vad presentatioin

TheIn and Outs

Of TheVentricular Assist Device

By: Nicholas Todd

Objectives

• Define Ventricle Assist Device• Identify hemodynamic differences in patients with

a VAD• List VAD related complication• Demonstrate how to assess a patient with a VAD• Describe how to treat VAD complications • Identify VAD resources that can be utilized when

caring for these patients

What is a VAD?

• A left ventricular assist device (LVAD) is a pump that is used for patients who have reached end-stage heart failure or awaiting a heart transplant. The LVAD’s are surgically implanted and are attached to the left ventricle and aorta. The LVAD is a battery-operated, mechanical pump, which then helps the left ventricle pump blood to the rest of the body.

Ventricular Assist Device (VAD)

• A mechanical pump that is surgically attached to one of the heart’s ventricles to augment or replace native ventricular function

• Can be used for the left (LVAD), right (RVAD), or both ventricles (BiVAD)

• Are powered by external power sources that connect to the implanted pump via a percutaneous lead (driveline) that exits the body on the right abdomen

• Pump output flow will be non-pulsatile

Indications for VAD Bridge to transplant

(BTT)• Most common• Allow rehab from

severe CHF while awaiting a donor heart

“Destination” therapy (DT)• Permanent device,

instead of transplant • Currently only in

transplant-ineligible patients

Bridge to recovery (BTR)• Unload heart, allow

“reverse remodeling”

• Can be short term or long term

Bridge to candidacy (BTC)/ Bridge to decision (BTD)• When eligibility

unclear at implant• Not true “indication”

but for many pts

VAD Setup Continuous-flow devices

• Impeller (spinning turbine-like rotor blade) propels blood continuously forward into systemic circulation.

• Axial flow: blood leaves impeller blades in the same direction as it enters (think fan or boat motor propeller).

Most implanted devices are LVADs only LVAD’s are quite and cannot be heard outside of the patient’s

body. Assess VAD status by auscultation over the apex of the LV. The VAD should have a continuous, smooth humming sound.

The Patient may have a weak, irregular, or non-palpable pulse

The Patient may have a narrow pulse pressure and may not be measurable with automated blood pressure monitors. This is due to the continuous forward outflow from the VAD. Recommended use of a Doppler and a manual B/P cuff to obtain B/P.

The Mean Arterial Pressure is the key in monitoring hemodynamics. Ideal range is 65-90 mmHg.

VAD Key Parameters Flow:• Measured in liters per minute• Correlates with pump speed (speed=flow,

↓speed=↓flow)• Dependent on Preload and Afterload

Speed:• How fast the impeller of the internal pump

spins• Measured in revolutions per minute (rpm)• Flow speed is set and determined by VAD

clinical team and usually cannot be manipulated outside of the hospital

VAD Key Parameters Power:• The amount of power the VAD consumes to

continually run at a set speed• Sudden or gradual sustained increases in the

power can indicate thrombus inside the VAD

Pulsatility Index (PI):• A measure of the pressure differential inside

the internal VAD pump during the native heart’s cardiac cycle

• Varies by patient• Indicates volume status, right ventricle

function, and native heart contractility

VAD Key Parameters

The device parameters are displayed numerically on the VAD console or controller

Will vary with each individual patient a VAD device

VAD ParametersParameters for VAD devices vary with

each device model

Patients and their care givers know the expectable parameter ranges and goals for their specific device

Contact the VAD Coordinator at the implanting medical center, they will be your best resource when treating a VAD patient.

Basic VAD Management

VADs are: Preload-dependent EKG-independent Afterload-sensitive Anticoagulated Prone to:• infection• bleeding• thrombosis/stroke• mechanical malfunction

MOST COMMON VADEQUIPMENT

HeartMate II LVAS Internally implanted, axial-flow (non-

pulsatile) device left heart support only speed: 8000-15000 rpm• flow: ~3-8 lpm

Medium- to long-term therapy (months to years)

bridge to transplant (FDA-approved) destination therapy (investigational)

VAD ISSUES

Problems And Complications

Major VAD Complications Bleeding Thrombosis Infection• sepsis is leading cause of death in long-

term VAD support RV dysfunction/failure Suckdown (low preload causes a

nonpulsatle VAD to collapse the ventricle)

Device failure/malfunction (highly variable by device type)

Hemolysis (the VAD destroys blood cells)


Other Common Issues Arrhythmias

• A patient can be in a lethal arrhythmia and be asymptomatic. Treat the patient not the monitor.

• Do not cardiovert/ defib. unless the patient is unstable with the arrhythmia.

• Do not initiate chest compressions unless instructed by a physician or VAD coordinator. Chest compressions can disrupt the implanted equipment causing bleeding and death

• Electrical shock from cardiovert/ defib. will not damage any of the VAD equipment


Other Common Issues Hypertension

• High afterload can limit VAD flow/ output

• Do not administer antihypertensive medications or nitrates unless instructed by a physician or VAD Coordinator

Hypotension/ loss of Preload• All VADs are preload dependent. A

loss or reduction in preload will compromise VAD function and limit flow/ output


Other Common Issues Depression/ Adjustment Disorders

• Living with a VAD is difficult to management for a lot of patients.

• A large percentage of patients experience symptoms of depression

Portability/ Ergonomics• The external VAD equipment is

heavy and cumbersome limiting a patient’s mobility and greatly impacting their quality of life.


Bleeding & Thrombosis Careful control of anticoagulation

is imperative• Patients are often on both

anticoagulants and platelet inhibitors

• Device thrombosis Typically revealed by increased

power and signs and symptoms of hemolysis


Bleeding & Thrombosis Treatment• Assess for signs and symptoms

of bleeding• Neuro Assessment to rule out

CVA• Initiate IV therapy and

administer fluid slowly to maintain preload

• Device Thrombus is treated with low dose lytics and/ or increasing anticoagulation therapy


Infection• The leading cause of mortality in

VAD patients• Higher incidence in pulsatile VADs• The driveline provides direct

access into the body and into the blood stream

• Often recurrent and difficult to treat


Suckdown LV collapse due to

hypovolemia/hypotension or VAD overdrive

Indicators: hypotension, PVCs/VT, low VAD flows.


Treating Suckdown• Initiate a peripheral IV and

slowly give volume to increase preload

• Assess for signs and symptoms of bleeding and sepsis


Device Failure This is a true emergency requiring

immediate transport to the implanting VAD center

Patients & caregivers are trained to identify signs and symptoms of device failure

May require the VAD to be replaced


Hemolysis Blood cells are destroyed as they

travel through the VAD


Treating Hemolysis• Initiate a peripheral IV and

slowly give volume• If thrombus is suspected to be

causing hemolysis, administer lytics and anticoagulants as able/ ordered

Alarms All VAD devices typically have two

distingue alarms to indicate a problem and it’s severity • Advisory Alarms• Critical/ Hazardous Alarms

Alarms Advisory Alarms are intermittent beeping

sounds that have a corresponding YELLOW light that illuminates on the system controller• Not critical but the device requires

attention• Likely due to low battery, cable

disconnected, or device not functioning properly.

Alarms Hazardous or Critical alarms are a loud,

continuous, shrill sound that have a corresponding RED light that illuminates on the system controller• Indicating the device needs

immediate attention• Often because the pump has

stopped or a problem is detected with the system controller

• Most likely intervention required is to change out the system controller

Field Management

All VADs are dependent on adequate preload in order to maintain proper functioning

Volume resuscitation in an unstable VAD patient is the first line of therapy before vasopressors but be cautious with fluid as to not over load the right ventricle in L VADs only.

Field ManagementNitrates can be detrimental to a VAD

patient because of the reduction in preload

• Results in decreased pump efficiency

• Consult with medical control before administering nitrates per protocol

Field Management

Initiate IV therapy with all VAD patients if possible

• Use aseptic technique due to the patient’s increased risks of infection

Field ManagementVAD patients are susceptible to other

injuries unrelated to the VAD

Contact the VAD Coordinator, they are your most valuable resource when encountering these patients

Consult with medical control about transport

Patient Transport This is emergency, resource and protocol driven

decision makingVAD patients require unique care that not all

medical centers are equipped to handle. Transport to the implanting center when able or the closest VAD center

Make sure when transporting to bring all VAD related equipment

Secure VAD batteries and the controller to prevent dropping or damage. If batteries need to be changed during transport, change one at a time system will alarm during battery change but this is normal and will stop.

Make sure to keep all cables tangle and kink free

Pre-Planning For Transport

Medical Control

• Inquire ahead of time the level of knowledge/ comfort with your medical directors regarding the management of VAD patient

Know Transport Options

• Air vs. Ground

• Know your tertiary facilities and their ability to management VAD patients

Things To Remember

EMS can walk into just about any situationDepending on the individuals- the family may

not be able to handle the emergencyListen to the family members that can handle

the emergency and “assist” them with whatever they need

The only resources/ tools you can truly rely on are the ones you bring to the call

Follow-up and educate yourself to new technologies that keep entering into the industry

Things To Remember

Ask for the contact number for the managing center’s VAD Coordinator as soon as you arrive, this should be on the person or close by. This is the coordinator they work very closely with and will be your best resource

Family, friends, co-workers- listen to them for direction, they should be educated/ trained to assist with most VAD related complications

911 activation may not be for a VAD related emergency

Things To Remember

Emergency bag containing back-up VAD supplies needs to stay with the patient at all times. Should contain extra batteries and the spare system controller

Ask the family for any trouble shooting guidelines that maybe available. This often includes various alarms and interventions

Remember that the family/ friends are not emergency responders or maybe too upset to assist you

If a VAD patient calls 911 it will not be for something simple like a battery change. VAD related emergencies are serious life threatening events

Additional resources materials and information please visit:

www.thoratec.comwww.jarvikheart.comwww.umm.edu/heart/index.htm

http://www.thoratec.com/

http://www.jarvikheart.com/

http://www.umm.edu/heart/index.htm

http://www.umm.edu/heart/index.htm

THANK YOU FOR YOUR TIME !!!!

vad presentatioin

Health & Medicine