powerpoint presentation: an overview of ventricular assist devices

Drill of the MonthDrill of the MonthDeveloped by Michael LindsayDeveloped by Michael Lindsay

An Overview of Ventricular Assist An Overview of Ventricular Assist DevicesDevices

&&Pre Hospital ManagementPre Hospital Management

Student ObjectivesStudent ObjectivesAt the conclusion of this Drill Students will At the conclusion of this Drill Students will be able to:be able to:

Define Heart FailureDefine Heart Failure Define Ventricular Assist Device (VAD) and their use in treating Define Ventricular Assist Device (VAD) and their use in treating

Heart FailureHeart Failure Identify types of Ventricular Assist DevicesIdentify types of Ventricular Assist Devices Explain the difference between Pulsatile and Nonpulsatile flowExplain the difference between Pulsatile and Nonpulsatile flow Identify hemodynamic differences in patients with a VADIdentify hemodynamic differences in patients with a VAD List VAD related complicationsList VAD related complications Demonstrate how to assess a patient with a VADDemonstrate how to assess a patient with a VAD Describe how to treat VAD complicationsDescribe how to treat VAD complications Identify VAD resources that can be utilized when caring for Identify VAD resources that can be utilized when caring for

these patients. these patients.

Heart FailureHeart Failure** Heart failure is a condition where the heart cannot Heart failure is a condition where the heart cannot

pump enough blood throughout the body. pump enough blood throughout the body. ** It develops over time as the pumping action of the It develops over time as the pumping action of the

heart grows weaker. heart grows weaker. ** Most cases involve the left side where the heart Most cases involve the left side where the heart

cannot pump enough oxygen-rich blood to the rest cannot pump enough oxygen-rich blood to the rest of the body. of the body.

** With right sided failure, the heart cannot effectively With right sided failure, the heart cannot effectively pump blood to the lungs where the blood picks up pump blood to the lungs where the blood picks up oxygen.oxygen.

What is a VAD?What is a VAD?A single system device that is surgically attached A single system device that is surgically attached

to the left ventricle of the heart and to the aorta to the left ventricle of the heart and to the aorta for left ventricular supportfor left ventricular support

For Right Ventricular support, the device is For Right Ventricular support, the device is attached to the right atrium and to the attached to the right atrium and to the pulmonary arterypulmonary artery

Ventricular Assist Device (VAD)Ventricular Assist Device (VAD) A mechanical pump that is surgically attached to one A mechanical pump that is surgically attached to one

of the heart’s ventricles to augment or replace native of the heart’s ventricles to augment or replace native ventricular function ventricular function

Can be used for the left (L VAD), right (R VAD), or both Can be used for the left (L VAD), right (R VAD), or both ventricles (Bi VAD)ventricles (Bi VAD)

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

Pump output flow can be pulsatile or nonpulsatilePump output flow can be pulsatile or nonpulsatile

Why Do We Need VADs?Why Do We Need VADs? Heart disease is the leading cause of death in the Heart disease is the leading cause of death in the

Western worldWestern world ~5 million people in the US have congestive heart ~5 million people in the US have congestive heart

failure (CHF)failure (CHF) 250,000 are in the most advanced stage of CHF250,000 are in the most advanced stage of CHF ~500,000 new cases each year~500,000 new cases each year ~50,000 deaths each year~50,000 deaths each year only effective treatment for end stage CHF is heart only effective treatment for end stage CHF is heart

transplanttransplant

Why Do We Need VADs?Why Do We Need VADs?

But, in 2008:But, in 2008:

7318 people were waiting for a heart7318 people were waiting for a heart

2210 received one2210 received one

623 died waiting623 died waiting

~1200-1500 VAD implanted in 2008~1200-1500 VAD implanted in 2008

Indications for VADIndications for VAD Bridge to transplant (BTT)Bridge to transplant (BTT)

most commonmost common allow rehab from severe allow rehab from severe

CHF while awaiting CHF while awaiting donordonor

Bridge to recovery (BTR)Bridge to recovery (BTR) unload heart, allow unload heart, allow

“reverse remodeling”“reverse remodeling” can be short- or long-can be short- or long-

termterm

““Destination” therapy (DT)Destination” therapy (DT) permanent device, permanent device,

instead of transplantinstead of transplant currently only in currently only in

transplant-ineligible transplant-ineligible patientspatients

Bridge to candidacy (BTC)/Bridge to candidacy (BTC)/Bridge to decision (BTD)Bridge to decision (BTD) when eligibility unclear when eligibility unclear

at implantat implant not true “indication” but not true “indication” but

true for many ptstrue for many pts

Types of VADsTypes of VADs

PulsatilePulsatileandand

Non PulsatileNon Pulsatile

PulsatilePulsatile Ventricle-like pumping sac device.Ventricle-like pumping sac device.

Blood enters via the inflow cannula and fills a flexible Blood enters via the inflow cannula and fills a flexible pumping chamber. pumping chamber.

Electric motor or pneumatic (air) pressure collapses the Electric motor or pneumatic (air) pressure collapses the chamber and forces blood into systemic circulation via the chamber and forces blood into systemic circulation via the outflow cannula. outflow cannula.

Can be LVAD, RVAD, or BiVADCan be LVAD, RVAD, or BiVAD

First-generation devices (in use since early 1980s)First-generation devices (in use since early 1980s)

Patients will have a palpable pulse and a measurable blood Patients will have a palpable pulse and a measurable blood pressure. Both are generated from the VAD output flow.pressure. Both are generated from the VAD output flow.

Pulsatile VAD Key ParametersPulsatile VAD Key Parameters Pump Rate:Pump Rate:

How fast the VAD is pumping (filling & emptying)How fast the VAD is pumping (filling & emptying) Can be set at a fixed rate or can automatically Can be set at a fixed rate or can automatically

adjustadjust Pulsatile VADs are loud and the rate can be Pulsatile VADs are loud and the rate can be

assessed by listening assessed by listening

Output:Output: The amount of blood ejected from the VADThe amount of blood ejected from the VAD Measured is liters per minuteMeasured is liters per minute Is dependent upon preload, afterload, and pump Is dependent upon preload, afterload, and pump

raterate

Non-PulsatileNon-Pulsatile Continuous-flow devicesContinuous-flow devices

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

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

Most implanted devices are LVADs onlyMost implanted devices are LVADs only

Are quite and cannot be heard outside of the patient’s body. Assess VAD 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 status by auscultation over the apex of the LV. The VAD should have a continuous, smooth humming sound.continuous, smooth humming sound.

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

The Patient may have a narrow pulse pressure and may not be The Patient may have a narrow pulse pressure and may not be measurable with automated blood pressure monitors. This is due to the measurable with automated blood pressure monitors. This is due to the continuous forward outflow from the VAD.continuous forward outflow from the VAD.

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

Non Pulsatile VAD Key ParametersNon Pulsatile VAD Key Parameters Flow:Flow:

Measured in liters per minuteMeasured in liters per minute Correlates with pump speed (Correlates with pump speed (speed=speed=flow, flow,

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

Speed:Speed: How fast the impeller of the internal pump spinsHow fast the impeller of the internal pump spins Measured in revolutions per minute (rpm)Measured in revolutions per minute (rpm) Flow speed is set and determined by VAD clinical Flow speed is set and determined by VAD clinical

team and usually cannot be manipulated outside of team and usually cannot be manipulated outside of the hospitalthe hospital

Non Pulsatile VAD Key ParametersNon Pulsatile VAD Key Parameters Power:Power:

The amount of power the VAD consumes to The amount of power the VAD consumes to continually run at a set speedcontinually run at a set speed

Sudden or gradual sustained increases in the power Sudden or gradual sustained increases in the power can indicate thrombus inside the VADcan indicate thrombus inside the VAD

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

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

Varies by patientVaries by patient Indicates volume status, right ventricle function, and Indicates volume status, right ventricle function, and

native heart contractilitynative heart contractility

Non Pulsatile VAD Key ParametersNon Pulsatile VAD Key Parameters

The device parameters are displayed numerically on The device parameters are displayed numerically on the VAD console or Controllerthe VAD console or Controller

Will vary with each individual patient and VAD deviceWill vary with each individual patient and VAD device

VAD ParametersVAD Parameters Parameters for pulsatile and non pulsatile Parameters for pulsatile and non pulsatile

devices vary with each device modeldevices vary with each device model

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

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

Basic VAD ManagementBasic VAD Management ALL VADs are:ALL VADs are:

Preload-dependentPreload-dependent EKG-independentEKG-independent Afterload-sensitiveAfterload-sensitive Anticoagulated Anticoagulated Prone to:Prone to:

• infectioninfection• bleedingbleeding• thrombosis/strokethrombosis/stroke• mechanical malfunctionmechanical malfunction

Key differences depend on pulsatile vs. non-pulsatile Key differences depend on pulsatile vs. non-pulsatile devicedevice

VADs commonly seen in the VADs commonly seen in the communitycommunity

Thoratec VAD (pVAD/iVAD)Thoratec VAD (pVAD/iVAD) Pneumatic, external(pVAD) or internal (iVAD), Pneumatic, external(pVAD) or internal (iVAD), pulsatilepulsatile pump(s) pump(s)

right-, left-, or bi-ventricular support (RVAD/LVAD/BiVAD) right-, left-, or bi-ventricular support (RVAD/LVAD/BiVAD) up to ~7.2 lpm flowup to ~7.2 lpm flow

Short- to medium-term use (up to ~1-2 years)Short- to medium-term use (up to ~1-2 years) bridge to recovery bridge to recovery bridge to transplantbridge to transplant hospital discharge possiblehospital discharge possible

iVAD pVAD

Thoratec pVADThoratec pVAD

HeartMate XVE LVASHeartMate XVE LVAS Internally implanted, electric Internally implanted, electric pulsatilepulsatile pump pump

left heart support onlyleft heart support only up to 10 lpm flowup to 10 lpm flow

Medium- to long-term therapy (months to years)Medium- to long-term therapy (months to years) bridge to transplantbridge to transplant destination therapy (only FDA-approved DT device)destination therapy (only FDA-approved DT device)

HeartMate II LVASHeartMate II LVAS Internally implanted, axial-flow (Internally implanted, axial-flow (non-pulsatilenon-pulsatile) device) device

left heart support onlyleft heart support only speed: 8000-15000 rpmspeed: 8000-15000 rpm

• flow: ~3-8 lpmflow: ~3-8 lpm Medium- to long-term therapy (months to years)Medium- to long-term therapy (months to years)

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

Jarvik 2000 LVADJarvik 2000 LVAD Axial-flow (Axial-flow (non-pulsatilenon-pulsatile) pump) pump

electric, intra-ventricularelectric, intra-ventricular left heart support onlyleft heart support only

Speed: 8000-12000 rpmSpeed: 8000-12000 rpm flow: ~3-5 lpmflow: ~3-5 lpm

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

(investigational)(investigational)

Jarvik 2000 LVADJarvik 2000 LVAD

VAD IssuesVAD Issues

Problems/ComplicationsProblems/Complications Major VAD ComplicationsMajor VAD Complications

BleedingBleeding

Thrombosis Thrombosis

InfectionInfection

• sepsis is leading cause of death in long-term VAD supportsepsis is leading cause of death in long-term VAD support

RV dysfunction/failure RV dysfunction/failure

Suckdown (low preload causes a nonpulsatle VAD to collapse Suckdown (low preload causes a nonpulsatle VAD to collapse

the ventricle)the ventricle)

Device failure/malfunction (highly variable by device type)Device failure/malfunction (highly variable by device type)

Hemolysis (the VAD destroys blood cells)Hemolysis (the VAD destroys blood cells)

Problems/ComplicationsProblems/Complications Other Common IssuesOther Common Issues

ArrhythmiasArrhythmias

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

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

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

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


HypertensionHypertension

• High afterload can limit VAD flow/ output High afterload can limit VAD flow/ output

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

Hypotension/ loss of PreloadHypotension/ loss of Preload

• All VADs are preload dependent. A loss or reduction in All VADs are preload dependent. A loss or reduction in preload will compromise VAD function and limit flow/ preload will compromise VAD function and limit flow/ output output


Depression/ Adjustment DisordersDepression/ Adjustment Disorders

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

• A large percentage of patients experience symptoms of A large percentage of patients experience symptoms of depressiondepression

Portability/ ErgonomicsPortability/ Ergonomics

• The external VAD equipment is heavy and cumbersome The external VAD equipment is heavy and cumbersome limiting a patient’s mobility and greatly impacting their limiting a patient’s mobility and greatly impacting their quality of life. quality of life.

Problems/ComplicationsProblems/Complications

Bleeding & ThrombosisBleeding & Thrombosis Careful control of anticoagulation is Careful control of anticoagulation is

imperativeimperative• Patients are often on both anticoagulants and Patients are often on both anticoagulants and

platelet inhibitorsplatelet inhibitors• Device thrombosisDevice thrombosis

rare in pulsatile devicesrare in pulsatile devices typically revealed by increased power and signs and typically revealed by increased power and signs and

symptoms of hemolysissymptoms of hemolysis

Problems/ComplicationsProblems/Complications Bleeding & Thrombosis TxBleeding & Thrombosis Tx

Assess for signs and symptoms of bleedingAssess for signs and symptoms of bleeding Neuro Assessment to rule out CVANeuro Assessment to rule out CVA Initiate IV therapy and administer fluid slowly Initiate IV therapy and administer fluid slowly

to maintain preloadto maintain preload Device Thrombus is treated with low dose Device Thrombus is treated with low dose

lytics and/ or increasing anticoagulation lytics and/ or increasing anticoagulation therapytherapy

Problems/ComplicationsProblems/Complications InfectionInfection

*The leading cause of mortality in VAD *The leading cause of mortality in VAD patientspatients

*Higher incidence in pulsatile VADs*Higher incidence in pulsatile VADs

*The driveline provides direct access into *The driveline provides direct access into the body and into the blood streamthe body and into the blood stream

*Often recurrent and difficult to treat*Often recurrent and difficult to treat

Problems/ComplicationsProblems/Complications Preventing InfectionPreventing Infection

* Always observe clean/ sterile * Always observe clean/ sterile technique when abletechnique when able

* Make sure driveline exit site is * Make sure driveline exit site is covered with a clean, dry gauze covered with a clean, dry gauze dressingdressing


SuckdownSuckdown LV collapse due to hypovolemia/hypotension LV collapse due to hypovolemia/hypotension

or VAD overdriveor VAD overdrive nonpulsatile devices onlynonpulsatile devices only indicators: hypotension, PVCs/VT, low VAD indicators: hypotension, PVCs/VT, low VAD

flows.flows.


Treating SuckdownTreating Suckdown Initiate a peripheral IV and Initiate a peripheral IV and slowly give slowly give

volume to increase preloadvolume to increase preload If able and instructed by the VAD If able and instructed by the VAD

Coordinator, reduce the speed of the Coordinator, reduce the speed of the VADVAD

Assess for signs and symptoms of Assess for signs and symptoms of bleeding and sepsisbleeding and sepsis

Problems/ComplicationsProblems/Complications Device FailureDevice Failure

This is a true emergency requiring immediate This is a true emergency requiring immediate transport to the implanting VAD centertransport to the implanting VAD center

Most common in pulsatile devicesMost common in pulsatile devices Patients & caregivers are trained to identify Patients & caregivers are trained to identify

signs and symptoms of device failuresigns and symptoms of device failure May require the VAD to be replacedMay require the VAD to be replaced


HemolysisHemolysis

Blood cells are destroyed as they travel Blood cells are destroyed as they travel through the VADthrough the VAD

More common in non pulsatile devicesMore common in non pulsatile devices

Problems/ComplicationsProblems/Complications Treating HemolysisTreating Hemolysis

Initiate a peripheral IV and Initiate a peripheral IV and slowly give slowly give volumevolume

If able and instructed by the VAD If able and instructed by the VAD Coordinator, reduce the speed of the VADCoordinator, reduce the speed of the VAD

If thrombus is suspected to be causing If thrombus is suspected to be causing hemolysis, administer lytics and hemolysis, administer lytics and anticoagulants as able/ orderedanticoagulants as able/ ordered

AlarmsAlarms

All VAD devices typically have two All VAD devices typically have two distingue alarms to indicate a problem and distingue alarms to indicate a problem and it’s severity it’s severity Advisory AlarmsAdvisory Alarms Critical/ Hazardous AlarmsCritical/ Hazardous Alarms

AlarmsAlarms

Advisory Alarms are intermittent beeping Advisory Alarms are intermittent beeping sounds that have a corresponding sounds that have a corresponding YELLOWYELLOW light that illuminates on the light that illuminates on the system controllersystem controller Not critical but the device requires attentionNot critical but the device requires attention Likely due to low battery, cable disconnected, Likely due to low battery, cable disconnected,

or device not functioning properly. or device not functioning properly.

AlarmsAlarms HazardousHazardous or or Critical Critical alarms are a loud, alarms are a loud,

continuous, shrill sound that have a continuous, shrill sound that have a corresponding corresponding REDRED light that illuminates on the light that illuminates on the system controllersystem controller Indicating the device needs immediate attentionIndicating the device needs immediate attention Often because the pump has stopped or a problem Often because the pump has stopped or a problem

is detected with the system controller is detected with the system controller Most likely intervention required is to change out the Most likely intervention required is to change out the

system controllersystem controller

Field ManagementField Management

All VADs are dependant on adequate All VADs are dependant on adequate preload in order to maintain proper preload in order to maintain proper functioningfunctioning

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


Nitrates can be detrimental to a VAD Nitrates can be detrimental to a VAD patient because of the reduction in preloadpatient because of the reduction in preload Results in decreased pump efficiencyResults in decreased pump efficiency Consult with medical control before Consult with medical control before

administering nitrates per protocoladministering nitrates per protocol


Initiate IV therapy with all VAD patients if Initiate IV therapy with all VAD patients if possiblepossible Use aseptic technique due to the patient’s Use aseptic technique due to the patient’s

increased risks of infectionincreased risks of infection


VAD patients are susceptible to other VAD patients are susceptible to other injuries unrelated to the VADinjuries unrelated to the VAD

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

Consult with medical control about Consult with medical control about transporttransport

Patient TransportPatient Transport This is emergency, resource and protocol driven This is emergency, resource and protocol driven

decision makingdecision making VAD patients require unique care that not all medical VAD patients require unique care that not all medical

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

Make sure when transporting to bring all VAD related Make sure when transporting to bring all VAD related equipmentequipment

Secure VAD batteries and the controller to prevent Secure VAD batteries and the controller to prevent dropping or damagedropping or damage

Make sure to keep all cables tangle and kink freeMake sure to keep all cables tangle and kink free

PreplanningPreplanning

Medical ControlMedical Control Inquire ahead of time the level of knowledge/ Inquire ahead of time the level of knowledge/

comfort with your medical directors regarding comfort with your medical directors regarding the management of VAD patientthe management of VAD patient

Know Transport OptionsKnow Transport Options Air vs. GroundAir vs. Ground Know your tertiary facilities and their ability to Know your tertiary facilities and their ability to

management VAD patientsmanagement VAD patients

Remember…Remember… EMS can walk into just about any situationEMS can walk into just about any situation Depending on the individuals- the family may Depending on the individuals- the family may

not be able to handle the emergencynot be able to handle the emergency Listen to the family members that can handle Listen to the family members that can handle

the emergency and “assist” them with whatever the emergency and “assist” them with whatever they needthey need

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

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

Remember…Remember… Ask for the contact number for the managing Ask for the contact number for the managing

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

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

911 activation may not be for a VAD related 911 activation may not be for a VAD related emergencyemergency

Remember…Remember… Emergency bag containing back-up VAD supplies Emergency bag containing back-up VAD supplies

needs to stay with the patient at all times. Should needs to stay with the patient at all times. Should contain extra batteries and the spare system controllercontain extra batteries and the spare system controller

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

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

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

For additional resources materials For additional resources materials and information please visit:and information please visit:

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

http://www.thoratec.com/

http://www.jarvikheart.com/

Thank You!Thank You!

powerpoint presentation: an overview of ventricular assist devices

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