
For Lara Iezzi, April Fool’s Day is one to celebrate. This isn’t because she’s unaware of how serious her daughter, Gabby’s heart condition is. Rather, it’s because there was no trickery in the Berlin Heart Left Ventricular Assist Device (LVAD) that was implanted to provide her 2-year-old daughter with the bridge to transplant that Gabby needed to continue to live.
LVADs are mechanical devices designed to do the bulk of the heart’s work for patients suffering from extreme heart failure. The first prototype, the Jarvik Artificial Heart, was introduced more than 25 years ago. Several generations later, today’s LVADs are much more prevalent than their predecessors. Street level providers are faced with the complexity of the patient s underlying medical condition and specifics to the device.
The Berlin Heart, which is a longterm pulsatile ventricular assist device (VAD) comes in four pump sizes and can be used in adult and pediatric populations. The federal Food and Drug Administration allows its use on a case-by-case basis because it’s one of the only proven long-term assist devices available for use in infants and small children who do not respond to typical treatments via medication.
The Berlin Heart pump is about the size of a grapefruit. It has catheters that attach to either the aorta or pulmonary artery depending on the area of myocardial weakness. It’s been found to be more beneficial than other emergent treatments, including Extra Corporeal Membrane Oxygenation (ECMO) in which the heart is directly oxygenated, similar to dialysis. In one statement, it was noted that they Berlin Heart VAD provided “moderate to longterm support and preserves the options of bridging to transplantation or recovery for children. In addition, the Berlin Heart VAD appears to have fewer bleeding complications compared to ECMO with decreased blood product utilization during support,” according to one study published in a 2005 edition of Artifical Organ. Additionally, the device can be used to assist patients through periods of failure secondary to infection.
Although several devices exist on the market and the technology is in its third configuration, generally devices will fall into two categories of producing a pulse or being non-pulsatile, or axial flow. This second version doesn’t produce a pulse, but rather provides a continuous flow of oxygen-rich perfusion to the body, hence patients with no pulse. This occurs by a turbine that spins 9,000 to 10,000 revolutions per minute and produces 5-5.5L of cardiac output. These patients may be in a sinus rhythm and have a mean arterial pressure (MAP) of 70-80.
MAP = (DBPx2) + SBP
3
SBP = systolic blood pressure
DBP = diastolic blood pressure
The newer generation devices react similarly to the human heart when they respond to an increased left-sided venous return by increasing the rate and volume. Many of these patients will hold a reasonable quality of life with the LVAD. They may not only live at home but might have an active lifestyle that includes eating out at restaurants, going to theater shows, and watching children s sports games.
Perhaps as important as the need to know the device is the need to transport the patients either by ground or air to the facility where the device was inserted and make notifications to that hospital as early as possible. In many cases the emergency department staff, patient caseworker and transplant surgical staff must be notified to be ready when you arrive with the patient.
Dr. Todd Dewey, a cardiothoracic surgeon and director of Medical City Dallas Hospital’s Mechanical Circulatory Support group, says these patients have to go to the hospital where the device was implanted. Otherwise, “it would be like taking your car in for repairs at a boat shop.” The analogy is important because although both do repairs, one shop completely lacks the necessary technology, staffing and experience to handle the additional workload.
Specific to Dewey’s facility, Medical City Children’s Hospital has been involved with pediatric heart cases since November 2003 and treated patients from 125 communities through outreach clinics. This level of experience is important because while some hospitals may be great chest pain centers or pediatric facilities, they may not be familiar with the specifics of implanted devices. So, it s important to involve institutions familiar with this level of care with your patient.
Good clinical assessments should not be forgotten simply because of the technology involved. The patients mental status, capnograph waveform, pulses and blood pressures are good ways to assess patients who have implanted LVADs. On the most basic level, mental status can be powerful indicators of how well a patient is perfusing their most important organ, the brain. Capnographs may give you an idea of how well the patient is oxygenating while peripheral pulses and blood pressure will determine how well the body is perfusing distally.
Additionally, providers may be able to auscultate the chest and hear the machine make a whirring sound in the chest when it is functioning properly.
As you can see, patients with no pulse can be much more than an everyday call, especially if they’re up and talking to you. Like any significant event, pre-planning can go a long way to treating both the patients conditions and the crew s concerns over these devices. Most important is to enter scenes with high-tech artificial hearts armed with confidence and knowledge so you can make not just their day but their life.
Christopher Suprun, NREMT-P, CCEMT-P, is a frequent EMS and fire author and presenter at conferences across the country. He can be contacted through his Web site at http://www.consurgo.org.