Step by Step Nurses’ Guide to Measure a CVP/RAP

So, it’s the middle of the night and your provider asks you to get a CVP on your patient.  You think to yourself, “I haven’t done one since orientation. How do I do that again?”  Fear not, we got you, bestie.

First of all, what is a CVP?  A CVP stands for Central Venous Pressure, and it measures the fluid status on the right side of the heart or the right heart preload.  The normal value is 2 – 6 mm Hg.   You may also see the CVP referred to as the RAP, which stands for Right Atrial Pressure.  It’s the same thing.

Here is a normal CVP tracing.  CVP tracings are atrial tracings with an A, C, and a V waveform.

How to measure a CVP – 

1. Make sure the patient has a central line.
2. Hook your distal lumen (with the clave removed) to a pressure monitoring system. 
3. Perform a square wave test to assess if the system is dampened.  Make sure the system doesn’t have any kinks or obstructions.  When priming the system, do it while your fluid is not on a pressure bag to avoid any microbubbles in your tubing. Microbubbles will dampen the system.
4. Zero and level the system to the patient’s phlebostatic axis, which is the 4th intercostal space mid-anterior posterior of the chest wall.  HOB can range between 0 – 45 degrees.
5. Press freeze waves on your cardiac monitoring system.
6. Read your CVP tracing at the end of expiration.
7. Identify the end of the PR interval on your EKG strip and follow it down to the CVP tracing.  This is the A wave.  Bisect the A wave to find the CVP value.  Alternatively, you can take the top of the A wave and the bottom of the A wave, add them together, and divide them in half. 
8. If your patient is in atrial fibrillation, use the Z-point method.  Go to the end of QRS and follow it directly down to your CVP waveform.  Where it intersects with the CVP tracing is your CVP.

Would you like more information on hemodynamic monitoring or tips for Critical Care?

• Be sure to check out Nicole’s Course Hemodynamic Monitoring Boot Camp: Invasive & Non-Invasive Strategies which offers valuable information that is easy to digest. 

Here is a recent review from someone who took this course:

Nicole has a way of simplifying and explaining hemodynamic concepts that makes learning fun and easy. The case reviews at the end of the course are my favorite part. The case reviews help me visualize the patient and apply concepts I learned. – B.D.

• You can also check out Nicole’s Critical Care Survival Guide for all things Critical Care or the CCRN Certification Review Course or the CCRN Study Guide if planning on taking the CCRN Exam.

References:

https://www.uptodate.com/contents/pulmonary-artery-catheterization-interpretation-of-hemodynamic-values-and-waveforms-in-adults?search=hemodynamic%20monitoring&source=search_result&selectedTitle=5%7E150&usage_type=default&display_rank=5

https://www.aacn.org/docs/Photos/Procedure-67-hgavcgfd.pdf