12. Arterial Lines Flashcards
what can happen if the art line tubing becomes disconnected?
the pt could rapidly bleed to death
2 purposes for arterial lines
- real time blood pressure
- blood samples
how often does an art line provide blood pressure
every time the heart beats
why cant you draw blood out of an IV?
pressure in veins is too low (7mmHg)
vein would flatten
adult art line sizing
20ga
18ga
radial/brachial catheter size
20ga
femoral catheter size
18ga
peds art line sizing
20-22ga
neonates art line sizing
22-24ga
NIBP reading vs art line
NIBP under-reads systolic
NIBP over-reads diastolic
Art line vs NIBP
Art systolic is higher than NIBP
Art diastolic is lower than NIBP
gold std for BP monitoring
arterial lines
pressure transducer
senses BP inside artery
why do some providers use heparinized saline?
less chance of art line system clotting
why do some providers not use heparinized saline?
eliminates possiblity of HIT
2 purposes of pressure bag
prevents blood from backing into tubing
allows fluid flush of artery
when the 500mL bag of N/S is pressurized, it allows
the pressure in the tubing to be higher than the pressure in the blood
when do you fluid flush an art line into the pt
after labs are drawn to flush the blood back into the pt
can you give drugs through an arterial line
no
why should you not give drugs via art line
cause vasoconstriction and ischemia
what should never be flushed into artery
air bubbles
which direction should the stopcock be turned in order to flush?
off to air
4 reasons an art line wont flush
- stopcock turned off to the line
- closed roller clamp
- “under pressurized” pressure bag
- clotted off catheter
how to fix a clotted off art line?
try to aspirate clot w/syringe
flush line
materials required to insert art line
chloraprep
guaze
tegadern
tape
lidocaine
arrow/angiocath
wrist support/roll
2 catheter types for art lines
20ga arrow catheter
regular 20ga catheter
what pressure do you inflate the N/S bag to?
250-300mmHg
what rate will the fluid drip into the artery with a correctly pressurized bag?
3-6mL per hour
when can the transducer be exposed to the atmosphere?
- if the stopcock if off to the pt, the stopcock will be open to air
- before the link is hooked up to the catheter in the artery
how do you zero the art line?
open the system to the atmosphere
press “zero”
steps to zeroing transducer
- change monitor to 8 wave
- turn stopcock OFF to pt (OPEN to air) and remove cap
- push zero
- turn stopcock OFF to atmosphere
- replace cap
what direction is the stopcock off to pt
away from transducer
towards noncompliant tubing
MAP
area under the curve
upstroke
systole
cardiac contractilioty
sharp vertical upstroke
good contractility
sloped sluggish upstroke
poorer contractility
downstroke
diastole
SVR
slow fall downstroke
vasoconstriction
high SVR
shar fall downstroke
vasodilation
low SVR
dicrotic notch
diastolic blood hits the aortic valve
overdamped waveform
smoother/lower amplitude
underestimates systolic
overestimates diastolic
no change to MAP
are overdamped waveforms accurate?
overdamped waveforms are inaccurate
causes of damping in waveform
- partially clotted catheter
- kinked catheter from wrist flexion
- compliance in tubing
- low pressure in system
- air bubbles
why is art line tubing non-compliant?
to reduce dampning
increase pressure accuracy
how to fix dampened wave form?
- aspirate blood/flush tubing
- extend wrist
- ensure adequate pressure (250-300 mmHg)
- aspirate air bubbles