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


All vascular devices (peripheral, central venous or arterial) can be a source for blood stream infection. Stict aseptic technqiue should be maintained at all times during insertion, dressing changes, medication administration and accessing of intravascular devices. . 

All central venous and arterial lines that are inserted without strict adherence to sterile techniques/established safety bundles should be changed as soon as possible.  Lines inserted during any resuscitation (e.g., trauma resuscusitation, during a crash OR or in another hospital) should be evaluated and considered for replacement. Unless there is clear documentation in the chart to confirm that insertion techniques were maintained, lines should be considered at risk and changed as soon as possible using a new site whenever possible. 

All peripheral IVs should be inserted using aseptic technique. Site should not be touched unless wearing sterile gloves after prepping.  Peripheral IVs should be removed if insertion technique is unknown or within 96 hours.

The insertion of all arterial and central venous lines should adhere to the Central Venous and Arterial Line Safety Checklist and Procedure Note. These forms should be completed and placed in the Progress Note of the Clinical Records. Separate insertion trays are available for arterial and central venous lines.

Arterial and central venous dressing changes should also be done using aseptic technique. Special dressing trays for "Arterial and Central Venous Dressing Trays" are available.

Please refer to the Safety Bundles for Arterial and Central Venous Lines





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 pressure measurement, following patient repositioning 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 any invasive hemodynamic pressure, evaluate the quality/accuracy of the pressure waveform, assess the transducer level and ensure that sufficient flush volume and pressure is present in the system..

When comparing NIBP to arterial line pressures, Mean BP 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 in the 24 Hour graphic record each hour to confirm that the alarm was checked hourly and is "on".

The 24 Hour graphic record has a code to identify whether an arterial line is positional during the hourly checks.

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. This should include the reason for disabling the alarm and should describe troubleshooting strategies.  The "positional" code on the graphic can then be used to explain why the arterial line alarm is turned "off".

If an arterial line becomes positional or it can no longer be used for blood sampling, the physician should be notified and line change considered.  The plan for line management should be documented in the Plan of Care and communicated to the oncoming nurse.


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

The expectation for patient

Positional arterial lines are an important potential source for intravascular infection. Catheter movement activates inflammation at the site and movement of the catheter in and out of the tract can introduce pathogens.

Catheters should be secured to prevent movement and positional arterial lines should be removed.




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. Alcohol impregnated sampling port caps should be maintained on all sampling ports.

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. Stopcocks should be turned to 45 degrees between syringe changes.
Luer-lock needleless access caps should be changed before drawing a blood culture and any time the port has visible blood.

Flush thoroughly after blood sampling and maintain adequate counter pressure to prevent thrombus formation. Reconfirm waveform after flushing.



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


Thrombosis poses a risk to the perfusion of the distal extremity and increases the risk for colonization of pathogens.


Change Dressings

Arterial line dressings are changed q 7 days and PRN when using CHG transparent dressings, or Q 24 H when using gauze.

Dressings should be changed prn if occlusivity is disrupted or if the CHG pad becomes boggy.

Record any redness or abnormal findings in the AI record and report to the physician. See Procedure for Arterial and Central Line Dressings.

Dressing changes should be performed aseptically.  Arterial and Central Venous Dressing Trays are available for ease of collecting supplies.

Non-sterile cap, gown and mask with face shield plus sterile gloves are required.

See Safety Bundles for Arterial and Central Venous Lines



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.

Lines should be removed if there are signs of infection.


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 and waveform q shift and document in the 12 hour assessment record. Assess patency q shift and evaluated q 4 h and document in the intravascular device section of the flow sheet.

A waveform should be printed at the start of each shift and prn and posted to the chart.

Document dressing changes in the graphic record and * 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: December 10, 2015 , December 10, 2015

Morgan, Brenda CNS CCTC



Center for Disease Control (2011). Guidelines for Prevention of Intravascular Infections.

LHSC Procedure for Care, Use and Maintenance of Central Intravascular devices. (2012).

Safer Health Care Now. Central Line Infection Reduciton.



LHSCHealth Professionals

Last Updated December 10, 2015 | © 2007, LHSC, London Ontario Canada