Abiomed Impella 2.5
Flattened Motor Signal
- If you see a flattented motor signal both the inlet and outlet areas are in the LV and the cannula needs to be pulled back. - Depending on how far the catheter is in the LV the placement signal may be either aortic or ventricular.
Purge Fluid
After initial setup Heparin is added to the fluid in the event that blood enters into the motor gap the Heparin will help maintain the patentcy of the purge pathway.
What the pump does
An intigrated microaxial pump in the proximal end of the cannula rotates to pull blood from the ventricle into the aorta. This action provides hemodynamic support to the patient by increasing cardiac output. When placed correctly across the aortic valve it transports blood in the same manner as the natural heart. It pulls blood from the ventricle through the aortic valve into the root of the ascending aorta.
Impella Alarms
Blood damage can occur when there is interference with or obstruction of blooe flow through the catheter. If the inlet area is obstructed by ventricular structures and the flow rate remain unchanged blood will travel faster to enter through the unobstructed inlet windows. At this higher speed the blood will be subjected to higher shear forces against the cannula wall and other structures. These forces can pull blood cells apart resulting in hemolysis.
Verifying Placement
Impella 2.5 correctly placed if: - Placement signal = aortic - Motor current = pulsatile - Verify proper placement with fluoroscopy - Monitor automated impella controller placement screen - Reposition if needed and remove excess slack
Impella in Aorta
Impella 2.5 off and in the Aorta: - Flow = 0 L/min - Aortic placement signal - No motor current when Impella is off - Flow is not calculated
Patient Factors to Assess prior to Insertion
LV thrombus: Thrombus could cause Impella motor to stop. Aortic stenosis/Calcification: Inability to pass motor aross valve. Mechaical aortic valve: Damaged valve/aortic insufficiency. Tortuous iliac artery: Difficulty with insertion - use 30cm Cook sheath. Multiple access (scar tissue): Closure complications; pre- closure failure.
General Patient Management Considerations
Monitor patient's being supported with the Impella for signs of right and left heart failure. Look for: - Reduced flow from the Impella catheter. - Suction alarms. - Elevated filling pressures. - Signs of liver failure. - Elevated pulmonary pressures. - Consider treatment for patients exibiting signs of RVF using standard of care.
Soft Buttons
Mute alarms: Silences or clears an alarm; bell icon with red "x" displayed when alarm is muted for two minutes or until a new alarm is detected. Flow control: Sets flow rate to AUTO or Boost, or one of nine P-level settings: P-0 through P-8. Display: Opens a menu from which you can select different display screens and change time and display scale. Purge system: Opens the purge system menu for selecting various purge procedures (e.g. changing the purge, componants or cassetts).
Impella Alarms
One of the most effective means of preventing migration and maintaining proper position is to remove catheter slack and carefully position the inlet area 3.5 cm below the aortic valve. In this postion the inlet area is unobstruction and the outlet area is above the aortic valve. The inlet and outlet area are positioned to avoid the anterior leaflet of the mitral valve.
Backload
Pre-assembled easy guide lumen facilitates loading the placement guidewire. Advancing the Impella 2.5 - Advance Impella through the 13 Fr sheath - Follow and confirm position with fluoroscopy
Menu
Setting/service Alarm History Start data snapshot (time data recording) Case start
Placement of the Impella Catheter
Setup and Insertion Kit: - Impella 2.5 introducer kit - Purge Cassette - Connector Cable - Impella 2.5 Introducer Kit - 0.018" placement guide wire
Impella Alarms
When both the inlet and oulet areas are in the same pressure environment, motor current will be flat and the flow may be higher than expected for the current performance setting.
Impella Alarms
When the catheter operates at High Flow Rates the catheter is pulled into the LV. The best method in preventing inward migration, remove excess slack from catheter after placement. - Tighten the TB valve and note the catheter position in cm. - If patient is very active or uncooperative immobilize the leg to prevent catheter movement (use knee immbolizer). - Obtain a baseline Echo after inserting or suspected catheter movement.
Required Hospital Supplies
For set-up: 500cc bag of D20 For Placement: - 5-8 Fr introducer and 10 Fr dilator - 6 Fr ALI or MP diagnostic catheter without side holes or 4-5 Fr pigtail with or without side holes - Standard 0.035" x 175 cm j-tip guidewire For switch to the standard configuration: - NS flush solution with pressure bag - Standard IV infusion set - 500cc bag of D20 w/ 50 units/ml Heparin
Impella Position Monitoring
If the catheter is fully in the ventricle the placement signal is ventricular and the motor current signal if flattented. If the controller detects an aortic signal and flattened motor current signal it will know the Impella position is wrong; however it will not be able to determine whether the catheter is fully in the aorta or whether both the inlet and ourlet area are in the ventricle and the open pressure port is in the aorta.
Impella Alarms
If you detect suction confirm adequate volume status and evaluate Impella catheter position using placement and motor current waveforms as well as imaging. Reposition catheter if necessary. Also, confirm RV function. The Impella creates foward physiologic flow, flow from the outlet creates foward thrust like the motor behind a boat. The Impella therefore, which extends from the groin all the way to the LV has a tendency to be drawn deep into the LV. After insertion EXPECT inward migration and plan accordingly.
Catheter Supplies and Equipment
Impella 2.5 set-up and insertion kit - Impella 2.5 catheter - Impella 2.5 introducer kit - Purge cassette - Connector cable Hospital supplies provided - D20 in 500cc bag - ALI or MP diagnostic catheter without side holes or 4- 5 Fr pigtail with or without side holes - Automated Impella Controller
Vascular Access
- Access the femoral artery - Pre-dilate and place 13 Fr introducer - Achieve ACT of 250 seconds or higher - Remove the dilator
Common Screen Elements System Power
- Battery status - Full-partial green > 50% charged - Partial yellow 16% to < 50% charged - Partial red <15% charged - Moving green charging - AC plug indicator - Green: running on AC - Gray w/ red "X": running on battery
Common Screen Elements Impella Flow
- Current flow rate - Max/min and mean flow rate in L/min - Catheter operation icon
General Patient Management Considerations
- Do not raise HOB > 30 degrees - Use knee immobilizer as needed to maintain site straight - Perform dressing changes per hospital protocol using aseptic technique - Assess access site for bleeding and hematoma. - Be careful not to pull on the Impella catheter when transferring a patient from one bed to another - Monitor pedal pulses
Ventricular Access
- Insert a 6 Fr ALI or MP without side holes or a 4-5 Fr pigtail with or without sideholes into the LV over a 0.035" guidewire - Exchange the 0.035" guidewire for 0.018" placement guidewire. - Remove the diagnostic catheter.
Technology Overview
- Intravascular micoaxial blood pump - Support patient's circulation - Inserted percutaneously through the femoral artery orsurgically through the axillary artery into the left ventricle. - The inlet area of the catheter sits in the mid- ventriclular space. The outlet area sits in the ascending aorta.
Impella Alarms
- Myoglobinemia with muscle damage (compartment syndrome). - Seen with vascular deficit often resulting in fasciotomy. - Metabolic conditions (i.e. transfusion reactions/drug reactions - rare) Once these conditions are ruled out the likely cause of red urine in a patient on Impella support is hemolysis due to incorrect catheter positioning or low volume. Add volume if hemolysis occurs with CVP or PCWP < 10 mmHg.
Starting the Controller
- Press and hold the power switch for 3 seconds to turn the controller on (on the right side). - Controller automatically performs a system test when powered on.
Transfer to standard configuration
- Press the purge system - Select "Transfer to standard configuation" Controller switiches to P-level mode; AUTO will no longer be an option - Select "OK"
Automated Impella Controller
- Provides an interface for monitoring and controlling the Impella catheter - Provides purge fluid to the Impella Catheter - Provides backup power when the Impella system is opertaed away from AC power. Can operate on its internal battery at least 60 minutes when fully charged.
Impella 2.5 Initial Setup
- Purge flow regulated to keep purge pressure at 600mmHg. - Impella 2.5 standard setup - purge flow: 2-30 ml/hr - purge pressure: 300 - 1100 mmHg Controller warnings/alarms - purge pressure too high or too low - purge system blockage detected - purge rate increases or decreases by 2.5ml/hr
Common Screen Elements Purge System
- Purge system marquee - Y connector icon - Purge flow in ml/hr
Impella 2.5 patient management topics
- Target Hemodynamics - Monitoring Impella 2.5 position - Managing the purge system - General patient management consideration
Impella Alarms
An obstruction within the cannula such as a clot or stray fibers narrows the passageways through which blood must pass. This can also increase shear force and potentially lyse RBCs. Blood cells can also be damaged if the aortic valve or aortic wall interferes with blood exiting the outlet area of the catheter.
Understanding Impella Position Monitoring
- The automatic Impella controller uses the placement signal to monitor whether the impella catheter is correctly positioned across the aortic valve. - Placement signal is based on physiologic pressures. - Open pressure port just distal to the impella motor provides BP measurement for position monitoring to an integrated physiologic pressure transducer in the RED Impella plug. - The placement signal is displayed on the placement screen.
Catheter is Ready for Insertion
1. Confirm fluid exiting catheter 2. Enter the purge fluid information and select OK Purge volume - 500ml Dextrose Concentration - 20% Heparin Concentration - 50 units/ml
When Weaning from Impella
1. Decrease flow rate by 2 P-level increments as cardiac function allows. Do NOT decrease flow below P-2 (< or = 0.5L/min) until just before removing the catheter from the LV. 2. Maintain support at P-2 (< or = 0.5 L/min) or above until hemodynamics are stable. 3. Remove sutures or stat-lock, loosen Tuohy-Borst valve and disconnect it from the sterile sleeve. 4. If desired, pull catheter into aorta. 5. When ACT < 150 seconds, reduces flow to P-0 (0.0 L/min) and remove the Impella catheter. 6. Pull catheter and hold manuel pressure for 40 mnuter or per protocol.
Conditions Requiring CPR
1. Initiate CPR per protocol 2. Reduce the Impella P-level to P-2 3. When cardiac function has been restored: - Return P-level to previous level - Assess placement signal on the automated Impella controller.
Shutting Down the Impella
1. Reduce P-level to P-0 to turn off the motor. 2. Disconnect the connector cable and turn the controller off. 3. Press and hold the power switches for 3 seconds. 4. Select "OK".
Starting the Controller: STEP 3
AUTO De-air the purge system A. Connect yellow to yellow B. Connect red to red C. Controller de-airs purge lumen and advances to the next screen D. Squeeze the flush valve for 10 seconds and confirm fluid is exiting the catheter
Abiomed Recommentation
Abiomed recommends setting flow control to AUTO which automatically sets the motor speed of the Impella to achieve the maximum possible flow without causing suction. Controller maximizes flow for 5 minutes and then returns to auto setting (or P-8 if previously running in P-level mode) P-level mode: flow determined by 1 or 9 P-levels (P0 through P8). Controller automatically switches to P-level mode after transfer to standard configuration or after 3 hours of Impella catheter runtime.
Automatic Transfer to P-level After 3 Hours
After 3 hours of Impella runtime if the controller has not been transfered to the standard configuration. - If running in AUTO Mode the controller automatically switches to P-level mode at P-8 and the auto mode option is no longer available. - If running in P-level mode the controller continues to opertate at the previous P-level and the AUTO mode option is no longer available.
Starting the Controller: STEP 2
Attach catheter to controller: AUTO Detect A. Open the white connector cable and Impella catheter B. Connect black end of white connector cable to the red Impella plug C. Snap the clip on sidearm to the cable D. Plug the white cable into the controller E. Controller automatically detects the catheter type
Automatic Purge System
Automatically adjusts the purge pressure for more efficient patient management. The soft button display opens and closes menus. The selector knob is a rotating push button that can be turned clock wise and counter clockwise to navigate through menu items.
Impella 2.5 Introducer Kit
Comes with: - 13 Fr peel-away introducer with hemostatic valve - 13 Fr dilator - 18 Ga Seldinger needle - 10 cc syringe - 0.035" stiff access guide wire
Purge Cassette
Delivers purge fluid to Impella catheter. Purge fluid enters the catheter through purge tubing connected to the yellow check valve; which prevents retrograde purge flow during tubing changes.
Purge System
Delivers rinsing fluid (purge fluid) to prevent blood from entering the Impella Catheter Motor. It consist of: Purge Cassette, Purge Pressure Transmitter, Purge Tubing, Y Connnector
The Home Screen
Displays a heart pictagram and to the left of the heart an Impella positioning message. The heart image displays a visual representation of the current Impella catheter position. The controller evaluate the placement signal and motor curent signal to determine the catheter position. The heart image may be overlayed with a yellow question mark when the controller can't determine the catheter position or detect that the catheter position is incorrect. In these situations imaging should be used to determine the Impella position.
Home Screen
Displays operating parameters and information for the entire Impella system. When the heart displays a question mark over it with the words "Impella Position Wrong": 1. controller can't determine catheter position. 2. position is wrong. 3. placement monitoring is suspended or disabled.
Purge Screen
Displays purge system information displayed as a function of time. The pressure sensor on the controller reads purge pressure from the purge pressure transmitter and automatically adjust the purge flow to stay within the specified range, issues warnings if purge pressure is too high or low.
Placement Screen
Displays real-time operating data for the system. This is the default screen once case start is complete. The screen displaysa - Placement signal waveform - Motor current waveform These waveforms are useful for determining the location of the catheter with respect to the aortic valve.
Infusion History Screen
Displays the infusion volume as well as the amount of Heparin and Dextrose infused each hour
Impella Alarms
Echo is recommeded for position adjustment if there is any evidence of hemolysis even if the catheter appears to be correctly positioned. - Cultivate an attitude of "Migration Expectation" - It will move if you let it? - Do not ignore positioning alarms. - Turn down speed to P-2 before moving catheter.
Impella Alarms
Echo is recommeded: - In cath lab to confirm fluroscopic positioning images. - After moving the patient. - If you suspect catheter movement. - If the controller suggests incorrect catheter position. - If you suspect blood damage. - During weaning, flow reduction to document native LV recovery.
Impella Alarms
Echocardiograpy is the BEST tools for evaluating Impella position outside the cath lab, when using Echo for position management, the preferred view is the parasternal long axis view obtained with TEE or TTE. This view limits foreshortening. The inlet area should be about 3.5cm below the aortic valve; free from the anterior leaflet or the subannular structures.
General Patient Management Considerations
Impella catheter is designed to be operated with Heparin in the purge system. - Heparin has been shown to be protective to the Impella motor - HIT should be verified by positive ELISA test and by positive Serotonin Release Test - Many experts in the field stat that HIT should not be diagnosed unless Megakaryocytes are present on peripheral smear - If they must remove Heparin, clinicians can use any systemic DTI (Direct Thrombin Inhibitor) and aim to keep ACT between 160 - 180 seconds.
Managing the Purge System
Implement one or more steps from this check list to resolve a low pressure alarm indicative of purge pressure < 300 mmHg and Purge flow > 30 cc/hr: 1. Look for any leaks in the purge cassette, Y connector or lever connections to the catheter. Tighten any loose connections. 2. Is the dextrose (purge fluid) concentration too low? Increase the dextrose concentration. 3. Is the leak coming from the purge cassette? Replace the purge cassette.
When to turn the Controller ON
Once catheter is positioned arcoss the aortic valve turn it ON by pressing the flow control soft button to select start pump. - The controller starts in AUTO, which automatically increases the flow rate over 20 seconds. - The placement screen will show an aortic placement signal and a pulsatile motor current. - Impella flow will be displayed in the flow window.
Automated Impella Controller
One touch and the catheter automatically - primes - detects - de-airs The high resolution display provides insight at a glance. Transport capable - Ambulance - Helicopter - Fixed wing
Automatic Purge Pressure Management
Pressure sensor reads purge pressure from the purge pressure transmitter. - Controller automatically adjusts purge flow - Warnings and alarms are displayed if purge pressure is too high or too low, or if it detects a blockage. - An advisory alarm is displayed when the purge flow rate increases or decreases by 2.5ml/hr.
Starting the Controller: STEP 1
Prime the purge cassette (auto prime) A. Press MENU and select case start B. Open purge casette (Using sterile technique) C. Spike D20 bag with purge cassette spike D. Insert the purge cassette E. Controller automatically begins priming cassette tubing
Components of the Purge System
Purge Fluid: 5-40% Dextrose in Water (20% Dextrose recommended) in 500ml bag for initial setup. Provides the rinsing action setup. Preventing blood from entering the motor. - The dextrose concentration is proportional to the viscosity of the purge fluid. - The viscosity of fluid is a factor in determing what flow is needed to maintaining safe pressure barrier to prevent blood from entering motor.
Why and How of the Purge System
Purpose: To prevent blood from entering the motor. Mechanism: Pressure barrier from purge fluid flowing in the opposite direction of blood flow. PURGE PRESSURE MUST ALWAYS BE > SBP
Impella Alarms
Red urine may be a sign of hemolysis; destruction of RBCs. Hemolysis may be caused by mechanical forces generated by medical procedures or devices. There are however other possible reasons for excessive red pigment in the urine including: Blood in the urine. - Simple urinalysis - pfHgb (plasma free hemohlobin) - simple colormetric test - check spun plasma color (if pfHgb not available)
Moving the blood Flow through the catheter decreases end diastolic volume and pressure (EDV, EDP) and increases mean aortic pressure and flow.
Rotation creates a negative pressure that pulls blood through the cannula from the inlet to the outlet area. The operator controls how fast the catheter rotates. The rotational speed is proportional to the flow. Faster rotation = Faster flow.
Impella Alarms
Suction can cause lower than expected Impella flow. Patient's may not benefit from the full Impella support. If the controller detects suction while running in auto mode it automatically reduces flow rate and displays Impella flow reduced advisory alarm. If this does not resolve suction the controller displays the suction alarm. The information on the placement screen can also be used to detect suction. To watch for signs of suction monitor position alarms and note lower that expected flows for a given flow rate the 5 minute time scale display may show reduced mean motor current. In addition, the patient's BP may be lower due to reduction in Impella output.
Impella Alarms
Suction may occur if the inlet area is incorrectly positioned in the LV, if the catheter is too far in the LV or lodged in the papillary muscle blood flow to the inlet area may be restricted. Suction can also be caused by inadvertant filling of the LV due to poor RV function, inadequate volume status or obstruction.
Managing the Purge System
The automated Impella controller automatically adjust purge flow to maintain purge pressure between 300 to 11oo mmHg. Purge pressure > 1100 mmHg and purge flow < 2 cc/hr: 1. Look for kinks anywhere in the purge system pathway from the IV tubing to the red Impella plug. 2. Closely examine the clear side arm between the air filter and the red Impella plug as well as the area just distal to the red Impella plug along the 9 Fr catheter. Kinks maybe difficult to see or may occur along the section of the catheter that has been inserted into the vasculature.
Impella Alarms
The controller may not be able to determine whether the catheter is correctly positioned in patient's with low native heart pulsitility. This is because the placement algorhythms require a minimal amount of native cardiac function to generate a pressure difference across the aortic valve. when native function is depressed the catheter will continue to provide up to the maximum of forward flow. The placement signal may be pulsatile with dampeded amplitude or flattened due to low aortic presure and depressed cardiac function. The motor current signal may be dampeded or flat due to the small pressure gradient between the inlet and outlet areas.
To determine if the catheter is properly positioned across the aortic valve.
The controller uses 2 pieces of information: 1. The placement signal, 2. Motor current signal software algorhythm evaluates whether the placement signal is characteristic of aortic or ventricular pressure and wheter the motor current signal is pulsatile or flattented. If the catheter is correctly positioned the placement signal is aortic and the motor current signal is pulsatile.
Impella Alarms
The home screen may display a yellow question mark over the heart icon with the message "Impella Position Unknown". In cases of low native pulsatility monitor the position of the catheter using patient's hemodynamic and periodic Echo assessment. If low pulsitility is due to decreased native contractility or if the catheter is completely unloading the LV this alarm may be triggered even though the Impella position has not changed. Position monitoring in this circumstance is unrelieable. Note: If flows are higher than predicted for the current performance setting this may indicate incorrect position due to catheter migration. Echo can verify catheter position if migration is a concern.
Monitoring Impella 2.5 Position
To ensure patients receive the benefits of Impella support the Impella position must be correctly positioned across the aortic valve. Monitor position by using: - Placement screen - Home screen Controller monitors: - Placement signal - Motor current signal Displays alarm if Impella catheter position is incorrect. At low flow rates placement monitoring may be suspended.
Target Hemodynamics
To pump blood the Impella must have enough blood in the ventricle to prevent suction and support Impella flow. - Low CVP could precipitate a suction alarm. - Controller may reduce motor speed if a low volume state exists. - Rapid infusion of appropriate crystalloid solution may be required to resolve the alarm. If swan in place the Swan cardiac output = Impella flow + native heart. Subtract Impella flow from CO and assume its the contribution of the left ventricle. - Native LV will be in competition for volume with Impella and will normally be reduced (unloaded) from baseline.
Managing the Purge System
To resolve high purge pressures due to kinks, attempt to straighten the kinks to resolve flow to the purge lumen. Next, check the dextrose concentration of the purge fluid. Reducting the concentration from 20% to 5% reduces the viscoscity of the purge fluid and reduces purge pressure. It is important to resolve low purge flow conditions if the purge pressure remains too high. The Impella purge system will not be able to deliver adequate rinsing fluid to the Impella motor. Blood might migrate into the motor gap causing the Impella to stop functioning.
