy?
Increased morbidity (pain, anesthetic risk, cost, dehiscence, infection)
What are some therapeutic indications for laparotomy?
Free gas Dilated SI Foreign body Herniation GDV Abdominocentesis (blood, urine, bacteria, bile)
What is in the cranial quadrant of the abdomen?
Diaphragm
Liver, gallbladder
Stomach
Pancreas
What is in the mid-abdomen
Spleen
Intestine
Mesenteric lymph nodes
What is in the caudal quadrant of the abdomen?
Colon
Bladder
Prostate/Uterus
What is in the abdominal gutters?
Kidneys
Ureters
Adrenal
Ovaries
In LA GI surgery, where should the initial incision be made?
Midline alone linea alba
10-12 inches long
In LA GI surgery, what are examples of non-ischemic and ischemic diseases?
Non-ischemic: obstruction, non-strangulating displacements
Ischemic: strangulating lesions, infarction
In LA GI surgery, what can be exteriorized from abdomen?
Jejunum
Apex and body of cecum
Middle of small colon
Most of large colon
In LA GI surgery, what cannot be exteriorized from abdomen?
Stomach Duodenum Part of ileum Base of cecum Small colon R Dorsal colon Transverse colon
What are clinical signs associated with enteroliths in horses?
Low-grade, recurrent colic
In right dorsal displacement of the colon, the pelvic flexure moves _____.
Cranial
What is the treatment for nephrosplenic entrapment/left dorsal displaced colon?
IV phenylephrine and mild exercise
Rolling
Surgery
“Cure by trailer ride”
What is GR trocar?
Instrument used to prevent recurrence of nephroplenic entrapment- barbed suture to prevent from moving backwards
Strangulating lipomas are most common in what part of equine intestine?
Small intestine
Cribbers are more prone to what disease?
Epiploic foramen entrapment
What is the difference between inguinal hernias in adult horses vs foals?
Adult: acquired, very painful, needs emergency surgery
Foals: congenital, no strangulation, not painful, usually will go away with time
How do you assess viability of tissue with fluorescein?
Strangulated/ischemic tissue does not take up dye and will not fluoresce
How much of the equine SI be removed safely?
<40 feet
How can you avoid over-inversion of intestine during surgical anastamoses in equine GI surgery?
Cut intestine at 60 degrees
Use lembert suture
Suture close to edge of tissue
What are some predispositions that quarter horses have? Broodmares? Foals?
Quarter horses - HYPP
Broodmares - osteopenia
Foals - ascarid impaction
What is the risk of death for healthy horses undergoing anesthesia?
1/1000
Risk of anesthesia in horses depends on what?
Primary disease
Overall health
When do you fast LA before surgery?
Horses - only with specific procedures where decreased GI fill is needed, NEVER in neonates
Ruminants - fast for 48 hours, NPO 24 hours, no fasting in neonates
What should you consider in a location for field procedures (LA)?
Shade Soft ground Sufficient space for recovery Relatively clean Away from other animals
What are some potential consequences of improper positioning of LA during surgery?
Myopathy (from ischemia)
Neuropathy (from excessive pressure on nerves)
What are some guidelines for positioning LA during anesthesia?
Thick padding
Entire body on pad
Remove halter or other tack
Lateral: Dependent forelimb pulled forward
Dorsal: keep hindlimbs flexed, shoulder trough well padded
When is the most dangerous time for equine patients during anesthesia?
Recovery
What are some potential post-anesthetic complications that horses experience?
Impaction colic
Increased risk of GI disease/colitis (from NSAID, antimicrobial therapies)
If has cast or splint- pressure sores
What are some common complications of LA surgery?
Anesthesia complications (myopathy, neuopathy) Hemorrhage Airway obstruction Infection Dehiscence Post-op colic Laminitis
What muscles are at risk for myopathies in LA surgery?
Masseter
Triceps
Gluteal
What nerves are at risk for neuropathies in LA surgery?
Facial n
Radial n
What is the risk of fractures or ST injury in post-anesthetic period for LA?
2/1000
Chances of infection following LA surgery increase with ____.
length and type of surgery
