Ventricular Assist Device Ems Continuing Education

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Learning Objectives
>> Describe the indications and function of ventricular assist devices (VAD).
>> Assess patients with an implanted VAD.
>> Differentiate between emergency care for the VAD patient and other patients in
cardiogenic shock.
>> Outline a treatment algorithm for an emergency related to a VAD device.

Key Terms
Ejection fraction: The amount of blood released during each contraction of a ventricle compared with the total volume of blood released by both ventricles.
Hypertension: Marked high blood pressure persistently exceeding 140/90.
Hypovolemia: Lowered solute concentration on one side of a semipermeable membrane than on the other.
Myocarditis: Inflammation of the cardiac muscle.
Ventricular assist device: An artificial device implanted in the chest to assist a damaged or weakened heart in pumping blood–also called a VAD, or an LVAD when the device is connected to the left ventricle.

Check for a left-ventricular assist device
"Medic 11: Respond to a private residence at 3550 Main Street for a 68-year-old male–possible GI bleed."

On arrival at the scene, Medic 11 finds the first responders are preparing to start CPR. In a tense and somewhat confused voice, the captain says, "He has no pulse, but his wife won't let us do CPR. What should we do?" The patient is lying on his couch with an absorbent pad under his buttocks, and you notice dark blood on the pad. The senior paramedic from Medic 11 immediately feels for his radial and carotid pulses and finds none. Then he hears the man's wife repeatedly saying, "He has a VAD." The medic sees a cord coming out of the patient's abdomen, connected to a small electronic pack attached to the patient's belt. His ECG shows ventricular tachycardia (v tach), and his wife hands you a card and says, "Call this special ventricular assist device consultation line; they will tell you what to do."

This uncomfortable situation is continually being replayed in the minds of EMS providers who encounter heart failure patients with implanted ventricular assist devices (VADs) in the field.

In this case, the patient is lucky his wife is present to stop the responders from starting compressions and causing further harm. Many responders have learned that former Vice President Dick Cheney wears such a device; they have seen him on television shows talking about it, removing its primary battery to show that it has a backup, and they have heard him say that the device keeps his blood supply moving. It doesn't generate a palapable peripheral pulse. But many others have never heard of a VAD and are confused when they first encounter a patient wearing one. That's why this is an important article. With the growing popularity of VAD use, it's more likely that EMS providers will interact with and care for these patients. It's important that EMS providers understand how to assess these patients, make accurate decisions about their care and overcome the challenges and concerns associated with their conditions.

According to the American Heart Association, more than 5 million people are living with heart failure, and 600,000 new cases are diagnosed each year. Deaths from heart failure reach 250,000 annually in the U.S.¹ Even with optimal treatment, heart failure will progress over time, causing end organ failure.

Heart failure is a weakening of the heart muscle to a point where the heart can no longer efficiently pump blood out to the body, causing blood to back up in the venous system, a decrease in blood pressure and poor perfusion to the body's tissues. There are numerous causes of heart failure, including untreated hypertension and muscle damage caused by heart attacks (one or several resulting in scar tissue). Other causes include such structural abnormalities as valvular disease, myocarditis or damage caused from a toxin, such as chemotherapeutic medications or iron from repeated blood transfusions. In a large number of cases, the etiology of a dilated, weakened heart (idiopathic cardiomyopathy) can't be established.

Standard medical therapy for treatment of heart failure includes the administration of certain beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin-receptor blockers (ARBs) and diuretics. Chronic use of beta-blockers and ACE inhibitors is associated with increased survival in heart failure patients. Diuretics, such as furosemide, are used for symptom control in fluid overloaded patients.

Case Continuation
After applying oxygen and getting a quick history from the patient's wife, the patient's ECG spontaneously converts to sinus tachycardia and he awakes and begins talking with you.

He's oriented and talking clearly. His skin is warm and dry. He explains that he has been bleeding from his rectum since 10 p.m. A check of his underwear reveals large clots of blood, estimated by the crew to equal about 500 ccs of blood.

His wife confirms where his VAD is placed under the skin in his left lower chest, and the driveline unit connecting to the battery pack. The senior paramedic places his stethoscope near the VAD and hears a hum emitted from it. The device isn't alarming, but they're worried about the amount of blood he has lost from his rectum.

Ventricular Assist Devices
A VAD is a mechanical device that's surgically implanted into the patient's chest to augment cardiac output, or the ability to pump blood. VADs can be used as a "bridge to transplant" or as "destination therapy." The compact size and portability of VADs affords patients the opportunity to be discharged from the hospital and have an improved survival and quality of life.

VADs are used as a bridge to transplant in patients who meet the qualifications for cardiac transplantation but need temporary support to survive their condition until a suitable heart donor becomes available.

VADs are also used as destination therapy for patients with advanced heart failure who are symptomatic despite optimal medical therapy and who don't meet the qualifications for cardiac transplantation.² The goal of destination therapy is to minimize heart failure symptoms and improve quality of life. Destination therapy means that the patient will live with the device for the rest of their life. It's used not as a temporary solution, but as a permanent therapy to improve quality of life. There's no expectation or plan to progress to heart transplant.

The majority of patients with a VAD have an ejection fraction (EF)–the percentage of blood pumped from the left ventricle with each contraction–of less than 25%. Normal EF is 55—65%.

The most common type of VAD is a left-ventricular assist device (LVAD, when the device is connected to the left ventricle to augment the flow of blood to the body), but VADs may also be placed, as in the right-ventricular, known as an RVAD, or both ventricles, known as a BiVAD. It's estimated that approximately 60,000 patients are living in the U.S. with advanced heart failure that could benefit from an LVAD.³

Case Continuation
The patient remains alert and seems comfortable but continues to have clots of blood exit his rectum. At this point, the crew considers giving him a fluid bolus but debates it because he has end-stage heart failure and they don't want to cause pulmonary edema.

LVAD Functionality & Complications
The principle behind the LVAD is to assist the left ventricle with its ability to generate cardiac output. Surgically implanting the VAD and augmenting blood flow through the pump assists the left ventricle with cardiac output. Blood follows the normal path through the heart until it reaches the left ventricle. The implanted LVAD has a cannula placed in the apex of the heart that drains the blood from the left ventricle into the system pump.

Blood is then pumped into the aorta. The internal pump is placed in the left lower chest, generally under the left rib cage.

A percutaneous cable, also called the driveline, exits the abdominal wall, connecting the internal pump to the external controller, which is connected to an electrical source (batteries or an AC-power based unit). The controller is the brains of the device and contains the settings, alarms and diagnostic information about the pump.

It's important for EMS personnel to know that VAD patients are typically on anticoagulation medications to prevent clotting with the VAD and blood stream. Complications from VADs usually result from anticoagulation or pump thrombosis (clot). Complications include but are not limited to nasal, gastrointestinal (GI) and intracranial bleeds and thromboembolic events, such as cerebrovascular accidents. Pump thrombosis can also sometimes cause the pump to malfunction, or even stop.⁴

Special Care Considerations
Patients who have a VAD, or a family member, are likely to have communicated with their VAD coordinator prior to your arrival. The VAD coordinator can provide you with valuable information about their type of device, pre-existing conditions and recent medication changes. The VAD coordinator can therefore assist you and help you make treatment and transportation destination decisions about the patient and should be involved as quickly as possible during any emergency call to a patient with a VAD. In the event you're unable to get in touch with the emergency on-call VAD coordinator, consult with your medical control physician or see if you can get connected with the on-call cardiologist.

Assessment
Although most of the assessment of a VAD patient is the same as any other patient, there are minor differences to keep in mind. In general, be extremely careful not to cut, twist or bend the driveline coming from the patient's abdomen. Remember, this is connecting the power source to the pump.

Start with the ABCs as normal. When you get to "C," the normal assessment will be changed slightly. Although some VADs produce pulsatile flow, most VADs use continuous flow technology, creating a non-pulsatile continuous flow. This means most patients with a VAD will not have a palpable pulse, and unfortunately, taking a blood pressure with a manual cuff and stethoscope will rarely allow you to hear a pressure.

If available, use an automatic non-invasive blood pressure (NIBP) device, and you may be successful. Although rarely available on an EMS unit, a Doppler unit is the best way to obtain a blood pressure on a VAD patient. Many medical helicopter teams carry Doppler units. When using a Doppler, you use a normal cuff but listen with the Doppler instead of a stethoscope. The first sound heard is approximately equivalent to the mean arterial pressure (normal Doppler pressure range is 60—90 mmHg). A pressure of 60—90 mmHg is considered acceptable.

Another barrier to normal assessment is pulse oximetry. Oximetry readings may not be accurate due to weak or absent pulses. Assessing the patient's mental status, skin and lips are likely to be most helpful in determining the overall condition of the patient's oxygenation, volume status and to help you decide how critical their condition may be. Note that you may or may not hear normal heart tones on VAD patients.

Outside of a normal physical exam, it's important to assess whether the pump is functioning. Listen with a stethoscope over the pump pocket at the lower left rib margin on the anterior chest. A distinct hum will be heard if the device is running. If possible, use the VAD coordinator and family in the event the VAD is alarming because they're the equipment experts.

VAD Alarm
If the VAD is alarming, make sure the driveline and two sources of power (dual batteries or AC power) are connected to the system controller. Make sure you have an invertor in your ambulance and that it's in good, working condition.

If the VAD pump is not working or is stopped, the patient will go back into heart failure. Some patients may tolerate this condition well, while others may decompensate rapidly.

In the event of a pump failure, contact the VAD coordinator for guidance and instruction. Restarting a pump that has been stopped isn't recommended because it will increase the patient's risk of stroke or thromboembolism. This is due to the stagnant blood that may have developed in the system while the pump was off.

If there are no signs of compromised circulation and the pump is alarm free, continue to assess your patient for their chief complaint. Take an ECG, and if you find a concerning arrhythmia, make sure to assess the patient's condition and communicate with the VAD coordinator before you decide to intervene.

Believe it or not, it's possible for a patient to be in ventricular fibrillation or v tach while awake and talking if the pump is working properly.⁵ In one study, researchers reported 19 of 61 patients had a ventricular arrhythmia after having a VAD placed, showing the prevalence of concerning arrhythmias.⁶ If the patient requires defibrillation or cardioversion, these can be performed as normal; however, do not place the defibrillation pads over the pump. (Note that anterior/posterior placement is acceptable.) Do not stop the VAD prior to delivering the shock.

It's important that your patient is confirmed in complete cardiac arrest before CPR is started. This would include poor perfusion of their skin, complete lack of responsiveness and some indication that their pump isn't functioning. It's especially important to use the guidance of the VAD coordinator before initiating CPR.

Remember that VAD patients often call 9-1-1 for problems unrelated to their VAD, so you shouldn't get distracted from your usual approach to patient care. If you're called for stroke symptoms, it's important to establish a time of onset, document a neurological exam and expedite transport. As in our case, you may be called for epistaxis or GI bleeding because these patients will be on anticoagulation medication. A determination about the severity of bleeding and amount of blood loss should guide your fluid resuscitation as usual.

Interventions in all of these examples should be based on you current clinical protocols and operating guidelines. However, it is highly recommended that you discuss your plans with the VAD coordinator if they're immediately available by phone. If the patient has compromised circulation, they may need inotropic support with a sympathomimetic medication, such as Dobutamine or epinephrine, as long as they don't have hypovolemia.

Case Continuation
After IV access is established, the patient's ECG rhythm stays in a normal sinus rhythm. Your automatic cuff still won't give you a blood pressure. At this point, his wife hands you the phone and you're able to speak with the VAD coordinator. After describing your findings and your impression of the patient's condition, she reviews his records and suggests it would be safe to give him a 500 cc bolus of normal saline. She then helps determine the most appropriate facility for the patient.

Decision about Transport
Having a pre-plan for VAD patients is key to any successful program. A typical EMS VAD protocol emphasizes the primary assessment to make a determination of an immediate life threat. The protocol should also reinforce the cooperation with the patient's family and VAD coordinator.

When making a decision about VAD patient's disposition, discuss with the VAD coordinator the most appropriate receiving facility. If the patient appears to have an immediate life threat, you'll most likely be directed to go the closest hospital for stabilization. However, if the patient appears stable and the problem isn't with the device, you may be directed to take the patient to the facility that placed the VAD.

Prior to transport, be careful when putting the patient on your stretcher. Be sure that the driveline doesn't get pulled or become kinked, and that the controller and battery packs are close to the patient and aren't dangling off the side of the cot.

Important aspects of VAD transport include having the patient's emergency travel pack with them at all times. This pack usually contains extra batteries and a back-up controller. Other important aspects of transport include allowing a family member to ride along with the patient because the family member can be an invaluable resource for you. They're trained in the equipment and know how to handle an emergency. They can also be a comfort to the patient.

Conclusion
As you transport the stabilized patient to the hospital, he's happy to tell you all about his VAD. Because you were educated on VADs in advance of the case, you were able to easily handle the patient and transport him to the most appropriate hospital for his continued care. You return to your station, write up the case and send it to your medical director who passes it along to the other crews so they are better prepared to handle a similar case. JEMS

References
1. Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics–2011 update: A report from the American Heart Association. Circulation. 2011;123(4):e18—e209. [Epub Dec. 15, 2010.]
2. American Heart Association (June 16, 2011). Implantable Medical Devices for Heart Failure. In American Heart Association. Retrieved Nov. 20, 2011, from www.heart.org/HEARTORG/Conditions/HeartFailure/PreventionTreatmentofHeartFailure/Implantable-Medical-Devices-for-Heart-Failure_UCM_306354_Article.jsp.
3. Slaughter, MD, Rogers, JG, Milano CA, et al. Advanced heart failure treated with continous-flow left ventricular assist device. N Eng J Med. 2009;361(23):2241—2251.
4. Kato TS, Schulze PC, Yang J, et al. Pre-operative and post-operative risk factors associated with neurologic complications in patients with advanced heart failure supported by a left ventricular assist device. J Heart Lung Transplant. 2012;31(1):1—8. [Epub Oct. 8, 2011.]
5. Patel P, Williams JG, Brice JH. Sustained ventricular fibrillation in an alert patient: Preserved hemo-dynamics with a left ventricular assist device. Prehosp Emerg Care. 2011;15(4):533—536. [Epub Aug 1. 2011.]
6. Brenyo A, Rao M, Koneru S, et al. Risk of mortality for ventricular arrhythmia in ambulatory LVAD patients. J Cardiovasc Electrophysiol. Nov. 14, 2011.

Quick Tips for Left Ventricular Assist Devices (LVADs)
>> Let patient and/or caregiver lead. They will be
your experts.
>> Remember not to perform chest compressions because they could dislodge the pump, making the patient bleed to death. (Unless the patient is in obvious cardiac arrest and the pump isn't working. Use the assistance of the VAD coordinator to figure this out before starting any compressions).
>> Perform all other BLS/ACLS protocols as written.
>> Defibrillate/cardiovert as normal. Don't place pads over the device under the patient's skin.
>> Remember that these patients typically have an extremely reduced pulse rate or none at all.
>> A Doppler device and manual blood pressure cuff are the most accurate way to obtain blood pressure. The first sound heard is approximately equivalent to the mean arterial pressure, and 60—90 mmHg is the acceptable range.
>> Keep in mind that it may be difficult to obtain accurate O2 saturation because of little or no pulse.
>> Be careful when removing/cutting off clothes to ensure you don't cut through the driveline, which is the power cord of the pump.
>> Avoid kinking or twisting driveline when strapping the patient onto the stretcher.
>> Keep batteries and controller in reach and secured to the patient during transport. Keep them dry.
>> Take the patient's emergency travel bag when leaving the scene. It has an extra controller, batteries and the VAD coordinator's emergency contact number.
>> Keep in mind that the most common complications are bleeding (nasal, gastrointestinal or intracranial), thromboemboli (pulmonary embolism, myocardial infarction or cerebrovascular accident), right-sided heart failure, pump malfunction and infection.

The Abbott-Northwestern (Minn.) Ventricular Assist Device Program
Although most of us haven't had the opportunity to take care of a patient with a VAD, increasingly more patients in the U.S. are being implanted with these life-saving devices. Implantation of these devices occurs in highly specialized cardiac care centers. If your local cardiology group or cardiac specialty healthcare systems hasn't yet contacted you, the authors recommend giving them a call. If they have a VAD program, they can help with local education and alert you when they know a VAD patient is being sent home, or refer you to the local center performing these.

Approximately 200 people with VAD devices currently live in Minnesota. According to an Abbott-Northwestern Hospital survey, 17% of 330 EMS providers in Minnesota had cared for a patient with a VAD and only 20% of the respondents had any education in VADs.

In this system, a VAD coordinator is available 24 hours a day, seven days a week by phone. These coordinators have delivered more than 100 hours of education to local EMS services. Since the start of the Abbott Northwestern VAD program two years ago, EMS providers have interfaced and consulted with coordinators more than 30 times.

This article originally appeared in February 2012 JEMS as "No Pulse?: Check for a left-ventricular assist device."

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Source: https://www.jems.com/patient-care/patients-ventricular-assist-device-need/

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