Presentation on theme: "An Overview of Ventricular Assist Devices Pre Hospital Management"— Presentation transcript:
1An Overview of Ventricular Assist Devices Pre Hospital Management Drill of the MonthDeveloped by Michael LindsayAn Overview of Ventricular Assist Devices&Pre Hospital Management
2Student Objectives At the conclusion of this Drill Students will be able to: Define Heart FailureDefine Ventricular Assist Device (VAD) and their use in treating Heart FailureIdentify types of Ventricular Assist DevicesExplain the difference between Pulsatile and Nonpulsatile flowIdentify hemodynamic differences in patients with a VADList VAD related complicationsDemonstrate how to assess a patient with a VADDescribe how to treat VAD complicationsIdentify VAD resources that can be utilized when caring for these patients.
3Heart 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.
4What 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 supportFor Right Ventricular support, the device is attached to the right atrium and to the pulmonary artery
5Ventricular Assist Device (VAD) A mechanical pump that is surgically attached to one of the heart’s ventricles to augment or replace native ventricular functionCan 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 abdomenPump output flow can be pulsatile or nonpulsatile
6Why 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 yearonly effective treatment for end stage CHF is heart transplantCounterpulsation is the key to proper use of the IAB with the goal of ….
7Why Do We Need VADs? But, in 2008: 7318 people were waiting for a heart2210 received one623 died waiting~ VAD implanted in 2008Counterpulsation is the key to proper use of the IAB with the goal of ….
8Indications for VAD Bridge to transplant (BTT) most commonallow rehab from severe CHF while awaiting donorBridge to recovery (BTR)unload heart, allow “reverse remodeling”can be short- or long-term“Destination” therapy (DT)permanent device, instead of transplantcurrently only in transplant-ineligible patientsBridge to candidacy (BTC)/ Bridge to decision (BTD)when eligibility unclear at implantnot true “indication” but true for many pts
10Pulsatile 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 BiVADFirst-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.
11Pulsatile VAD Key Parameters Pump Rate:How fast the VAD is pumping (filling & emptying)Can be set at a fixed rate or can automatically adjustPulsatile VADs are loud and the rate can be assessed by listeningOutput:The amount of blood ejected from the VADMeasured is liters per minuteIs dependent upon preload, afterload, and pump rate
12Non-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 onlyAre 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 pulseThe 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.
13Non Pulsatile VAD Key Parameters Flow:Measured in liters per minuteCorrelates with pump speed (speed=flow, ↓speed=↓flow)Dependent on Preload and AfterloadSpeed:How fast the impeller of the internal pump spinsMeasured in revolutions per minute (rpm)Flow speed is set and determined by VAD clinical team and usually cannot be manipulated outside of the hospital
14Non Pulsatile VAD Key Parameters Power:The amount of power the VAD consumes to continually run at a set speedSudden or gradual sustained increases in the power can indicate thrombus inside the VADPulsatility Index (PI):A measure of the pressure differential inside the internal VAD pump during the native heart’s cardiac cycleVaries by patientIndicates volume status, right ventricle function, and native heart contractility
15Non Pulsatile VAD Key Parameters The device parameters are displayed numerically on the VAD console or ControllerWill vary with each individual patient and VAD device
16VAD ParametersParameters for pulsatile and non pulsatile devices vary with each device modelPatients and their care givers know the expectable parameter ranges and goals for their specific deviceContact the VAD Coordinator at the implanting medical center, they will be your best resource when treating a VAD patient.
17Basic VAD Management ALL VADs are: Preload-dependent EKG-independent Afterload-sensitiveAnticoagulatedProne to:infectionbleedingthrombosis/strokemechanical malfunctionKey differences depend on pulsatile vs. non-pulsatile deviceCounterpulsation is the key to proper use of the IAB with the goal of ….
18VADs 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.
19Thoratec 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 flowShort- to medium-term use (up to ~1-2 years)bridge to recoverybridge to transplanthospital discharge possibleOne 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.iVADpVAD
21HeartMate XVE LVAS Internally implanted, electric pulsatile pump left heart support onlyup to 10 lpm flowMedium- to long-term therapy (months to years)bridge to transplantdestination 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.
22HeartMate II LVASInternally implanted, axial-flow (non-pulsatile) deviceleft heart support onlyspeed: rpmflow: ~3-8 lpmMedium- 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.
23Jarvik 2000 LVAD Axial-flow (non-pulsatile) pump electric, intra-ventricularleft heart support onlySpeed: rpmflow: ~3-5 lpmMedium- to long-term therapy (months to years)bridge to transplant (investigational)
26Problems/Complications Major VAD ComplicationsBleedingThrombosisInfectionsepsis is leading cause of death in long-term VAD supportRV dysfunction/failureSuckdown (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 ….
27Problems/Complications Other Common IssuesArrhythmiasA 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 deathElectrical shock from cardiovert/ defib. will not damage any of the VAD equipmentCounterpulsation is the key to proper use of the IAB with the goal of ….
28Problems/Complications Other Common IssuesHypertensionHigh afterload can limit VAD flow/ outputDo not administer antihypertensive medications or nitrates unless instructed by a physician or VAD CoordinatorHypotension/ loss of PreloadAll VADs are preload dependent. A loss or reduction in preload will compromise VAD function and limit flow/ outputCounterpulsation is the key to proper use of the IAB with the goal of ….
29Problems/Complications Other Common IssuesDepression/ Adjustment DisordersLiving with a VAD is difficult to management for a lot of patients.A large percentage of patients experience symptoms of depressionPortability/ ErgonomicsThe 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 ….
30Problems/Complications Bleeding & ThrombosisCareful control of anticoagulation is imperativePatients are often on both anticoagulants and platelet inhibitorsDevice thrombosisrare in pulsatile devicestypically revealed by increased power and signs and symptoms of hemolysisCounterpulsation is the key to proper use of the IAB with the goal of ….
31Problems/Complications Bleeding & Thrombosis TxAssess for signs and symptoms of bleedingNeuro Assessment to rule out CVAInitiate IV therapy and administer fluid slowly to maintain preloadDevice Thrombus is treated with low dose lytics and/ or increasing anticoagulation therapy
32Problems/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 treatCounterpulsation is the key to proper use of the IAB with the goal of ….
33Problems/Complications Preventing Infection* Always observe clean/ sterile technique when able* Make sure driveline exit site is covered with a clean, dry gauze dressing
34Problems/Complications SuckdownLV collapse due to hypovolemia/hypotension or VAD overdrivenonpulsatile devices onlyindicators: hypotension, PVCs/VT, low VAD flows.Counterpulsation is the key to proper use of the IAB with the goal of ….
35Problems/Complications Treating SuckdownInitiate a peripheral IV and slowly give volume to increase preloadIf able and instructed by the VAD Coordinator, reduce the speed of the VADAssess for signs and symptoms of bleeding and sepsis
36Problems/Complications Device FailureThis is a true emergency requiring immediate transport to the implanting VAD centerMost common in pulsatile devicesPatients & caregivers are trained to identify signs and symptoms of device failureMay require the VAD to be replacedCounterpulsation is the key to proper use of the IAB with the goal of ….
37Problems/Complications HemolysisBlood cells are destroyed as they travel through the VADMore common in non pulsatile devicesCounterpulsation is the key to proper use of the IAB with the goal of ….
38Problems/Complications Treating HemolysisInitiate a peripheral IV and slowly give volumeIf able and instructed by the VAD Coordinator, reduce the speed of the VADIf thrombus is suspected to be causing hemolysis, administer lytics and anticoagulants as able/ ordered
39AlarmsAll VAD devices typically have two distingue alarms to indicate a problem and it’s severityAdvisory AlarmsCritical/ Hazardous Alarms
40AlarmsAdvisory Alarms are intermittent beeping sounds that have a corresponding YELLOW light that illuminates on the system controllerNot critical but the device requires attentionLikely due to low battery, cable disconnected, or device not functioning properly.
41AlarmsHazardous or Critical alarms are a loud, continuous, shrill sound that have a corresponding RED light that illuminates on the system controllerIndicating the device needs immediate attentionOften because the pump has stopped or a problem is detected with the system controllerMost likely intervention required is to change out the system controller
42Field ManagementAll VADs are dependant on adequate preload in order to maintain proper functioningVolume 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.
43Field ManagementNitrates can be detrimental to a VAD patient because of the reduction in preloadResults in decreased pump efficiencyConsult with medical control before administering nitrates per protocol
44Field Management Initiate IV therapy with all VAD patients if possible Use aseptic technique due to the patient’s increased risks of infection
45Field ManagementVAD patients are susceptible to other injuries unrelated to the VADContact the VAD Coordinator, they are your most valuable resource when encountering these patientsConsult with medical control about transport
46Patient TransportThis is emergency, resource and protocol driven decision makingVAD patients require unique care that not all medical centers are equipped to handle. Transport to the implanting center when able or the closest VAD centerMake sure when transporting to bring all VAD related equipmentSecure VAD batteries and the controller to prevent dropping or damageMake sure to keep all cables tangle and kink free
47Preplanning Medical Control Know Transport Options Inquire ahead of time the level of knowledge/ comfort with your medical directors regarding the management of VAD patientKnow Transport OptionsAir vs. GroundKnow your tertiary facilities and their ability to management VAD patients
48Remember… EMS can walk into just about any situation Depending on the individuals- the family may not be able to handle the emergencyListen to the family members that can handle the emergency and “assist” them with whatever they needThe only resources/ tools you can truly rely on are the ones you bring to the callFollow-up and educate yourself to new technologies that keep entering into the industry
49Remember…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 resourceFamily, friends, co-workers- listen to them for direction, they should be educated/ trained to assist with most VAD related complications911 activation may not be for a VAD related emergency
50Remember…Emergency bag containing back-up VAD supplies needs to stay with the patient at all times. Should contain extra batteries and the spare system controllerAsk the family for any trouble shooting guidelines that maybe available. This often includes various alarms and interventionsRemember that the family/ friends are not emergency responders or maybe too upset to assist youIf 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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