Bedside Topline

What It Does: Microaxial pump across the aortic valve: draws blood from the left ventricle and ejects it into the ascending aorta, adding forward flow and unloading the LV.
Key Settings & Targets: P-2 or higher: lowest level with adequate flow and no suction
MAP per protocol (typical 60–65 mmHg; the IFU gives no MAP target)
ACT 160–180 s during support
Purge 300–1100 mmHg
Check Every Hour: Distal pulses, color and temperature
P-level, flow, suction and position alarms
Purge pressure and purge line
Urine output and access-site bleeding
Top Alarm → First Move: Suction alarm: lower the P-level 1–2 levels, then check volume, PEEP, rhythm and position.
Never: Clamp, kink or compress the catheter or purge line
Add saline to the purge system
Put sandbags or compression devices over the access site
Take the patient into MRI
Escalate Now If: Suction or position alarm that persists after lowering P-level
Flow below 0.5 L/min or loss of pulsatility
Dark urine, falling hemoglobin or rising plasma free hemoglobin
Limb ischemia or major bleeding

Overview & How It Works

The Impella is a catheter-mounted microaxial pump. It sits across the aortic valve and draws blood out of the left ventricle. Then it pushes that blood into the ascending aorta. You get temporary forward flow, and the LV gets unloaded. US labeling covers high-risk PCI and cardiogenic shock.

Key Components

Component	Where It Sits	What It Does
Catheter and pump head	Inlet in the LV, about 3.5 cm below the aortic annulus (about 3 cm in small hearts)	Pumps blood from the LV to the aorta
Outlet	Ascending aorta, well above the valve	Returns pumped blood to the systemic arterial tree
Purge system	Cassette on the controller, line to the catheter	Delivers dextrose-heparin purge fluid to the motor and keeps blood out of it
Automated Impella Controller	Bedside console and battery	Drives the motor; shows P-level, flow, pressures, waveforms and alarms
Introducer or repositioning sheath	Femoral or axillary artery access	Allows insertion and removal; keeps the catheter secured

Flow Path

Blood enters the pump inlet in the left ventricle.
The impeller in the catheter pushes blood through the cannula across the aortic valve.
Blood exits the outlet in the ascending aorta and enters the systemic circulation.
Purge fluid takes its own path. It runs from the cassette through the catheter to the motor. It never reaches the bloodstream.

Key Point: Impella support rests on three things. The LV has to be filled. The aortic pressure has to be reasonable. The catheter has to stay in position. Most problems trace back to one of those three.

Physiology & Hemodynamic Effects

What It Does

Parameter	Effect	Why It Matters
LV end-diastolic pressure and volume	↓	Less LV distension and less wall stress; lower myocardial oxygen demand
Mean arterial pressure	↑	Device flow adds to native LV output, so systemic and coronary perfusion improve
Forward cardiac output	↑	Device flow plus residual LV output; read it against CI and CPO
Pulmonary capillary wedge pressure	↓	Less pulmonary congestion when the LV is unloaded
Coronary perfusion	↑	Better perfusion with lower LV pressure, when the pump runs at an adequate P-level
Aortic valve flow	↔ or retrograde	Retrograde flow across the aortic valve occurs if catheter flow falls below 0.5 L/min (IFU)

What It Depends On

Preload: an underfilled LV gives you suction alarms and low flow
Afterload: high systemic vascular resistance cuts forward flow and adds LV work
Rhythm: arrhythmias change LV filling. They can trigger suction
Native LV and RV function: RV failure starves the LV of preload and caps device output
Device position: a malpositioned inlet sets off suction or position alarms

Clinical Pearl: Low flow on the controller is a symptom. It is not a diagnosis. Before you raise the P-level, check preload, afterload, rhythm, RV function and position.

Types, Modes & Configurations

Type	Route	Support	Best For	Key Limitation
Impella CP with SmartAssist	Femoral or axillary artery (IFU)	Mean flow 3.3–3.7 L/min at P-9; systolic peak up to 4.3 L/min. Mean 1.1–2.1 L/min at P-2 (IFU Table 5.2)	High-risk PCI (labeled up to 6 hours) and cardiogenic shock (labeled up to 4 days)	Limb ischemia, hemolysis and bleeding at the access site
Impella 5.5 with SmartAssist	Surgical axillary graft	Mean flow up to 5.5 L/min at P-9 (IFU Table 5.2, 30–60 mmHg differential)	Cardiogenic shock (under 48 hours after acute MI or open heart surgery, or cardiomyopathy or myocarditis), short-term use up to 14 days (IFU)	Requires surgical access and an MCS-team setting
Impella 5.0 (older surgical model)	Surgical access (route not verified here)	Not stated here	Cardiogenic shock, labeled up to 14 days (manufacturer)	Older model; confirm local availability
Impella RP Flex with SmartAssist	Venous: internal jugular insertion, advanced over a wire into the pulmonary artery (manufacturer)	Manufacturer claims conflict (up to 4.0 to greater than 4.0 L/min); use the IFU P-level table, not the controller display	Temporary right ventricular support up to 14 days (BSA 1.5 m² or more) for acute right heart failure within 48 hours of LVAD, MI, heart transplant or open-heart surgery, without profound shock, end-organ failure or acute neurologic injury (manufacturer; the RP System approval order, reference 12, gives the same 14-day and BSA 1.5 m² or more limits; RP Flex labeling not yet located)	Labeled contraindications (manufacturer summary of PMA labeling): disorders of the pulmonary artery wall that would preclude placement; mechanical valves; severe stenosis or regurgitation of the tricuspid or pulmonary valve; mural thrombus of the right atrium or vena cava. Class I recall (PMA P170011, initiated January 27, 2026): dP sensor drift can make displayed flow, PA placement signal and PAPi inaccurate; follow the IFU P-level flow values and confirm position with imaging
Impella 2.5 (historical model)	Femoral arterial	Continuous maximum about 2.1–2.4 L/min at P-8; BOOST up to 2.5 L/min for 5 min (2015 IFU)	High-risk PCI, labeled under 6 hours (2015 IFU)	Lower flow; historical model; confirm local availability

P-Level Modes

P-level mode: the CP IFU lists P-0 to P-9. Pick the lowest level recommended, P-2 or higher, that gives adequate flow without suction
AUTO mode: the controller sets motor speed for maximum flow without suction (up to P-9). After 3 hours it switches to P-level mode (IFU)
Setting the level: the MCS team's protocol decides the starting P-level, whether you use AUTO and any target flow

Note: What's on the shelf changes, and so does what the label allows. Know which devices your system stocks and which labeling applies before any protocol decision. The Impella RP Flex row rests on manufacturer and FDA recall sources. Its route, indication, duration and contraindications have not been checked against RP Flex labeling. Confirm all four in the current IFU before any decision.

Indications, Contraindications & Evidence

Indications

High-risk PCI (CP labeling): elective or urgent, hemodynamically stable patients with severe coronary disease when the heart team judges high-risk PCI appropriate; temporary, up to 6 hours
Cardiogenic shock (CP labeling): ongoing shock within 48 hours of acute MI or open heart surgery, or cardiomyopathy including peripartum cardiomyopathy or myocarditis, not responsive to optimal medical therapy; short-term use up to 4 days
Clinical intent: take work off the ventricle, support recovery and assess residual LV function early

Contraindications

Absolute (CP labeling)	Use Caution or Relative
LV mural thrombus	Unrepaired aortic aneurysm or dissection: special care during insertion (IFU)
Mechanical aortic valve or constrictive heart device	Aortic valve disease: observe for aortic insufficiency (IFU)
Aortic stenosis (valve area 0.6 cm² or less)	Peripheral arterial disease: limits access; choose an alternative route or device
Moderate to severe aortic insufficiency (2+ or greater)	Active CPR: insertion is harder and CPR can move the device
Septal defect, including post-infarct VSD	Severe anemia or thrombocytopenia: raises bleeding risk
Severe arterial disease precluding placement	—
Significant right heart failure, LV rupture, tamponade or combined cardiorespiratory failure (shock indication)	—

Warning: In a rushed shock workup, a mechanical aortic valve or LV thrombus is easy to miss. Both are absolute contraindications. Check the valve and the LV on echo before insertion.

Limitations

Hemolysis, bleeding and limb ischemia are common enough that you watch for them the whole time (see Complications)
With the device in place, MRI is unsafe (IFU)
The device does not treat the cause of shock. It buys time for revascularization, recovery or a more definitive therapy
The advanced heart failure or MCS team picks the patients. Your job at the bedside is early recognition and early calls

Key Evidence

Trial or Guideline (Year)	Population	Bottom Line
DanGer Shock (2024)	360 randomized patients with STEMI and cardiogenic shock (arterial lactate 2.5 mmol/L or higher; LVEF below 45%); 355 analyzed. Excluded: shock lasting over 24 hours, RV failure, mechanical MI complications, other causes of shock, and out-of-hospital arrest with persistent GCS below 8 after return of circulation (arrest in an ambulance or after hospital arrival was not an exclusion)	180-day all-cause death 45.8% with Impella plus standard care vs 58.5% with standard care alone (HR 0.74, 95% CI 0.55–0.99). Composite safety events 24.0% vs 6.2%; renal replacement therapy 41.9% vs 26.7%. The benefit applies to selected STEMI-related shock, not all cardiogenic shock
IABP-SHOCK II (2012, landmark trial)	600 randomized patients with cardiogenic shock from acute MI	No reduction in 30-day mortality with the intra-aortic balloon pump (39.7% vs 41.3%). Mechanical support is not automatically beneficial
SCAI shock classification (2019)	All cardiogenic shock presentations	Staging (A to E) describes severity and trajectory; stage C to E patients are the usual MCS discussion

Note: The 2025 ACC/AHA/ACEP/NAEMSP/SCAI ACS guideline (Circulation 2025;151:e771–e862) gives a microaxial flow pump a Class 2a for select patients with acute MI-related cardiogenic shock. It drops routine IABP and VA-ECMO to Class 3. Those classes come from ACC summaries, since the primary guideline text was not accessible, so confirm the exact class and wording before you quote it. The ESC 2023 ACS guideline also addresses MCS in AMI-related shock. The selected DanGer Shock population was STEMI with arterial lactate 2.5 mmol/L or higher, LVEF below 45% and shock under 24 hours. Comatose survivors of out-of-hospital arrest, RV failure and mechanical complications were excluded. Bleeding, limb ischemia and renal replacement therapy ran higher with the pump, so watch for these harms actively.

Setup, Settings & Targets

Parameter	Typical Target	If Below	If Above
P-level	P-2 or higher, lowest that gives adequate flow (IFU)	Flow falls and retrograde flow risk rises below 0.5 L/min; check position and volume	Suction risk and hemolysis risk; reduce P-level 1–2 levels
MAP	60–65 mmHg typical; set by institutional protocol (the IFU gives no MAP target)	Check P-level, volume, RV, rhythm; add vasopressor per protocol	Afterload is limiting flow; reduce afterload per team
Purge pressure	300–1100 mmHg (IFU)	Alarm; inspect the purge system for leaks	Alarm; check the purge line for kinks and blockage
Purge flow	2–30 mL/hr (IFU)	Check for leaks or an open purge system	Check for blockage or a pressure problem
ACT	160–180 s during support (IFU)	Adjust heparin per protocol; account for purge heparin	Bleeding risk; reduce systemic heparin per protocol
Head of bed	30° or less (IFU)	—	Above 30° risks catheter movement and position alarms
Inlet position	3.5 cm below the aortic annulus; 3 cm in small hearts (IFU)	Pull back under imaging if too deep; check for subvalvular or wall contact	Advance under imaging if too shallow

Initial Settings

P-level: start at the protocol's level, then move to the lowest level that gives adequate flow without suction
Purge: confirm the purge solution and heparin concentration against the order (IFU lists 25 or 50 units/mL heparin)
Placement check: confirm the aortic placement signal and the LV waveform on the console
Echo: confirm inlet position and valve clearance after insertion, after position alarms and after CPR

Sizing & Positioning

Position the inlet about 3.5 cm below the aortic annulus, away from papillary muscles and subannular structures (IFU)
Use about 3 cm in small ventricles (IFU)
Keep the knee immobilizer or support in place to keep the access leg straight (IFU)

Impella position check

Inlet 3.5 cm below annulus; outlet above the valve; aortic placement signal visible

Calculations & Derived Values

Cardiac power output (CPO)

CPO (W) = MAP (mmHg) × CO (L/min) ÷ 451

Pulmonary artery pulsatility index (PAPi)

PAPi = (PASP − PADP) ÷ RAP

Variable	Formula	Typical Value	Why You Care
CPO	MAP × CO ÷ 451	0.6 W or higher (typical target)	Low CPO indicates undersupported shock despite a device
PAPi	(PASP − PADP) ÷ RAP	Below 0.9 suggests significant RV dysfunction	RV failure limits LV preload and Impella output
Cardiac output	Measured total CO (thermodilution or Fick)	Method per local practice	The controller asks for total CO for its calculations; use one method consistently

Clinical Pearl: Plug the numbers in and see where you land. MAP 60 mmHg with CO 4.0 L/min gives CPO of 240 ÷ 451, about 0.53 W. That's under the 0.6 W typical target. Pair the number with the trend and the cause before you decide on escalation.

Waveforms & Console Interpretation

Normal

Placement signal: an aortic-type waveform shows when the catheter sits correctly. If it doesn't, pull back under imaging until it appears, then follow the repositioning guide (IFU)
LV pressure waveform: systolic load comes down. Diastolic filling looks reasonable, with no deep negative swings
Motor current: a stable trace. A sudden change points to a motor, position or obstruction problem
Flow and P-level: flow climbs with the P-level, then holds at the set level

Abnormal Patterns

Pattern	What You See	Cause	Fix
Intermittent suction	LV pressure dips in diastole and recovers	Low preload, high P-level, arrhythmia	Lower P-level 1–2 levels; volume if underfilled; treat arrhythmia
Continuous suction	LV pressure stays negative	Inlet against the LV wall or mitral apparatus; thrombus at the inlet	Lower P-level; echo; reposition under imaging
Position alarm	Placement signal lost or abnormal; alarm shows "Impella Position In Ventricle" or "Impella Position Wrong"	Migration into the LV or aorta	Reduce to P-2 under imaging, reposition, return to preferred P-level and confirm with imaging (IFU)
Low flow with retrograde risk	Flow below 0.5 L/min	P-level too low; malposition; severe underfilling	Raise P-level as tolerated; check position and volume
Loss of pulsatility	Flat or minimal pulsatile waveform on the placement or LV trace	Severe LV standstill or malposition	Confirm with echo; involve the MCS team

Warning: Loss of pulsatility on the console is a red flag, so get echo to confirm position and LV function. Don't assume the device is working until you have that.

Monitoring & Ongoing Care

Frequency	What to Check	Expected or Action Threshold
Hourly	Distal pulses, color, temperature; console P-level, flow, alarms; purge pressure; urine output	Purge 300–1100 mmHg; act on any suction or position alarm; flow stable at set P-level
Every 4–6 h	MAP, CVP, PCWP or PAPi per protocol; ACT per protocol; access site and bleeding	MAP at protocol target (typical 60–65 mmHg); ACT 160–180 s (IFU)
Every 12–24 h	CBC (hemoglobin, platelets), plasma free hemoglobin, LDH, bilirubin, creatinine, lactate	Rising PfHgb, falling hemoglobin, or rising lactate prompts MCS-team review
Daily	Echo for position and LV/RV function; anticoagulation review; limb checks	Position confirmed; RV function and valve status documented

Positioning & Mobility

Keep the head of the bed at 30° or less (IFU)
Do not pull the catheter when moving or transferring the patient; use a log roll and secure the purge line (IFU)
Secure the catheter at the skin and the purge tubing so it does not kink

Clinical Pearl: Watch the purge pressure trend, not just the reading. A falling trend is often the first sign of a leak or line problem, and it shows before any alarm sounds.

Anticoagulation & Hematology

Strategy or Agent	Typical Target	Monitoring	Watch For
Unfractionated heparin with purge heparin High-alert	ACT 160–180 s during support (IFU)	ACT per protocol; count purge heparin in total heparin	Bleeding at access sites; hyper-coagulation when purge heparin is ignored
Bivalirudin or argatroban High-alert	Per institutional protocol (IFU lists them as heparin alternatives for insertion)	aPTT or ACT per protocol	Bleeding; argatroban dosing changes with liver function
Heparin-free purge	Not established	—	IFU: operation without heparin in the purge is not tested; do not change without the MCS team

Purge Solution

The IFU calls for dextrose in water with heparin at 25 or 50 units/mL. Saline is not permitted in the purge system (IFU)
Some centers use bicarbonate-based purge solutions when heparin is unsuitable. The FDA-hosted IFU does not describe them. Published experience is limited to case reports and abstracts. Use them only under an institutional protocol with MCS-team approval
Purge heparin counts toward total anticoagulation. Reduce systemic heparin per protocol. Don't stack more heparin on top

Hemolysis

Best marker: plasma free hemoglobin (PfHgb) is what confirms significant hemolysis (IFU)
Clinical clues: dark or blood-colored urine, falling hemoglobin, rising LDH or bilirubin, acute kidney injury
Common causes: malposition, suction, high P-level, hypovolemia, pump or inlet thrombus
Management: check position on echo, lower the P-level as tolerated, correct preload and rhythm, and bring in the MCS team early. The IFU gives no numeric PfHgb threshold, so use the institutional one

Bleeding & Platelets

Thrombocytopenia: from consumption, heparin exposure (including HIT) and the device itself
Acquired von Willebrand syndrome: high shear causes it, and it can lead to GI bleeding
Reversal: per protocol, protamine reverses heparin. See the protamine page

Key Medications & Drug Considerations

Medication	Role Here	Typical Adult Dose / Target	Device-Specific Notes
Heparin (systemic) High-alert	Systemic anticoagulation	Per protocol; ACT 160–180 s (IFU)	Account for purge heparin; see heparin page
Norepinephrine High-alert	MAP support	0.05–0.5 mcg/kg/min IV infusion; titrate to MAP (norepinephrine page)	Vasoconstriction raises afterload and can lower Impella flow; titrate to MAP and monitor flow
Dobutamine High-alert	Inotropy	2–20 mcg/kg/min IV infusion (dobutamine page)	Increases heart rate and arrhythmia risk; watch for suction after changes
Milrinone High-alert	Inodilator	0.375–0.75 mcg/kg/min IV (milrinone page)	Vasodilation can drop MAP; renal dosing applies
Vasopressin	Vasopressor add-on	0.03 units/min IV, fixed (vasopressin page)	Raises MAP and afterload; follow the MAP target and watch Impella flow
Amiodarone High-alert	Arrhythmia control	Stable VT: 150 mg IV over 10 min (amiodarone page)	Treat arrhythmias that cause suction; see the medication page for other indications
Dexmedetomidine High-alert	Sedation	0.2–0.7 mcg/kg/hr IV (dexmedetomidine page)	Light to moderate sedation prevents large movements that displace the catheter

Note: Doses vary by protocol; follow local protocols and medical direction. The tags use the ISMP acute-care classes to mark high-alert drugs: IV adrenergic agonists, IV inotropes, IV antiarrhythmics, IV moderate sedation agents, IV anticoagulants. Vasopressin is not a listed class member, so it carries no tag.

Alarms & Troubleshooting

Alarm or Problem	What You See	Likely Causes	First Actions
Suction (diastolic or continuous)	LV pressure negative in diastole; suction alarms	Hypovolemia, RV failure, high PEEP, high P-level, malposition	1) Lower P-level 1–2 levels 2) Give volume if underfilled; check PEEP 3) Echo for position; call MCS team
Position alarm	"Impella Position In Ventricle" (IFU name) or "Impella Position Wrong" (banner wording from an unverified console photo; not in the CP 2020 IFU alarm table); placement signal lost	Migration or repositioning after movement or CPR	1) Under imaging, reduce to P-2 and pull back until the aortic waveform shows; then pull back about 3 cm more (IFU) 2) Confirm position with echo or fluoroscopy 3) Return to preferred P-level; confirm with imaging
Purge pressure low	Purge pressure below 300 mmHg	Leak or disconnection in the purge system; purge fluid with too little dextrose	1) Inspect the purge system for leaks 2) If none, change to a higher-dextrose purge fluid: PURGE MENU > Change Purge Fluid Bag 3) If pressure stabilizes, no further action 4) If the alarm persists for more than 20 min, replace the purge cassette. Call the MCS team throughout
Purge pressure high or purge blocked	Purge pressure above 1100 mmHg	Kinked line, blockage, purge fluid concentration issue	1) Check and straighten tubing 2) Decrease purge dextrose concentration to 5% if it is higher (IFU) 3) Call MCS team if unresolved
Low flow or retrograde risk	Flow below 0.5 L/min	P-level too low, malposition, underfilling	1) Raise P-level as tolerated 2) Check preload and position 3) Echo
Hemolysis	Dark urine, falling hemoglobin, rising PfHgb	Suction, malposition, high P-level, pump thrombus	1) Lower P-level as tolerated 2) Correct preload and position 3) MCS team review
Access-site bleeding	Oozing or hematoma at insertion site	Anticoagulation; sheath or catheter movement	1) Manual pressure around the catheter, not on it 2) Review ACT and anticoagulation 3) Call cardiology or vascular team

Never: Don't clamp, kink or compress the catheter or purge line. Saline stays out of the purge system. A suction or position alarm does not get ignored. Don't run the pump below P-2 without a documented MCS-team decision. No MRI with the device in place.

Clinical Pearl: Work outward, from the patient to the circuit. Check the patient first. Then the tubing, then the console, then the settings.

Complications & Red Flags

Insertion

Complication	How You Recognize It	Immediate Action	Prevention
Vascular injury or access-site bleeding	Hematoma, bleeding, hemodynamic drop	Pressure around the catheter; call vascular or cardiology	Ultrasound-guided access. Reach ACT 250 s or higher before dilator removal to help prevent thrombus entering the catheter (IFU); this is a thrombosis step, not bleeding control
Limb ischemia	Cool, pale, pulseless, painful limb	Check pulses; alert team immediately; check catheter position	Check distal pulses before and after insertion; keep the leg straight

During Use

Complication	How You Recognize It	Immediate Action	Prevention
Hemolysis	Dark urine, falling hemoglobin, rising PfHgb	Lower P-level as tolerated; check position; MCS team	Maintain position; avoid high P-levels and suction
Bleeding	GI or access-site bleeding; falling hemoglobin	Review ACT and heparin; transfuse per protocol	Match systemic heparin to purge heparin per protocol
Thrombocytopenia or acquired von Willebrand syndrome	Falling platelets; mucosal bleeding	Check HIT when suspected; hematology input	Monitor platelets and coagulation trends
Aortic valve injury or new aortic insufficiency	New murmur or aortic regurgitation on echo	Echo; reposition or remove per MCS team	Echo after insertion and after position changes
Stroke or systemic embolism	New focal deficit, altered mental status	Stroke alert; echo; review anticoagulation per protocol	Avoid LV thrombus; maintain anticoagulation within target
Acute kidney injury	Rising creatinine, falling urine output	Check perfusion, hemolysis and drug exposure; nephrology	Watch for hemolysis; maintain MAP and perfusion

Removal

Complication	How You Recognize It	Immediate Action	Prevention
Access-site bleeding after removal	Oozing, expanding hematoma	Manual compression (IFU: 40 minutes or per protocol); call team	Confirm ACT below 150 s before introducer removal (IFU)

Red Flags: Call Immediately

Limb ischemia or new cold, pulseless leg
Dark urine or falling hemoglobin with rising PfHgb
New neurologic deficit
Suction alarm that persists after lowering the P-level
Major bleeding, including GI or access-site bleeding
Position alarm that does not resolve with P-2 and imaging

Emergencies: Arrest, Power Loss & Device Failure

Cardiac Arrest on Impella

Start CPR immediately per ACLS and hospital protocol. Follow the 2025 AHA ACLS guidance; the device changes catheter flow, not the compression, rhythm-check and drug sequence.
Reduce catheter flow when CPR starts (IFU: "reduce the Impella Catheter flow rate"). The IFU gives no numeric level; the MCS team or trained operator sets the P-level.
Defibrillate per ACLS. During shock, do not touch the catheter, cables or controller (IFU).
After return of circulation, return flow to the previous level and check the placement signal (IFU).
Echo to confirm position after CPR; CPR can move the device (IFU).
Call the MCS team.

Power or Console Failure

Keep the patient alive first: manage rhythm, MAP and oxygenation.
Check connections: cable, power switch and the controller's battery indicator.
Switch to battery or backup console per the manufacturer and hospital plan. The controller runs on its internal battery for at least 60 minutes when fully charged (IFU).
Call the MCS team for a backup console or a plan to maintain support.

Dislodgement or Position Loss

Do not pull or push the catheter.
Reduce to P-2 while the team arranges imaging.
Confirm position under echo or fluoroscopy with the MCS team.

Purge Line Disconnection or Air in the System

Keep the purge line closed to the patient and stop bleed-back.
Inspect the purge system for leaks. If none is visible, replace the purge cassette (IFU, Purge System Open alarm).
Call the MCS team before any reconnection.

Weaning & Discontinuation

Readiness Criteria

Underlying cause improving: reperfusion complete or myocarditis resolving
MAP at the protocol target (typically 60–65 mmHg) without escalating vasopressors
CI of 2.2 L/min/m² or higher and adequate CPO, with lactate normalizing (targets per protocol)
Improving LV function on echo; no significant pulmonary edema

Weaning Steps

Reduce the P-level in 2-level steps as cardiac function allows (IFU). Watch MAP, CI, lactate and echo after each step.
Keep the P-level at P-2 or above until the catheter is ready to be explanted from the left ventricle (IFU).
When hemodynamics are stable, reduce to P-2 and pull the catheter back across the aortic valve into the aorta (IFU). Removal steps begin only after this pullback.
If hemodynamics remain stable with the catheter in the aorta, proceed to the removal steps below (IFU).

Failure Criteria: Step Back Up

MAP falls below target or lactate rises
New suction or position alarms
Echo shows LV dilation or worsening function
Return to the prior P-level and reassess with the team

Removal & Post-Removal Care

Removal follows the pullback step above. How you remove it depends on how the catheter is secured (IFU):

Introducer in place: reduce to P-0; remove the catheter through the introducer; wait until ACT is below 150 s; disconnect the cable and power down the controller; when ACT is below 150 s, remove the introducer; apply manual compression for 40 minutes or per hospital protocol.
Repositioning sheath: when ACT is below 150 s, reduce to P-0; remove the catheter and sheath together (the catheter does not pass through the sheath); disconnect and power down the controller; apply manual compression for 40 minutes or per hospital protocol.
Check distal pulses and the access site frequently after removal.

Escalation

Persistent shock or RV failure: discuss VA-ECMO (ECPELLA) or RP Flex with the MCS team
Refractory left-sided failure needing surgery: 5.5 or surgical options

Protocol Varies: Weaning rates, duration and removal timing differ from center to center. Follow the MCS team's protocol.

Transport Considerations

Before You Move

Fully charge the controller and keep it on AC power or an AC inverter whenever possible. When fully charged, the controller runs on battery for at least 60 minutes. For longer disconnected periods, use a vehicle with a DC-to-AC inverter (IFU).
Confirm the current P-level, flow, purge pressure and the last ACT (IFU: maintain ACT 160–180 s or the level the physician sets).
Secure the catheter, purge line and console together. Don't stress the connector cable. It can move the catheter (IFU).
If a peel-away introducer is still in place, remove it before transport once ACT is below 150 s (IFU). If the catheter is secured with a repositioning sheath, keep the sheath stopcock closed.
Confirm that receiving staff know the device type, P-level and anticoagulation.

If You Are Not the Device Specialist

Scope: monitor, report and call the MCS team. Do not change P-level, flow or purge settings unless the MCS team directs you
Watch for: suction, position, purge and low-flow alarms; limb perfusion; bleeding
Never touch: the catheter at the groin, the purge line or the controller settings unless the MCS team instructs you
Who to call: the MCS team and the receiving center's device team
CPR and defibrillation: start CPR per ACLS; do not touch the catheter or cables during shock (IFU)

During Transport

Keep the head of the bed at 30° or less (IFU)
Do not pull the catheter when moving the patient; use a log roll
Check limb perfusion at each handoff and every transport interval
Watch purge pressure through changes in altitude (IFU)

Air Medical & Altitude

Do not transport on a commercial aircraft. Radiofrequency interference may cause loss of support (IFU).
Ground, helicopter and fixed-wing transport of critically ill patients is the scenario the IFU covers. Plan power for the whole transfer, including time off AC power (IFU).
Carefully monitor purge pressure during changes in altitude (IFU).
Abiomed recommends that air carriers follow FAA Advisory Circular AC 91-21.1B (IFU section 9).

Handoff

Device type, insertion side and date
P-level, flow, purge pressure and recent alarms
Anticoagulation, last ACT and labs (hemoglobin, platelets, PfHgb, creatinine, lactate)
Access-site and limb checks; goals of care

Transport Pearl: Before you leave the unit, check battery life and the purge reservoir. Know which alarms mean "reduce P-level" and which mean "call the MCS team."

Special Populations

Pediatric & Neonatal

Impella is not established in children. The labeled indications are for adults. Children get it only at specialized centers. See pediatric shock and pediatric vascular access.

Pregnancy & Peripartum

Peripartum cardiomyopathy is a labeled cardiogenic shock indication (IFU). Pregnancy changes volume status and anticoagulation needs. The MCS team and the obstetric team decide together.

Other

Renal impairment: in DanGer Shock, renal replacement therapy was more frequent with Impella (41.9% vs 26.7%). Plan renal support early
Peripheral arterial disease: it limits access. Plan an alternative route or device
Older adults: bleeding and vascular complication risk is higher. Watch access sites and limbs more closely

Note: The MCS team should decide on pediatric or pregnancy use, with specialty input.

Bedside Pearls & Teaching Script

Systematic Walk-Through

Indication: shock stage, cause and reason for device
Mode: P-level, AUTO or fixed; placement signal
Settings: MAP, CVP or PCWP, CPO and PAPi trends
Anticoagulation: ACT, heparin and purge heparin
Complications: hemolysis, bleeding, limb, neurologic status
Today's goal: recovery, bridge, or escalation

Pearls

Lower the P-level to fix suction. Don't chase it with fluids alone
P-2 or higher is the usual floor. Stay there until explant
A position alarm means move to P-2 and get imaging. It is not a reason to reposition at the bedside
Purge pressure trends warn you before the alarms do
Count purge heparin when you read ACT and heparin rates

References

Møller JE, Engstrøm T, Jensen LO, et al. (2024). Microaxial flow pump or standard care in infarct-related cardiogenic shock (DanGer Shock). New England Journal of Medicine, 390(15), 1382–1393. https://doi.org/10.1056/NEJMoa2312572 (landmark trial)
Thiele H, Zeymer U, Neumann FJ, et al. (2012). Intraaortic balloon support for myocardial infarction with cardiogenic shock (IABP-SHOCK II). New England Journal of Medicine, 367, 1287–1296. https://doi.org/10.1056/NEJMoa1208410 (landmark trial)
Baran DA, Grines CL, Bailey S, et al. (2019). SCAI clinical expert consensus statement on the classification of cardiogenic shock. Catheterization and Cardiovascular Interventions, 94(1), 29–37. https://doi.org/10.1002/ccd.28329
Byrne RA, Rossello X, Coughlan JJ, et al. (2023). 2023 ESC Guidelines for the management of acute coronary syndromes. European Heart Journal, 44(38), 3720–3826. https://doi.org/10.1093/eurheartj/ehad191
Rao SV, O'Donoghue ML, Ruel M, et al. (2025). 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes. Circulation, 151(13), e771–e862. https://doi.org/10.1161/CIR.0000000000001309
Abiomed. (2020). Impella CP with SmartAssist: Instructions for Use and Clinical Reference Manual (United States). FDA-hosted copy (© 2020). https://www.fda.gov/media/140767/download
Heart Recovery (Abiomed). (2026). Impella RP Flex with SmartAssist [manufacturer product page; not the FDA labeling and not verified against it]. Accessed October 14, 2026. https://www.heartrecovery.com/en-us/products-and-services/impella/impella-rp-flex-with-smartassist
American Heart Association. (2025). Part 9: Adult advanced life support: 2025 American Heart Association guidelines for CPR and ECC. Circulation, 152(16 suppl 2), S538–S577. https://doi.org/10.1161/CIR.0000000000001376
Abiomed. (2015). Impella 2.5 with the Automated Impella Controller: Instructions for Use and Clinical Reference Manual (United States), Document No. 0042-9011 Rev. A. FDA-hosted PMA copy (historical device). https://www.accessdata.fda.gov/cdrh_docs/pdf14/P140003c.pdf
American College of Cardiology. (2024). Microaxial Flow Pump in Infarct-Related Cardiogenic Shock (DanGer Shock) [trial summary, eligibility criteria]. Accessed October 14, 2026. https://www.acc.org/Latest-in-Cardiology/Clinical-Trials/2024/04/05/04/44/danger-shock
Abiomed. (2020). Impella 5.5 with SmartAssist: Instructions for Use and Clinical Reference Manual (United States). FDA-hosted copy (© 2020). https://www.fda.gov/media/140766/download
U.S. Food and Drug Administration. (2026). Heart pump correction: Abiomed updates instructions for use, Impella RP with SmartAssist and Impella RP Flex with SmartAssist (Class I recall; PMA P170011; initiated January 27, 2026). https://www.fda.gov/medical-devices/medical-device-recalls-and-early-alerts/heart-pump-correction-abiomed-updates-use-instructions-impella-rp-smartassist-devices Approval order for the same PMA (RP System, approved September 20, 2017, 14 days and BSA 1.5 m² or more): https://www.accessdata.fda.gov/cdrh_docs/pdf17/P170011A.pdf

Last updated October 2026 Spotted something wrong? Report an error and include the page URL.

Medical Disclaimer

For Educational Purposes Only: This content is intended for educational reference and should not be used for clinical decision-making.
Not a Substitute for Professional Judgment: Always consult your local protocols, institutional guidelines, and supervising physicians.
Verify Before Acting: Users are responsible for verifying information through authoritative sources before any clinical application.

AI Assistance Notice

AI was used to assist in organizing, paraphrasing, and formatting this information.

Impella Devices