Prodigy Films F to O Flashcards
What are FA & FI?
FA - fractional concentration of anesthetic in the ALVEOLI
FI - - - - - - INSPIRED GAS
explain FA FI importance
faster FA/FI = 1 faster induction will occur
how to increase FA/FI
increase minute ventilation Decrease FRC & CO Increase FGF > 4 L/min Decrease circuit volume, Decrease agent solubility (helps circuit absorbs less too)
what is most important factor in the rate of rise in the FA/FI
uptake
how does uptake affect FA/FI? how about CO?
decreases FA, so it slows the rate of rise of FA/FI
increased CO increases uptake and decreases FA even more
What factors increase MAC? (need more Gas)
Young age Chronic alcohol abuse CNS stimulants Hyperthermia Hyperthyroidism Hypernatremia Red hair female
What factors decrease MAC?
increased age (6% per decade) Pregnancy Metabolic acidosis lithium acute alcohol ingestion anemia Lidocaine, Opioids, Ketamine, Benzo, Alpha 2 agonists, hypothermia, Hypoxia, Hyponatremia, Hypoosmolarity
What is MAC?
necessary to prevent skeletal muscle movement 50% pt’s to noxious stimuli
Name factors that don’t affect MAC
Duration of anesthetic Gender Hypo/Hypercapnia K imbalances Metabolic alkalosis HTN
what factors affect fetal transfer of drugs
Molecular weight < 500 Daltons (BB, NTG, Nitro)
lipid solubility (fent/ Ketamine)
ionization
concentration gradient
what drugs do not cross placenta
Heparin ,Insulin, Protamine (all large Daltons > 1000)
Glyco / SUX ( water soluble drugs do not)
What drugs do cross placenta
beta blockers
NTG
Nitroprusside
Fentanyl / Ketamine (lipid soluble)
what is Fick’s Law of DIssusion?
What factors affect it (4)?
- rate of diffusion across membrane,
- takes into account
1 molecular weight (inversely proportional),
2 solubility
3 concentration gradient (directly proportional),
4 membrane thickness
(helps explain diffusion hypoxia)
what is first pass metabolism
orally administered drugs are metabolized by the liver prior to entering circulation
flow volume loops
what does point in top left corner represent?
middle right ?
lower left corner?
top left = peak expiraotry flow rate
right most point = residual volume
lower left corner = TLC
flow volume loop X & Y axis?
X = volume 8 to 1 L Y = flow 0 to 7.5 up and 0 to 7.5 down
what is a dyne?
1/100,000 of a newton which is equal to 102 grams. its just a very small unit of measurement for body since a newton is too big.
what is Frank starling mechanism?
more blood that returns to heart allows more blood to be ejected since actin and myosin align
what is the sphincter of Oddi?
where common bile duct & pancreatic duct meet to empty into the duodenum.
what is Gay Lussacs Law?
p1T2 = p2T1, direct relationship, think heating a cylinder
GFR normal level?
what increases GFR & what decreases it?
normal 125 mL / min
increased = by Dilation afferent arteriole, increased renal blood flow and increased efferent arteriole resistance
decreased = by increased afferent arteriole tone
what does glossopharyngeal nerve innervate?
posterior 1/3 of tongue, tonsils, pharyngeal wall
what is brain glucose consumption #?
5 mg /100g / min
closely parallels CMRO2
hyperglycemia above 180 can be detrimental as produces lactic acid but hypoglycemia can be bad as well.
What is grahams law of Diffusion ( Effusion) ?
the rate of diffusion of a gas is inversely proportional to its molecular weight. ( smaller particles spread out faster than bigger particles!!!!!!!!!)
effusion = rate that gas particles escape thru tiny hole
what is conductive heat loss?
transfer of heat by direct contact between a warmer object and cooler object.
what is convection heat loss?
heat from our skin cools the air around onur skin .
second greatest source of heat loss. (radiation is #1)
what is evaporation heat loss? what causes it and what can we do about it?
liquid to gas,
use lower gas flows and in line humidifiers , caused by alcohol and sterile preps
what is radiation heat loss?
- transfer of infrared energy from body to cooler operating room environment, - ———- greatest amount of heat loss,
- occurs in areas of greatest blood flow and the head is number 1, why wrap head in warm blankets
hematologic effects of renal disease? what is treatment and how to best check it?
even pt’s with normal PT/PTT and PLTS can bleed from epistaxis, GIB & subdural bleed, from uremic bleeding
best to check bleeding time
treat with desmopressin 0.3 mcg/kg IV preoperatively peaks in 2-4 hrs and lasts 6-8 hrs
what is hemodiaysis
removing waste by diffusion thru semipermeable membrane, reduces BUN by 70%
SE = hypotension and hypoexmia, muscle cramping, dysrhythmias & reaction to tubing
what is Henry’s Law?
amount of gas dissolved in liquid is directly proportional to partial pressure of gas above it,
why you can turn sevo to 6% and get more gas in blood than 2%
explain henry law and Sevo gas?
the delivery of a higher concentration of anesthetic than the desired end point can speed the uptake of the anesthetic.
what is hepatic clearance
rate of drug metabolism = hepatic blood flow x (drug conc going in - out)
what is hepatic extraction ratio
% of drug the liver can clear as it passes through
liver receives how much of CO
25%
how much blood can liver hold and whats its spinal innervation?
1L
T3-T11
what is Hering Breur Reflex?
stretch receptors send signals to dorsal respiratory group
triggered by 1.5L overinflation of lungs, feedback loop that can increase RR
what is hyperparathyroidism
90% from benign adenoma or from
parathyroid carcinoma or multple endocrine neoplasia
what are s/s of hyperparathyroidism
same as elevated Ca
kidney stones, GI ulcers/ cramping, muscle weakness, polyuria/polydipsia/confusion
HTN, short QT, prolong PR & QRS, bradycardia
treatment of hyperparathyroidism
tumor removal, NSS infusion, LOOP diuretics, biphosphonates & calcitonin
