Drill of the Month

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Drill of the Month

• Developed by Michael Lindsay
• An Overview of Ventricular Assist Devices
• Pre Hospital Management

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

• Define Heart Failure
• Define Ventricular Assist Device (VAD) and their
  use in treating Heart Failure
• Identify types of Ventricular Assist Devices
• Explain the difference between Pulsatile and
  Nonpulsatile flow
• Identify hemodynamic differences in patients with
  a VAD
• List VAD related complications
• 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.

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Heart Failure

• Heart failure is a condition where the heart
  cannot pump enough blood throughout the body.
• It develops over time as the pumping action of
  the heart grows weaker.
• Most cases involve the left side where the
  heart cannot pump enough oxygen-rich blood to the
  rest of the body.
• With right sided failure, the heart cannot
  effectively pump blood to the lungs where the
  blood picks up oxygen.

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What is a VAD?

• A single system device that is surgically
  attached to the left ventricle of the heart and
  to the aorta for left ventricular support
• For Right Ventricular support, the device is
  attached to the right atrium and to the pulmonary
  artery

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Ventricular Assist Device (VAD)

• A mechanical pump that is surgically attached to
  one of the hearts ventricles to augment or
  replace native ventricular function
• Can be used for the left (L VAD), right (R VAD),
  or both ventricles (Bi VAD)
• 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 can be pulsatile or nonpulsatile

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Why Do We Need VADs?

• Heart disease is the leading cause of death in
  the Western world
• 5 million people in the US have congestive heart
  failure (CHF)
• 250,000 are in the most advanced stage of CHF
• 500,000 new cases each year
• 50,000 deaths each year
• only effective treatment for end stage CHF is
  heart transplant

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Why Do We Need VADs?

• But, in 2008
• 7318 people were waiting for a heart
• 2210 received one
• 623 died waiting
• 1200-1500 VAD implanted in 2008

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Indications for VAD

• Bridge to transplant (BTT)
• most common
• allow rehab from severe CHF while awaiting donor
• Bridge to recovery (BTR)
• unload heart, allow reverse remodeling
• can be short- or long-term

• Destination therapy (DT)
• permanent device, instead of transplant
• currently only in transplant-ineligible patients
• Bridge to candidacy (BTC)/Bridge to decision
  (BTD)
• when eligibility unclear at implant
• not true indication but true for many pts

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Types of VADs

• Pulsatile
• and
• Non Pulsatile

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Pulsatile

• Ventricle-like pumping sac device.
• Blood enters via the inflow cannula and fills a
  flexible pumping chamber.
• Electric motor or pneumatic (air) pressure
  collapses the chamber and forces blood into
  systemic circulation via the outflow cannula.
• Can be LVAD, RVAD, or BiVAD
• First-generation devices (in use since early
  1980s)
• Patients will have a palpable pulse and a
  measurable blood pressure. Both are generated
  from the VAD output flow.

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Pulsatile VAD Key Parameters

• Pump Rate
• How fast the VAD is pumping (filling emptying)
• Can be set at a fixed rate or can automatically
  adjust
• Pulsatile VADs are loud and the rate can be
  assessed by listening
• Output
• The amount of blood ejected from the VAD
• Measured is liters per minute
• Is dependent upon preload, afterload, and pump
  rate

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Non-Pulsatile

• 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
• Are quite and cannot be heard outside of the
  patients 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.
• The Mean Arterial Pressure is the key in
  monitoring hemodynamics. Ideal range is 65-90
  mmHg.

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Non Pulsatile 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

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Non Pulsatile 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 hearts
  cardiac cycle
• Varies by patient
• Indicates volume status, right ventricle
  function, and native heart contractility

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Non Pulsatile VAD Key Parameters

• The device parameters are displayed numerically
  on the VAD console or Controller
• Will vary with each individual patient and VAD
  device

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VAD Parameters

• Parameters for pulsatile and non pulsatile
  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.

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Basic VAD Management

• ALL VADs are
• Preload-dependent
• EKG-independent
• Afterload-sensitive
• Anticoagulated
• Prone to
• infection
• bleeding
• thrombosis/stroke
• mechanical malfunction
• Key differences depend on pulsatile vs.
  non-pulsatile device

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VADs commonly seen in the community
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Thoratec VAD (pVAD/iVAD)

• Pneumatic, external(pVAD) or internal (iVAD),
  pulsatile pump(s)
• right-, left-, or bi-ventricular support
  (RVAD/LVAD/BiVAD)
• up to 7.2 lpm flow
• Short- to medium-term use (up to 1-2 years)
• bridge to recovery
• bridge to transplant
• hospital discharge possible

iVAD
pVAD
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Thoratec pVAD
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HeartMate XVE LVAS

• Internally implanted, electric pulsatile pump
• left heart support only
• up to 10 lpm flow
• Medium- to long-term therapy (months to years)
• bridge to transplant
• destination therapy (only FDA-approved DT device)

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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)

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Jarvik 2000 LVAD

• Axial-flow (non-pulsatile) pump
• electric, intra-ventricular
• left heart support only
• Speed 8000-12000 rpm
• flow 3-5 lpm

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

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Jarvik 2000 LVAD
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VAD Issues
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Problems/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)

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Problems/Complications

• 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

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Problems/Complications

• 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

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Problems/Complications

• 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 patients mobility and
  greatly impacting their quality of life.

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Problems/Complications

• Bleeding Thrombosis
• Careful control of anticoagulation is imperative
• Patients are often on both anticoagulants and
  platelet inhibitors
• Device thrombosis
• rare in pulsatile devices
• typically revealed by increased power and signs
  and symptoms of hemolysis

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Problems/Complications

• Bleeding Thrombosis Tx
• 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

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Problems/Complications

• 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

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Problems/Complications

• Preventing Infection
• Always observe clean/ sterile technique
  when able
• Make sure driveline exit site is covered
  with a clean, dry gauze dressing

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Problems/Complications

• Suckdown
• LV collapse due to hypovolemia/hypotension or VAD
  overdrive
• nonpulsatile devices only
• indicators hypotension, PVCs/VT, low VAD flows.

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Problems/Complications

• Treating Suckdown
• Initiate a peripheral IV and slowly give volume
  to increase preload
• If able and instructed by the VAD Coordinator,
  reduce the speed of the VAD
• Assess for signs and symptoms of bleeding and
  sepsis

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Problems/Complications

• Device Failure
• This is a true emergency requiring immediate
  transport to the implanting VAD center
• Most common in pulsatile devices
• Patients caregivers are trained to identify
  signs and symptoms of device failure
• May require the VAD to be replaced

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Problems/Complications

• Hemolysis
• Blood cells are destroyed as they travel through
  the VAD
• More common in non pulsatile devices

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Problems/Complications

• Treating Hemolysis
• Initiate a peripheral IV and slowly give volume
• If able and instructed by the VAD Coordinator,
  reduce the speed of the VAD
• If thrombus is suspected to be causing hemolysis,
  administer lytics and anticoagulants as able/
  ordered

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Alarms

• All VAD devices typically have two distingue
  alarms to indicate a problem and its severity
• Advisory Alarms
• Critical/ Hazardous Alarms

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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.

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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

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Field Management

• All VADs are dependant 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.

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Field Management

• Nitrates 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

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Field Management

• Initiate IV therapy with all VAD patients if
  possible
• Use aseptic technique due to the patients
  increased risks of infection

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Field Management

• VAD 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

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Patient Transport

• This is emergency, resource and protocol driven
  decision making
• VAD 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
• Make sure to keep all cables tangle and kink free

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Preplanning

• 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

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Remember

• EMS can walk into just about any situation
• Depending on the individuals- the family may not
  be able to handle the emergency
• Listen 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

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Remember

• Ask for the contact number for the managing
  centers 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

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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

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For additional resources materials and
information please visit

• www.thoratec.com
• www.jarvikheart.com
• www.umm.edu/heart/index.htm

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Thank You!