Hemodynamic Monitoring(ABP, CVP, Ao)

Anesthesia Technology Fundamentals

ANES 1502

College of DuPage

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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

3

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 15

• 4th intercostal space, mid-axillary line

• Level of the atria

(Edwards Lifesciences, n.d.)

More on Leveling and Zeroing

• HOB 0–60 degrees

• No lateral positioning

• Phlebostatic axis with any position (dotted line)

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(Edwards Lifesciences, n.d.)

Dynamic Flush 17

• 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.

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

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(Edwards Lifesciences, n.d.)

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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Pressure Measurement

1. Record Ao and CVP on the same strip

2. 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.

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1510

50

-5CVP=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 ms

{200 ms

{

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403020100

-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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40302010

0-10

Same patient 20 minutes later

40302010

0-10

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1510

50

-5

CVP=13

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 & Resources

Burns, 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

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