Hemodynamic Monitoring Part I ABP CVP Ao MICU

Hemodynamic Monitoring Part I (ABP, CVP, Ao) MICU Competencies 2006 -2007 1

What is Hemodynamic Monitoring? • Non-invasive = clinical assessment & NBP • Direct measurement of arterial pressure • Invasive hemodynamic monitoring 2

Noninvasive Hemodynamic Monitoring • Noninvasive BP • Heart Rate, pulses • Mental Status • Skin Temperature • Capillary Refill • Urine Output • Mottling (absent) 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 4

Why A Properly Fitting Cuff? • Too small causes false-high reading • Too LARGE causes false-low reading 5

Indications for Arterial Blood Pressure • Frequent titration of vasoactive drips • Unstable blood pressures • Frequent ABGs or labs • Unable to obtain Non-invasive BP 6

Supplies to Gather • Arterial Catheter • Pressure Tubing • Pressure Bag • Flush – 500 cc NS • Pressure Cable 7

Supplies to Gather • Sterile Gown (2) • Suture (silk 2. 0) • Sterile Towels (3) • Chlorhexidine Swabs • Sterile Gloves • Mask 8

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 9

Potential Complications Associated With Arterial Lines • Hemorrhage • Air Emboli • Infection • Altered Skin Integrity • Impaired Circulation 10

Documentation • Insertion procedure note • ABP readings as ordered • Neurovascular checks every two hours (in musculoskeletal assessment of HED) • Pressure line flush amounts (3 ml/hr) • Tubing and dressing changes 11

Central Venous Pressure Assesses. . . • Intravascular volume status • Right ventricular function • Patient response to drugs &/or fluids 12

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 13

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 14

Phlebostatic Axis • 4 th intercostal space, mid-axillary line • Level of the atria (Edwards Lifesciences, n. d. ) 15

More on Leveling and Zeroing • HOB 0 – 60 degrees • No lateral positioning • Phlebostatic axis with any position (dotted line) (Edwards Lifesciences, n. d. ) 16

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 17

System Maintenance • Change tubing and fluid bag q 96 hrs • No pressors through CVP port • Antibiotics, NS boluses, blood, & IV pushes are allowed through the CVP line 18

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 19

Troubleshooting Damped Waveforms üPressure bag inflated to 300 mm. Hg üReposition extremity or patient üVerify appropriate scale üFlush or aspirate line üCheck or replace module or cable 20

Troubleshooting Inability to obtain/zero waveform üConnections between cable & monitor üPosition of stopcocks üRetry zeroing after above adjustments 21

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 22

Supplies to Gather • Pressure Cable • Pressure Tubing • Connector (Edwards Lifesciences, n. d. ) 23

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) 24

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 25

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. 15 10 5 0 -5 CVP=13 26

Assist-Control { CVP { Ao 200 ms 27

CPAP with Pressure Support { { Ao 200 ms CVP 200 ms 28

CPAP without Pressure Support { { Ao 200 ms CVP 200 ms 29

40 30 20 10 0 -10 Incorrect method! This point was identified as endexpiration 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. 30

Same patient 20 minutes later 4040 3030 2020 1010 00 -10 31

15 10 5 0 -5 CVP=13 32

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 33

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) 34

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. Mc. Graw-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 35