Airway

See Chapters 59 and 112.

• Use head tilt and chin lift or jaw thrust to open the airway. Use suction to clear the airway if needed. Place an oropharyngeal or nasopharyngeal device to maintain an open airway.
• Endotracheal intubation or placement of a supraglottic airway can be done by an experienced operator.

Ventilation

See Chapter 112.

• Use a bag-valve device, which allows ventilation with 100% oxygen. Aim for a tidal volume of 400–600 mL. This is adequate for oxygenation, and less likely to cause gastric insufflation (which increases the risk of vomiting and aspiration) than larger volumes. Over-ventilation may also cause barotrauma, pneumothorax and cardiovascular compromise.
• The ratio of chest compressions to ventilations should be 30:2. However, if an endotracheal tube or supraglottic airway has been placed, give 8–10 ventilations/min, not synchronized with chest compressions.
• Waveform capnography enables end-tidal CO₂ (E_T CO₂) to be monitored during CPR. Measurement of E_T CO₂ can confirm appropriate placement of an endotracheal tube, assess the adequacy of CPR and indicate ROSC (when E_T CO₂ increases) during CPR.

1. Chest compression
   • Chest compressions should be performed at a rate of 100–120/min.
   • Compress the chest by 5–6 cm, allowing the chest to recoil completely after each compression.
   • Minimize interruptions to chest compression. To maintain high-quality chest compression, ideally change the person doing chest compressions after each cycle of CPR.
2. Defibrillation for ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT)
   • Place the sternal electrode to the right of the sternum, below the clavicle. Place the apical electrode in the mid-axillary line, clear of any breast tissue.
   • Continue chest compressions during defibrillator charging. Remove any oxygen mask or nasal cannulae and place them at least 1 m away from the patient's chest during defibrillation.
   • Deliver defibrillation with an interruption in chest compressions of no more than 5 seconds. Immediately resume chest compressions following defibrillation. Only check the pulse between shocks if the ECG waveform changes to one compatible with a spontaneous output. Deliver the first shock with an energy of at least 150 J. If this is unsuccessful, deliver the second and subsequent shocks with a higher energy level if the defibrillator is capable of this. If VF/pVT recurs during a cardiac arrest (refibrillation), give subsequent shocks with a higher energy level if the defibrillator is capable of this.
3. Pulseless electrical activity (PEA)/asystole
   • Check electrode positions and contacts before concluding the rhythm is not VF/pVT.
   • Consider the potentially reversible causes of cardiac arrest with PEA/asystole and address these (Table 6.1).
4. Specific drug therapy and drug delivery
   • If a central venous line is not already in place, put a wide-bore cannula in a large peripheral vein. Use a flush of 20 mL of normal saline and elevation of the limb after drug administration to facilitate delivery to the central circulation.
   • If IV access is not possible, the intraosseous route can be used.

Adrenaline

Amiodarone

Sodium bicarbonate

Fibrinolytic therapy

See Chapter 114.

• Focused echocardiography/ultrasonography by an experienced operator may help identify a potentially reversible cause of cardiac arrest (e.g. cardiac tamponade, pulmonary embolism, hypovolaemia).
• If the probe is placed just before chest compressions are paused for a planned rhythm assessment, views can be obtained within 10 seconds.

1. Management of tachycardia and bradycardia after ROSC
   • See Figures 6.3 and 6.4.
   • Further information about the management of arrhythmias is given in Chapters 39, 40, 41, 42, 43, 44.
2. When to stop resuscitation
   • Resuscitation should be stopped if a: ‘Do not attempt cardiopulmonary resuscitation’ (DNACPR) order (Appendix 6.1) has been written, or the circumstances of the patient indicate that one should have been.
   • Resuscitation should be stopped if there is refractory asystole for more than 20 min (except when cardiac arrest is due to hypothermia). Resuscitation should not be stopped while the rhythm is ventricular fibrillation.
   • Absence of cardiac motion on echocardiography during CPR is highly predictive of death, but should not be the sole basis for the decision to stop CPR.
3. After successful resuscitation
   • Protect the airway until the patient is fully conscious. Adjust inspired oxygen to achieve arterial oxygen saturation 94–98%. Mechanical ventilation should be continued if:
     • The patient's conscious level is reduced (Glasgow Coma Scale score 8 or below).
     • There is severe pulmonary oedema.
     • Arterial PO₂ is <9kPa or PCO₂ is >6.5kPa.
   • Insert a nasogastric tube to decompress the stomach and prevent splinting of the diaphragm by gastric distension in patients needing mechanical ventilation.
   • Check arterial blood gases and other blood tests (Table 6.2). Maintain ECG monitoring. Record a 12-lead ECG, and check the blood pressure. Arrange a chest X-ray. Perform focused echocardiography/ultrasonography.
   • Decide why the arrest occurred, and take action to deal with the underlying causes.
     • If there is evidence of ST elevation acute coronary syndrome, consider revascularization by thrombolysis or PCI (Table 25.2).
     • If cardiac arrest was due to primary brady-asystole (Chapter 44), arrange placement of a temporary pacing system (Chapter 119).
     • Correct derangements of plasma potassium, calcium and magnesium (Chapters 86, 87, 88).
     • Arrange CT brain if conscious level is reduced or a primary neurological cause for cardiac arrest is suspected.
   • Transfer the patient to the appropriate ward (CCU, HDU or ITU), with ECG monitoring during transfer. Prevent sepsis: IV lines inserted without sterile technique during the resuscitation should be changed.
   • Protect the brain:
     • Optimize cerebral perfusion. Correct arrhythmias that are causing haemodynamic instability (Figures 6.3 and 6.4; Chapters 39, 40, 41, 42, 43, 44). Post-resuscitation myocardial dysfunction (lasting 24–48h) may result in hypotension and low cardiac output, requiring inotropic vasopressor support (Chapter 2).
     • Control seizures (Chapter 16).
     • Control blood glucose (Chapters 81 and 82).
     • Treat hyperthermia by fanning, tepid sponging or paracetamol.
     • If there is coma, therapeutic hypothermia (32–36°C, for 24h) is indicated.