What is the protocol for initiating right side Impella (Intra-Aortic Balloon Pump) support in a patient with right ventricular failure?

Right-Side Impella (Impella RP) Protocol

The Impella RP should be initiated in patients with right ventricular failure refractory to medical management, with immediate hemodynamic monitoring and anticoagulation starting with a UFH bolus of 100 U/kg (maximum 5000 units) at implantation. 1

Patient Selection and Indications

Primary indications for Impella RP include:

• Right ventricular failure following left ventricular assist device (LVAD) implantation 2
• Right ventricular failure after acute myocardial infarction with right ventricular involvement 3, 2
• Right ventricular failure post-cardiotomy 2
• Acute-on-chronic right heart decompensation 4
• Biventricular failure requiring combined left and right ventricular support 1, 5

The device is specifically designed for right ventricular support, providing up to 4.0 L/min of flow through a percutaneous approach. 1

Pre-Implantation Assessment

Before device placement, confirm:

• Refractory right ventricular failure despite optimal medical therapy (typically requiring ≥3 inotropes/vasopressors) 2
• Baseline hemodynamics showing elevated central venous pressure (typically >15-19 mm Hg) and reduced cardiac index (typically <2.0 L/min/m²) 2
• Absence of contraindications including severe peripheral artery disease, right ventricular thrombus, or severe tricuspid stenosis 1

Implantation Protocol

The Impella RP is inserted percutaneously via the right internal jugular vein or femoral vein approach: 6, 2

• The device is advanced through the inferior vena cava, right atrium, and right ventricle, with the inlet positioned in the inferior vena cava and outlet in the pulmonary artery 1
• Fluoroscopic guidance is used to ensure proper positioning 2
• Device delivery success rate is approximately 97% 2

Anticoagulation Management

Initiate anticoagulation immediately at implantation: 1

• Administer UFH bolus of 100 U/kg (maximum 5000 units) at device insertion 1
• Maintain continuous UFH infusion targeting aPTT 1.5-2.0 times control or anti-Xa levels 0.3-0.5 units/mL 1
• Critical caveat: Bleeding requiring transfusion occurs in 63.6% of patients, necessitating careful balance between thrombotic and hemorrhagic risks 5

Hemodynamic Monitoring Protocol

Immediate post-implantation monitoring should document: 1, 2

• Cardiac index improvement (expect increase from ~1.8 to ~3.3 L/min/m²) 2
• Central venous pressure reduction (expect decrease from ~19 to ~13 mm Hg) 2
• Mean arterial pressure maintenance >65 mm Hg 1
• End-organ perfusion markers (lactate clearance, urine output, mental status) 1

Monitor motor current continuously as it reflects device function and hemodynamic status. 1

Inotrope and Vasopressor Management

After device initiation: 1, 5

• Begin weaning inotropes and vasopressors as hemodynamics improve 5
• When additional vasopressor support is needed, prefer vasopressin or norepinephrine as they increase systemic afterload without significantly increasing pulmonary vascular resistance 1
• Avoid excessive inotrope use that increases myocardial oxygen demand 1

Daily Management and Monitoring

Daily assessments must include: 3, 1

• Hemodynamic parameters (cardiac output, central venous pressure, mean arterial pressure) 1
• Device function verification (motor current, flow parameters, absence of suction alarms) 7
• Laboratory monitoring: complete blood count (hemolysis occurs in 86.4% of patients), renal function (68.2% require hemodialysis), coagulation parameters 5
• Echocardiographic assessment of right ventricular function recovery 1
• Volume status and diuretic requirements 3

Critical pitfall: Hemolysis is nearly universal (86.4%) with Impella RP support and requires close monitoring of hemoglobin, LDH, haptoglobin, and plasma-free hemoglobin. 5

Duration of Support

Typical support duration is 3-7 days (range 0.5-14 days): 5, 2

• Average duration in clinical trials: 3.0 ± 1.5 days 2
• Extended support up to 14 days has been reported 5
• Duration depends on right ventricular recovery, resolution of precipitating factors, and transition to definitive therapy 1

Weaning Protocol

Initiate weaning when the following criteria are met: 1

• Improved right ventricular function on serial echocardiography 1
• Reduced inotrope/vasopressor requirements 1
• Adequate end-organ perfusion without device support 1
• Resolution of precipitating factors (if applicable) 1

Weaning approach:

• Gradually reduce device flow while monitoring hemodynamics 1
• If hemodynamics deteriorate during weaning, resume full support and reassess in 24-48 hours 1
• For patients failing weaning attempts, consider longer support duration or transition to durable mechanical circulatory support 1

Management of Complications

Suction alarms require immediate assessment: 7

• Verify power connections and battery status 7
• Assess device position with fluoroscopy or echocardiography 7
• Optimize volume status (hypovolemia is the most common cause) 7
• Consider controller malfunction and exchange if persistent 7

Bleeding management: 5

• Occurs in 63.6% of patients requiring transfusion 5
• Balance anticoagulation intensity against bleeding risk 1
• Consider reducing anticoagulation targets in active bleeding while maintaining minimum therapeutic levels 1

Hemolysis management: 5

• Expected in 86.4% of patients 5
• Monitor hemolysis markers daily 5
• Severe hemolysis may necessitate device removal 5

Escalation Strategy for Inadequate Response

If patient deteriorates despite Impella RP support: 1

• Assess for device malfunction or inadequate positioning 1
• For biventricular failure, add left-sided Impella support to create bilateral Impella configuration 1
• Consider VA-ECMO for patients requiring greater systemic circulatory support, maintaining Impella RP for right ventricular decompression 1
• Evaluate for candidacy for durable LVAD, biventricular assist device, or heart transplantation 1

Outcomes and Prognosis

Expected outcomes with Impella RP support: 5, 2

• Overall 30-day survival: 68-73% 5, 2
• All patients discharged alive remain alive at 180 days 2
• Among survivors: transition to heart transplant, durable LVAD, or recovery to discharge 5
• 30-day heart failure readmission rate: 20% 5

Prognostic factors: Patients in SCAI stage D-E cardiogenic shock have the highest mortality risk, with stage E patients showing 27.3% representation in recent series. 5