What is the usual rate for a bicarbonate drip purge device on an Impella (Intra-Aortic Balloon Pump)?

Bicarbonate Drip Purge Device Rate for Impella

The usual rate for a bicarbonate drip purge solution on an Impella device should be maintained to achieve adequate purge pressure without significant changes in flow, typically starting at 25 mL/hour and titrating as needed to maintain purge pressures between 300-1100 mmHg.

Purge Solution Options and Rates

Standard Purge Solutions

• Traditionally, heparinized purge solutions have been the standard for Impella devices:
  • Standard concentration: 50 units/mL of heparin in dextrose solution
  • Alternative concentration: 25 units/mL of heparin in dextrose solution 1
  • Diluent options: 5% dextrose (D5) or 20% dextrose (D20) 2

Bicarbonate Purge Solution

• Sodium bicarbonate purge solution is an FDA-approved alternative (since April 2022) when heparin is contraindicated 3
• Indications for bicarbonate purge solution include:
  • Heparin-induced thrombocytopenia (HIT) 4
  • Major bleeding complications 3
  • High bleeding risk patients

Initial Rate and Titration

• Starting rate: 25 mL/hour
• Target purge pressure: 300-1100 mmHg (device-specific)
• Titration: Adjust rate based on purge pressure readings
• Monitor for:
  • Stable purge pressure
  • Consistent flow
  • Absence of motor current spikes

Clinical Considerations

Monitoring Parameters

• Daily transthoracic echocardiography to assess device positioning 5
• Regular monitoring of purge pressure and flow
• Assessment for signs of hemolysis
• Monitoring for device-related complications 5

Potential Complications

• When using heparinized purge solutions:
  • D5 diluent may lead to higher purge flow rates than D20 due to lower viscosity 2
  • Higher purge rates can increase systemic heparin exposure, potentially leading to supratherapeutic anticoagulation 2
  • ACT levels >168s are associated with increased 30-day mortality 6

Bicarbonate Solution Benefits

• Successful use in patients with HIT without significant changes in purge pressure or flow 4
• Can be used for extended periods (documented for up to 13 days) 4
• Prevents protein deposition in device gaps and device dysfunction 4
• Effective in stopping bleeding when switched from heparin purge solution 3

Practical Management Tips

• For patients with bleeding complications or HIT, consider switching to bicarbonate purge solution
• When using bicarbonate purge solution, maintain the same initial rate as with heparin solutions
• Coordinate fluid management with overall hemodynamic status 5
• Place any additional vascular access (e.g., CRRT) away from Impella insertion sites 5
• Regular assessment of device position via echocardiography and chest X-ray is essential 5

Caution

• Avoid excessive flow rates that may contribute to hemolysis
• Monitor for signs of device thrombosis if anticoagulation is reduced or eliminated
• Be vigilant for bleeding complications, especially when combining purge solution with systemic anticoagulation