VENTRICULAR ASSISTIVE DEVICE

PURPOSE

Mechanically pumps blood from the lower heart chambers to the rest of the body as a bridge to transplant or destination therapy for end-stage heart failure.

INDICATIONS AND TREATMENT GOALS

• Bridge to Transplant (BTT): Supports patient until a donor heart becomes available.

• Destination Therapy (DT): Permanent support for patients with end-stage heart failure who are not candidates for heart transplantation.

• Bridge to Recovery (BTR): Temporary support allowing a stunned myocardium (e.g., severe myocarditis) to rest and recover.

MECHANISM

An inflow cannula is inserted into the left ventricular apex, drawing oxygenated blood into a mechanical pump, which then propels it through an outflow graft directly into the ascending aorta. A percutaneous driveline exits the abdominal wall to connect the pump to an external controller and power source (batteries/AC power).

PRE OP NURSING CARE

• Psychosocial & Driveline Education:

  • Educate the patient and primary caregiver on device management

  • power source changing

  • emergency battery swaps

  • driveline sterile exit-site care.

• Baseline Diagnostics: Obtain 12-lead ECG, Echocardiogram, CBC, CMP, Coagulation Panel (PT/INR, PTT, Fibrinogen), Blood Cultures, and blood crossmatch.

• Infection Prevention: Chlorhexidine gluconate (CHG) skin prep; ensure strict sterile technique during pre-op preparation.

• Right Ventricular (RV) Evaluation:

  • Assess RV function via Echo/RHC.

  • A failing right ventricle cannot push blood to the lungs to supply the LVAD

  • Risking acute right heart failure post-op.

POST OP NURSING CARE

• Blood Pressure Monitoring via Doppler:

  • Standard automated cuff BP is unreliable due to continuous non-pulsatile flow.

  • Measure BP using a manual cuff and Doppler ultrasound probe over the brachial or radial artery. The first swooshing sound heard as the cuff deflates is the Mean Arterial Pressure (MAP).

  • Target MAP: Maintain MAP strictly between 70 and 85 mmHg. High MAP (> 90 mmHg) increases pump workload (afterload), reduces forward flow, and increases stroke risk.

• Driveline Care (Strict Sterile Technique):

  • Sterile dressing changes performed per hospital protocol using surgical mask and sterile gloves to prevent driveline exit-site infection. Secure the driveline with an anchoring device (e.g., Foley anchor or stabilization belt) to prevent traction/trauma.

• Chest Tube & Drainage Assessment:

  • Monitor mediastinal chest tubes hourly.

  • High risk of postoperative hemorrhage due to intraoperative heparin, pre-existing liver congestion, and destruction of von Willebrand factor by the mechanical pump.

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• Device Parameters Monitoring:

  • Record pump parameters continuously: Flow rate (L/min), Speed (RPM), Power (Watts), and Index (PI - Pulsatility Index). Sudden changes signal hypovolemia, suction events, or clot formation.

Things to Watch Out For & Complications

• Driveline Infection / Sepsis:

  • Leading cause of rehospitalization. Look for redness, warmth, purulent drainage at the abdominal exit site, or elevated WBCs and fever.

• Right Ventricular (RV) Failure: Signs include severe peripheral edema, rising CVP (> 15–18 mmHg), jugular venous distention (JVD), liver congestion, and dropping LVAD flow rates despite adequate pump RPMs.

• Suction Events: Occurs when LV volume is too low (dehydration, RV failure, bleeding) and the pump cannula pulls against the ventricular septum. Triggers pump alarms and ventricular dysrhythmias. Treatment: Give IV fluid bolus and lower RPM as ordered.

• Pump Thrombosis: Indicated by a sudden increase in pump power (Watts), dark/hemolyzed urine (hemoglobinuria), elevated LDH levels, and signs of heart failure or stroke.

• Acquired von Willebrand Syndrome / Gastrointestinal (GI) Bleeding: Mechanical shear stress from the pump destroys vWF proteins and forms arteriovenous malformations (AVMs) in the GI tract, causing active GI bleeding (melena, hematemesis).

DRUGS TO HOLD

• ORAL ANTICOAGULANTS

• ANTIPLATELET

• ACE INHIBITORS / ARB - 24H

  • Prevents refractory vasoplegic shock upon coming off Cardiopulmonary Bypass.

MEDICATIONS TO GIVE

• ANTTICOAGULANTS

  • Essential to prevent pump thrombosis. Target INR is typically 2.0–3.0 (or 2.5–3.5 depending on device model).

• ANTIPLATELET

  • ASPIRIN POST OP D1-2

  • Combined with Warfarin to prevent thromboembolism and pump clots.

• Afterload Reducers (Antihypertensives)

  • Lisinopril, Hydralazine, Isosorbide Dinitrate

  • POST OP CONTINUOUSLY

  • Maintains target MAP (70–85 mmHg). High afterload decreases LVAD efficiency.

• INOTROPES AND RV SUPPORT

  • Milrinone, Dobutamine, Sildenafil

    • POST OP IV TITRATION

  • Supports Right Ventricular contractility and lowers pulmonary vascular resistance to prevent RV failure.

• ANTIBIOTICS