Mechanical CPR Devices (LUCAS, AutoPulse)

Mechanical CPR keeps compressions going when manual CPR is impractical or unsafe. Every device deployment must keep compressions interrupted for as short a time as possible.

A mechanical device does the compressing. That means compressions keep going when a rescuer cannot deliver them safely or consistently. Two device families are in use. The machine does not change ACLS: rhythm checks, shocks and drugs stay on the same timing.

How It Works

• Piston-type device: the pad sits on the lower sternum. A piston drives it down against a backplate slid under the patient.
• Band-type device: a load-distributing band wraps the chest and cinches down on a backboard. Compressions spread over the whole chest.
• Deployment: manual compressions stop for a moment while the backplate and device go on. Then the device starts.
• Verification: the device is a compression source and nothing more. Pulse, EtCO₂ and rhythm checks still tell you whether the patient is perfused.

Where It Fits

Don't reach for it by default. AHA 2025 and the 2026 ILCOR systematic review both advise against routine use of mechanical CPR devices. Both still leave room for settings where high-quality manual compressions are difficult or dangerous for the rescuer. The condition: interruptions stay strictly limited during deployment and removal.

Look at the trial evidence and no benefit shows up. Taken overall, the three largest trials showed no benefit, or harm. PARAMEDIC (LUCAS-2) found 30-day survival of 6% vs 7%, and a worse adjusted 3-month neurologic outcome (aOR 0.72, 95% CI 0.52–0.99). ASPIRE, a band device, had fewer patients with a favorable neurologic outcome at discharge (RR 0.41, 95% CI 0.21–0.79). One trial suggests shockable-rhythm outcomes may have suffered from first shocks that came late, after early placement.

Indications

• Transport during arrest: the patient is moving or the ambulance is. Manual compressions turn unsafe or ineffective (ILCOR names transport as an example).
• Confined or hazardous spaces: stairs, elevators, small rooms or the cath lab. Anywhere a rescuer cannot compress safely.
• Prolonged resuscitation: rescuers tire, and compression quality falls with them.
• Bridge to ECPR: keeps compressions going while extracorporeal cannulation is set up. Follow the local ECPR protocol.

Absolute Contraindications

• None for a patient in cardiac arrest, provided a trained team can deploy the device without a long pause. The manufacturer IFU sets device size and chest limits.

Relative Contraindications & Cautions

• Patient too large or too small for the device: the LINC trial excluded them. Check the IFU before you choose a device.
• Suspected pregnancy: the trials excluded it. Follow the obstetric arrest pathway per local protocol.
• Traumatic arrest: the large trials excluded it. Apply the trauma arrest protocol first.
• ROSC or a conscious patient: skip the device when compressions are not needed.
• No trained operator: a badly deployed device means long pauses, and worse CPR than a practiced manual team gives.

Consider an Alternative

• High-quality manual CPR: rotate two rescuers about every 2 min, with a feedback device where you have one.
• Defibrillation first: for a shockable rhythm, see the defibrillation page.

Team Roles During the Procedure

• Operator: places the pad or band and starts the device.
• Airway and ventilation: keeps the airway and breaths going during the pause.
• Medication clinician: keeps drug timing on the rhythm-check schedule.
• Monitor and recorder: times pauses and records EtCO₂, rhythm and device events.

Piston Pad

1. Expose the chest: remove clothing. Do not remove working defibrillation or pacing pads to place the device; if pads are not yet on, apply them in an anterolateral or anteroposterior position clear of the pad or band.
2. Find the lower half of the sternum: keep the pad above the xiphoid.
3. Place the backplate: slide it under the back during a pause, then attach the pad and piston.
4. Confirm the pad is centered: check that it does not slip toward the abdomen or the upper chest.

Chest Band

1. Place the backboard: the patient must be supine on a firm surface.
2. Pass the band under the patient: lay it flat on the backboard and roll the patient gently.
3. Secure the band: fasten it snug per IFU, with the chest centered in the band.

Equipment

• Mechanical CPR device: piston pad with backplate, or band with backboard; check battery charge and spare battery.
• Backboard: firm, flat surface for band devices and for stretcher transport.
• Defibrillator: pads applied before deployment, in a position clear of the compression pad or band. Do not move working pads to make room.
• Waveform capnography: continuous EtCO₂ for confirmation during the arrest.
• Backup: a trained manual compressor and a second device or manual kit if the first fails.

Sizing

Every device has size and chest limits, and the IFU publishes them. Trial patients who were too big or too small for the device were excluded. For a child or a very large patient, read the IFU before you choose.

Patient Positioning & Preparation

Flat on the back, on a firm surface. Put the defibrillator pads on and set the airway plan before the device goes on. That keeps those jobs out of the pause.

These are typical adult and pediatric references. Check them against local protocol and current drug labeling.

Each device presets its own rate and depth. Check the manufacturer IFU for your unit, then compare the output with the manual target of 100–120/min and 5–6 cm. In the field, pause duration is the setting that matters most.

Phase 1: Prepare

1. Confirm the need: manual CPR is impractical or unsafe for this patient and setting.
2. Pick the device: confirm size, battery and backboard before the pause.
3. Assign roles: two trained staff deploy the device; one keeps the airway and ventilation going.

Phase 2: Deploy

4. Pause manual CPR: start the pause timer at the first interruption.
5. Place the backplate or band: move the patient only as far as needed, with the backboard under them.
6. Attach and start the device: confirm the pad or band is centered before the first compression.

7. Confirm the device is compressing: the chest visibly compresses and recoils fully, and an EtCO₂ waveform is present. A low or falling EtCO₂ means check position and device output.
8. Resume the ACLS routine: rhythm checks, shocks and drugs continue on the same schedule.

Phase 3: Confirm & Transport

9. Check the device at each move: pad or band position and tension are rechecked after every move.
10. Remove the device only at a pause: manual compressions resume immediately after removal.

Alternative Technique: Manual CPR Backup

The device fails, will not go on quickly, or the patient cannot be secured to the backboard? Return to manual CPR at once. Do not spend the pause troubleshooting the device.

Primary Confirmation

A running device is not proof of effective compressions. Check continuous EtCO₂ and the pulse at each rhythm check, and confirm perfusion with both. EtCO₂ is a trend of perfusion quality, not a target. Low or falling? Check position, rhythm and device output. A sudden, sustained rise can signal ROSC.

Secondary Confirmation

• Pad or band position: centered and secure, without slipping toward the abdomen
• Compression depth: the device reports depth per the IFU. Still, watch the chest move.
• Pause duration: recorded by the monitor and kept within the protocol

Ongoing Monitoring

• Every 2 min: rhythm check with EtCO₂ and pulse.
• Pulse checks: palpation is unreliable while the device compresses. Check the pulse in the planned rhythm-check pause, or use an arterial line or ultrasound where available.
• After each move: device position, tension and battery.
• After ROSC: remove the device per protocol and reassess perfusion.

PARAMEDIC recorded no serious adverse events. It did record seven clinical adverse events in the device group (chest bruising, chest lacerations and blood in the mouth), and none in the manual group. ILCOR 2026 found no significant difference in serious resuscitation-related or CPR-related injuries across the trials that reported them. Certainty is low. A 2023 retrospective cohort of 335 patients found abdominal injuries after skeletal and thoracic injuries. It also found more CPR-related injuries in device-assisted patients (aOR 6.2, 95% CI 2.5–15.4). It is observational, so treat it as a signal: check position and reassess.

Pediatrics

• No pediatric evidence: the large trials enrolled adults only. Children get manual CPR per the pediatric protocol. Do not put an adult device on a child.
• Sizing and dosing: see Equipment Sizing, Weight-Based Dosing and Pediatric Cardiac Arrest.
• Vascular access: see Pediatric Vascular Access; the arrest drugs follow the pediatric algorithm.

Pregnancy

• Trial exclusion: the trials left out known pregnancy.
• Pathway: follow the obstetric arrest pathway per local protocol.

Trauma / C-spine

• Traumatic arrest: the large trials left it out. Apply the trauma arrest protocol first.
• Spinal care: maintain alignment during deployment and transport per local protocol.

Physiologically Difficult

• Very large or very small bodies: several trials had them outside the device range. Check the IFU before deployment.

Immediate Aftercare

• After ROSC: remove the device at a pause and reassess perfusion and skin.
• After termination: record the device and time; follow local termination rules.
• Post-ROSC care: see the post-cardiac arrest care page.

Ongoing Maintenance

• Battery: keep a charged spare on the unit.
• Skin: check under the pad or band at each move.

Transport Considerations

• Securing: the backboard and device are secured before the vehicle moves.
• Reassessment: check position and tension after every move, turn or lift.
• Vibration and noise: rely on EtCO₂ and the monitor when the device or ambulance is loud.
• Safety: the device is an alternative to unsafe manual CPR, not an excuse to ignore scene safety.

Pearls

• Deploy during a planned pause: stop, place, start, then resume the ACLS schedule.
• Pre-place pads: defibrillator pads go on before the device. The pause then never gets spent on them.
• Practice the sequence: two staff deploying the device should rehearse it on a manikin.
• Trust the numbers: EtCO₂ and pulse show perfusion. The device display does not.

Common Pitfalls

• Long deployment → rehearse: practice the deployment until it fits the protocol pause target.
• Device replaces manual skills → keep manual CPR first: manual CPR remains the default.
• Device running with no pulse → check perfusion: confirm with EtCO₂ and pulse, then decide.

Skill Maintenance

• Simulation: practice deployment at least every quarter on a manikin.
• Checklist: use the pre-procedure checklist during each drill.
• Debriefing: review pause times and device placement after each drill.
• Familiarization: learn the battery and fault indicators on your unit.