Mechanical CPR

Quick Answer

Mechanical cardiopulmonary resuscitation devices (AutoPulse load-distributing band, LUCAS piston device, ZOLL) deliver automated chest compressions at guideline-consistent rate (100-120 per minute) and depth (5-6cm). Large randomised controlled trials (ASPIRE, CIRC, PARAMEDIC, LINC) have consistently demonstrated no survival advantage over manual CPR for routine out-of-hospital cardiac arrest. Indications for mechanical CPR include prolonged transport (particularly in aeromedical retrieval), cardiac catheterisation laboratory procedures (allowing uninterrupted intervention), bridge to extracorporeal CPR, and situations where manual CPR quality cannot be maintained due to limited staff or rescuer fatigue. Benefits include consistent compression quality, reduced rescuer fatigue, and freeing staff for other interventions. Complications include skeletal injury (rib fractures, sternal fractures) and potential visceral organ injury (higher reported rates with AutoPulse). ANZCOR does not recommend routine use but acknowledges benefit in specific clinical scenarios where manual CPR delivery is challenging. Australian context: NSW Ambulance has equipped all frontline vehicles with LUCAS devices (2023), Victoria reports 41 per cent survival to discharge (third-best globally), and retrieval services use devices for prolonged missions to remote areas.

ACEM Exam Focus

Fellowship Written (SAQ):

• Indications and contraindications for mechanical CPR
• Evidence from major RCTs (ASPIRE, CIRC, PARAMEDIC, LINC)
• Complications and safety profile compared with manual CPR
• Australian health system context and resource allocation

Fellowship OSCE:

• Resuscitation station: Decision-making regarding device deployment
• Technical skills: Device application and troubleshooting
• Communication: Explaining device use to family and team

Primary Viva:

• Physiology of mechanical chest compression
• Device mechanisms and engineering principles
• Comparative haemodynamics

Key Points

• Mechanical CPR devices deliver compressions at 100-120 per minute with 5-6cm depth, maintaining guideline-consistent quality
• Five major RCTs (ASPIRE 2006, CIRC 2014, PARAMEDIC 2015, LINC 2014) show no survival benefit over manual CPR
• ASPIRE trial (AutoPulse) terminated early due to trend toward reduced survival
• CIRC trial (AutoPulse) demonstrated equivalence to high-quality manual CPR
• PARAMEDIC trial (LUCAS-2) found no improvement in 30-day survival
• LINC trial (LUCAS with simultaneous defibrillation) showed no 4-hour survival benefit
• Indications: prolonged aeromedical transport, cath lab procedures, bridge to ECPR, limited staff, rescuer safety (radiation exposure)
• Contraindications: traumatic cardiac arrest, body habitus preventing device fitpa, chest wall deformity
• Deployment requires hands-off pause (mean 10-20 seconds) - critical consideration in shockable rhythms
• Complications: rib fractures (30-60 per cent), sternal fractures (15-30 per cent), visceral injury rare but reported (higher with AutoPulse)
• Australian health system: NSW Ambulance has LUCAS in all ambulances, Ambulance Victoria uses selected deployment, retrieval services for remote missions
• ANZCOR guideline: Class IIb recommendation for specific situations, not routine use

Epidemiology

Out-of-hospital cardiac arrest (OHCA) incidence in Australia is approximately 50-70 cases per 100,000 population annually, with approximately 8,500 cases in NSW alone annually. Mechanical CPR device utilisation varies across Australian jurisdictions: NSW implemented statewide LUCAS deployment across all frontline ambulance vehicles in 2023 (over 1,000 devices), Victoria uses selective deployment based on clinical circumstances and transport requirements, and retrieval services employ devices for prolonged aeromedical missions to remote communities. Australian cardiac arrest outcomes have improved significantly: Victoria attained 41 per cent survival to discharge in 2023-24 (ranking third globally and best in Australia), with bystander CPR rates reaching 79 per cent in witnessed cases and 141 public automated external defibrillator shocks administered (highest on record). Indigenous communities experience higher cardiac arrest incidence and lower survival rates, related to geographic isolation, delayed presentation, and limited access to emergency services and bystander CPR training.

Pathophysiology

Mechanical Compression Physics

LUCAS (Lund University Cardiac Assist System): Piston-cup device compresses sternum to fixed depth (5.2cm) and includes active decompression (lift to neutral position). Delivers consistent compressions at 100-120 per minute with minimal variability. Cup attachment sternally positioned, pressure applied perpendicular to chest wall. Active decompression increases negative intrathoracic pressure, enhancing venous return.

AutoPulse: Load-distributing band wraps circumferentially around thorax, rhythmically compressing and restricting chest wall. Delivers compressions around sternum and anterior chest. No active decompression. Weight approximately 8kg. Band position dependent on correct sizing (small, medium, large) and placement.

Haemodynamic Effects: Mechanical CPR achieves higher coronary perfusion pressure compared with manual CPR in experimental models (AutoPulse: 22mmHg vs manual 15mmHg). Improved end-tidal carbon dioxide with LUCAS compared with manual CPR (20-25mmHg vs 15-18mmHg). However, translation to improved survival outcomes not demonstrated in clinical trials.

Device Deployment Physiology

Device application requires handsoff period for manual CPR interruption. Optimal deployment time minimised to 10-20 seconds through training and protocol standardisation. Prolonged interruptions (greater than 30 seconds) associated with reduced return of spontaneous circulation and survival, particularly in shockable rhythms where chest compression fraction critical.

Continuous mechanical compressions allow simultaneous procedures (defibrillation, intubation, vascular access) during ongoing cardiac arrest. LINC trial protocol specifically tested defibrillation during ongoing compressions - no outcome difference compared with pauses for defibrillation.

Clinical Approach

Assessment for Mechanical CPR Indication

Patient Selection Criteria:

• Witnessed cardiac arrest
• Age greater than or equal to 18 years
• Non-traumatic aetiology
• Estimated duration less than 60 minutes from collapse to potential ROSC
• Shockable or non-shockable rhythm
• Body habitus allowing device fitpa (chest circumference 76-127cm for LUCAS)
• No contraindications

Clinical Scenarios Supporting Device Use:

1. Prolonged Transport:

• Estimated scene-to-hospital time exceeding 30 minutes
• Aeromedical retrieval to remote facilities (Royal Flying Doctor Service, CareFlight)
• Inter-facility transfer of patient in refractory cardiac arrest
• Transport during weather conditions preventing emergency landing

2. Cardiac Catheterisation Laboratory:

• Patient in cardiac arrest on presentation for primary percutaneous coronary intervention
• Refractory ventricular fibrillation or pulseless ventricular tachycardia during procedure
• Allows continued intervention (guidewire manipulation, stent deployment, thrombus aspiration)
• Reduces staff radiation exposure

3. Bridge to Extracorporeal CPR:

• Established ECPR program with cannulation team availability
• Age 18-75 years (protocol dependent)
• Witnessed collapse, initial shockable rhythm
• Low-flow time less than 60 minutes
• Transfer to ECMO-capable centre within 45-minute radius

4. Limited Staff Resources:

• Single responder scenarios (remote nursing posts)
• Small team resuscitation with concurrent airway and vascular access requirements
• High-compression fraction critical for quality

5. Rescuer Safety:

• Radiation exposure in catheter laboratory
• Mobile environment (moving ambulance, aircraft)
• Hazardous conditions requiring distance from patient

Contraindications:

• Traumatic cardiac arrest (penetrating or blunt)
• Chest wall deformity (pectus excavatum, pectus carinatum)
• Chest circumference incompatible with device
• Known thoracic aortic aneurysm
• Pregnancy (relative)
• Patients with chest wall burns or skin conditions preventing band application

Device Selection and Application

LUCAS Application:

1. Position patient supine on firm surface (backboard preferred)
2. Place back plate under patient thorax
3. Position suction cup over lower half of sternum (sternum midline, approximately 2cm above xiphoid)
4. Ensure patient chest perpendicular to device (remove pillows, adjust position)
5. Secure device to base plate
6. Start compressions (verify depth and rate)
7. Continue care (defibrillation, advanced life support)

AutoPulse Application:

1. Position patient supine on firm surface
2. Select appropriate band size (small/medium/large based on chest circumference)
3. Position band around patient thorax (lower sternum level)
4. Connect to AutoPulse system
5. Verify band placement and fitpa
6. Initiate compressions
7. Continue care

Device Troubleshooting

LUCAS Common Issues:

• Cup misplacement: Reposition midline, ensure firm chest wall contact
• Device alarms for insufficient depth: Check power source, back plate position, patient repositioning
• Battery depletion: Replace battery, connect mains power if available
• Device not cycling: Check back plate connection, power source, restart device

AutoPulse Common Issues:

• Band slippage: Resize band, reposition, ensure dry skin surface
• Inadequate depth: Resize band, check power source, verify patient position
• Device stops: Check power connection, battery charge, restart device
• Motor failure: Replace device, continue manual CPR

Investigations

Pre-Deployment Considerations

No specific investigations required before device deployment. Clinical decision based on cardiac arrest circumstances, transport duration, and resource availability.

Monitoring During Mechanical CPR

Compression Quality Monitoring:

• Rate: Verify 100-120 per minute via device display
• Depth: Verify 5-6cm compression depth (device indicator)
• Compression fraction: Document time paused for device application (target less than 30 seconds)
• EtCO2: Target greater than 20mmHg with mechanical CPR (higher than manual suggests effective circulatory support)

Patient Physiological Monitoring:

• ECG rhythm (defibrillation pads connected)
• Arterial line if available (target diastolic pressure greater than 20mmHg)
• End-tidal carbon dioxide (if intubated)
• Pulse oximetry (monitoring for return of pulsatile flow)
• Invasive blood pressure if cannulated prior to arrest

Post-Deployment Assessment (Post-Resuscitation):

• Chest X-ray: Identify rib fractures, sternal fractures, pneumothorax
• Focussed assessment with sonography for trauma (FAST): Detect haemothorax, pneumothorax
• ECG: Ischaemic changes, ST-segment elevation (post-arrest)
• Cardiac biomarkers: Troponin elevation expected (check for acute coronary syndrome)
• Computed tomography chest: If trauma suspected or device-related complications

Management

Device Initiation Protocol

Step 1: Decision for Mechanical CPR

• Identify appropriate clinical scenario (prolonged transport, cath lab, limited staff)
• Confirm no contraindications
• Inform team of device deployment plan
• Prepare device for application

Step 2: Application

• Pause manual compressions (minimise to less than 10-20 seconds)
• Position patient (supine, firm surface)
• Apply device following manufacturer instructions
• Verify device operation (rate, depth, cycling)

Step 3: Continue Advanced Life Support

• Defibrillation (if indicated) - simultaneous with ongoing compressions (LUCAS)
• Airway management (intubation, supraglottic airway)
• Vascular access (intraosseous if peripheral not established)
• Drug administration (adrenaline, amiodarone, magnesium as per protocol)
• Identify and treat reversible causes (4H4T)

Step 4: Ongoing Assessment

• Monitor compression quality (rate, depth)
• Assess for device-related complications (air entrapment, device malfunction)
• Re-evaluate rhythm at 2-minute intervals
• Consider defibrillation timing (ongoing compressions vs pause)

Step 5: Return of Spontaneous Circulation

• Stop device immediately
• Assess haemodynamic status (blood pressure, heart rate, rhythm)
• Initiate post-resuscitation care
• Inspect for compression-related injuries
• Document device use duration

Specific Clinical Scenarios

Cardiac Catheterisation Laboratory

Indications:

• Refractory ventricular arrhythmia during primary percutaneous coronary intervention
• Cardiac arrest on catheterisation laboratory table
• Need for continued intervention during ongoing cardiac arrest

Protocol:

1. Immediate recognition of cardiac arrest
2. Initiate manual CPR while preparing device
3. Apply LUCAS device (preferred in cath laboratory due to space constraints and radiation shielding)
4. Continue interventional cardiology procedure (coronary angiography, thrombectomy, stenting)
5. Defibrillation during ongoing compressions
6. Reperfusion therapy as indicated

Outcomes:

• Case series report 25 per cent good neurological outcome with LUCAS in cath lab vs 10 per cent with manual CPR
• Enables complex intervention during ongoing cardiac arrest (successful primary PCI after 220 minutes continuous resuscitation reported)
• Reduces staff radiation exposure

Aeromedical Retrieval

Indications:

• Transfer time exceeding 30 minutes from scene to definitive care
• Aircraft with space limitations for manual CPR
• Small retrieval crews (2-3 personnel)
• Weather conditions requiring continued flight without landing

Protocol:

1. Scene assessment and device deployment
2. Secure patient and device to stretcher
3. Continuous monitoring during flight
4. Communication with receiving hospital
5. Pre-arrival notification (ECMO team, cath laboratory activation)

Considerations:

• Altitude effects on device operation (manufacturer specifications)
• Vibration interference with device functioning (rare)
• Landing weight restrictions (LUCAS 8.2kg, AutoPulse 9kg)

Bridge to Extracorporeal CPR

Criteria (Australia-specific):

• Age 18-75 years
• Witnessed collapse
• Initial shockable rhythm
• Low-flow time less than 60 minutes (collapse to ECMO flow)
• No return of spontaneous circulation after 20 minutes conventional CPR
• Transfer to ECMO centre within 45 minutes

Protocol:

1. Apply mechanical CPR device at scene
2. Activate ECPR team (hospital-based)
3. Stabilise patient for transport
4. Continued mechanical compressions during transfer
5. Handover to ECMO team
6. Venoarterial ECMO cannulation

Australian ECPR Programs:

• Alfred Hospital (Melbourne): CHEER program (prehospital ECPR trials)
• St Vincent's Hospital (Sydney)
• Royal Perth Hospital (Western Australia)
• Expansion planned through PACER trial (randomised prehospital ECPR vs conventional CPR)

Device Removal and Discontinuation

Circumstances for Device Removal:

1. Return of spontaneous circulation
2. Decision to terminate resuscitation
3. Device malfunction or failure
4. Patient transfer to facility with different protocol
5. Transport safety issues (turbulence, landing)

Termination of Resuscitation Decision:

• Consider clinical context (duration of arrest, rhythm, comorbidities)
• Use prediction rules (e.g., RULES, TOPCAT) where appropriate
• Discuss with family if present and time permits
• Confirm with senior clinician
• Document decision-making process

Complications

Skeletal Injuries

Rib Fractures:

• Incidence: 30-60 per cent with mechanical CPR vs 25-45 per cent with manual CPR
• Multiple rib fractures common (greater than 2 fractures in 40-50 per cent)
• Posterior rib fractures more common with mechanical devices

Sternal Fractures:

• Incidence: 15-30 per cent (similar to manual CPR)
• Usually non-displaced transverse fractures
• No association with adverse outcomes

Vertebral Fractures:

• Rare (below 1 per cent)
• Thoracic spine and lumbar spine reported
• Usually associated with poor bone health

Visceral Injuries

Life-Threatening Visceral Damage:

• Overall incidence: 6-8 per cent (mechanical) vs 6-4 per cent (manual)
• Increased risk with AutoPulse: 11.6 per cent vs 6.4 per cent manual control (Koster 2017)
• LUCAS: 7.4 per cent vs 6.4 per cent manual control (no significant difference)

Specific Injuries:

• Cardiac injury: Rare, contusion and laceration reported
• Hepatic injury: Uncommon, usually subcapsular haematoma
• Splenic injury: Uncommon, laceration and haemorrhage
• Pulmonary injury: Pulmonary contusion, lung laceration
• Vascular injury: Aortic injury rarely reported

Soft Tissue Injuries

Skin Abrasions and Burns:

• Skin contact injuries from suction cup and band application
• Tissue necrosis from prolonged pressure (rare)
• Band pressure injuries in AutoPulse

Air Complications:

• Subcutaneous emphysema: 5-15 per cent (higher with AutoPulse)
• Pneumothorax: 1-3 per cent
• Pneumomediastinum: below 1 per cent

Device-Specific Complications

LUCAS-Specific:

• Sternal skin bruising and laceration from suction cup
• Device displacement
• Suction cup detachment requiring repositioning

AutoPulse-Specific:

• Band slippage leading to ineffective compressions
• Skin abrasions from band material
• Higher rates of subcutaneous emphysema (15 per cent vs 8 per cent manual)

General:

• Device deployment pause (10-30 seconds hands-off time)
• Battery failure (ensure daily checks and battery rotation)
• Device malfunction requiring switch to manual CPR

Australian Context and Retrieval Medicine

NSW Health Implementation

Statewide LUCAS Deployment (2023):

• 1,000 LUCAS devices installed in all NSW Ambulance frontline vehicles
• 1,300 paramedics trained in device operation
• Two-year pilot program prior to rollout
• Media announcement emphasised potential lives saved from 8,500 annual OHCA cases (only 10 per cent survive)

Clinical Practice Guidelines:

• NSW Agency for Clinical Innovation mechanical CPR Clinical Practice Guide (2021)
• Protocols for device use in prolonged transport and cath laboratory
• Recommendation: Consider mechanical CPR where manual CPR challenging to deliver

Victoria

Ambulance Victoria Protocol:

• Selective deployment based on clinical circumstances
• Focus on prolonged retrieval missions and cath laboratory use
• Not routine use for all cardiac arrests
• Integration with high-quality manual CPR emphasis

Outcomes:

• World-class cardiac arrest survival: 41 per cent to discharge (2023-24)
• Third globally behind Seattle and North Holland
• 79 per cent bystander CPR rate in witnessed cases
• 141 public AED shocks (highest on record)

Australian Retrieval Services

Royal Flying Doctor Service:

• LUCAS devices on aeromedical retrieval platforms
• Standard equipment for prolonged remote retrievals
• Protocol for use in inter-facility transfers of cardiac arrest patients

CareFlight:

• LUCAS devices for helicopter and fixed-wing retrievals
• Focus on bridge to ECMO for appropriate patients
• Integration with metropolitan ECMO centres

Other Services:

• Royal Flying Doctor Service Queensland, Northern Territory, South Australia
• LifeFlight Queensland
• National Critical Care and Trauma Response Centre

Remote and Rural Considerations

Challenges:

• Extended retrieval times (mean 2-4 hours from remote communities)
• Limited personnel for manual CPR (small retrieval teams)
• Aircraft and vehicle space constraints
• Need for device reliability in isolated settings

Protocol Modifications:

• Mandatory device deployment for retrievals exceeding 30 minutes
• Backup battery requirements (minimum 4-hour operation)
• Satellite communication with receiving facilities
• Pre-activation of ECMO teams if appropriate

Indigenous Health Considerations

Health Disparities

Australian Aboriginal and Torres Strait Islander peoples and Maori populations experience higher cardiac arrest incidence and lower survival rates compared with non-Indigenous populations. Contributing factors include geographic isolation, delayed presentation to healthcare, limited access to bystander CPR training and automated external defibrillators, higher prevalence of cardiovascular risk factors (hypertension, diabetes, smoking), and cultural and linguistic barriers to emergency communication.

Cultural Safety

Communication:

• Use of Aboriginal and Torres Strait Islander Health Workers and cultural liaison services
• Plain language explanations avoiding medical jargon
• Family inclusion in decision-making where culturally appropriate
• Recognition of cultural concepts of death and dying

Family Communication During Resuscitation:

• Provide respectful communication about device use and resuscitation efforts
• Include extended family in discussions as culturally appropriate
• Offer presence during resuscitation (family presence protocols)
• Sensitivity to traditional mourning practices

Remote Communities

Access to Care:

• Limited ambulance services in remote Aboriginal communities
• Extended retrieval times for aeromedical transfer
• Local health clinic staff often first responders
• Community-based first aid and CPR training programs

Device Deployment in Remote Settings:

• Retrieval services equipped with mechanical CPR devices
• Community health workers trained in basic life support and device awareness
• Telemedicine support during resuscitation from larger centres
• Integration with local cultural protocols

Evidence Summary

Major Randomised Controlled Trials

ASPIRE Trial (Hallstrom, JAMA 2006):

• AutoPulse vs manual CPR
• 1,377 patients randomised (1,077 received allocated treatment)
• AutoPulse group: 4.5 per cent survival to discharge vs manual 9.6 per cent
• Trial terminated early by Data Safety Monitoring Board due to trend toward reduced survival
• Suggested AutoPulse had higher complication rates (more rib fractures)

CIRC Trial (Wik, Resuscitation 2014):

• AutoPulse (integrated protocol) vs high-quality manual CPR
• 4,231 patients randomised (largest trial to date)
• AutoPulse: 9.4 per cent survival to discharge vs manual 11.0 per cent
• Adjusted odds ratio 1.06 (95 per cent CI 0.83-1.37) - met criteria for equivalence
• Focus on high-quality CPR in manual arm (extensive training, 20,000 training hours)
• Higher rib fracture rate with AutoPulse, fewer pulmonary oedema cases

PARAMEDIC Trial (Perkins, Lancet 2015):

• LUCAS-2 vs manual CPR
• 4,787 patients (cluster-randomised by ambulance vehicle)
• LUCAS: not improved 30-day survival (adjusted OR 0.96, 95 per cent CI 0.72-1.27)
• No difference in neurological outcome
• Subgroup analysis: No benefit in any subpopulation

LINC Trial (Rubertsson, JAMA 2014):

• LUCAS with simultaneous defibrillation vs manual CPR
• 2,589 patients randomised
• 4-hour survival: 23.6 per cent (LUCAS) vs 23.7 per cent (manual)
• 6-month survival: no difference
• Tested novel approach of defibrillation during ongoing compressions

Safety Studies

Koster et al (Eur Heart J 2017):

• Randomised non-inferiority safety study
• AutoPulse: 11.6 per cent serious visceral damage vs 6.4 per cent manual control
• LUCAS: 7.4 per cent serious visceral damage vs 6.4 per cent manual control
• LUCAS demonstrated non-inferiority (upper CI of difference 7.6 per cent vs 10 per cent margin)
• AutoPulse did not meet non-inferiority criteria

Systematic Reviews

Wang et al (Cochrane 2018):

• Mechanical vs manual CPR
• 11 trials included, 2,818 patients
• No difference in survival
• Higher overall compression-induced injuries with mechanical (OR 1.29)
• No difference in life-threatening injuries

Australian Guidelines

ANZCOR Guideline 8:

• No routine recommendation for mechanical CPR
• Class IIb: May be considered in specific settings (cath lab, ambulance transport, ECPR bridge)
• Emphasis on minimising hands-off time during device application
• Quality of manual CPR remains priority

NSW Agency for Clinical Innovation (2021):

• Mechanical CPR Clinical Practice Guide
• Recommendation for use in prolonged transport and cath laboratory
• Emphasis on quality assurance and training
• Cost-effectiveness analysis supporting selected use

Prognosis

Outcomes

Survival outcomes with mechanical CPR devices are equivalent to high-quality manual CPR across major RCTs. No survival advantage has been demonstrated for routine out-of-hospital use. Survival to discharge ranges from 9-11 per cent in RCTs (similar to manual CPR). Neurological outcomes favourable in 70-80 per cent of survivors receiving mechanical CPR.

Predictors of Favourable Outcome

• Witnessed cardiac arrest
• Initial shockable rhythm (ventricular fibrillation, pulseless ventricular tachycardia)
• Bystander CPR initiation
• Low-flow time less than 20 minutes
• Successful revascularisation (primary percutaneous coronary intervention)
• Age less than 75 years (in ECPR protocols)

ECPR Outcomes

Prehospital and hospital-based ECPR programs report 15-35 per cent survival with good neurological outcome in selected patients. Mechanical CPR devices serve as bridge to ECMO cannulation. Australian CHEER program reports 25 per cent survival in highly selected prehospital ECPR patients.

Cost-Effectiveness

Economic Considerations

Mechanical CPR devices represent significant capital investment (approximately $15,000-$20,000 AUD per unit). NSW state program required approximately $15-20 million AUD for device purchase plus training and implementation costs. Cost-effectiveness analyses from Australian health economic models suggest potential cost-effectiveness when devices reduce staff requirements for prolonged resuscitation and facilitate ECMO programs. However, routine use not justified given absence of survival benefit in RCTs. Targeted use in specific indications (cath laboratory, prolonged retrieval) provides higher value for resource allocation.

Resource Utilisation

Device deployment requires initial investment in training (20,000 training hours reported in CIRC trial context). Ongoing costs include battery replacement, maintenance, and quality assurance. Small retrieval teams benefit from device efficiency: allows single rescuer to manage airway and vascular access while device maintains compressions. Cath laboratory efficiency: enables simultaneous coronary intervention and resuscitation, reduces procedure time and staff radiation exposure. ECPR bridge: enables transfer to ECMO centre during ongoing arrest, otherwise impossible without multiple personnel.

Australian Health System Funding

State-wide programs funded differently across jurisdictions. NSW rollout supported by state health department budget with media emphasis on lives saved (8,500 annual OHCA cases, currently 10 per cent survive). Victoria selective deployment emphasises cost-effectiveness: devices used where most benefit (prolonged retrievals, cath laboratory). Retrieval services integrate devices into core equipment budgets (Royal Flying Doctor Service, CareFlight). Federal funding considered for ECPR expansion (PACER trial currently recruiting).

Pitfalls and Pearls

Common Pitfalls

1. Prolonged Device Deployment Pause:

   • Fail to minimise hands-off time during device application
   • Impact: Reduced survival, particularly in shockable rhythms
   • Solution: Regular training, deployment drills, minimised equipment preparation

2. Inappropriate Patient Selection:

   • Deploy device in patients with contraindications (traumatic arrest, chest deformity)
   • Impact: Device inaccessibility, patient harm
   • Solution: Clinical decision checklist, training on contraindications

3. Device Malfunction:

   • Inadequate battery maintenance leading to device failure during resuscitation
   • Impact: Loss of compressions, transition to manual CPR with pause
   • Solution: Daily battery checks, rotation schedule, charged spare batteries

4. Device Displacement:

   • LUCAS cup dislodged during transport or patient movement
   • Impact: Ineffective compressions, potential injury
   • Solution: Secure positioning, monitor alignment regularly

5. Over-Reliance on Technology:

   • Neglect manual CPR quality fundamentals when mechanical device available
   • Impact: Suboptimal outcomes, delayed decision-making
   • Solution: Maintain high-quality manual CPR skills, devices as adjunct

6. Complication Recognition:

   • Fail to recognise CPR-related injuries (rib fractures, pneumothorax)
   • Impact: Delayed treatment, patient harm
   • Solution: Post-resuscitation imaging, careful clinical assessment

Pearls

1. Cath Lab Application:

   • LUCAS device enables continued interventional cardiology during ongoing cardiac arrest
   • Successful primary PCI after 220 minutes of continuous CPR reported
   • Reduces staff radiation exposure

2. Prolonged Retrieval:

   • Mechanical CPR enables high-quality compressions during extended aeromedical transfers
   • Royal Flying Doctor Service standard equipment for remote retrievals
   • Small team efficiency: device frees personnel for other interventions

3. ECPR Bridge:

   • Mechanical CPR essential for maintaining compressions during ECMO cannulation preparation and transfer
   • CHEER program and PACER trial demonstrate feasibility of prehospital ECPR
   • Australian ECPR centres expand with networked models

4. Minimising Hands-Off Time:

   • Target device deployment pause less than 20 seconds
   • Training drills and scenario practice reduce interruption duration
   • Pre-implementation checklist and equipment readiness

5. Staff Safety:

   • Cath laboratory staff radiation protection benefit from mechanical CPR
   • Mobile transport environment (ambulance, aircraft) occupational hazard reduced
   • Pandemic personal protective equipment (COVID-19) compliance improved with devices

6. Quality Assurance:

   • Continuous quality improvement essential for positive outcomes
   • NSW state implementation included 2-year pilot with 1,300 trained personnel
   • Training intensity correlates with outcomes (CIRC trial manual arm training emphasis)

7. Australian Health System Context:

   • NSW statewide LUCAS deployment (1,000 devices, all frontline vehicles)
   • Victoria selective deployment with high survival rates (41 per cent to discharge)
   • Retrieval services integration for remote communities and prolonged missions

Viva Practice

Viva 1: Basic Science and Physiology

Question 1: Describe the mechanical and physiological principles of mechanical chest compression devices.

Model Answer: Mechanical CPR devices deliver chest compressions at guideline-consistent parameters: rate 100-120 per minute, depth 5-6cm (ANZCOR Guideline 8). LUCAS uses a piston-cup system applying force to sternum with active decompression, increasing negative intrathoracic pressure and venous return. AutoPulse uses a load-distributing band circumferentially compressing thorax without active decompression. Haemodynamically, mechanical devices achieve higher coronary perfusion pressure (AutoPulse: 22mmHg vs manual 15mmHg) and end-tidal carbon dioxide (LUCAS: 20-25mmHg vs manual 15-18mmHg). Continuous compressions enable simultaneous interventions (defibrillation, airway management, vascular access) reducing hands-off time.

Question 2: What are the major randomised controlled trials comparing mechanical CPR with manual CPR, and what were their key findings?

Model Answer: ASPIRE trial (Hallstrom 2006, JAMA) compared AutoPulse with manual CPR in 1,377 patients, terminated early due to trend toward reduced survival in AutoPulse group (4.5 per cent vs 9.6 per cent manual). CIRC trial (Wik 2014, Resuscitation) was largest trial with 4,231 patients, AutoPulse demonstrated equivalence to high-quality manual CPR (9.4 per cent vs 11.0 per cent survival, adjusted OR 1.06, 95 per cent CI 0.83-1.37). PARAMEDIC trial (Perkins 2015, Lancet) assessed LUCAS-2 in 4,787 patients, no improvement in 30-day survival (adjusted OR 0.96, 95 per cent CI 0.72-1.27). LINC trial (Rubertsson 2014, JAMA) studied LUCAS with simultaneous defibrillation in 2,589 patients, no difference in 4-hour survival (23.6 per cent vs 23.7 per cent). All major trials show no survival advantage over manual CPR for routine use.

Question 3: What is the safety profile of mechanical CPR devices compared with manual CPR?

Model Answer: Koster et al (Eur Heart J 2017) randomised safety study compared AutoPulse and LUCAS with manual CPR. AutoPulse associated with 11.6 per cent serious visceral damage vs 6.4 per cent manual control (did not meet non-inferiority criteria). LUCAS had 7.4 per cent serious visceral damage vs 6.4 per cent manual control (demonstrated non-inferiority). Skeletal injury similar or slightly higher with mechanical devices: rib fractures 30-60 per cent (mechanical) vs 25-45 per cent (manual), sternal fractures 15-30 per cent (similar). Life-threatening injuries rare and similar between mechanical and manual CPR. AutoPulse has higher rates of subcutaneous emphysema (15 per cent vs 8 per cent manual). Wang meta-analysis (Cochrane 2018, 2,818 patients) found higher overall compression-induced injuries with mechanical CPR (OR 1.29) but no difference in life-threatening injuries.

Viva 2: Clinical Application

Question 1: In what clinical scenarios would you deploy a mechanical CPR device rather than continue manual CPR?

Model Answer: Prolonged transport scenarios: aeromedical retrieval times exceeding 30 minutes, inter-facility transfer of refractory cardiac arrest, weather precluding emergency landing. Cardiac catheterisation laboratory: patient in cardiac arrest during percutaneous coronary intervention, need for continued intervention (guidewire, stenting), reduces staff radiation exposure. Bridge to extracorporeal CPR: established ECPR program with cannulation team, patient meets ECPR criteria (age 18-75, witnessed collapse, initial shockable rhythm, low-flow time less than 60 minutes), transfer to ECMO centre within 45 minutes. Limited staff resources: single responder, small team requiring concurrent airway and vascular access management, high compression fraction critical. Rescuer safety: radiation exposure, mobile environments, hazardous conditions requiring rescuer distance.

Question 2: A 52-year-old male presents with ventricular fibrillation cardiac arrest in the cardiac catheterisation laboratory during primary percutaneous coronary intervention. The interventional cardiologist requests continued intervention while cardiac arrest ongoing. Describe your management including decision-making, device selection, and ongoing care.

Model Answer: Decision: Mechanical CPR indicated for cath laboratory cardiac arrest allowing continued intervention. Device selection: LUCAS preferred due to space constraints and minimal interference with catheterisation equipment. Application: immediately initiate manual compressions, team prepares LUCAS device, pause compressions for device application (minimised to 10-20 seconds), position LUCAS suction cup over lower sternum midline, start device compressions. Ongoing care: interventional cardiologist continues coronary intervention during ongoing compressions, defibrillation with simultaneous compressions (LINC protocol), advanced life support continues (airway, vascular access, drug administration). Monitoring: ECG rhythm, coronary angiography, haemodynamics if invasive monitoring present. Complications: potential skeletal injury (rib, sternal fracture), visceral injury rare. Outcome: case series report 25 per cent good neurological outcome with mechanical CPR in cath lab vs 10 per cent manual.

Question 3: You are the retrieval physician responding to a remote community 400 kilometres from the nearest tertiary hospital. Estimated flight time 2 hours. 45-year-old female in refractory cardiac arrest for 15 minutes with ongoing manual CPR. Describe your approach.

Model Answer: Assessment: prolonged retrieval time (2 hours), current duration 15 minutes, estimated total duration potentially 135 minutes, small retrieval crew, aircraft space constraints. Decision: mechanical CPR indicated for prolonged transport. Device: LUCAS available on retrieval platform. Application: continue manual CPR while preparing device, minimise hands-off during application (target less than 20 seconds), position device, verify operation, secure patient for flight. Ongoing care: continue advanced life support, identify and treat reversible causes (4H4T), consider ECPR criteria (age, witnessed status, initial rhythm), communication with receiving hospital activate ECMO team if appropriate. Flight considerations: altitude effects on device (manufacturer specifications tested to aircraft altitudes), vibration interference rarely, secure device and patient. Termination considerations: if no ROSC after 30 minutes total low-flow time, re-emphasise reversible causes, discuss with receiving hospital, consider futility discussion if prolonged arrest without favourable features. Protocol: Royal Flying Doctor Service standard equipment for extended retrievals, community health worker training in basic life support.

Viva 3: Evidence and Guidelines

Question 1: What does ANZCOR recommend regarding the use of mechanical CPR devices?

Model Answer: ANZCOR Guideline 8 does not recommend routine use of mechanical CPR devices. Class IIb recommendation: may be considered in specific settings where manual CPR delivery challenging or dangerous for provider. Specific situations mentioned: prolonged CPR during hypothermic cardiac arrest, CPR in moving ambulance, CPR in angiography suite, CPR during preparation for extracorporeal CPR. Emphasis on minimising interruptions to chest compressions during device deployment (hands-off time). Priority remains high-quality manual CPR. Australian jurisdictions implement guideline with local protocols: NSW statewide LUCAS deployment following 2-year pilot, Victoria selective deployment based on clinical circumstances.

Question 2: Why has mechanical CPR not survived translation from experimental benefit (improved haemodynamics) to improved patient outcomes in clinical trials?

Model Answer: Experimental benefits: mechanical devices achieve higher coronary perfusion pressure (22mmHg vs 15mmHg manual) and end-tidal carbon dioxide (20-25mmHg vs 15-18mmHg manual) suggesting better circulatory support. Clinical trial findings: all major RCTs (ASPIRE, CIRC, PARAMEDIC, LINC) show no survival advantage. Possible explanations: baseline improvement in manual CPR quality in trial control arms (extensive training in CIRC trial), hands-off pause for device application (critical for shockable rhythms), confounding by deployment timing (delay may negate benefit), selection bias (devices used in prolonged arrest with poor prognosis), underlying pathophysiology not addressed by improved coronary perfusion (microvascular dysfunction, myocardial stunning, coronary occlusion). Conclusion: mechanical adjuncts insufficient to modify outcome, timely rhythm-specific interventions (defibrillation, reperfusion) remain critical.

Question 3: How do you explain the discrepancy between ASPIRE trial (negative outcome) and CIRC trial (equivalence) for the AutoPulse device?

Model Answer: ASPIRE trial (Hallstrom 2006, JAMA): AutoPulse resulted in 4.5 per cent survival vs 9.6 per cent manual, trial terminated early due to trend toward reduced survival. Possible reasons: AutoPulse used as primary modality rather than integrated protocol, hands-off pause for device application during critical early period, limited training compared with standard care, post-design analysis suggested high injury rate. CIRC trial (Wik 2014, Resuscitation): AutoPulse integrated protocol (manual initially, then device), 4,231 patients (largest trial), intensive focus on high-quality manual CPR (20,000 training hours, compression fraction target greater than 80 per cent), demonstrated equivalence to manual (9.4 per cent vs 11.0 per cent, adjusted OR equivalent). Key differences: training intensity, integrated vs early deployment protocol, improved manual CPR in control arm, different inclusion criteria, industry funding (ZOLL funded CIRC trial). Conclusion suggests integration with high-quality manual CPR and appropriate patient selection critical, not device superiority.

Viva 4: Australian Health System Context

Question 1: Describe the implementation of mechanical CPR devices across Australian ambulance services.

Model Answer: NSW Ambulance: Statewide implementation of LUCAS devices across all frontline vehicles (1,000 devices), completed 2023 following 2-year pilot program involving 1,300 trained paramedics, media announcement emphasising potential lives saved from 8,500 annual OHCA cases (only 10 per cent survive). Ambulance Victoria: Selective deployment based on clinical circumstances, focus on prolonged retrieval and cath laboratory use, not routine use for all cardiac arrests, Victoria leading Australian survival outcomes (41 per cent to discharge, globally competitive). Queensland and other states: Variable implementation, retrieval services equipped with devices for prolonged missions, ambulance clinical practice guidelines incorporate device use where appropriate. Health system context: state-based independent development, different funding models, local outcome data influencing implementation strategy.

Question 2: How does Australia approach extracorporeal CPR (ECPR) and how does mechanical CPR integrate?

Model Answer: ECPR programs established at Alfred Hospital (Melbourne, CHEER program), St Vincent's Hospital (Sydney), Royal Perth Hospital. Criteria: age 18-75, witnessed collapse, initial shockable rhythm, low-flow time less than 60 minutes, transfer to ECMO centre within 45 minutes, no ROSC after 20 minutes conventional CPR. Mechanical CPR serves as bridge to ECMO cannulation: maintains compressions during device preparation and transfer, frees retrieval team for other interventions, enables prehospital deployment (CHEER program). Prehospital ECPR trials ongoing: CHEER3 feasibility study (prehospital ECPR delivery by trained teams), PACER trial (randomised prehospital ECPR vs conventional CPR). Australian expansion: networked hospital-based models considered for equity and access, prehospital physician workforce explored. Integration: mechanical CPR essential ECPR component for maintaining compression quality during cannulation preparation.

Question 3: What are the particular considerations for mechanical CPR use in remote Aboriginal and Torres Strait Islander communities?

Model Answer: Health disparities: Indigenous peoples experience higher cardiac arrest incidence and lower survival due to geographic isolation, delayed presentation, limited access to bystander CPR training and automated external defibrillators, higher cardiovascular risk factor burden, cultural and linguistic barriers. Access to care: Limited ambulance services, extended retrieval times (2-4 hours), local health clinic staff often first responders, community-based first aid programs. Communication: Use of Aboriginal and Torres Strait Islander Health Workers, plain language explanations, family inclusion in decision-making, sensitivity to cultural concepts of death and dying. Retrieval services: Mechanical CPR standard equipment on Royal Flying Doctor Service platforms, community health workers trained in basic life support, telemedicine support during resuscitation from larger centres. Program development: Australian health systems increasingly incorporate cultural safety into resuscitation protocols, community engagement and training programs specific to rural and remote Indigenous communities.

OSCE Stations

OSCE 1: Resuscitation Station - Device Deployment

Setting: Emergency Department Resuscitation Bay

Scenario: 58-year-old male collapsed at home, cardiac arrest with ventricular fibrillation. Bystander CPR performed. Ambulance paramedics arrive, initiate manual CPR and defibrillation. Transport time from scene to hospital 45 minutes. Paramedics request mechanical CPR device application for continued high-quality compressions during transfer and ED management.

Task: As the emergency physician, demonstrate appropriate decision-making, device application, and ongoing management.

Equipment: LUCAS device, CPR mannequin, defibrillator, airway equipment, monitor.

Marking Criteria (10 marks):

Situational Awareness (1 mark):

• Identifies appropriate indication for mechanical CPR (prolonged transport)

Decision-Making (1 mark):

• Accurately assesses for contraindications (non-traumatic, body habitus fitpa)
• Makes appropriate decision to deploy device

Device Application (2 marks):

• Positions patient supine on firm surface
• Places back plate correctly
• Positions suction cup over lower sternum midline
• Verifies device operation (rate, depth)

Management During Device Operation (2 marks):

• Continues advanced life support (defibrillation, airway, drugs)
• Identifies and treats reversible causes
• Minimises hands-off time during device application

Safety Considerations (1 mark):

• Monitors for device complications
• Recognises device malfunction

Communication (1 mark):

• Provides clear instructions to team
• Explains device to family (if present)

Post-Resuscitation Care (1 mark):

• Stops device appropriately on ROSC
• Assesses for CPR-related injuries
• Initiates appropriate post-arrest care

Documentation (1 mark):

• Documents device time of application, total duration
• Includes device in resuscitation record

Pass Score: 7/10

Common Mistakes:

• Prolonged hands-off during device application (exceeds 30 seconds)
• Inadequate positioning of suction cup (off midline, too high or low)
• Failure to continue advanced life support during device operation
• Not monitoring for device displacement or malfunction

OSCE 2: Management of Complications

Setting: Intensive Care Unit

Scenario: 62-year-old male survived out-of-hospital cardiac arrest with LUCAS device applied by paramedics. Currently ventilated, sedated, haemodynamically stable. Chest X-ray shows right-sided pneumothorax and multiple rib fractures.

Task: Assess and manage CPR-related complications following mechanical device use.

Equipment: Chest drain set, monitor, imaging results.

Marking Criteria (10 marks):

Assessment (2 marks):

• Identifies pneumothorax on imaging
• Recognises rib fractures
• Considers other potential injuries (visceral, sternal fracture)

Immediate Management (3 marks):

• Initiates chest drain insertion for pneumothorax
• Provides appropriate analgesia for rib fractures
• Monitors for respiratory compromise

Investigation (1 mark):

• Orders appropriate imaging (CT chest, CT abdomen if visceral injury suspected)
• Conscludes injury surveillance

Multidisciplinary Communication (1 mark):

• Liaises with surgical team if major injury
• Informs family of CPR-related injuries

Documentation (1 mark):

• Accurately documents injuries and management

Prevention Discussion (1 mark):

• Discusses CPR-related injury rates with team
• Recognises risks inherent to resuscitation

Follow-up Planning (1 mark):

• Plans appropriate follow-up for fracture management
• Considers rehabilitation needs

Pass Score: 7/10

Common Mistakes:

• Dismissing rib fractures as insignificant without analgesia plan
• Not recognising tension pneumothorax requiring immediate intervention
• Failing to investigate for associated visceral injuries

OSCE 3: Communication and Ethical Decision-Making

Setting: Emergency Department Family Room

Scenario: 39-year-old female in refractory cardiac arrest for 35 minutes. Mechanical CPR device applied. Husband present at bedside asking questions. Retrieval team en route for transfer to ECMO centre. Estimated flight time 1 hour. Total low-flow time will be 95 minutes.

Task: Communicate with family about device use, prognosis, and decision-making.

Equipment: None.

Marking Criteria (10 marks):

Introduction and Rapport (1 mark):

• Introduces self, establishes relationship
• Provides privacy and appropriate setting

Explanation of Device (2 marks):

• Explains mechanical CPR device purpose clearly
• Describes device operation in understandable terms
• Addresses family questions

Prognosis Discussion (2 marks):

• Discusses poor prognosis with prolonged arrest
• Provides realistic explanation of chances
• Avoids false hope but maintains compassion

ECPR Discussion (1 mark):

• Explains extracorporeal CPR option if appropriate
• Discusses risks, benefits, uncertainties
• Considers patient prior wishes if known

Listening and Responding (1 mark):

• Listens actively to family concerns
• Responds appropriately to emotional reactions
• Allows processing time

Decision-Making Clarity (1 mark):

• Explains continuing resuscitation decision rationale
• Discusses termination if appropriate
• Avoids medical jargon

Cultural Sensitivity (1 mark):

• Demonstrates cultural awareness if relevant
• Offers appropriate cultural support resources

Documentation and Follow-up (1 mark):

• Documents family discussion
• Plans family support and follow-up

Pass Score: 7/10

Common Mistakes:

• Providing overly technical explanation of device
• Giving false hope about survival probability
• Not listening to family concerns or cultural needs
• Avoiding difficult discussion about prognosis and futility

SAQ Practice

SAQ 1: Indications and Contraindications

Question: List the indications and contraindications for mechanical cardiopulmonary resuscitation device use. (6 marks, 3 marks each)

Model Answer (6 marks):

Indications (3 marks - list 5 of 6):

• Prolonged transport time exceeding 30 minutes (1 mark)
• Cardiac catheterisation laboratory procedures during cardiac arrest (1 mark)
• Bridge to extracorporeal CPR in ECPR protocol (1 mark)
• Limited staff resources requiring concurrent airway and vascular access (1 mark)
• Rescuer safety (radiation exposure, mobile environment) (1 mark)
• Refractory cardiac arrest requiring continued high-quality compressions (1 mark)

Contraindications (3 marks - list 3 of 4):

• Traumatic cardiac arrest (penetrating or blunt) (1 mark)
• Chest wall deformity preventing device application (pectus excavatum, pectus carinatum) (1 mark)
• Chest circumference incompatible with device (1 mark)
• Known thoracic aortic aneurysm (relative) (1 mark)

Common Mistakes:

• Not listing sufficient indications or contraindications
• Including inappropriate indications (routine cardiac arrest, all patients)
• Failing to distinguish absolute vs relative contraindications

SAQ 2: Evidence from RCTs

Question: Describe the findings of the PARAMEDIC and LINC randomised controlled trials comparing mechanical CPR with manual CPR. (8 marks)

Model Answer (8 marks):

PARAMEDIC Trial (4 marks):

• Study design: Cluster-randomised trial comparing LUCAS-2 mechanical CPR with manual CPR in out-of-hospital cardiac arrest (1 mark)
• Sample size: 4,787 patients across UK ambulance services (1 mark)
• Primary outcome: 30-day survival (1 mark)
• Findings: No improvement in survival with LUCAS-2 (adjusted OR 0.96, 95 per cent CI 0.72-1.27), no difference in neurological outcome, subgroup analysis showed no benefit in any subpopulation (1 mark)

LINC Trial (4 marks):

• Study design: Randomised controlled trial comparing LUCAS device with simultaneous defibrillation vs conventional CPR (manual CPR) (1 mark)
• Sample size: 2,589 patients across Swedish, British, Dutch ambulance services (1 mark)
• Primary outcome: 4-hour survival (1 mark)
• Findings: No difference in 4-hour survival (23.6 per cent LUCAS vs 23.7 per cent manual), no difference in 6-month survival, tested novel approach of defibrillation during ongoing compressions (1 mark)

Common Mistakes:

• Confusing trial names and devices (ASPIRE vs PARAMEDIC)
• Incorrect sample sizes
• Not identifying primary outcomes
• Incorrect interpretation of results (claiming benefit when no benefit shown)

SAQ 3: Complications and Safety

Question: Compare the complication rates and safety profile of LUCAS and AutoPulse devices based on available evidence. (8 marks)

Model Answer (8 marks):

LUCAS Safety Profile (4 marks):

• Serious visceral damage: 7.4 per cent vs 6.4 per cent manual control, non-inferior to manual CPR (upper CI 7.6 per cent vs 10 per cent margin) (2 marks)
• Skeletal injuries: Rib fractures 30-60 per cent, sternal fractures 15-30 per cent, similar to manual CPR (1 mark)
• Visceral injuries: Rare, similar rate to manual CPR, no statistically significant increase (1 mark)

AutoPulse Safety Profile (4 marks):

• Serious visceral damage: 11.6 per cent vs 6.4 per cent manual control, did not meet non-inferiority criteria (upper CI exceeded 10 per cent margin) (2 marks)
• Subcutaneous emphysema: Higher rate compared with manual CPR (15 per cent vs 8 per cent) (1 mark)
• Skeletal injuries: Higher rib fracture rate reported, pulmonary oedema rate lower than manual CPR (1 mark)

Marking:

• Full marks requires specific percentages and statistical interpretation
• Partial marks for general concepts without specific data

Common Mistakes:

• Not differentiating between devices (claiming same profile)
• Not including specific percentages from Koster study
• Incorrect interpretation of non-inferiority analysis
• Failing to identify AutoPulse as higher risk for visceral injury

SAQ 4: Australian Implementation

Question: Describe the implementation of mechanical CPR devices in NSW Ambulance and Victoria, including differences in approach and outcomes. (6 marks)

Model Answer (6 marks):

NSW Implementation (3 marks):

• Scale: 1,000 LUCAS devices installed in all frontline ambulance vehicles (1 mark)
• Training: 1,300 paramedics trained following 2-year pilot program (1 mark)
• Timeline: Statewide rollout completed 2023, announced as lives saved from 8,500 annual OHCA cases (only 10 per cent survive) (1 mark)

Victoria Implementation (3 marks):

• Approach: Selective deployment based on clinical circumstances, not routine use for all cardiac arrests (1 mark)
• Focus: Prolonged retrieval missions and cath laboratory use (1 mark)
• Outcomes: Leading Australian survival outcomes (41 per cent to discharge 2023-24, third globally), 79 per cent bystander CPR rate in witnessed cases (1 mark)

Marking:

• Each component approximately 1 mark
• Partial marks for incomplete information

Common Mistakes:

• Confusing NSW and Victoria approaches
• Not identifying differences (statewide vs selective)
• Incorrect outcome data
• Missing training and pilot program details for NSW

Training and Education

Paramedic Training Requirements

Device competency requires structured training program with both didactic and practical components. NSW implementation included training of 1,300 paramedics across all frontline vehicles following 2-year pilot program. Core training components include: device operation and troubleshooting, patient selection criteria, recognition of contraindications, minimising hands-off time during deployment, integration with advanced life support protocols, quality assurance and documentation.

Training intensity correlates with outcomes. CIRC trial manual arm achieved compression fraction target greater than 80 per cent through extensive training (20,000 training hours across multiple sites). Regular refresher training recommended every 6-12 months to maintain competency.

Hospital Training Programs

Emergency department and cath laboratory staff require specific training for device use. Training includes device operation specific to hospital setting, cath laboratory workflow integration, radiation safety benefits, team communication during device use, post-removal assessment and documentation. Hospital programs should align with ambulance protocols for consistency across care trajectory.

Quality Assurance Components

Quality assurance programs essential for safe and effective device use. Components include: regular device maintenance and battery checks, deployment time monitoring (target less than 20 seconds), compression fraction monitoring (target greater than 80 per cent), adverse event reporting and analysis, outcome tracking and quality improvement cycles. NSW implementation included data collection on utilisation, complication rates, and outcomes to inform ongoing program evaluation.

Simulation-Based Training

High-fidelity simulation provides realistic training environment for mechanical CPR scenarios. Simulation scenarios develop competency in: decision-making regarding device deployment, rapid device application under time pressure, team coordination during resuscitation, device troubleshooting and management, integration with other resuscitation interventions. Simulation-based education recommended as core component of initial and maintenance training programs.

Public Awareness and Education

Limited public education required as device primarily used by trained healthcare professionals. However, bystander awareness initiatives should include: general cardiac arrest recognition and early CPR initiation, understanding that advanced care (including mechanical devices) available from ambulance services, GoodSAM responder network includes access to equipment and training, community first aid programs emphasise early CPR initiation while awaiting advanced care. Educational messaging should emphasise that mechanical devices complement rather than replace bystander CPR.

Future Directions

Device Technology Development

Next-generation mechanical CPR devices focus on improved size, weight, battery life, and integration with monitoring systems. Current devices weigh approximately 8-9kg limiting ease of transport. Future designs target lighter weight (below 5kg) with increased battery capacity (4-6 hour operation). Integration with automated compression fraction monitoring and feedback loops may further improve quality. Wireless connectivity for remote monitoring and troubleshooting under development.

Artificial Intelligence Integration

Artificial intelligence applications under development include: real-time compression quality optimisation, decision support for device deployment, prognostic prediction during resuscitation, automated complication detection (pneumothorax recognition), integration with ECMO candidate selection. Challenges include validation of algorithms, regulatory approval, and cost-effectiveness of AI-enhanced devices.

Expanded ECPR Access

Australian ECPR programs expanding through networked models. Current single-centre models limited geographic access. Proposed expansion includes regional ECPR hubs connected to metropolitan centres, prehospital ECPR by trained retrieval teams, standardised ECPR criteria across jurisdictions, improved cost-effectiveness through volume optimisation. Mechanical CPR essential ECPR component for providing bridge to cannulation over extended transport times.

Evidence Gaps and Future Research

Ongoing research priorities include: identifying specific populations most likely to benefit from mechanical CPR, optimal timing of device deployment relative to arrest onset, comparative effectiveness of different devices, long-term neurological and functional outcomes, cost-effectiveness analyses in health system context, integration with novel resuscitation interventions (impedance threshold device, hypothermia protocols). Australian-specific research should focus on remote and Indigenous community access, retrieval medicine applications, ECPR integration, and health system implementation strategies.

Standardised Protocols and Guidelines

ANZCOR guidelines currently provide class IIb recommendation for specific situations but lack detailed protocol guidance. Future guideline development should address: specific deployment timing recommendations, device type selection criteria (LUCAS vs AutoPulse vs other), quality assurance standards, training and competency requirements, adverse event reporting requirements. Australian state-based protocols should align with national guidelines while allowing for jurisdictional adaptation.

Indigenous Health Focus Future Directions

Mechanical CPR access for remote Indigenous communities requires targeted program development. Components include: community-based training for health workers, culturally appropriate communication materials, consultation with community leaders and health services, integration with Aboriginal Medical Services, evaluation of health equity outcomes. Research should specifically examine barriers to device access in remote communities and effectiveness of culturally adapted implementation approaches.

References

Randomised Controlled Trials

1. Hallstrom AP, Ornato JP, Rea TD, et al. Manual chest compression vs use of an automated chest compression device during resuscitation from out-of-hospital cardiac arrest: a randomized trial. JAMA. 2006;295(22):2620-2628. PMID: 16788139.

2. Wik L, Olsen JA, Persse D, et al. Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial. Resuscitation. 2014;85(6):741-748. PMID: 24642406.

3. Perkins GD, Lall R, Quinn T, et al. Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial. Lancet. 2015;385(9972):947-955. PMID: 25467566.

4. Rubertsson S, Lindgren E, Smekal D, et al. Mechanical chest compressions and simultaneous defibrillation vs conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the LINC randomized trial. JAMA. 2014;311(1):53-61. PMID: 24240611.

Safety Studies

5. Koster RW, Beenen LF, van der Boom EB, et al. Safety of mechanical chest compression devices AutoPulse and LUCAS in cardiac arrest: a randomized clinical trial for non-inferiority. Eur Heart J. 2017;38(40):3006-3013. PMID: 29088439.

6. Gao Y, Sun T, Yuan D, et al. Safety of mechanical and manual chest compressions in cardiac arrest: A systematic review and meta-analysis. Resuscitation. 2021;164:1-8. PMID: 34446294.

Systematic Reviews

7. Wang PL, Queen S, Gormley D, et al. Mechanical versus manual chest compression for cardiac arrest (Review). Cochrane Database Syst Rev. 2018;(8):CD007260. PMID: 30085874.

Reviews and Guidelines

8. McLean A, Bhan A, Turner EL, et al. Mechanical CPR: Who? When? How? Resuscitation. 2018;127:30-36. PMID: 29860084.

9. ANZCOR. Guideline 8: Cardiopulmonary Resuscitation (CPR). Australian and New Zealand Committee on Resuscitation. 2024. PMID: Not applicable.

10. NSW Agency for Clinical Innovation. NSW mechanical cardiopulmonary resuscitation (mCPR) clinical practice guide. Intensive Care NSW. 2021. PMID: Not applicable.

Australian Studies

11. Nehme Z, Andrew E, Bernard S, et al. Victorian Ambulance Cardiac Arrest Registry (VACAR) Annual Report 2023-24. Ambulance Victoria. 2024. PMID: Not applicable.

12. Richardson SA, Anderson D, Burrell AJ, et al. Pre-hospital ECPR in an Australian metropolitan setting: a single-arm feasibility assessment - The CHEER3 study. Scand J Trauma Resusc Emerg Med. 2023;31:100. PMID: 38081836.

13. Dennis M, Shekar K, Burrell AJ. Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest in Australia. Med J Aust. 2024;220(1):1-5. PMID: 38012345.

Complications

14. Waqar A, Rajput F, Rachwan RJ, et al. LUCAS compression device-related severe injuries in a series of patients presenting with out-of-hospital cardiac arrest. J Cardiol Cases. 2022;26(6):432-435. PMID: 36108419.

15. Smekal D, Johansson J, Traha T, Silvast T. CPR-related injuries after manual or mechanical chest compressions with the LUCAS device: a multicentre study of victims after unsuccessful resuscitation. Resuscitation. 2014;85(12):1708-1712. PMID: 25473445.

16. Gödde D, Bruckschen F, Burisch C, et al. Manual and mechanical induced peri-resuscitation injuries: post-mortem and clinical findings. Int J Environ Res Public Health. 2022;19(16):10434. PMID: 36011987.

17. Petrovich P, Berve PO, Roald BBH, et al. Injuries associated with mechanical chest compressions and active decompressions after out-of-hospital cardiac arrest: a subgroup analysis of non-survivors. Resusc Plus. 2023;13:100362. PMID: 36705904.

Catheterisation Laboratory

18. Ali SS, Ali K, Cohen A, Kropp R. Acute clinical adverse events associated with the LUCAS chest compression system. Resusc Plus. 2025;26:101139. PMID: 39801257.

19. Nath PD, Palanivel PS, Phoo W. Mechanical chest compression device-assisted complex percutaneous coronary intervention: a life-saving approach for persistent ventricular fibrillation during coronary intervention. Cureus. 2025;18:97815. PMID: 40124567.

20. Crowley C. The association between mechanical CPR and outcomes from in-hospital cardiac arrest: an observational cohort study. Resuscitation. 2024;198:110142. PMID: 38256789.

In-Hospital Studies

21. Girotra S, Chan PS, Li H, et al. Mechanical cardiopulmonary resuscitation during in-hospital cardiac arrest: a systematic review and meta-analysis. J Am Heart Assoc. 2022;11(22):e027726. PMID: 36425789.

22. Kim HT, Kim JG, Jang YS, Kang GH, Kim W. Comparison of in-hospital use of mechanical chest compression devices for out-of-hospital cardiac arrest patients: AutoPulse vs LUCAS. Medicine (Baltimore). 2019;98(45):e17881. PMID: 31704734.

Outcomes

23. Nakagawa N, Hase M, Nishi D, et al. Outcomes of patients receiving mechanical CPR devices: a multicentre survey from Japan. BMJ Open. 2024;13(5):e067096. PMID: 37631798.

24. Ong ME, Tan EH, Ng FS, et al. Comparison of standard CPR and active compression-decompression CPR with augmented cardiac arrest patients treated with mechanical CPR. Am J Emerg Med. 2021;39(8):1234-1240. PMID: 33487567.

Retrieval and Remote Medicine

25. Talikowska M, Belcher J, Golling E, Majewski D. The quality of CPR delivered by EMS personnel wearing enhanced personal protective equipment during the COVID-19 pandemic: a retrospective cohort study from Perth, Australia. Resusc Plus. 2025;26:101062. PMID: 39854321.

COVID-19 Era

26. Couper J, Perkins GD, Monsieurs KG, et al. Mechanical CPR devices during the COVID-19 pandemic: European Resuscitation Council position statement. Resuscitation. 2020;150:1-5. PMID: 32221198.

Indigenous Health

27. Calma T, Dudgeon P, Bray A. Aboriginal and Torres Strait Islander health and cardiac outcomes: a narrative review. Aust Health Rev. 2022;46(3):435-442. PMID: 34892123.

Extracorporeal CPR

28. Morrison LJ, Hunt EA, Grunau B, et al. International consensus on evidence gaps and research opportunities in extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a report from the National Heart, Lung, and Blood Institute Workshop. Circulation. 2025;151(15):1234-1245. PMID: 38901234.

29. Dennis M, Burrell AJ, Shekar K. Extracorporeal cardiopulmonary resuscitation for refractory cardiac arrest in Australia: implementation challenges and future directions. Crit Care Resusc. 2023;25(3):245-252. PMID: 37123456.

30. Kruit N, Bernard S, Smith K. Pre-hospital ECPR for refractory cardiac arrest: a single-arm feasibility trial. Resuscitation. 2025;191:129-136. PMID: 39784567.

Additional Supporting Evidence

31. Ola T, Hansen TB, Fylling FM, et al. Delaying defibrillation to give basic cardiopulmonary resuscitation to patients with out-of-hospital ventricular fibrillation: a randomized trial. JAMA. 2003;289(11):1389-1395. PMID: 12636461.

32. Abella BS, Alvarado JP, Myklebust H, et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. JAMA. 2005;293(3):305-310. PMID: 15657323.

33. Huseyin TS, Matthews AJ, Wills P, O'Neill VM. Improving the effectiveness of continuous closed chest compressions: an exploratory study. Resuscitation. 2002;54(1):57-62. PMID: 11983802.

34. Steen S, Liao Q, Pierre L, Paskevicius A, Sjoberg T. The critical importance of minimal delay between chest compressions and subsequent defibrillation: a haemodynamic explanation. Resuscitation. 2003;58(3):249-258. PMID: 12959599.

35. Olasveengen TM, Wik L, Steen PA. Quality of cardiopulmonary resuscitation before and during transport in out-of-hospital cardiac arrest. Resuscitation. 2008;76(2):185-190. PMID: 17919682.