Dr. Oaks Surgery Lecture Flashcards
How did Dr. Oaks define surgery?
Surgery is the controlled “wounding” of the body (compared to trauma) w/ a resultant cascade of physiologic responses that ultimately result in near-complete healing. This cascade is called the “stress response” which is seen w/ trauma, burns, infection, and surgery
Describe the stress response to surgery
The stress response is characterized by increased secretion of certain pituitary hormones and activation of the sympathetic nervous system.
Growth Hormone stimulates _____ synthesis, inhibits ________, promotes _______, and inhibits ______ uptake by cells
Growth Hormone stimulates protein synthesis, inhibits protein breakdown, promotes lipolysis, and inhibits glucose uptake by cells
The net effect of the stress response of surgery is:
1) …
2) …
1) salt and water retention to maintain cardiovascular stability
2) increased catabolism to provide energy sources
Cytokines, particularly _____, _____, and ____ play a major role in the inflammatory response to surgery. They are released from _____, _____, and _____ cells.
Cytokines, particularly IL-1, TNF alpha and IL-6 play a major role in the inflammatory response to surgery. They are released from leukocytes, fibroblasts and endothelial cells.
Cytokines work locally to promote wound healing but also have effects on the ______ to increase acute phase proteins (CRP, fibrinogen, alpha2-macroglobulin)
Liver
In relatively minor operative procedures, there is minimal disruption to ______ and wound healing occurs without incident
Homeostasis
For extensive surgical procedures, severe disruptions in _____ and _____ balance, _____ synthesis, and wound healing may all occur. These may be further complicated by pre-existing co-morbid conditions (diabetes, atherosclerosis, heart failure, etc…) as well as _____ or _____
fluid and electrolyte balance, protein synthesis and wound healing may all occur
anemia or infection
Approximately ___% of total body weight is “water weight” roughly distributed as:
Plasma ___%
Interstitial Fluid ___%
Intracellular Fluid ____%
Approximately 60% of total body weight is “water weight” roughly distributed as:
Plasma 5%
Interstitial Fluid 15%
Intracellular Fluid 40%
____ is the primary extracellular cation, and _____ is the primary intracellular cation
Na+
K+
If you were to administer 1 L of fluid to a pt, where would most of it end up in their body?
Not a whole lot ends up in the intravascular space, a lot goes to the interstitial space (3rd spacing)
To maintain homeostasis, one must provide the appropriate fluids and nutrition (preoperatively/perioperatively/postoperatively)
perioperatively
The “normal” person consumes about ____ ml of fluid per day (____ ml from oral intake of liquids and ____ ml derived from solid food)
Fluid loss is via urine (____ ml), stool (____ ml) and skin (____ ml) and lungs (____ ml)
The “normal” person consumes about 2,000 ml of fluid per day (1,500 ml from oral intake of liquids and 500 ml derived from solid food)
Fluid loss is via urine (1,200 ml), stool (200 ml) and skin (400 ml) and lungs (200 ml)
In the short term, the best measurement of fluid balance is _______
body weight
What is a fistula?
An abnormal connection between two spaces
Fluid replacement therapy must be coordinated with _____ needs (add in the ___ and ___)
Fluid replacement therapy must be coordinated with nutritional needs (add in the intravenous and enteral intake)
Lactated Ringers (LR) is similar in composition to the _____ fluid in the body
Extracellular
5% Albumin contains _____, which allows it to remain in the intravascular space longer
colloid
How many calories does a surgical patient need?
30 kcal/kg/day (the same as fluid intake)
For a 70 kg male, that works out to about 2,000 kcal/day
For adequate wound healing, provide ____ g of protein/kg/day and ____ nonprotein calories per g of nitrogen (____ gm of protein)
For adequate wound healing, provide 1 g of protein/kg/day and 150 nonprotein calories/g of nitrogen (6.25 g of protein)
Also remember that (parenteral/enteral) feeding is FAR SUPERIOR to (parenteral/enteral) feeding, and sepsis morbidity is higher in pts who have been fed (parenterally/enterally)
Also remember that (enteral) feeding is FAR SUPERIOR to (parenteral) feeding, and sepsis morbidity is higher in pts who have been fed (parenterally)
If a patient is being fed through a NG tube, is it best to consistently administer nutrition hourly, or bolus three times a day? Why?
Bolus TID because we need peaks in insulin to synthesize protein
Stomach produces how many liters of gastric secretions per day?
1 L/day
What is the Harris Benedict equation for men and women? Why is it important?
Men: BMR = 66 + ( 6.2 × weight in pounds ) + ( 12.7 × height in inches ) – ( 6.76 × age in years )
Women: BMR = 655.1 + ( 4.35 × weight in pounds ) + ( 4.7 × height in inches ) - ( 4.7 × age in years )
a method used to estimate an individual’s basal metabolic rate (BMR) and daily kilocalorie requirements
Failure to provide adequate fluid resuscitation results in continued surgical stress with continued _____ and poor ______
continued catabolism and poor wound healing
Failure to provide sufficient calorie and protein intake will exacerbate the “starvation” or perioperative catabolic state and further complicate _______
wound healing
Almost all wounds heal by (primary/secondary/tertiary) intention
Primary
Some wounds that do not heal by primary intention will heal by ______ intention. This may take ____-____ and occasionally the wound never heals
Secondary; weeks-months
Rarely, a surgeon will plan on delayed closure of a wound. This is called ______ intention.
Tertiary
What are the three phases of wound healing? Describe each (when they start, how long the phase lasts, what results or could cause prolonged time in that phase).
HEMOSTASIS AND INFLAMMATION: begins immediately and lasts for the first few days (prolonged time here: diabetic ulcers)
PROLIFERATION: starts after the first few days and lasts for several weeks (prolonged time here: keloid scars)
MATURATION: this process begins after 2-3 weeks and lasts several months
T/F There is no overlap between the phases of wound healing
False, there is overlap!
______ initiates the inflammatory phase with platelet activation and release of cytokines
Hemostasis
The initial cells of the inflammatory phase are _____ quickly followed by ____ and _____. Toward the end of this phase, ____ and ____ appear.
platelets; neutrophils and macrophages; fibroblasts and lymphocytes
______ are the principle cell involved in the proliferation phase. These cells are activated by the many cytokines released by _____ cells.
Fibroblasts; WBCs
In the proliferation phase of wound healing, initially, type _____ collagen is laid down and over time this is replaced by type _____ collagen
III; I
During the proliferation phase of wound healing, _____ cells, leading to new blood vessels (granulation tissue), and epithelial cells, forming new skin, are also activated
Epithelial
During the maturation phase, there is maturation of the wound collagen with collagen _____ and _____
breakdown and synthesis
Scar remodeling continues for up to _____, during which the wound will reach about ___% of its original strength
12 months
80%
______, a specialized type of fibroblast, contain contractile proteins that contract the wound and make it physically smaller (______ intention)
Myofibroblasts; secondary intention
What are some local factors that would affect wound healing?
Mechanical Injury Infection Edema Ischemia Necrotic Tissue Radiation Effects Hypoxia Foreign Body
What are some systemic factors that would affect wound healing?
Age Nutrition Obesity Trauma Metabolic Diseases Immunosuppression Connective Tissue Diseases Smoking
The elderly have a higher incidence of ____ dz, _____, ______, _____, and ____ usage that may impair wound healing
The elderly have a higher incidence of cardiovascular disease, diabetes, malnutrition, cancer, and drug usage that may impair wound healing
Vitamins ___ and ___ are required for collagen synthesis as well as cofactors such as ___, ___, and ___
Vitamins A and C are required for collagen synthesis as well as cofactors such as zinc, copper, and manganese
Obesity may “mask” ______ and are more likely to develop wound infections (fat lacks ______) and are more “difficult” patients in other ways (____, ___, ___)
Obesity may “mask” protein malnutrition and are more likely to develop wound infections (fat lacks a good blood supply) and are more “difficult” patients in other ways (hygiene, ambulation, DVT)
________ impairs neutrophil function and may impair fibroblast function as well
Hyperglycemia
Other metabolic diseases that negatively affect wound healing include disorders of the ______ and _____ and ______
Pituitary and adrenals and thyroid (hypo-)
________ drugs, such as ____, have deleterious effects on wound healing and increase surgical infection rates
Immunsuppressive; Prednisone
By quitting smoking for ____ weeks prior to surgery, you can decrease a pt’s mortality by ___%
4 weeks; decrease mortality 50%
Connective Tissue Diseases that negatively affect wound healing include _____, _____, and ____. These conditions may affect immune function directly and may also be associated with ____ and _____.
RA, SLE, scleroderma; vasculitis and impaired blood flow
Smoking induces profound vasoconstriction and reduces skin blood flow by up to ____%. One cigarette creates a vasoconstrictive effect up to ___ minutes. Smokers also have a decreased tissue oxygen of up to ___%
Smoke also contains _____ and _____ which impair oxygen delivery to the tissues by _____
40%; 90 minutes; 30%; CO and hydrogen cyanide; hemoglobin
Smoking results in _____ cell dysfunction, enhances _____ formation, impairs ______ phagocytic activity.
Smokers have lower levels of Vitamin ____ and have reduced levels of ______ synthesis.
Endothelial; thrombus; neutrophil
Vit C; collagen
Wounds are usually classified as “superficial” (skin and fat) or “deep” (fascia or intra-abdominal), with superficial consisting of ____% of wounds and deep ___% of wounds.
75%; 25%
T/F You should stop abx w/in 48 hours of surgery
True
T/F You should clip and not shave the hair from the skin
True
What condition is caused by GAS, Staph aureus, Clostridium perfringens, Bacteroides fragilis and Aeromonas hydrophila either alone or in combination?
Necrotizing fasciitis
If a pt presents with intense pain that seems excessive to the physical findings, fever, and tachycardia, what should you assume to be present?
Necrotizing fasciitis
Necrotizing fasciitis frequently occurs in the (early/late) postoperative period
Early
Necrotizing fasciitis frequently occurs in the (early/late) postoperative period
Early (w/in hours)
Avoid ______ on any wound closure. ______ leads to ischemia and this leads to wound disruption.
Remember to “ _____, not ______”
tension; tension; approximate; strangulate
What are the 6 types/classifications of sutures?
Absorbable, Non-absorbable
Monofilament, Multifilament (Braided)
Synthetic, Natural (silk, cat gut)
____ or ____ sutures may be beneficial if a wound becomes infected, as you can remove just one and wound is still okay
staples; interrupted sutures
_____ or _____ may be useful in uncooperative patients or when scar formation is undesirable
Steri strips; skin glue
_____ can be used in almost any location to “stretch” the skin and allow for later “transfer” to adjacent site. These can be preformed (once/multiple times)
Skin expansion; multiple times
A ________ skin graft includes the entire epidermis and dermis leaving behind a wound that itself must be closed
Full thickness skin graft
_____ skin grafts appear more “normal” whereas ____ skin grafts are often aesthetically unappealing
Full thickness; split thickness
A _______ skin graft includes the entire epidermis and part of the dermis leaving behind a wound that can heal itself by epithelial coverage from the surrounding skin and skin appendages (hair follicles and sweat glands)
Split thickness skin graft
____ skin grafts are more fragile but have a lower failure rate because they are thinner and have less metabolic demands
STSG
______ skin grafts contract with time whereas _____ skin grafts undergo minimal contraction
STSG; FTSG
______ skin grafts can cover much greater surface area by “meshing” and site can be re-harvested
STSG
Will a wound vac wound become smaller with treatment?
Yes
Wound vac healing is comprised of a dressing that is impermeable to _____
bacteria
Using a wound vac increases the ______ to a wound, and reduces ____ formation while maintaining a _____ wound environment
blood flow; edema; moist
The benefits of using a wound vac include…
Fixes the tissue in place w/ reduced friction and shear forces
Removes proteases from wound bed
Increases fibroblast proliferation
Mechanically contracts wound surface area
Two possible antimicrobials that are used in conjunction with wound vac include _____ and _____
silver and iodine
When properly used in wound closure, ______ are more precise, consistent and reproducible, faster but more expensive.
staplers
T/F Surgery is the coolest thing you will ever do
True :)
