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