This document provides information on arterial line insertion and monitoring. It discusses indications for arterial lines, equipment needed, insertion techniques, complications, and troubleshooting. The radial artery is typically used as it has a low complication rate and is superficial, allowing for easy compression if needed. Continuous monitoring of arterial waveforms is important to ensure accurate blood pressure readings and detect any issues. Troubleshooting involves assessing the waveform, equipment, and catheter placement to address potential problems like dampening or resonance in the tracing.

1. Dr.Tinku Joseph
DM Pulmonary Medicine Resident
AIMS, Kochi.

2.  Indications
 Preparation & Equipments
 Positioning
 Insertion
 Complications
 Mechanism of Action
 Troubleshooting

3.  An arterial line is an
invasive method to
measure BP.

5. 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.

6. 3. Facilitation of reliable titration
of vasoactive medications.
4. Unable to obtain non invasive
BP.

7. 1) Known deficiencies in collateral
circulation: Raynauds phenomenon,
Thromboangitis obliterans, Brachial
artery insufficiency.
2) Infection of the site.
3) Trauma to the proposed site.
4) Excessive anticoagulation.

8. 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

9.  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.

10. 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.
 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.

11. 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.

14.  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.

15.  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.

16.  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

18. 1. Ensure that all pre-procedure steps are taken
2. Pressure tubing with transducer is connected to
bedside monitor.
3. Perform the Allen’s test to ensure adequate collateral
blood flow.
4. Wash hands and wear gloves
5. For the radial artery, the arm is restrained, palm up,
with an arm board to hold the wrist dorsiflexed

19. For the radial artery, the most
common insertion site, the arm is
restrained, palm up, with an
armboard to hold the wrist
dorsiflexed

20. 6. Apply anesthetic agent (local lidocaine 1-2% or
lidocaine cream).
7. Locate pulsating artery via palpation.
8. Cleanse area selected for arterial line
placement.
9. Prepare patient for puncture.
10. Stabilize artery by pulling skin taut.
11. Puncture skin at 45-60 degree angle for radial
artery; 90 degrees for femoral artery.

21. 12. Advance catheter when flash of blood is observed in
catheter.
13. Connect to pressure I.V. tubing and check for arterial
waveform on bedside monitor.
14. Cleanse area of any blood and allow site to dry.
15. Apply Benzoin to cleansed area and allow to dry.
16. Secure arterial line with tape and cover with a
Tegaderm dressing.
17. 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.
18. Properly dispose of the I.V. sharps and other used
materials.

22.  1. Direct cannulation
 2. Transfixation
 3. Guidewire (Seldinger)
technique

25.  Haemorrhage may occur if there are leaks in
the system. Connections must be tightly
secured.
 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

26.  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.

31.  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

32. 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

33.  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.

35.  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 leveled correctly-to make sure
that it’s at the fourth intercostal space, at the mid-
axillary line (Phlebostatic axis)

36.  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.

39.  To ensure accuracy of readings
 Flush the device & turn it off to patient but open to
atmosphere
 This exerts pressure on transducer
 This pressure is called zero
 Zero once per shift or if values are questionable
 Ensure flush bag is pumped up

40.  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.

41.  The highest point - systolic
pressure,
-the lowest is the diastolic.
Everybody see the little
notch on the diastolic down
slope? – 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”..

44.  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.

45.  Dampened trace

46.  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

47.  Resonant trace

48.  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)
• not-fully opened stopcock valve
 This type of trace:
 Over estimate SBP, under estimate DBP

49.  Arterial lines measure systolic BP approximately 5
mmHg higher and the diastolic BP
approximately 8 mmHg lower compared to non-
invasive BP (NIBP) measurement.

59.  “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.

60.  This probably means that the artery being monitored
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.

61. 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.

62.  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.

63.  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.

64.  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

65.  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

66.  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!