Hemodynamic Monitoring Part I (ABP, CVP, Ao) MICU Competencies 2006-2007

What is Hemodynamic Monitoring? Non-invasive = clinical assessment & NBP Direct measurement of arterial pressure Invasive hemodynamic monitoring

Noninvasive Hemodynamic Monitoring Noninvasive BP Heart Rate, pulses Mental Status Mottling (absent) Skin Temperature Capillary Refill Urine Output

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

Why A Properly Fitting Cuff? Too small causes false-high reading Too LARGE causes false-low reading

Indications for Arterial Blood Pressure Frequent titration of vasoactive drips Unstable blood pressures Frequent ABGs or labs Unable to obtain Non-invasive BP

Supplies to Gather Arterial Catheter Pressure Tubing Pressure Bag Pressure Cable Pressure Bag Flush – 500cc NS

Supplies to Gather Sterile Gown (2) Sterile Towels (3) Sterile Gloves Suture (silk 2.0) Chlorhexidine Swabs Mask

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

Potential Complications Associated With Arterial Lines Hemorrhage Air Emboli Infection Altered Skin Integrity Impaired Circulation

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

Central Venous Pressure Assesses . . . Intravascular volume status Right ventricular function Patient response to drugs &/or fluids

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

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

Phlebostatic Axis 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) (Edwards Lifesciences, n.d.)

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

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

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

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

Troubleshooting Inability to obtain/zero waveform Connections between cable & monitor Position of stopcocks Retry zeroing after above adjustments

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

Supplies to Gather Pressure Cable Pressure Tubing Connector (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)

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

Pressure Measurement CVP=13 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. 15 10 5 -5 CVP=13

Assist-Control 200 ms { Ao { CVP 200 ms

CPAP with Pressure Support 200 ms { Ao { 200 ms CVP

CPAP without Pressure Support 200 ms { Ao { 200 ms CVP

Incorrect method! This point was identified as end-expiration for a pt. who did not have an Ao set up. 40 30 20 10 -10 Correct method! 30 sec after the above tracing, Ao was added & true end-expiration clearly identified.

Same patient 20 minutes later 40 30 20 10 -10 40 30 20 10 -10

15 10 5 -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

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)

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