1. Set-Up Hemodynamic Circuit
  2. Maintain Accuracy
  3. Monitor Blood Pressure
  4. Display Waveform
  5. Maintain Arterial Line Alarms

  1. Maintain Closed System
  2. Obtain Blood Samples
  3. Change Dressings
  4. Monitor Arterial Site
  5. Document
  6. Remove Arterial Line




Set-Up Hemodynamic Circuit

Clinical Nurses in CCTC are responsible for the priming, zeroing, leveling, and maintenance of hemodynamic pressure monitoring circuits and for the assessment and monitoring of hemodynamic pressures and waveforms.

Clinical Nurses may flush hemodynamic monitoring circuits as required to maintain patency.


Clinical Nurses in CCTC have received additional education in the care of invasive monitoring circuits. Refer to Procedure for Hemodynamic Monitoring Circuits.



Maintain Accuracy

Hemodynamic transducers are zeroed at each initial setup, with the air-fluid interface (stopcock above transducer) leveled to the mid-axillary line.

Transducer levels should be validated at the beginning of each shift, prior to each PWP or CVP measurement, following position changes, and prn to validate hemodynamic pressures.

Document level confirmation in the graphic record. Documentation is required at the start of each shift and q6h, prior to each CVP and PWP measurement, and following transducer repositioning.


Zeroing eliminates the effect of atmospheric pressure on measured hemodyamic values.

Leveling eliminates the influence of hydrostatic pressure on the transducer. A transducer that is positioned below the patient's heart will produce falsely elevated pressures and a transducer positioned above the patient's heart will produce falsely low pressures.


Monitor Blood Pressure

Continuous arterial pressure monitoring is indicated for patients requiring BP monitoring >q1h, receiving continuous IV infusion of medications that affect cardiac output/blood pressure, requiring frequent blood gas monitoring or who are hemodynamically/neurologically unstable.

Prior to recording hemodynamic values, evaluate pressure waveforms, verify transducer levels, and ensure that sufficient flush volume and pressure is present.

When comparing NIBP to arterial line pressures, MBP provides the most appropriate comparison. Compare cuff to NIBP pressures taken from the same limb.


Cuff BP measurements become increasing less accurate when hypotension develops. Accuracy is also affected by user technique and cuff size. Insertion of an arterial line is easiest when a patient has an adequate BP. Continuous infusion of vasoactive drugs necessitates continuous BP monitoring to evaluate response to drug therapy and to identify adverse effects.

NIBP cuffs do not provide continuous pressure monitoring. Although more accurate than auscultative BP monitoring, NIBP cuffs can become inaccurate when peripheral circulation is compromised. NIBP cuffs are uncomfortable and can produce bruising in susceptible patients; they are not appropriate when >q1h BP monitoring is required. Repetitive inflation of a BP cuff can lead to falsely elevated readings.

Systolic BP readings obtained from invasive arterial catheters are often accentuated, with reduced diastolic readings. NIBP measurements utilize different technology and may produce systolic readings that do not match the arterial line systolic reading. MBP from arterial lines and NIBP circuits provide more appropriate correlation.

Patients may have differing BPs between left and right limbs, and peripheral circulation may be reduced in shock.

Arterial pressures may be falsely elevated if an artery is in spasm. This can occur following repeated insertion attempts. A warm towel wrapped around the site may help to reduce spasm.


Display Waveforms

Invasive arterial lines and right heart catheters must be connected to a monitor that provides a continuous waveform display.


Waveform quality must be assessed prior to acceptance of a displayed pressure value. Pressures are derived from the detected waveform; poor quality waveforms will produce inaccurate pressure readings.

The waveform from the tip of the right heart catheter must be displayed continually to demonstrate the catheter tip location within the heart. Continuous monitoring is required to promptly detect catheter migration into the right ventricle or pulmonary wedge position.


Maintain Arterial Line Alarms

alarms must be on for all patients requiring continuous arterial pressure monitoring. Alarm settings should be selected based on the degree of fluctuation in the patient's BP. Upper and lower alarm limits that represent clinically important changes are selected for each individual patient.

High and low alarm settings must be assessed and documented each hour in the graphic record.

Alarms may need to be disabled if an arterial line becomes positional. If an arterial line alarms is disabled, documentation in the AI record is required. Documentation should include the reason for disabling the alarm and should describe troubleshooting strategies.


Alarms provide prompt notification of both changes in the BP and accidental disconnection/opening of the circuit.


Maintain Closed System

All stopcocks must have dead-end (non-vented) luer lock caps or luer lock connected infusions. This includes stopcocks located on transducers.

Hemodynamic circuits are changed with each new line and prn.


To prevent accidental entry of air or contaminants. Accidental movement of a stopcock that does not have a dead end luer lock cap can result in hemorrhage/air embolus.


Obtain Blood Samples

Clinical Nurses may draw blood from indwelling arterial and venous lines. All infusion must be stopped (introducer, distal and proximal infusions from multiple lines) during blood withdrawal. Stopcocks should be turned to 45 degrees between syringe changes.
Clearlink (TM) access caps should be changed when drawing blood culture samples and a minimum of q 7 days and prn.



See Procedure for Blood Withdrawal; Blood Gases Arterial; and Blood Gases Venous.


Change Dressings

Arterial line dressings are changed q 2 days (tape and gauze)and prn, when using Tegaderm(TM) transparent dressing change q 7days and prn when occlusivity is disrupted. Document date of change in the graphic record and kardex. Record any redness or abnormal findings in the AI record and report to the physician.
See Procedure for Arterial and Central Line Dressings. Don appropriate PPE when accessing an arterial line.

Lines are changed prn for evidence of site infection or sepsis.



Dressings of tape and gauze are change q 2 days and prn in critically ill patients to allow site inspection and to reduce bacterial colonization Skin condition, diaphoresis and site oozing necessitates more frequent dressing changes in critically ill patients.

It is acceptable and prefered LHSC Infection Control practice to use a Tegaderm (TM) dressing that can be changed q7days as per general hospital policy, as long as occlusivity is maintained.

The Centre for Disease Control does not recommend routine line changes.


Monitor Arterial Site

Arterial line sites/dressing should be kept as visible as possible. Check the site q1h and prn to assess for bleeding.

Use minimal dressing material.

Assess distal extremity for evidence of compromised color, circulation or motion q1h.


Bleeding can occur very rapidly from dislodged arterial catheters or opened circuits.

Bulky dressings can mask bleeding. Pressure dressings will not stop arterial bleeding.

Thrombus, catheter spasm and small vessels can lead to compromised distal circulation.



Record S/D and M BP in the graphic record q1h and prn.

Assess site q shift and document in the 24 hour assessment record. Assess patency q shift and q 4 h and document in the intravascular device section of the flow sheet.

Sign for heparinized flush solution in the MAR.

Document dressing changes in flow sheet. Star and DAR abnormal findings.



Per hospital standards.


Remove Arterial Line

Clinical Nurses may remove arterial lines in CCTC, with an order from a physician. Document removal in the intravascular device section of the graphic record.

See Procedure for Removal of Peripheral Arterial Line or Femoral Arterial Line.





Last Update: March 30, 2010



Centers for Disease Control and Prevention.(2002) Guidelines for Prevention of Intravascular Catheter - Related Infections.

LHSC Procedure for Care, Use and Maintenance of Central Intravascular devices. (August, 2009).



LHSCHealth Professionals

Last Updated March 30, 2010 | © 2007, LHSC, London Ontario Canada