3. 1.Continuous, beat-to-beat blood pressure
measurement.
- Hemodynamically unstable pts /ICU pts requiring
inotropic support
- Patients undergoing major surgery
2.Frequent arterial blood gas analysis
-pts with respiratory failure on ventilator
-severe acid/base disturbance.
4. Advantages of IBP measurement
Continuous blood pressure recording
Accurate blood pressure recording even
when patients are profoundly hypotensive vs
NIBP which is difficult or inaccurate
Real time Visual Display
Disadvantages of IBP measurement
Potential complications
Skilled technique reqd
Expensive
5. The radial artery has low complication
rates compared with other sites.
It is a superficial artery which aids insertion, and
also makes it compressible for haemostasis
The ulnar, brachial, axillary, dorsalis
pedis, posterial tibial, femoral arteries are
alternatives.
6.
7. Allen’s test is recommended before
the insertion of a radial arterial line.
This is used to determine collateral
circulation between the ulnar and
radial arteries to the hand
If ulnar perfusion is poor and a
cannula occludes the radial artery,
blood flow to the hand may be
reduced.
The test is performed by asking the
patient to clench their hand. The ulnar
and radial arteries are occluded with
digital pressure.
The hand is unclenched and pressure
over the ulnar artery is released. If
there is good collateral perfusion, the
palm should flush in less than 6
seconds.
The idea here is to figure out if the ulnar
artery will supply the hand with enough
blood, if the radial artery is blocked with an
a-line.
8. Arterial cannula
Made from polytetrafluoroethylene („Teflon‟) to minimize
the risk of clot formation
20G (pink) cannula - adult patients
22G (blue)- paediatrics
24G (yellow) - neonates and small babies
Larger gauge cannulae increase the risk of thrombosis,
smaller cannulae cause damping of the signal.
The cannula is connected to an arterial giving set.
9.
10. Arterial set.
- Specialized plastic tubing, short and stiff to reduce resonance, connected to a 500 ml bag
of saline.
Saline bag
-500 ml 0.9% saline pressurized to 300 mmHg using a pressure bag, i.e. a pressure higher
than arterial systolic pressure to prevent backflow from the cannula into the giving set.
-The arterial set and pressurized saline bag with 2500units Heparin incorporate a
continuous slow flushing system of 3–4 ml per hour to keep the line free from clots.
-The arterial set and arterial line should be free from air bubbles.
- The line is attached to a transducer.
-Do not allow the saline bag to empty
◦ –To maintain patency of arterial cannula.
◦ –To prevent air embolism
◦ –To maintain accuracy of blood pressure reading
◦ –To maintain accuracy of fluid balance chart
◦ –To prevent backflow of blood
Transducer, amplifier and electrical recording equipment.
-The transducer is zeroed and placed level with the heart.
11. Tape and/or steri-strips
An arm board or towel roll
Opsite or Tegaderm cover dressing
Local anesthetic (1% or 2% lidocaine ,lidocaine
cream)
Suture material for femoral arterial line placement (2.0
silk)
Scissors
Monitor cable for transducing arterial waveform.
Benzoin solution
12. 1. Ensure that all preprocedure steps are
taken
2. Assure that pressure tubing with transducer
is connected to bedside monitor.
3. Perform the Allen‟s test to assure adequate
collateral blood flow if using the radial artery.
4. Wash hands and don gloves
5. For the radial artery, the arm is
restrained, palm up, with an armboard to
hold the wrist dorsiflexed
13. For the radial artery, the most common
insertion, the arm is restrained, palm
up, with an armboard to hold the wrist
dorsiflexed
14. 5. Apply anesthetic agent (local lidocaine 1-2% or lidocaine cream).
6. Locate pulsating artery via palpation.
7. Cleanse area selected for arterial line placement.
8. Prepare patient for puncture.
9. Stabilize artery by pulling skin taut.
10. Puncture skin at 45-60 degree angle for radial artery; 90
degrees for femoral artery.
11. Advance catheter when flash of blood is observed in catheter.
12. Connect to pressure I.V. tubing and check for arterial waveform
on bedside monitor.
13. Cleanse area of any blood and allow site to dry.
14. Apply Benzoin to cleansed area and allow to dry and become
“tacky.”
15. Secure arterial line with tape and cover with a Tegaderm
dressing.
16. Secure I.V. tubing to prevent it from being caught and pulling on
arterial catheter. If a femoral arterial line is placed, it should be
secured with a suture.
17. Properly dispose of the I.V. sharps and other used materials.
16. Haemorrhage may occur if there are leaks in the system. Connections
must be tightly secured and the giving set and line closely observed..
Emboli. Air or thrombo emboli may occur.
Care should be taken to aspirate air bubbles
Accidental drug injection may cause severe, irreversible damage to
the hand.
-No drugs should be injected via an arterial line
- The line should be labelled (in red) to reduce the likelihood of this
occurring
Arterial vasospasm
Partial occlusion due to large cannula width, multiple attempts at
insertion and long duration of use
Permanent total occlusion
Sepsis or bacteraemia secondary to infected radial arterial lines is very
rare (0.13%);
-local infection is more common.
-if the area looks inflamed the line site should be changed.
17.
18. –Concentration of a drug
into the tissues served by
the cannulated artery can
result in cell death
–Skin necrosis, severe
gangrene, limb ischemia,
amputation & permanent
disabilities
19. Mechanism of action
A transducer is a device that
reads the fluctuations in pressure
– it doesn’t matter if it’s arterial, or
central venous, or PA
The column of saline in the arterial
set transmits the pressure changes
to the diaphragm in the transducer
The transducer reads the changing
pressure, and changes it into an
electrical signal that goes up and
down as the pressure does which is
displayed as an arterial waveform
The transducer connects to the
bedside monitor with a cable, and
the wave shows up on the screen,
going from left to right
20. The transducer has to sit in a “transducer holder” – this is the
white plastic plate that screws onto the rolling pole that holds the
whole setup.
The transducer has to be levelled correctly-to make sure that it‟s at
the fourth intercostal space, at the mid-axillary line
(Phlebostatic axis)
Make sure there‟s no air in the line before you hook it up to the
patient – use the flusher to clear bubbles out of the tubing.
Zero the line to atmospheric pressure properly
Choose a screen scale that lets you see the waveform clearly.
21. To ensure accuracy of readings
Flush the device & turn it off to patient but open to
atmosphere
These exert pressure on transducer
This pressure is called zero
Zero once per shift or if values are questionable
Ensure flush bag is pumped up
22. Once inserted, an
arterial waveform trace
should be displayed at
all times
This confirms that the
invasive arterial BP
monitoring is set up
correctly, and
minimizes problems.
23. :
The highest point - systolic
pressure,
-the lowest is the diastolic.
Everybody see the little notch
on the diastolic downslope? –
there‟s one in each beat.
A little after the beginning of
diastole – the start of the
downward wave – the aortic
valve flips closed, generating a
little back-pressure bump:
called the “dicrotic notch”..
24. Now we know how the arterial pressure monitoring
system works, we need to be able to decide
whether or not the trace (and BP in
numerical format) is accurate.
Failure to notice this may lead to unnecessary, or
missed treatments for our patients.
There are 2 main abnormal tracing problems that
can occur once the monitor gain is set correctly.
26. Dampening occurs due to:
◦ air bubbles
◦ overly compliant, distensible tubing
◦ catheter kinks
◦ clots
◦ injection ports
◦ low flush bag pressure or no fluid in the flush bag
◦ Improper scaling
◦ Severe hypotension if everything else is ruled out
This type of trace Under estimate SBP, over estimate
DBP
28. Resonance occurs due to:
◦ long tubing
◦ overly stiff, non-compliant tubing
◦ increased vascular resistance
◦ reverberations in tubing causing harmonics that distort
the trace (i.e. high systolic and low diastolic)
◦ non-fully opened stopcock valve
This type of trace
Over estimate SBP, under estimate DBP
29. Arterial lines measure systolic BP approximately 5
mmHg higher and the diastolic BP
approximately 8 mmHg lower compared to non-
invasive BP (NIBP) measurement
31. “It takes a year just to learn which way to turn the
stopcocks!”
This is really true: some stopcocks point to where
they‟re open, and some point to where they‟re closed
– it just takes some time to learn which is which.
The trick is remembering which way to turn the
stopcock, and avoiding a mess.
Don‟t forget to clear the stopcock, recap, and then
flush the line.
Keep things nice and sterile.
32. This probably means that the artery being monitored
or gone into spasm.
You need to think about things that might make this
happen:
-Is the patient very cold?
-Are his extremities poorly perfused?
-Is he on a “shipload” of pressors, making his
arterial bed tighten up –
- Is he “dry” as well?
Sometimes arteries become unhappy with catheters in
them, and you just have to convince the team that the
patient needs a new one placed in another site.
33. The first thing to think about is:
1.Is the arterial catheter still in place? Yes? Try drawing
with a 3cc syringe from the stopcock – if it draws normally,
then you‟ve got a hardware problem
2.Cables become loose?
3.Did the screen scale get accidentally set to, say, 40,
instead of 150 or 200mm of pressure?- you‟ll only see a flat
line.
4.Is it a transducer setup Failure – try a new setup.
If the line doesn‟t draw –
-Is there a clot in the hub?
-Try taking the site dressing down – is the catheter kinked
going into the patient?
- Sometimes art-lines just fail – the artery spasms and
won‟t open up – time for a new site.
34. The routine now is 96 hours – make sure that you
label the line setup when you hang it. Obviously,
change the line setup if it is contaminated in any
way.
35. Usually this will be pretty obvious:
the pulse will diminish, or go away altogether. The
hand may look dusky, or be cold, or lose some
sensation – remember to assess for coloring,
sensation, motion, and capillary refill.
If you think that the a-line is threatening the
patient’s hand, let the team know right away, and be
ready to set up for another insertion somewhere else if
the line is still necessary.
36. Compress the site with a sterile 4x4 for at least 5
minutes, or longer if the patient is anticoagulated.
Assess the perfusion of the hand.
Make sure you put the patient on the non-
invasive cuff at meaningful intervals while you
talk to the team about replacing the line
37. This is usually pretty obvious – the patient is
hemodynamically stable, needs only one or two
blood draws in a day, no more need for ABGs
38. Disconnect the cable from the monitor which will
automatically turn off the alarms.
Take out the sutures in the usual way with a fresh sterile kit.
Have a gauzepiece ready, pull the catheter, and manually
compress the site for at least 3 to 5 minutes.
Make sure the patient‟s hand is still perfused.
Check for hematoma or bleeding, put a compression
dressing on the site (not too tight!), which you can then take
off after about an hour.
Recheck the site hourly for a few hours afterwards – a
hematoma could still form, and since there isn‟t a whole lot of
room in a wrist, you‟d definitely want to know!
