Exam 3 Part II Flashcards
an INCREASE in CO will _______________ the onset of action of your INH agent during induction
slow
T/F: the more soluble the INH agent, the greater the impact CO has on its speed of onset
TRUE
majority of blood/agent from lungs goes to the ___________________
vessel rich group
N2O will increase ___________________ in closed spaces, and increase ____________ expandable tissues
pressure; volume
N2O is ___________x more soluble in the body than nitrogen
34
anywhere ______________ can exist in the body, N20 can occupy and expand
nitrogen
what areas would you expect an increase in pressure with N2O, thus its use is c/i with these procedures
Middle ear paranasal sinuses cerebral ventricles eyeball
T/F: you may have to adjust the volume of the cuff in cuffed equipment with nitrous use
TRUE
what equipment could be expanded with use of N20
- ETT cuff 2. LMA cuff 3. PA catheter tip
75% N2O will expand pneumothorax, ______________ size in 10 min, and __________ size in 30 min
double; triple
in compliant spaces (volume) - with use of N20 the space will expand until when?
sufficient pressure is generated to further oppose N2O flows
T/F: N2O is a great gas choice for your trauma patients
FALSE
why is uptake of INH agents faster in children than adults
INH agent is less blood soluble –> faster tissue uptake
neonates (first 28 days of life) have a _______________ MAC
decreased
infants and children have _____________x higher MAC than a 40 y/o adult
1.5-1.8x
during what age is MAC the highest?
1mo - 6 mo of age
adverse reaction of INH agents in pediatric
emergence delirium
the ____________ the child the greater risk of emergence delirium
younger
interventions to decrease emergence reactions/agitation in pediatrics
- allow parental presence on induction 2. pain control 3. meds: fentanyl, precedex, propofol, ketamine
T/F: precedex is FDA approved for emergence delirium prevention in pediatric populations
FALSE
T/F: obesity will have a clinical effect on INH uptake
FALSE
INH agent effects with obesity
- no clinical effect on uptake 2. may have prolonged emergence/recovery with long procedures (>4 hrs) d/t saturation of tissues
INH anesthetics effects with pregnancy
- increased uptake 2/2 increased MV 2. decreased uptake 2/2 increased CO these two things normally cancel eachother out –> uptake being similar to non-pregnant women
soda lime allows for rebreathing by conserving ________, ___________, & _________ without rebreathing ____________
O2, N20, & humidity; CO2
if you increase FGF = _____________ your absorption in your soda lime
decrease
soda lime will help prevent what metabolic imbalance
respiratory acidosis
if your soda-lime exhausts intraoperatively you should _________________
increase FGF to help blow off CO2
T/F: CO poisoning is difficult to detect under GA
TRUE
degradation of soda lime produces _______________ especially if the soda lime is _______________
CO; dry
what agents produce CO in soda lime
desflurane and isoflurane (w/ des > iso)
_____________ & __________ produce very little CO in soda lime
halothane and sevoflurane
sevoflurane degrades to __________________ which is toxic to the ____________
compound A; kidneys
you should not administer sevoflurane at _____ hrs due to nephrotoxicity
2; 2
you can have increased production of compound A in what situations?
- low flow 2. closed circuit systems 3. warm or very dry CO2 absorbant
drying of soda lime is a ________________ reaction
exothermic
all commonly used INH agents are either __________________ or ______________
ethers; hydrocarbons (alkanes)
which Inhalational agent is the only one that is an alkane
halothane
which inhalational agent is the only one that has Bromine added?
halothane
INH agents can be straight or branched hydrocarbons, but they cannot consist of more than ___________ carbon atoms
4
T/F: anesthetic effect of INH agent is lost if there are more than 4-5 carbon atoms
TRUE
halogenation of hydrocarbons and ethers include the addition of __________, __________, _________ or _________
flourine, bromine, chlorine, idodine
isoflurane has __________ fluorine’s added to it, desflurane has __________ F added to it, and sevoflurane has _________ F added to it
5; 6; 7
what are the effects (advantages) of halogenation
- reduces flammability 2. increase potency 3. increases brain solubility 4. decrease arrhythmias 5. more stable
halogenation reduces __________________
flammability
fluorination reduces _________________ in blood and fat
solubility
triflourocarbon groups (to INH agents) add _________________
stability (longer storage)
halogenated alkanes precipitate _______________
arrythmias (ex: halothane)
___________ halogens = arrhythmogenic; __________ halogens, arrhythmias are no longer an issue
5 ; 6
the more fluorines the ____________ resistant to biodegradation
less
place the INH agents in order from most metabolized to least
halothane > enflurane > sevo > iso > desflurane > N20
where do we THINK inhalational agents are working in the CNS?
neocortex hippocampus amygdala diencephalon (thalamus) brainstem (reticular formation) spinal cord
effects of INH agents in the CNS
- sedation 2. amnesia 3. unconsciousness 4. immobility
unitary hypothesis of how INH work?
all work via a similar although undefined MOA but not necessarily at the same site of action
INH agents are defined as _________________ meaning they are both hydrophillic and lipophillic
amphipathic
T/F: effects of INH agents are dose related
TRUE
what is the meyer Overton Theory
correlation between lipid solubility and potency of gas has been debunked bc does not apply to all gases
Unconsciousness effect of INH agents is due to effects where?
cortex, thalamus, and brainstem
amnesia effects of INH agents is due to the effects where?
amygdala and hippocampus (working on GABA by increasing Cl conductance)
analgesia effects of INH agents are due to the action where?
spinothalamic tract (of the spinal cord)
immobility effects of INH agents are due to the action where?
spinal cord , central pattern generators (via potentiation of glycine R)
volatile agents inhibit ______________ release and antagonize ______________ receptors –> CNS depression
glycine; glycine
profile of the ideal INH agent
- able to produce unconsciousness, analgesia, and immobility 2. pleasant smell/non bronchial irritant 3. low B:G solubility 4. stable in storage 5. non-flammable; non-explosive 6. non-toxic, non-allergenic 7. readily reversible CNS effects 8. sufficient potency (so can use high FiO2/low MAC) 9. minimal depression of CV and respiration 10. no interactions with other drugs 11. eliminated completely, rapidly, unchanged via lungs
how do you calculate pts MAC level
ET of the anesthetic agent /MAC of the agent
factors that influence s/e of INH agents
- anesthetic concentration 2. patient age 3. coexisting dz 4. IV fluid volume (low vol –> Hypotension) 5. preoperative meds 6. additional IV anesthetics 7. variations from normocapnia 8. concomitant drug therapy 9. alteration in body temperature
CNS effects of INH agents
- decreased CMRO2 2. increase or decrease or no effect on CBF 3. uncoupling 4. dose related suppression of EEG and Evoked potentials (increase latency or decrease amplitude) 5. cerebral vascular response to CO2 (normally vasoconstrict to hypocapnia, no effect with volatiles)
effects on CBF is dependent on?
- dose of volatile 2. administration of other drugs (narcotics, propofol, nitrous 3. Mv - rate of change in CO2
Which action potential (evoked potential) is the most resistant to changes in the presence of volatiles
brainstem evoked potentials
which evoked potentials are the most sensitive to changes 2/2 volatile anesthetics
visual evoked potentials
increased latency or decreased amplitude on evoked potentials is a sign of what
- ischemia 2. use of volatiles
T/F: all volatiles effect latency of evoked potentials equally
TRUE
what are your best INH agents for neuromonitoring cases
sevo or des
__________________ can produce epileptiform changes on EEG during induction and emergence
sevoflurane
the incidence of seizures with sevoflurane doubles in the presence of ________________
hypocapnia
If increased ICP is suspected during your case, what should you do
turn off the volatiles & switch to TIVA
T/F: INH agents are okay to use for patients with elevated ICP
FALSE
cerebral autoregulation is maintained with all INH anesthetics except ____________________
halothane
all volatiles decrease CMRO2 except _______________
N20 = slight increase in CMRO2
CNS recieves _____________% of CO and consumes _____________% of oxygen under normal conditions
20; 20
what two INH gases are the standard agents for inhalational inductions?
sevoflurane; N2O
why are sevo and N20 used for inhalational inductions?
low incidence of breath holding, coughing, secretions, and laryngospasm
respiratory effects of INH agents (in spont ventilating pt)
- dose dependent depressant effect 2. decrease TV and increase RR 3. increased PaCO2 & decreased Mv 4. bronchodilation
dose dependent respiratory depression of INH anesthetics occurs in the _______________ and is due to ________________
medullary ventilatory center; blunts CNS response (2/2 increased PaCO2 and decreased PaO2)
INH agents in the lungs cause ____________2/2 CNS effect, but locally are _________________
bronchodilation; bronchoconstriction
why may you have increased secretions at the end of a general anesthetic case (with INH agents)
INH agents decrease ciliary movement –> increased secretions
respiratory considerations with INH agents on emergence
- be mindful of hypercarbia 2. Et of volatiles may persist with recent narcotic administration 3. 0.1 MAC (except desflurane) can inhibit response to hypoxia
T/F: PVR is unchanged by inhalational agents
TRUE
kidneys recieve ___________% of CO
20
T/F: autoregulation of kidneys stays intact with INH agent administration
TRUE
what UOP is adequate for an anesthetic case?
0.5 mL/kg/hr
which inhalational agent alters renal integrity the LEAST?
desflurane
describe the effects of INH agents on the kidneys (general)
they decrease SBP –> decreased renal vascular resistance –> decreased GFR –> decreased intraoperative urine output
compound A (from sevo) causes ________________________ in rats
proximal corticomedullary tubular necrosis
sevo + dessicated soda lime = __________________
anesthesia machine fire
sevo + soda lime = _______________________
compound A (theorized to be nephrotoxic) + compound B
to determine renal damage, you would evaluate the level of increase in?
- Cr 2. BUN 3. serum inorganic fluoride concentrations
which inhlational agent causes volatile induced hepatotoxicity THE MOST
halothane
all volatile anesthetics _______________ total hepatic blood flow
decrease
all volatile anesthetics ____________ hepatic artery blood flow EXCEPT ___________
increase/maintain; halothane
T/F: volatile anesthetics decrease portal vein flow
false, portal vein flow changes are very limited by INH agents
increased __________________ helps to resist hepatic degradation
fluroination