Back to Basics: The LVAD Patient

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November 17, 2015 by dailybolusoflr

By: Casey Carr, MD

Basics

  • Ventricular assist devices (VADs) are circulatory support pumps that are used in end stage heart failure both as a bridge to transplant and as destination therapy
  • They are implanted in the upper abdomen and connected to an external power supply
  • Blood flows from a tube in the left ventricle, to the VAD, to the aorta
  • Typically patients have no pulse; mean arterial pressures (MAP) need to be measured using Doppler
    • MAPs between 70 to 80 are ideal

Complications

Bleeding

  • LVAD patients are commonly anticoagulated
  • Most commonly have bleeding complications following recovery from implantation
  • LVAD patients with continuous flow devices (mostly standard now) are prone to developing acquired von Willebrand disease due to shear stress on cells

    Thrombosis

    • High risk in patients who are inadequately anticoagulated
    • Pump itself is prone to developing stasis clots
      • Pump can become obstructed
      • Clots can embolize as well
      • Think pump thrombosis if evidence of hemolysis (change in urine color, elevated LDH, decreased renal function, reduced haptoglobin) and poor pump performance (low flow alarm!)
        • Needs immediate pump replacement

      Infection

      • Common bugs -> Staph aureus and coagulase-negative staph
      • May present on a broad spectrum, from localized skin erythema to sepsis

        Arrhythmias 

        • Most patients have an underlying ischemic heart disease, and thus are prone to arrhythmias
        • Sustained VT/VF will quickly lead to RV failure; need immediate cardioversion if unstable 

          Right sided heart failure

          • Major cause of morbidity and mortality after LVAD placement
          • May present with hepatic dysfunction, renal insufficiency, pedal edema, and RV dysfunction on echo

            References:

            1. La Franca, E, et al. Heart failure and mechanical circulatory assist devices. Global Journal of Health Science. 2013 May 14;5(5):11-9
            2. Greenwood, JC, et al. Mechanical circulatory support. Emergency Medicine Clinics of North America. 2014 Nov;32(4):851-69

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