Care of the Left Ventricular Assist Device Patient

Presented by

Jude Melendez, MS, RN, CCRN- CSC and

Loretta Nerney, BS, RN, CCRN

Post Operative Care of the Left Ventricular Assist Device Patient in the Acute Care Setting

Key Concepts

The newly implanted LVAD patient is a post op cardiac surgery patient first, LVAD patient second.

Nurses need a good understanding of LVAD pump physiology for hemodynamic monitoring.

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Goal of LVAD therapy:

Increase CO

Improve end-organ function

Improve Quality of Life

Improve morbidity and mortality

Reprinted with the permission of Thoratec Corporation

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Pump Physiology

Continuous-flow LVADs deliver flow throughout the entire cardiac cycle

Flow is determined by

Pump speed: Flow increases with speed increases

Preload dependent

Afterload sensitive

The aortic valve may not always open and patients may not have a palpable pulse

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Pulsatility Index (PI)

As the left ventricle contracts and relaxes, the flow through the pump increases and decreases, adding a degree of pulsatility

PI is the magnitude of this flow pulse

The pulsatility index (PI) will normally decrease as pump speed is increased

PI will change with patient conditions that normally affect stroke volume (physiologic demand, volume status, RV function)

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Suction Events

If pump speed is set too high or conditions exist to affect preload, the pump may decompress the LV to the point of collapsing the walls together.

Evaluate the cause they are the

same complications that can arise

for any cardiac surgery patient

Hypovolemia/vasodilation (affecting

preload)

Post-operative bleeding

Tamponade

Arrhythmia

RV failure

Reprinted with the permission of Thoratec Corporation

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Nursing Assessments

Systems Survey

Device Parameters and Hemodynamics

Monitoring for complications

Patient and Caregiver needs

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Hemodynamic Assessments

Arterial line

Swan-Ganz catheter

Physical S/S of good perfusion

TEE when in doubt

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Device Parameters

Monitor for variations from patient baseline

Put in complications section

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Arterial waveform for LVAD patients

http://pics3.this-pic.com/key/dampened%20arterial%20line%20waveform

Systems Survey: Cardiac

Therapy Goals & Interventions

MAP 70-85 mmHg

Normothermia

Pressors (dopamine, vasopressin, levophed)

Fluid resuscitation

Cardiac Index > 2.2, LVAD flow > 3.5 liters/minute

Adequate preload

Balance RV failure vs. adequate LVAD filling

Increase RV contractility (epi, primacor)

Decrease RV afterload: iNO

Treat arrhythmias promptly protect heart function

Monitor labs: abg, mvg, lactic acid

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Systems Survey

Neuro status

Pain management and sedation

Evaluate for CVA

Pulmonary status

If on iNO, ventilator dependent until weaned off

SaO2 may not be obtainable; correlate to abg

Underlying pulmonary dysfunction

Hematologic status

Assess for bleeding: chest tubes, incisions, drive line site

Monitor H/H, TEG, Coags

Hemolysis? Monitor LDH

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Systems Survey

Renal function: assess for adequate perfusion & functioning

Monitor/replace electrolytes

Monitor urine output

Monitor BUN/creatinine

Hepatic function: assess for dysfunction from pre-op history of heart failure

Assess for coagulopathies

Blood glucose control

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Systems Survey

Infection control

Antibiotic prophylaxis

Address all risk factors: nutrition, mobility & skin integrity, glucose control, sterile dressing changes, drive line protection

GI function & Nutrition

Promote gastrointestinal motility post op

Assess pre-albumin levels

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RED HEART ALARM

Rule out power failure or equipment malfunction.

Otherwise, there is a low pump flow state. Assess the patient for post-op complications.

Reprinted with the permission of Thoratec Corporation

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Complications: LOW FLOW

Low Flow and Low CVP

Replace volume

Give vasoconstrictors if right heart is weak

Check H/H; rule out bleeding

Rule out mechanical versus coagulopathy

Monitor H/H, platelet, PT, PTT, Fibrinogen, TEG : replace products, administer protamine

Monitor chest tube drainage

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Complications: LOW FLOW

High CVP & suction events

RV Failure

Possible Causes : Any increase in RV afterload; pulmonary HTN, volume overload, acidosis, hypoxia, ischemia, pulmonary embolus

Cardiac Tamponade

S/S: Hypotension, elevated filling pressures, reduced SvO2, reduced urine output, slowed chest tube output

CXR/CT scan

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Complications: LOW FLOW

Other Low Flow Considerations

Pump thrombus

may see power spikes, grating or rough pump noise, falsely high pump flows, clinical signs of heart failure, increased native pulsatility, hemolysis

Treatment: anticoagulant or thrombolytic therapy, possible pump exchange

Arrhythmia

NO CHEST COMPRESSIONS/ OK TO DEFIBRILLATE

Inflow cannula obstruction (septal occlusion)

may see reduced pump speed and hear device chatter

High afterload

Rx with vasodilators

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Safety Pearls

No chest compressions

ACLS drugs and cardiac defibrillation OK to give

No MRI

Avoid getting system components wet

Maintain patient equipment and keep a spare system controller and a spare power source with the patient at all times

Transitioning care

Psychosocial needs

Educational needs

Elements for discharge to home

VAD support group

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References

OShea, G. (2012). Ventricular Assist Devices: What Intensive Care Unit Nurses Need to Know About Postoperative Management. AACN Advanced Critical Care. 23(1) 69-83.

Slaughter, M., Pagani, F., Rogers, J., Miller, L., Sun, B., Russell, S. Farrar, D.(2010). Clinical Management of Continuous-flow Left Ventricular Assist Devices in Advanced Heart Failure. The Journal of Heart and Lung Transplantation. 29 (4S) S1-S39.

Thoratec Corporation. (2012). HeartMate II Left Ventricular Assist System LVAS: Instructions for Use. Pleasanton, CA: Thoratec Corporation.