New algorithms offer guidance on LVAD emergencies

By Scott Baltic

NEW YORK (Reuters Health) - A new set of algorithms for emergencies involving left ventricular assist devices (LVADs) will “improve safety for adult LVAD recipients who experience an out-of-hospital emergency,” according to experts from the UK consortium that developed the guidelines.

Structured as a series of three flowcharts, the algorithms were created to aid in caring for the increasing number of LVAD recipients. These patients may face life-threatening emergencies such as device failure, stroke, bleeding, LVAD thrombosis, and systemic infection.

The four LVAD models now in use each include a rotating impeller to push blood from the left ventricle to the aorta. While these devices let patients live independently and travel, LVAD failure can lead to retrograde blood flow during ventricular diastole or to a fatal loss of cardiac output.

Historically, UK hospitals where LVADs were implanted often made safety arrangements for LVAD patients at hospital discharge, Dr. Christopher T. Bowles, of Harefield Hospital, London, told Reuters Health by email. Those arrangements included notifying and training emergency medical services near the patient’s home, which often led to training programs that were particular to the local hospital’s preferred LVAD.

Patients with LVADs often travel extensively, though, Dr. Bowles explained. Nevertheless, ongoing, comprehensive training of paramedics and emergency department staff in the various LVAD designs “is hard to justify and implement, given the relatively low prevalence of (LVADs).”

Evidence indicates, however, that out-of-hospital LVAD emergencies have been mismanaged, Dr. Bowles said. “Consequently, the (new algorithms) were designed to address an unmet clinical need” and to be useful for all current LVAD designs.

The three algorithms, published online November 10 in Emergency Medicine Journal, cover initial assessment, LVAD troubleshooting, and ensuring adequate circulation. The initial-assessment algorithm, for example, notes that emergency responders should not expect a pulse, because LVADs produce continuous, non-pulsatile blood flow.

The algorithms also address the controversial issue of whether to perform chest compressions and/or defibrillation, if either is indicated.

To his knowledge, Dr. Bowles said, a national initiative such as this has not been reported in the U.S. or elsewhere. The consortium has received expressions of interest from Israel, which is considering national implementation of the algorithms or a modified form of them, he added.

Although not groundbreaking, this project was “extremely well done. . . . I like the algorithmic concept,” Dr. Rade Vukmir, a professor of emergency medicine at Temple University, Philadelphia, and a spokesperson for the American College of Emergency Physicians, told Reuters Health by telephone.

He also noted that the same makes and models of LVADs are used in the United States.

The first flowchart, Dr. Vukmir noted, addresses the crucial first question in an LVAD emergency: Is the device working? (Is it humming? Is its alarm sounding?)

A crucial issue is whether the patient is in cardiac arrest. When LVADs were new, their manufacturers advised against compression, Dr. Vukmir noted, although opinion has changed somewhat since then.

The UK report notes a shortage of high-quality evidence about compression in this clinical setting and suggests that shorter, rather than longer, periods of chest compression appear to be associated with favorable outcomes.

Another major issue is whether to defibrillate, said Dr. Vukmir, who added that patients with LVADs typically are not affected much by ventricular tachycardia. “Shocking is probably less harmful than compressions,” he said.

Overall, this report is “a very nice addition to the literature on this subject,” according to Dr. Vukmir. “The more education we can do for patients, the public, providers, EMS - it all helps.”

The project was funded by Medtronic, which makes LVADs.

SOURCE: https://bit.ly/2B9edmf

Emerg Med J 2017.