LVAD What is a Ventricular Assist Device (VAD)?
A ventricular assist device (VAD) is a mechanical pump that’s used to support heart
function and blood flow in people who have weakened hearts.
How does a VAD work?
The device takes blood from a lower chamber of the heart and helps pump it to the body
and vital organs, just as a healthy heart would.
What are the parts of a VAD?
The basic parts of a VAD include: a small tube that carries blood out of your heart into a
pump; another tube that carries blood from the pump to your blood vessels, which
deliver the blood to your body; and a power source.
What is the power source?
The power source is either batteries or AC power. The power source is connected to a
control unit that monitors the VAD’s functions. The batteries are carried in a case
usually located in a holster in a vest wrapped around the patients’ shoulders. Batteries
can last about 10-12 hours under normal physiologic conditions
What does the control unit or controller do?
The control unit gives warnings, or alarms, if the power is low or if it senses that the
device isn’t working right. It is a computer. •
MOST patients have a tag located on the controller around their waist that
says what type of device it is, what institution put it in and a number to call.
Most importantly is the color of the tag – it matches this EMS Field Guide
and allows you to quickly locate the device you are caring for.
Unstable Patients 1. Risk of bleeding due to anticoagulant and antiplatelet therapy 2. Risk of retrograde flow. There are no valves. Pt may have symptoms of heart failure, pulmonary congestion, cardiogenic shock, LOC or death. 3. Risk of decreased pump flow. The pump flow is dependent on preload and afterload. If patient is dehydrated or bleeding; risk for decreased pump flow. Patient is hypertensive (MAP <90); risk of decreased pump flow. Assessing Patient 1. Peripheral pulses may not be palpable due to continuous flow of the LVAD. § Assess circulation by: o Cap Refill o Skin Color and Temp o POX may be unreliable or inaccurate o Use capnography § Inadequate perfusion o Pt lightheaded; dizzy; cold, clammy skin; cyanosis of the nail beds or lips; deteriorating mental status or LOC 2. BP may need to be checked using a Doppler ultrasound; standard measures may be unreliable and inaccurate. § Systolic BP should be less than 120 § MAP less than 90 3. EKG should not be affected. Follow ACLS protocols regarding treatment for arrhythmias. Not all arrhythmias need immediate treatment because the LVAD may maintain cardiac output. Evaluate carefully before cardioversion or defibrillation. Some patient with a Heart Mate II may still be awake and conscious while in V Tach or fibrillation. It doesn’t interfere with cardiac conduction system. Do not turn off the pump if cardioverting or defibrillating the patient. 4. If defibrillation is necessary § Do not place pads over the pump pocket located in the LUQ § Do not disconnect the controller from the driveline or stop the device 5. If chest compressions occur § May cause disruption of the tubes and the patient may exsanguinate. v If the pump is still working and the patient is unresponsive, cardiac output is still maintained because the machine, the LVAD, is still working. Consider if chest compression are really necessary. Assessing the Pump 1. Listen over the pump pocket, located in the left upper quadrant. A hum will be heard if it is running. 2. Check that the controller power leads are connected to power; either a battery or power module. The green light on the system controller means it is receiving power it does not indicate the pump is running or receiving power. Green pump arrows on the pocket system controller means the pump is running and receiving power. (The system controller and pocket system controller are 2 different kind of controllers that the patient may have) 3. Check for active alarms. 4. If the patient is unstable or perfusion is inadequate check to make sure the drive line is connected; check for damage to the drive line. 5. If the device stopped (even for a few min) there is an increased risk for stroke or thromboembolism if it is restarted. Questions to ask your patients: 1.
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Do you have a pulse? Do you have a hand pump? Do you have an emergency backup bag? Do you have your home power source with you? Where is your portable power cord? How do you reach the VAD coordinator? Do you have a binder of information about your device? v Don’t assume the LVAD is the main cause of your problem if your patient is unresponsive. Is the patient hypoglycemic? Did they overdose? Etc… v Be cautious cutting off clothing…you do not want to cut a cable. A Left Ventricular Access Device is used with patient with severe heart failure; they probably would not be alive if they did not have this in place. There are several patients in the area that have these devices and may show up in the ED. This is just a quick guide so you can become familiar with the device. There is a binder at the charge desk with the specific information regarding the devices. There is also a website you can go to and receive more information. Remember to call the LVAD coordinator ASAP. www.thoratecu.com www.mylvad.com Maggie