1. An Overview of Ventricular Assist Devices Pre Hospital Management
Drill of the Month
Developed by Michael Lindsay
An Overview of Ventricular Assist Devices
&
Pre Hospital Management

2. Student Objectives At 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.

3. 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.

4. 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

5. 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 (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

6. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

7. Why Do We Need VADs? But, in 2008:
7318 people were waiting for a heart
2210 received one
623 died waiting
~ VAD implanted in 2008
Counterpulsation is the key to proper use of the IAB with the goal of ….

8. 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

9. Types of VADs
Pulsatile
and
Non Pulsatile

10. 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.

11. 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

12. 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 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.
The Mean Arterial Pressure is the key in monitoring hemodynamics. Ideal range is mmHg.

13. 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

14. 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 heart’s cardiac cycle
Varies by patient
Indicates volume status, right ventricle function, and native heart contractility

15. 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

16. 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.

17. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

18. VADs commonly seen in the community
We are probably all familiar with the first line of defense used on the patient presenting with angina, low blood pressure or the high risk cath or CABG patient… the IABP. Introduced almost 40 years ago the device has now become very common available in almost every hospital.

19. 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
One of the most vesatile ventricular assist devices is the Thoratec VAD. This pneumatic pump rests on the outside of the body with inflow and outflow cannula connecting the pump to the circulatory system. Because this pump is outside the body it can be used in the smaller patients that do not have enough room for an implantable pump. Adding to its versatility it can be used as an RVAD, LVAD or biVAD in instances of bridge to transplant, post cardiotomy and myocardial recovery.
iVAD
pVAD

20. Thoratec pVAD

21. 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)
One of the most vesatile ventricular assist devices is the Thoratec VAD. This pneumatic pump rests on the outside of the body with inflow and outflow cannula connecting the pump to the circulatory system. Because this pump is outside the body it can be used in the smaller patients that do not have enough room for an implantable pump. Adding to its versatility it can be used as an RVAD, LVAD or biVAD in instances of bridge to transplant, post cardiotomy and myocardial recovery.

22. HeartMate II LVAS
Internally implanted, axial-flow (non-pulsatile) device
left heart support only
speed: rpm
flow: ~3-8 lpm
Medium- to long-term therapy (months to years)
bridge to transplant (FDA-approved)
destination therapy (investigational)
One of the most vesatile ventricular assist devices is the Thoratec VAD. This pneumatic pump rests on the outside of the body with inflow and outflow cannula connecting the pump to the circulatory system. Because this pump is outside the body it can be used in the smaller patients that do not have enough room for an implantable pump. Adding to its versatility it can be used as an RVAD, LVAD or biVAD in instances of bridge to transplant, post cardiotomy and myocardial recovery.

23. Jarvik 2000 LVAD Axial-flow (non-pulsatile) pump
electric, intra-ventricular
left heart support only
Speed: rpm
flow: ~3-5 lpm
Medium- to long-term therapy (months to years)
bridge to transplant (investigational)

24. Jarvik 2000 LVAD

25. VAD Issues

26. 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)
Counterpulsation is the key to proper use of the IAB with the goal of ….

27. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

28. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

29. 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 patient’s mobility and greatly impacting their quality of life.
Counterpulsation is the key to proper use of the IAB with the goal of ….

30. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

31. 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

32. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

33. Problems/Complications
Preventing Infection
* Always observe clean/ sterile technique when able
* Make sure driveline exit site is covered with a clean, dry gauze dressing

34. Problems/Complications
Suckdown
LV collapse due to hypovolemia/hypotension or VAD overdrive
nonpulsatile devices only
indicators: hypotension, PVCs/VT, low VAD flows.
Counterpulsation is the key to proper use of the IAB with the goal of ….

35. 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

36. 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
Counterpulsation is the key to proper use of the IAB with the goal of ….

37. Problems/Complications
Hemolysis
Blood cells are destroyed as they travel through the VAD
More common in non pulsatile devices
Counterpulsation is the key to proper use of the IAB with the goal of ….

38. 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

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

40. 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.

41. 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

42. 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.

43. 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

44. Field Management Initiate IV therapy with all VAD patients if possible
Use aseptic technique due to the patient’s increased risks of infection

45. 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

46. 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

47. Preplanning Medical Control Know Transport Options
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

48. 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

49. 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

50. 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

51. For additional resources materials and information please visit:

52. Thank You!