algorithms – Love. Laughter. Life. Medicine.

There’s been a big debate re: who should care for LVAD patients… a general anesthesiologist or a cardiac anesthesiologist? See below for pros and cons of each. Ultimately, I think all anesthesiologists should be comfortable caring for these patients as we’ll see more and more LVAD patients undergoing procedures.

Troubleshooting the Left Ventricular Assist Device. Emergency Medicine. 2016 February;48(2):58-63.

LVAD Parameter Abnormalities:

High power, low-pulsatility index and fluctuating pump speed: Consider pump thrombosis or hypotension, vasodilation, initial response to exercise.
High power with high pulsatility index: Consider fluid overload, normal physiological response to increased demand; myocardial recovery.
Low power, low pulsatility index, and unchanging speed: Consider hypertension or inflow/outflow obstruction, LV failure, dysrhythmia.
Low power with normal or high pulsatility index: Consider suction event.

Pro: Cardiothoracic Anesthesiologists Should Provide Anesthetic Care for Patients With Ventricular Assist Devices Undergoing Noncardiac Surgery. JCVA, February 2017. Volume 31, Issue 1, Pages 378–381

Con: Cardiothoracic Anesthesiologists Are Not Necessary for the Management of Patients With Ventricular Assist Devices Undergoing Noncardiac Surgery. JCVA, February 2017. Volume 31, Issue 1, Pages 382–387.

Ventricular assist devices and non-cardiac surgery. BMC Anesthesiology201515:185

Goals of care for LVAD patients undergoing non-cardiac surgery should be directed at maintaining forward flow and adequate perfusion. Three main factors that affect LVAD flow are preload, RV function, and afterload.
The right ventricle is the primary means of LVAD filling; therefore, maintaining RV function is imperative.
Marked increases in systemic vascular resistance should be avoided.
Generally, decreases in pump flow should first be treated with a fluid challenge. Hypovolemia should be avoided and intraoperative losses should be replaced aggressively. Second line treatment should include inotropic support for the right ventricle.
Low-dose vasopressin (<2.4 U/h) may be the vasopressor of choice due to its minimal effect on pulmonary vascular resistance.
Standard Advanced Cardiovascular Life Support Guidelines should be followed; however, external chest compressions should be avoided during cardiac arrest.
Steep Trendelenburg may increase venous return, risking RV strain. Peritoneal insufflation for laparoscopic surgery also increases afterload and has detrimental effects on preload. Insufflation should utilize minimum pressures and be increased in a gradual, step-wise fashion.
TEE can be extremely valuable in diagnosing the cause of obstruction.

Perioperative management of patients with left ventricular assist devices undergoing noncardiac surgery. Annals of cardiac anaesthesia 2016. Vol 19, Issue 4: 676-686.

LVAD: What Should I report? Feb 2017 ASE conference. **ECHO**

Higher the RPMs (pump speed)
- More LV compression, smaller LV size
- Less functional MR
- More AI, less AV opening
- Less LVED diameter
De Novo Aortic Regurgitation Post LVAD
- Proposed mechanisms
  - Aortic valve remains closed during systole
  - Commissural fusion of the aortic valve from disuse
  - Subsequent degeneration of valve
  - Turbulent blood backflow from small outflow cannula onto a closed valve
  - Persistent elevation of aortic root pressure –> aortic root dilation and valve incompetence
- Treatment
  - Lower LVAD speed (but that may worsen mitral regurgitation)
  - Aortic valve surgery or percutaneous intervention
  - Heart transplant
RV Fractional Area Change (RV FAC)
- RVFAC is a rough measure of RV systolic function (4 chamber view)
- RVFAC = (RVEDA – RVESA) / RVEDA
- Normal RVFAC = 35 – 63%