Chapter 14. Prehospital cardiac arrest

Prehospital cardiac arrest (out-of-hospital cardiac arrest, OHCA) presents unique challenges compared to in-hospital arrests. These include environmental constraints, limited trained personnel, and difficulties in patient access. However, the key principles of ALS still apply, with an emphasis on early recognition, high-quality CPR, and early defibrillation.

Key aspects of prehospital cardiac arrest management include:

• Scene management and team coordination
• Optimising airway, breathing, and circulation
• Deciding whether to remain on scene or transport the patient
• Recognition of life extinct (ROLE)
• Post-resuscitation care and structured handovers

Key Topics Covered in Chapter 14

 Resuscitation at the Scene vs. Transport to Hospital

• Treatment should begin at the scene to identify and correct life-threatening causes.
• If ROSC is not achieved, transport is only advised if further interventions are possible at the hospital.
• Examples where transport is essential:
  • Patients with penetrating trauma and haemodynamic instability
  • Patients needing emergency PCI for STEMI post-ROSC
  • Refractory ventricular fibrillation requiring advanced hospital care

Team Approach to Prehospital Cardiac Arrest

Prehospital resuscitation requires strong teamwork and leadership. The four key roles include:

 Position 1 – Airway management (at the head of the patient)
 Position 2 – Chest compressions & defibrillation (left side of the patient)
 Position 3 – Circulatory access & drug administration (right side of the patient)
 Position 4 – Team leader (oversees resuscitation and decision-making)

 Key principles:

• Ensure 360° access to the patient.
• Use clear role assignments and a checklist to enhance efficiency.
• Minimise interruptions to chest compressions.

 Prehospital Airway Management

Maintaining a patent airway is crucial for oxygenation and ventilation. Stepwise airway management is recommended:

Basic airway interventions:

• Head tilt–chin lift (or jaw thrust if cervical injury is suspected).
• Oropharyngeal (Guedel) or Nasopharyngeal airways to prevent obstruction.

Advanced airway interventions:

• Supraglottic airway (SGA) – Easier than intubation, preferred in many cases.
• Tracheal intubation – Should be performed only by trained personnel, as incorrect placement can cause harm.

 Important Considerations:

• Avoid cricoid pressure during intubation, as it may make the procedure more difficult.
• Use continuous waveform capnography to confirm tube placement.

 Circulatory Support & Defibrillation

Defibrillation is time-critical, with 10% increase in mortality per minute of delay. The key steps are:

• Immediate rhythm assessment and shock delivery if VF/pVT is present.
• Use of Automated External Defibrillators (AEDs) in public areas.
• Consider alternative electrode positions (anterior-posterior) if VF is refractory.

Vascular access:

• IV access is preferred, but intraosseous (IO) access should be used if IV attempts fail.
• Limit IV attempts to 2 minutes before switching to IO access.

 Use of Mechanical Chest Compression Devices

• Routine use is not superior to manual compressions.
• Can be beneficial in specific situations such as:
  • During transport (to maintain CPR quality).
  • Patients requiring prolonged CPR (e.g., hypothermic arrest).

 Recognition of Life Extinct (ROLE) – When NOT to Start Resuscitation

Resuscitation should not be started if:

• Decapitation, massive head trauma, or hemicorporectomy is present.
• Full-thickness burns (>95%) have occurred.
• Decomposition, rigor mortis, or hypostasis is evident.
• A valid DNACPR decision is in place.

When to Stop Resuscitation:

• Asystole >20 min with no reversible cause (except hypothermia, drowning, or poisoning).
• Prolonged PEA with no response to treatment.

 Prehospital Post-Resuscitation Care

Once ROSC is achieved, the focus shifts to:

 Haemodynamic Management

• Systolic BP goal: ≥100 mmHg (IV fluids ± vasopressors if needed).
• Bolus adrenaline (0.05–0.1 mg IV/IO) for shock-resistant hypotension.

 Ventilation & Oxygenation

• SpO₂ target: 94–98%
• Avoid hyperventilation (PaCO₂ 4.6–6.0 kPa) to prevent cerebral vasoconstriction.

 Targeted Temperature Management (TTM)

• Keep core temperature ≤36°C.
• Passive cooling is preferred (avoid aggressive cooling with IV fluids).

 Sedation for Combative Patients

• Use midazolam or diazepam cautiously if needed for agitation.

 Transporting Patients Post-ROSC

• Aim for ROSC before transport – CPR during transport is less effective.
• Patient positioning:
  • Supine or 30° head-up for optimal cerebral perfusion.
  • Feet-first down stairs for stability.

Cardiac Arrest Centres:

• Patients with STEMI should go directly to PCI-capable centres.
• Early pre-alert to the receiving hospital using ATMIST handover format:
  • Age
  • Time of onset
  • Medical history
  • Investigations
  • Signs (vital signs)
  • Treatment provided

 Team Handover & Debriefing

🚑 Structured handovers improve care. Use ATMIST or RSVP formats.
📊 Debriefing after resuscitation is critical for team learning and emotional well-being.
📈 Audit & Quality Improvement – Modern defibrillators record CPR quality metrics to help improve future performance.

 Summary of Key Points

✔ Remain on scene for ROSC unless transport is essential.
✔ Assign clear roles in prehospital cardiac arrest teams.
✔ Use a stepwise airway approach, preferring SGA over intubation.
✔ Defibrillation should be rapid and repeated if necessary.
✔ IV access is preferred, but IO should be used if IV is difficult.
✔ Mechanical CPR is only useful in select cases.
✔ Do not start or continue resuscitation when futility is clear.
✔ Post-ROSC care should focus on haemodynamics, oxygenation, and TTM.
✔ Early pre-alerting and structured handovers ensure seamless hospital transition.
✔ Debriefing and audits are essential for continuous improvement.