Pump up the volume

Caring for patients with ventricular assist devices in EMS


Assessment and treatment of a patient with a ventricular assist device (VAD) is slightly different than what is expected in any other patient out there. Let’s look at what we need to know with a patient who has a VAD who is having a VAD-related problem.

What is your initial impression? Are they alert and oriented? Pink, warm and dry? As the VAD is responsible for delivering oxygenated blood to the rest of the body, a patient who is alert and able to answer questions, who has good skin color and temperature, tells us that the VAD is doing its job.

You will NOT feel a pulse on your VAD patient – radial, brachial, carotid, femoral, etc.

A left ventricular assist device (LVAD) pumping blood from the left ventricle to the aorta, connected to an externally worn control unit and battery pack.
A left ventricular assist device (LVAD) pumping blood from the left ventricle to the aorta, connected to an externally worn control unit and battery pack. (Photo/Wikipedia)

That will make you take pause for a minute.

This patient is sitting there and talking to you, and you can’t feel a pulse. This is normal. The VAD is not a pulsatile pump. There isn’t the surge from a pulsation to give you the feel of a pulse.

What about heart sounds? While the heart is still beating, the lub-dub that we expect to hear can’t be heard over the VAD sounds. And that’s exactly what you should be charting, “unable to assess heart tones due to VAD sounds.” The sound of a VAD is a constant high pitched whirring sound. You can put in the narrative portion of your chart that the VAD sounds are constant and high pitched. What you don’t want to hear is crunching noises. “Ice in a blender” is a good description of what you don’t want. This indicates blood clots that are being pulverized by the pump as the blood flows through it [3].

How about blood pressure? As you can’t hear Korotkoff sounds, you will not be able to take a manual blood pressure. In all VAD patients, we look at their mean arterial pressure (MAP). This is usually found in between the systolic and diastolic reading in parenthesis. A VAD patient should have a MAP of 70-90 mmHg to ensure they are getting perfusion to all areas of their brain without increasing the workload of the VAD and the patient’s vascular system [1,6,8].

Because there are no pulsations in the patient’s circulatory system, it will also be hard to determine whether a pulse oximetry is reliable.

The best way to assess a patient with a VAD is to focus on skin color, temperature, and capillary refill, level of consciousness and make sure their MAP is 70-90 mmHg [10].

Ventricular assist device complications

Some of the more common reasons why a VAD patient would call 911 are for controller alarms, shortness of breath, hypotension, chest pain, GI bleed and altered mental status [2]. Controller alarms can be something as benign as needing to replace the batteries or a low flow alarm.

The actual screen of a Heartmate 2 VAD measures 2x2 inches. There are only three buttons on this controller. One is the battery button and will indicate when your patient should change their batteries. The silence alarm button does just that; it silences the very loud alarm that tells your patient they need to address a VAD problem. Get comfortable with pressing the alarm silence button.

There are four settings can be found when scrolling through the controller/user interface screen. When assessing your patient and/or talking with the VAD coordinator, this information can pinpoint a problem that could be easily fixed. We refer to these as “the 4 Ps of controller settings:”

  1. Pump flow. How much blood is being pumped in one minute
  2. Pump speed. How fast the pump is cycling in rotations/rounds per minute
  3. Pulse index. How efficient the pump is working versus the native heart function
  4. Power. How much electricity/battery power it is pulling to operate

Most important of all, you cannot hurt a patient by pushing any of these buttons. You will not change how this VAD works or doesn’t work by pushing these buttons. Don’t be afraid of handling the controller.

What happens if you have a low flow alarm, or your patient is pale and diaphoretic? What did we learn in EMT class? Lay them flat and raise their legs. If you are ALS, you could consider getting IV access and giving them a small fluid bolus, but remember, these patients have a VAD because they are in heart failure. Be cautious with fluids.

Every VAD patient has a VAD coordinator. This is a 24/7 on-call expert in VADs. Ask your patient for the number to their VAD coordinator and call them for suggestions as to what needs to be done [9]. You can also access the comprehensive VAD guide which includes every VAD that is on the market, including those that aren’t implanted in the U.S. This guide has color-coded pages for each brand of VAD, including pictures of each VAD, how to change batteries, FAQs, etc. This guide is free and not copyrighted and can be downloaded to a kindle app on your phone or printed off and left in your ambulance for reference. The VAD guide can be found here [10].


Read more:

Read more:

The arresting LVAD patient: A review of the updated recommendations

An evidence-based, consensus approach to managing unconscious and arresting patients with a mechanical assist device, like LVAD


References

  1. Bennett, M. K., & Adatya, S. (2015, December). Blood Pressure management in mechanical circulatory support [Article from industry article]. Journal of Thoracic Disease, 7(12), 2125-2128. http://dx.doi.org/https://dx.doi.org/10.3978%2Fj.issn.2072-1439.2015.11.05
  2. Trinquero, P., Pirotte, A., Gallagher, Lauren., Iwaki, Kimberly., Beach, Christopher., Wilcox, Jane. West J Emerg Med. 2018 Sep; 19(5): 834–841. Published online 2018 Jul 26. doi: 10.5811/westjem.2018.5.37023
  3. Caring for patients with a left ventricular assist device [Online magazine]. (2017, May). American Nurse Today, 12(5). Retrieved from https://www.americannursetoday.com/caring-patients-left-ventricular-assist-device/
  4. Givertz, M. (2011, September). Ventricular Assist Devices [article]. Circulation (American Heart Association), 124, 305-311. http://dx.doi.org/DOI: 10.1161/CIRCULATIONAHA.111.018226
  5. Mid-Atlantic Regional Pre-Hospital Mechanical Circulatory Support Task Force 2009 Field Guide. (2009). In Mid-Atlantic Regional Pre-Hospital Mechanical Circulatory Support Task Force Field Guide.
  6. Najjar, S., Slaughter, M., Pagani, F., Starling, R., McGee, E., Eckman, P., ... Boyce, S. (2014, January). An analysis of pump thrombus events in patients in the HeartWare ADVANCE Bridge to transplant and continued access protocol trial. [Article]. Journal of Heart and Lung Transplant, 33(1), 23-34. http://dx.doi.org/10.1016/j.healun.2013.12.001
  7. Partyka, C., & Taylor, B. (2014, April 7, 2014). Review Article: Ventricular Assist Devices in the Emergency Department [Article]. Emergency Medicine Australasia, 26(2), 104-112. http://dx.doi.org/https://doi.org/10.1111/1742-6723.12171
  8. Saeed, O., Jermyn, R., Kargoli, F., Madan, S., Mannem, S., Gunda, S., ... Patel, S. (2015, May). Blood pressure and adverse events during continuous flow left ventricular assist device support [Article]. Circulation Heart Failure, 8(3), 551-556. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/25870369
  9. Guglin, M. 2020 The Journal of Heart and Lung Transplantation. Vol 39, Issue 4, Supplement, S491. DOI. https://doi.org/10.1016/j.healun.2020.01.068
  10. Thoratec. (2021). EMS Guide to Mechanical Circulatory Support Organization. Retrieved from https://www.mylvad.com/sites/default/files/EMS%20Field%20Guides/2021%20Field%20Guides/ICCAC_Emergency_Guides_20_21-1.pdf

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