Approach to the LVAD Patient: Part 2


    Approach to the LVAD Patient: Part 2

    There is a critical addendum to yesterday’s post, courtesy of Sam Schuberg. Patients with LVAD’s can go into dysrhythmias (VT, VF) despite the appearance of stability. Obtain an ECG on arrival in unstable patients with an LVAD. Thanks for reading the pearl, Sam.

    Now, on with today’s #TRPearl

    There are four parameters the LVAD monitor will provide you with: speed, flow, power, and pulsatility index (PI). Speed is reported in RPM’s, and is determined by the operator. The other values are dependent variables:

    Power, measured in watts, represents how much work the LVAD has to do to produce a set number of RPM’s. Power and flow are directly related. However, if power increases (LVAD is doing more work to maintain the same RPM) and flow remains the same, think about pump thrombosis.

    Flow, measured in L/min, is related to both the pump speed (RPM) and the pressure differential (“pressure head”) across the pump. For example, if the patient becomes septic and systemic vascular resistance drops, flow will increase without a change in the pump speed.

    Pulsatility index (PI) is the most abstract of these parameters, but may be the most clinically relevant. To produce this value, the LVAD measures the flow pulses from native left ventricular contractions, and averages them over a 15 second interval. The PI demonstrates the relationship between the native LV function and the amount of ventricular unloading the pump does. If you increase the pump speed, the PI falls. If the native LV function falls, the PI will also fall. In pathologic states that make the native cardiac output fall such as decreased preload through hypovolemia/hemorrhage, the PI will also fall. Low PI (patient should know what their baseline PI is) should clue you into the possibility of hypovolemia, hemorrhage, or acute worsening in native LV function.

    I’ll spend more time in part three going through how to apply these values clinically.


    Pratt, Alexandra K., Nimesh S. Shah, and Steven W. Boyce. “Left ventricular assist device management in the ICU.” Critical care medicine 42.1 (2014): 158-168.

    Slaughter, Mark S., et al. “Clinical management of continuous-flow left ventricular assist devices in advanced heart failure.” The Journal of Heart and Lung Transplantation 29.4 (2010): S1-S39.


    • Welcome! This is the website for the Mount Sinai Emergency Ultrasound Division. It serves as an information resource for residents, fellows, medical students and others seeking information about point-of-care ultrasound. There is a lot ofRead more

    • bicarbonate revisited

      Previous post reviewed the safety of balanced crystalloids in hyper K. But what was up with serum bicarbonate decreasing with saline administration? This post introduces a new way of looking at the anion gap to possiblyRead more

    • hyperkalemia and balanced crystalloids

      Is it safe to give LR or plasmalyte to a hyperkalemic patient (these balanced crystalloids have 4-5 mEq/L K as opposed to 0 mEq/L K in normal saline)? Postponing the discussion of renal handling of potassium toRead more

    • hyperkalemia physiology

      You’ll likely encounter hyperkalemia on your next Resus / Cardiac shift, and you’ll instinctively treat it. But take a moment to review the fascinating physiology behind the “cocktail”! First, consider how K+ is buffered byRead more

    • Slow down your tachycardia (but not really)

      You’re sitting in resus bemoaning the departure of your most beloved attending when suddenly a patient wheels in without warning. The patient looks relatively stable but the triage RN tells you her heart rate wasRead more

    • Otitis externa: use the ear wick!

      Acute otitis externa (AOE) is a common complaint seen in pediatric as well as adult emergency departments. AOE is typically not accompanied by acute otitis media, although concurrent cases are possible. Also called “swimmer’s ear”Read more

    • Reach for the COWS

      Your patient in intake is miserable. Doubled over, complaining of pain everywhere, sweating, ill-appearing but not unstable. He tells you that the last time he used heroin was two nights ago, and he is askingRead more

    • Tis the season, summer edition

      As the late spring rains have begun to fade and the temperature rises mercilessly into the 80s and beyond, summer is finally upon us. And with summer comes a host of diseases for the emergencyRead more

    • Meet the newest member of your team

      We have a new resource in the Sinai ED. Say hello to your friendly ED pharmacist. In the past several years, the ED pharmacy has been centralized in a non-ED location. We all know wellRead more