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Hemodynamic MonitoringPart I

(ABP, CVP, Ao)

MICU Competencies2006-2007

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What is Hemodynamic Monitoring?

• Non-invasive = clinical assessment & NBP

• Direct measurement of arterial pressure

• Invasive hemodynamic monitoring

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Noninvasive Hemodynamic Monitoring

• Noninvasive BP

• Heart Rate, pulses

• Mental Status

• Mottling (absent)

• Skin Temperature

• Capillary Refill

• Urine Output

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Proper Fit of a Blood Pressure Cuff

• Width of bladder = 2/3 of upper arm

• Length of bladder encircles 80% arm

• Lower edge of cuff approximately 2.5 cm above the antecubital space

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Why A Properly Fitting Cuff?

• Too small causes false-high reading

• Too LARGE causes false-low reading

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Indications for Arterial Blood Pressure

• Frequent titration of vasoactive drips

• Unstable blood pressures

• Frequent ABGs or labs

• Unable to obtain Non-invasive BP

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Supplies to Gather• Arterial Catheter

• Pressure Tubing

• Pressure Cable

• Pressure Bag

• Flush – 500cc NS

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Supplies to Gather• Sterile Gown (2)

• Sterile Towels (3)

• Sterile Gloves

• Suture (silk 2.0)

• Chlorhexidine Swabs

• Mask

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Leveling and Zeroing• Leveling

– Before/after insertion– If patient, bed or transducer move

• Zeroing – Performed before insertion & readings

• Level and zero at the insertion site

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Potential Complications Associated With Arterial Lines

• Hemorrhage

• Air Emboli

• Infection

• Altered Skin Integrity

• Impaired Circulation

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Documentation• Insertion procedure note

• ABP readings as ordered

• Neurovascular checks every two hours(in musculoskeletal assessment of HED)

• Pressure line flush amounts (3ml/hr)

• Tubing and dressing changes

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Central Venous Pressure Assesses . . .

• Intravascular volume status

• Right ventricular function

• Patient response to drugs &/or fluids

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Central Venous Pressure (CVP)• Central line or pulmonary artery catheter

• Normal values = 2 – 8 mm Hg

• Low CVP = hypovolemia or ↓ venous return

• High CVP = over hydration, ↑ venous return, or right-sided heart failure

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Leveling and Zeroing

• Leveling – Before/after insertion– After patient, bed or transducer move– Aligns transducer with catheter tip

• Zeroing – Performed before insertion & readings

• Level and zero transducer at the phlebostatic axis

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Phlebostatic Axis• 4th intercostal space, mid-axillary line

• Level of the atria

(Edwards Lifesciences, n.d.)

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More on Leveling and Zeroing

• HOB 0 – 60 degrees

• No lateral positioning

• Phlebostatic axis with any position (dotted line)

(Edwards Lifesciences, n.d.)

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Dynamic Flush

Dynamic flush ensures the integrity of the pressure tubing system. Notice how it ascends - forms a square pattern - and bounces below the baseline before returning to the original waveform.•Check dynamic flush after zeroing any pressure tubing system

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System Maintenance

• Change tubing and fluid bag q 96hrs

• No pressors through CVP port

• Antibiotics, NS boluses, blood, & IV pushes are allowed through the CVP line

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Troubleshooting• Improper set-up and equipment

malfunction are the primary causes for hemodynamic monitoring problems

• Retracing the set-up process or tubing (patient to monitor) may identify the problem and solution quickly

• Use your staff resources: Help All, Charge Nurse, Educator, Preceptors, MICU experts

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Troubleshooting Damped Waveforms

Pressure bag inflated to 300 mmHg

Reposition extremity or patient

Verify appropriate scale

Flush or aspirate line

Check or replace module or cable

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Troubleshooting

Inability to obtain/zero waveform

Connections between cable & monitor

Position of stopcocks

Retry zeroing after above adjustments

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Continuous Airway Pressure (Ao)• Also known as Paw, Ao• Purpose:

– Improves accuracy of hemodynamic waveform measurements

– Identification of end-expiration• Positive waveform deflections = positive

pressure ventilation• Negative deflections = spontaneous

inspiratory effort

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Supplies to Gather

• Pressure Cable

• Pressure Tubing

• Connector

(Edwards Lifesciences, n.d.)

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Setting up the Ao

• Discard infusion spike end & cap port

• Connect pressure tubing to vent tubing (using connector opposite heating cable)

• Connect cables • Zero the tubing (leveling not necessary)

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Troubleshooting Ao• Do not prime tubing with fluids!

• Damping will occur with fluid or secretions

• To evacuate any fluids, disconnect pressure tubing from vent tubing and push air through the pressure tubing with a 10 ml syringe connected at one end until fluid-free

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1) Record Ao and CVP on the same strip2) Find end-expiration by drawing a vertical line with a straight edge 200 ms prior to the rise or dip in Ao (1 large

box) associated with a breath.3) Draw a horizontal line through the visually assessed average vascular pressure starting at end-expiration going

backward 200 ms (1 large box).4) Read the pressure at the horizontal line.

Pressure Measurement

1515

10 10 5500

-5-5CVP=13 CVP=13

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200 ms

Assist-Control

Ao

CVP

{{

200 ms

{{

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CPAP with Pressure Support

Ao

CVP

200 ms

{{

200 ms

{{

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CPAP without Pressure Support

Ao

CVP

200 200 msms

{200 ms{{

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40302010

0-10

Incorrect method!This point was identified as end-expiration for a pt. who did not have an Ao set up.

Correct method!30 sec after the above tracing, Ao was added & true end-expiration clearly identified.

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4040303020201010

00-10-10

Same patient 20 minutes later

404030302020101000

-10-10

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1515

10 10 5500

-5-5

CVP=13

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Summary

•Record Ao with CVP

•Read mean CVP at end-expiration as described. No need read vascular pressure at any particular time in the cardiac cycle

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Documentation of CVP• Include on waveform strip

– Position of the HOB– Vasopressors and rates– Amount of PEEP– Scale– CVP measurement– Signature of the nurse

(post in green chart behind graphics tab)

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References & ResourcesBurns, S. M. (2004). Continuous airway pressure monitoring. Critical Care Nurse, 24(6),

70-74.

Chulay, M., & Burns, S. M. (2006). AACN Essentials of critical care. McGraw-Hill: New York.

Edwards. (2006). Pulmonary Artery Catheter Educational Project. http://www.pacep.org

Edwards Lifesciences. (n.d.) Educational videos. www.edwards.com

MICU Routine Practice Guidelines. www.vanderbiltmicu.com

MICU Bedside Resource Books

MICU Education Kits (Red cart in conference room)

MICU Preceptors, Help All Nurses, & Charge Nurses

VUMC policies. http://vumcpolicies.mc.vanderbilt.edu