Midterm One Flashcards
What is the strict definition of infection in surgical sites/tissue in terms of the amount of bacteria?
(10 to the 5th bacterial organisms per gram of tissue)
What are the four NRC classifications for surgery?
(Clean, clean-contaminated, contaminated, and dirty)
A spay, gastrotomy, or enterotomy would all be defined as what NRC classification of surgery?
(Clean-contaminated)
Describe how a clean-contaminated surgery can transition to a contaminated surgery.
(Contents of the organ you enter in a clean-contaminated surgery spill into a space in the body i.e. intestinal contents during an enterotomy spill into the abdominal cavity)
Performing a surgery on a dog with pyoderma would be considered what NRC classification? (Not that you should do this)
(Dirty)
What two endocrinopathies are shown to increase risk factors for surgical site infections in dogs?
(Hyperadrenocorticism/cushings and hypothyroidism)
(T/F) An animal with diabetes mellitus has an increased risk for surgical site infections.
(F, no studies support this conclusion though diabetes mellitus predisposes to other types of infection)
What are the two most important things you as a practitioner can do to prevent surgical site infections?
(Practice aseptic technique and maintain healthy tissue)
What three areas, often caused by infection, can antibiotics not kill any bacteria in?
(Devitalized tissue, fluid pockets, and biofilms)
What are the six Halsted principles?
(Gentle tissue handling, meticulous control of hemorrhage, appose tissues accurately with minimal tension, preserve blood supply to tissues, eliminate dead space, and strict aseptic technique)
How can you determine the difference between a seroma and an abscess in the most simple way?
(Abscess would be hot and painful upon palpation, seroma would not be)
What is the difference between prophylactic and therapeutic uses of antibiotics in terms of surgical use?
(Prophylactic abx are given during surgery only (they prevent infection), therapeutic abx are given during to after surgery (they treat infection)
For which NRC classification of surgery would you use prophylactic antibiotics?
(All except clean)
For which NRC classification of surgery would you use therapeutic antibiotics?
(Dirty for sure, contaminated debated)
For time-dependent antibiotics and use in surgery, when should you redose?
(Every 2 half-lives for as long as your incision is open)
(T/F) Either diluted iodine or chlorhexidine can be used to surgical prepare for an eye surgery.
(F, only dilute iodine, chlorhexidine is toxic to the eyeball)
How would you go about differentiating between a true and spastic entropion?
(Apply a topical anesthetic to the eye to determine if the response it so pain of the eye, if it is spastic the eyelid should return to a normal position and it will not if it is a true entropion)
What three scenarios is temporary tacking to correct an entropion typically used for?
(Young animals, patients with high anesthetic risk, and spastic entropion)
What are the two closure layers for a lateral canthotomy?
(Tarsoconjunctival layer and the skin layer)
Why can strabismus result after a proptosis case?
(Extraocular muscle damage)
How long should tarsorrhaphy sutures be left in place in proptosis cases?
(4 weeks)
What are the four structures that need to be removed in an enucleation?
(Globe, third eyelid and associated gland, conjunctiva, and eyelid margin with meibomian glands)
Why should you avoid pulling on the globe when performing an enucleation, especially in cats?
(You can damage the optic chiasm and blind the other eye)
When should the third eyelid be removed in an enucleation, before or after the eye is removed?
(Doesn’t matter)
How much of the eyelid margin needs to be removed to ensure that you remove the Miebomian glands?
(5-8mm)
What are the three portions of closure in an enucleation?
(Orbital cone, subcutaneous tissue, and skin)
If an eyelid mass involves less than what fraction of the eyelid margin, you can pursue a wedge or house resection.
(Less than ⅓ of the eyelid margin, this involves the mass and the 1mm of eyelid needed on each side for the resection)
The length of the proliferative phase depends on what characteristic of a wound?
(The size)
The inflammatory/debridement phase of wound healing is typically a couple of days/3-6 days, what two issues can lengthen that time period?
(Infection or necrosis)
(T/F) Skin never regains 100% strength after a wound has healed.
(T)
Collagen decreases/increases (choose) in the inflammatory/debridement phase of wound healing.
(Decreases → break stuff down phase)
What is the predominant cell type in the early inflammation stage of wound healing?
(Neutrophils → kill bacteria, debride necrotic tissue)
What is the predominant cell type in the late inflammation stage of wound healing?
(Macrophages → phagocytosis)
What are the five classical signs of inflammation?
(Heat, redness, swelling, pain, loss of function)
Which phase of wound healing is associated with the most exudative discharge?
(Inflammatory phase)
What is the predominant cell type in the proliferative stage of wound healing?
(Fibroblasts)
What are the three components to granulation tissue on a microscopic level?
(Capillaries, collagen, and fibroblasts)
Does granulation tissue have low/high (choose) tissue oxygen tension?
(High)
Granulation tissue is highly resistant/pervious (choose) to infection.
(Resistant)
How do epithelial cells know when to stop migrating during epithelialization?
(Contact inhibition → when they touch each other, they stop migrating)
What cell type is responsible for contraction of a wound?
(Myofibroblasts → contain actin to help pull things together)
What are the two main reasons that high oxygen tension is important for wound healing?
(Neutrophils needs oxygen to kill bacteria and collagen production requires oxygen)
What are the basic solutions (so nothing added in) that can be chosen for lavaging a wound?
(Tap water, 0.9% saline, any IV fluid)
What are the two antimicrobial additives commonly used for lavaging wounds? Be specific.
(Chlorhexidine and povidone-iodine SOLUTION (not scrub, no bubbles they make fibroblasts angry!), these have not been shown to have a better rate of success in wound care clinically but you do you, can’t tell you how many times I’ve diluted iodine to ‘weak tea’)
What is the ideal pressure to lavage a wound with?
(8 psi → large syringe or fluid bag with pressure system with an 18g needle, holes poked in the top of a saline bottle, lots of options)
What are the two goals of your primary bandage layer during the inflammatory phase of a wound?
(Debridement and reduce bacterial contamination)
What are the two goals of your primary bandage layer during the proliferative phase of a wound?
(To not disrupt new fragile tissue and to hold cells/cytokines in → so you want a non-adherent (does not stick) and occlusive (holds moisture in) bandage)
Why is using a wet-to-dry bandage discouraged?
(Though it is great for debridement, it removes healthy tissue as well (non-selective) and is painful for the patient)
How often does a bandage need to be changed during the inflammatory phase of a wound?
(Once a day)
How often does a bandage need to be changed during the proliferative phase of a wound?
(Every other day and above, go by the look of the wound, longest between is 5-7 days maximum)
If you close a wound a day or two after it was initially made but prior to granulation tissue formation, what type of closure is that?
(Delayed primary)
If you close a wound on day one, what type of closure is that?
(Primary)
If you allow a wound to heal by contraction and epithelialization, what type of closure is that?
(Second intention healing)
If you are closing skin over granulation tissue, what type of closure is that?
(Secondary)
Antibiotics are generally indicated during which phase of wound healing?
(Inflammatory/debridement)
Systemic antibiotics should be reserved for what instance related to wound healing?
(When there is INFECTED (not contaminated) tissue/when the wound is dirty under NRC classification)
What is the definition of absorbable suture?
(Suture that will lose tensile strength within 60-90 days/2-3 months in living mammalian tissue, it may be present > 60/90 days but with negligible tensile strength)
If you are performing a surgery and you want an absorbable suture that is a monofilament, what would you tell your tech to grab? Two answers.
(Monocryl or PDS)
If you are performing a surgery and you want an absorbable suture that is a multifilament, what would you tell your tech to grab? Two answers.
(Catgut or vicryl)
If you are performing a surgery and you want a non-absorbable suture that is a multifilament, what would you tell your tech to grab?
(Silk)
If you are performing a surgery and you want a non-absorbable suture that is a monofilament, what would you tell your tech to grab? Two answers.
(Nylon or prolene)
When choosing a synthetic suture material over a natural material, what are the pros and cons of that decision?
(Pros → more predictable in loss of tensile strength, cons → decreased handling due to increased memory)
When choosing a monofilament suture over a multifilament suture, what are the pros and cons of that decision?
(Pros → less tissue drag, less capillarity, decreased risk of nidus, cons → less pliable, increased memory, susceptible to damage)
Is monofilament or multifilament suture stronger?
(Multifilament)
If you are working with tendons, ligaments, joint capsules, and fascia, what type of suture should you use?
(Prolene, it’s the least thrombogenic and is resistant to degradation)
What are the two most commonly used treatment options for aural hematomas?
(Drainage and intralesional steroid injections OR surgical drainage with suture placement)
If you choose to use intralesional steroids when correcting an aural hematoma, what do you need to monitor for?
(Abscess formation)
What is the most common feline cutaneous neoplasm?
(Basal cell tumor, second most common is mast cell tumor)
What diagnostic imaging is best for visualizing the entire ear but especially the middle ear?
(Computed tomography)
What are the goals of a lateral ear canal resection/Zepp’s procedure?
(Improve ventilation, reduce secretions, and allow for easier medical management)
What situation is a vertical ear canal resection appropriate for?
(When the vertical ear canal is affected but the horizontal canal is clear)
What nerve do you need to be careful of when performing a total ear canal ablation?
(The facial nerve)
What additional procedure is necessary to perform along with a TECA to prevent build up of secretions that can lead to fistulas, abscesses, and vestibular signs?
(A lateral bulla osteotomy → remove the secretory epithelium of the bulla)
What is the difference between dogs and cats when it comes to lateral bulla osteotomies?
(Cats have two chambers in their bulla so you need to ensure you clear both chambers of secretory epithelium, dogs only have one chamber)
What are the two locations where feline inflammatory polyps are found?
(The bulla of the ear and the nasopharynx)
How are nasopharyngeal feline inflammatory polyps removed?
(With traction via a nasopharyngoscopy)
How are bulla feline inflammatory polyps removed?
(Ventral bulla osteotomy)
You are testing the PCV/TS on fluid you obtained from the abdominal cavity of a HBC patient, if the PCV falls into what range or higher would you suspect this patient is bleeding into their abdomen?
(2-5%, PCV of abdominal fluid does not need to get super close to serum PCV to be diagnostic for hemorrhage due to a dilution effect)
Lactate should be higher/lower and glucose should be higher/lower than your serum values to indicate bacterial involvement in abdominal fluid.
(Lactate should be higher and glucose should be lower)
Differentiate between a true and false hernia.
(True hernia → contents of the hernia are contained in an anatomical sac, false hernia → contents of the hernia lack a sac)
(T/F) You should optimally not freshen the edges of the ring created by a hernia.
(T)
(T/F) Most traumatic hernias are not emergencies.
(T, stabilize your patient first)
What is a benefit to stabilizing a trauma patient first (up to a 3-5 day period) prior to performing your hernia repair?
(This allows time for nonviable tissue to declare itself and you’ll know to remove it then)
Of the diagnostic imaging options available, which can determine the GFR of the kidneys?
(Scintigraphy)
What are the natural retractors for visualizing the kidneys?
(Mesocolon and mesoduodenum)
What is the normal size of a kidney on radiographs?
(2-2.5 times the adjacent vertebrae)
Why are renal biopsies no longer a common procedure?
(They are thought to cause kidney damage no matter how you perform them)
What surgical procedure is preferred over a nephrotomy because there is no occlusion of renal blood flow and no damage to renal parenchyma?
(Pyelolithotomy → incising into the renal pelvis)
When performing a nephrectomy, where should the ureter be ligated?
(Right at its entry into the bladder)
Sympathetic innervation is important for urine retention/excretion (choose).
(Retention, sympathetic hypogastric nerves relax the detrusor and contract the urethral smooth muscles hence retention)
Parasympathetic innervation is important for urine retention/excretion (choose).
(Excretion, parasympathetic pelvic nerve contracts the detrusor muscle during urination)
Which nerve innervates the external urethral sphincter and is it sympathetic/parasympathetic?
(Pudendal nerve and trick question, it is a somatic nerve)
What is the holding layer of the bladder?
(The submucosa)
You should use absorbable/non-absorbable suture for the bladder.
(Absorbable)
Normograde/retrograde (choose) hydropulsion is preferred for making sure all calculi are removed from the urinary tract during a cystotomy.
(Retrograde)
(T/F) You can remove up to 75% of the bladder and if you avoid the trigone, the bladder will be fine and functional.
(T, prognosis can be very good)
What are the preferred locations of urethrostomy sites in dogs versus cats?
(Scrotal for dogs, perineal for cats)
What is the most common classification of peritonitis that practitioners come across?
(Generalized secondary septic peritonitis)
What aspects of the history you obtain from your owner could help to indicate peritonitis?
(Hx of abdominal sx/FB, hx of NSAID/steroid usage, trauma, or intact status)
What are the most pertinent clinical findings that would indicate peritonitis?
(Abdominal pain/fluid wave/distension, will also have generalized signs of fever, anorexia, v/d, lethargy)
What are changes you expect to see on a CBC of a patient with peritonitis?
(Marked neutrophilia with toxic changes unless you caught the patient when they are decompensating they may be very low, and anemia)
What are the changes you expect to see on a chem of a patient with peritonitis?
(Hypoproteinemia, hyper/hypoglycemia, hyponatremia, hypochloremia, hypokalemia, and then azotemia/liver enzyme elevation depending on cause of peritonitis and if both this indicates MODS)
What radiographic finding is usually a very reliable indicator of peritonitis?
(Gas in the abdomen)
What are two tried and true antibiotic choices for peritonitis?
(Cefoxitin and ampicillin sulbactam/unasyn)
What should you add to your warm saline when lavaging an abdomen with peritonitis?
(Nothing, just lavage with warm saline until it runs clear)
(T/F) Breed and sex are not prognostically useful when it comes to oncology or oncological surgery.
(T)
(T/F) Palpation alone of a lymph node cannot determine if a cancer is metastatic or not.
(T, need sampling of the node to determine if cancer cells are present or other diagnostics that could indicate cancer elsewhere in the body)
What are examples of when you should choose a biopsy over an FNA?
(Anytime when information about the tumor type/grade would result in a change in 1) choice of treatment, 2) extent of treatment (margins), or 3) owner’s willingness to treat)
(T/F) FNAs can be diagnostic for certain types of tumors.
(T, think MCT)
Why should FNAs not be performed on TCC or adrenal masses?
(TCC → linked to tumor seeding in the abdomen; adrenal → very sensitive and some of the hormones secreted can be detrimental to the patient if the mass is triggered by the FNA)
What is the main factor to consider when you are considering a biopsy for a mass?
(Eventual definitive treatment, this will indicate how and where to take your biopsy)
What is the disadvantage of needle-core biopsies and how would you get around that disadvantage?
(The tissue sample taken is small and could potentially be non-diagnostic/non-representative → can obtain multiple samples to improve diagnostic accuracy)
(T/F) Oral tumor biopsies can be done without local anesthetic, just mild sedation on board.
(T, oral tumors do not usually have nociception but remember that they will still bleed)
Why is it necessary to be able to resect a biopsy site/scar en bloc with the tumor during the definitive treatment?
(Because those biopsy tracts should be considered contaminated with cancer cells and will need to be removed to prevent cancer from growing in the biopsy site)
What does it mean that an excisional biopsy is diagnostic but not usually therapeutic (unless you are dealing with a benign mass)?
(You can get the tumor type and grade easily with an excision biopsy but the margins are unlikely to be clear of cancer cells so it is not therapeutic, will need a revision surgery to get the appropriate margins)
What is the most common mistake in relation to oncological surgery?
(Using too low of a surgical dose, remember that the first surgery performed on the tumor is your best chance at removing all of the tumor)
What are your treatment options when an unplanned marginal resection occurs?
(Monitor, staging resection, wide resection of the surgical wound, or adjuvant radiation therapy)
What is the recommended wide lateral margin size for benign masses?
(1 cm)
What is the recommended wide lateral margin size for grade 1-2 tumors/low grade MCTs?
(2 cm)
What is the recommended wide lateral margin size for soft tissue sarcomas?
(3 cm)
What is the recommended wide lateral margin size for feline injection site sarcomas?
(5 cm)
What is the minimum recommendation for the deep margins for a wide surgical dose?
(Minimum of 1 fascial plane, 2 for injection site sarcomas)
Why should drains and flaps be avoided when dealing with tumors in surgery?
(Because the draining tract and donor site for the flap should be considered contaminated with cancer cells)
