CP Final: Ventricular Assist Device Flashcards
What is a VAD?
a blood pump, that is a mechanical device that supports one or both ventricles
What are the indications of a VAD?
advanced heart failure, NYHA functional class 4 or AHA D symptoms despite optimal medical therapy
peak VO2 less than 12 ml/kg/min
What are heart failure treatments?
- lifestyle changes
- invasive interventions
- medical management
What are the goals of mechanical support?
- bridge to therapy
- destination therapy
- bridge to recovery
What is Bridge to transplant?
VAD is implanted to improve survival and quality of life while awaiting transplant
What is destination therapy?
indefinite mechanical support b/c pt doesn’t want transplant or patient not a candidate for surgery
What are reasons pt may not be eligible for transplant?
age, co-morbidity, size, immune sensitivity , neoplasm, social/financial support
What is bridge to recovery?
temporary support, recovery is expected without need for transplant, can be weaned or removed
any type of acute incident: MI
What are physiological benefits of VAD?
increases CO, VO2 peak, reverse remodeling, improved survival, improved QOL
Do patients with VAD still have heart failure?
Yes, max benefits won’t be achieved till 12 weeks post surgery
pts will improve AC and other aspects of training but then improvement will level off
How long will it take pt to realize where they are functionally?
4-6 months
What are the three different locations of a VAD?
- left ventricle- inflow: left ventricle apex, outflow: aorta
- right ventricle- inflow: RA or RV, outflow: pulm artery
- biventricular
What are short term devices used for?
days to weeks, bridge to recovery, not designed for mobility, usually in ICU
What are long term devices used for?
months to years, bridge to transplant + destination therapy, designed for mobility
What do PT need to know?
someone on site needs to know:
- how to operate the device
- how to interpret data
- how to respond to alarms
- what to do in case of emergency
What are differences in inpatient vs outpatient role of PT?
IN: you teach them about device
OUT: pt should know information
What are considerations for CPR in pts with VAD?
no chest compressions
Who are important team members involved with VAD?
VAD coordinator
What is important to consider about the Driveline?
its percutaneous so watch for infection and delivers power and date to pump
What are the two types of pump classifications?
- pulsatile
2. continuous flow
What is pulsatile pump?
flow is produced by vacuum induced pressure changes creating periods of systole and diastole
pumping chambers consists of a mobile sac and diaphragm, valves prevent backflow
What do pulsatile VAD’s have their own?
- rate (bpm)- when you palpate pulse its bc of the device
- stroke volume (ml)
- volume output (L/min)
If you have a LVAD what is true about hemodynamic measures?
HR via palplation (VAD) does NOT equal HR via ECG (native heart)
BP: as usual
What are the two types of VAD rates with pulsatile pump?
- fixed- set by medical team
2. variable- pump chamber fills to capacity before emptying
What is fixed?
stroke volume variable, chamber empties regardless of SV
What is variable?
SV is fixed, CO dept on preload, allows for variability with rest and exercise however its not that common
What is a continuous flow pump?
axial flow or centrifugal flow, pump flow follows native cardiac pulse
no valves
How are HD measured in continuous pumps?
HR- telemetry, auscultation- don’t need it if stable
BP: MAP is most relevant, doppler + sphyg
What is MAP?
mean arterial pressure- average blood pressure in the system at any given time
MAP over 60 mmHG needed
MAP under 60 mmHG is RED flag, unless a known baseline and is well tolerated by pt
What is MAP equation?
MAP= SBP + 2 (DBP)/ 3
What is flow with continuous VAD?
amount of blood moving through the device, usually an estimate so may not account for entire CO
What is a yellow flag for VAD flow?
if the flow is lower than normal but watch for symptoms and suction event as that would be a red flag
What is speed with continuous VAD?
set by surgical team, if changed between PT sessions watch for exercise tolerance changes
What is pump power with continuous VAD?
amount of power then pump requires to maintain speed
major red flag if: sudden increase in power as it could be a blood clot
What is pulse index/pulsatility with continuous VAD?
difference between max flow and min flow divided average flow
What does a higher vs lower pulsatility mean?
higher: native heart doing more work- usually with exercise
lower- VAD doing most of work, very low is OTN
What is a sucction event?
occurs only in continuous devices, LV drops below filling threshold, may cause VTach usually caused by hypovolemia, OTN usually during PT which is a red flag
What are precautions with VAD?
same sternal precautions, avoid trauma to driveline, avoid moisture to all components
How do you manage VAD post op?
wean inotrope meds, all pts go on anti coags, optimize fluid balance, physical rehab and pt education
What are common post -op complications?
clots, bleeding, infection
What are potential impairments specific to patient with LVAD?
arousal, pain, circulation, integument, muscle performance, gait, AC, ventilation
Why are VAD at a fall risk?
lines and wires, cognition, alteration of COM
How is ventilation affected with VAD pts?
dyspnea may be a primary impairment due to limited diaphragm excursion, as well as post-op atelectasis, pulm edema
What types of rhythms could affect pts on VAD?
a fib, v tach
pts not be symtomatic of VT, VF or asystole if on a bivad this is still a red flag but may not threaten life—lay pt flat and assess HD and call EMS/VAD coordinator
What can a Heart Mate 2 tell you?
flow, pump speed, pulse index, pump power
suction can be detected only if connected to monitor
