inhaled 3 Flashcards
when des/sevo/iso increase, MAP
decreases
decrease in MAP reflects a decrease in
SVR (dilation)
halothane decreases MAP by
decreasing CO
N20 causes ___ MAP
unchanged or mildly increased
he substitution of nitrous for a portion of iso produces (cardiac)
less decrease in SPB
increase gas concentration, HR will
increase
increase in HR during induction is seen with which gas
des
linear, dose dependent inc in HR is seen with iso starting at __ MAC
.25
linear, dose dependent inc in HR is seen with des at __ MAC
> 1
inc in HR is seen with sevo at
> 1.5 MAC
minimal increase in HR with des at concentrations
<1 MAC
which gas effects EF
des- minor increase
do inhaled agents predispose the heart to PVC’s?
no just halo
avoid ___ in patients with known long Qt syndrome
sevo
coronary steal
iso’s ability to dilate small-diameter coronary arteries might cause a susceptible patient to develop regional myocardial ischemia as a result of coronary vasodilation. not found valid
ischemic preconditioning
protective against myocardial ischemia in setting of compromised regional perfusion
first period of ischemic preconditioning
1-2 hours after the conditioning episode
second period of ischemic preconditioning
benefit reappears 24h later and can last as long as 3 days
as anesthetic increases, patients will breathe
faster and shallower (increased rate, decreased volumes)
anesthetic effect on minute ventilation
relatively preserved but the decreased TV leads to greater dead space ventilation relative to alveolar ventilation
gas exchange becomes ___ efficient as anesthetic depth increases
less
PaCO2 ___ proportionate to anesthetic depth
increases
anesthetic response to resp response to increased CO2 and arterial hypoxemia
blunted
anesthetic gases ___ FRC
decrease
which gases are non-pungent
sevo, halo, n2O
which gases are pungent
des and iso. avoid with asthmatics and smokers
inhalation agents ___ CMRO2 (cerebral oxygen demand)
decrease
anesthetic gases have __ effect on cerebral vascular response to changes in PACO2
no
in normocapnic patients, cerebral vasodilation occurs at concentrations above __ MAC
0.6 (think about half)
at higher concentrations, >1 MAC, cerebral blood flow ___
increases, esp if systemic BP is maintained at awake values (be careful with neuro pt!)
n20 ___ CMRO2
increases
n20 causes cerebral ___
vasodilaton
ICP increases with all volatile anesthetics at doses
> 1 MAC
auto regulation is impaired at concentrations
< 1 MAC
autoregulation maintains
MAP
evoked potentials may be abolished at
1 MAC
N20 and __ MAC inhalation abolish EP
0.5
isoelectric occurs at __ MAC
1.5-2
increased depth of anesthesia is characterized by
increased amplitude and synchrony on the EEG
which gas is associated with epileptiform activity on the EEG (can cause seizures)
sevo
neuromuscular effect of gases
dose dependent skeletal muscle relaxation and enhance the activity of neuromuscular blocking drugs.
causative agent of hepatic damage
trifluoroacetate metabolite
compound A comes from the breakdown of
sevo and halo
compound A is toxic to the
kidneys
keep flows at at least ___ to prevent nephrotoxicity r/t compound A
2L/min
n20 is contraindicated for people with pre-existing vitamin __ deficiency
B12
nitrous inactivates methionine synthase…. affect on heart
its the enzyme that regulates vitamin b12 and folate metabolism. homocysteine levels also elevated, resulting in increased risk of adverse coronary events
preferential transfer of N20 causes the volume/pressure of air-filled cavities to ___
increase . compliant wall it will increase volume, non compliant wall it will increase pressure.
the blood gas coefficient for nitrous is ___ times greater than nitogen
34
high fresh gas flow rates ___ the desiccation of CO2 absorbents
accelerate
degradation is an ___ process, which may cause extremely high ___, esp with ___
exothermic , temps, sevo
iso and des produce ___ when exposed to ___ absorbent
carbon monoxide , desiccated
if you see an increase in inspiratory CO2, suspect
rebreathing - desiccated absorbent
which agents do we use variable bypass vaporizers
iso and sevo
variable-bypass is temperature ___
compensated
des vapor pressure
700mmHg at 20degrees C
heated vaporizer tec 6 heats des to ___ atm of pressure
2
tec 6 and altitude
does not altitude adjust - you have to!
___ causes bradycardia <1 mac *
sevo
whats the physio behind ischemic preconditioning?
opening of mitochondrial adenosine triphosphate (ATP)-sensitive potassium channels
how does the chest wall change
cephalad displacement of the diaphragm and inward displacement of the rib cage occur from enhanced expiratory muscle activity. this results in a reduction in FRC.
atelectasis…
occurs in dependent areas of the lung and to a greater extent when spot vent is permitted
at .5MAC, what happens to cerebral blood flow
the decrease in CMRO2 offsets the vasodilation such that cerebral blood flow does not change significantly
low concentrations 0.2-0.3 MAC decrease the reliability of ____evoked potentials
motor
which gas has lowest boiling point
sevo
reduce compound A risk by
low sevo,. high flow, use soda lime
inhaled moves CO2 response
down to the R
sevo is broken down to
inorganic fluoride
des and iso is broken down to
inorganic fluoride ions
principal catalyst for CO2 absorption in soda lime and baralyme is
sodium hydroxide
n20 ___ PVR
increases
CO production highest in
des > nef > iso
n20 __ CMRO2 and CBF
increases
volatile anesthetics produce a dose dependent ___ in cbf
increase
when vascular resistance is decreased, CBF, CBV, and CSFP ___
increase
at high altitudes, partial pressure of des will be ___, so you will ___ someone If no adjustments are made.
lower, under dose.
