High-quality cardiopulmonary resuscitation is critical to the management of cardiac arrest and consists primarily of basic life support and advanced life support. Successful cardiopulmonary resuscitation requires a set of coordinated measures with closely linked components, i.e., forming a 5-loop chain of survival: 1) immediate recognition of sudden cardiac arrest (SCA) and activation of the EMS system; 2) early CPR with emphasis on external cardiac compressions; 3) rapid defibrillation; 4) effective advanced life support; and 5) comprehensive post-SCA management.
I. Adult Basic Life Support (BLS)
Immediate recognition and call to emergency system
Pulse check Lay personnel can start chest compressions directly without checking the pulse. Medical personnel check pulse for less than 10 seconds.
Early CPR
The most important cause of SCA is fatal arrhythmia. Circulatory support is more important than respiratory support, so chest compressions are performed first, followed by open airway and artificial respiration.
Airway management Use head-up chin lift for patients without head or neck trauma; for suspected cervical spine injury, use double chin-up without stretching the head.
Artificial respiration Mouth-to-mouth or balloon mask artificial respiration with the following requirements: greater than 1 second per ventilation; sufficient tidal volume to allow thoracic elevation; 30:2 compression-ventilation ratio; and careful release of the patient’s nose between breaths.
Defibrillator/AED for early defibrillation and immediate chest compressions.
II. Advanced cardiovascular life support (ACLS)
ACLS refers to resuscitation measures implemented by professionals applying equipment and drugs, and good BLS is the basis of ACLS.
Airway management and ventilation Includes balloon-mask, oropharyngeal ventilation tube, nasopharyngeal ventilation tube and tracheal intubation. Unconscious patients should not be ventilated by balloon-mask; 8-10 ventilations per minute after tracheal intubation and CPR for adults is 500-600 ml of tidal volume (6-7 ml/kg).
Advanced management of SCA 1) Ventricular fibrillation/pulseless ventricular tachycardia: defibrillator gives one electric shock with energy of 200 J for biphasic wave and 360 J for monophasic wave. when arrhythmia persists after 2 minutes of CPR immediately after electric shock, epinephrine or vasopressin is given. When vasoactive drugs do not reflect, give amiodarone or lidocaine. 2) Pulseless electrical activity/ventricular arrest: immediately perform CPR for 2 minutes, then give CPR for 2 minutes, then check the rhythm and observe for any changes, if there is no change continue with the above resuscitation measures. Epinephrine or vasopressin may be given, atropine is not recommended.
Common drugs for SCA
Adrenaline
Agonizes alpha-adrenergic receptors and increases coronary and cerebral perfusion pressure. 1 mg epinephrine injected every 3-5 minutes, incremental method does not improve patient survival, and other vasoactive drugs (e.g., isoprenaline, phenylephrine) do not improve survival compared to epinephrine.
There is no difference in prognosis between vasopressin and epinephrine. A single dose of vasopressin 40u can be substituted for epinephrine.
Amiodarone and lidocaine Amiodarone can be used for ventricular fibrillation or pulseless ventricular tachycardia that does not respond to defibrillation and vasoactive drugs. An initial 300 mg (or 5 mg/kg) injection followed by 1 dose of electrical defibrillation, followed by 150 mg given again at 10-15 minutes if failure to convert, and repeated 6-8 times if needed. Subsequent 6 hours 1mg/min, 18 hours 0,5mg/min maintenance, 24 hours total not to exceed 2,0-2,2g. without amiodarone, lidocaine is available, initial dose 1-1,5mg/kg IV, repeatable every 5-10 minutes 0,5-0,75mg/kg, maximum amount 3mg/kg.
Sodium bicarbonate Not recommended, use sodium bicarbonate only if metabolic acidosis is the etiology.
Thrombolytic therapy Routinely not recommended due to increased risk of intracranial hemorrhage. However, empirical thrombolytic therapy may be considered when pulmonary embolism is suspected or established.
III. Comprehensive management after SCA
After restoration of autonomic circulation, systematic and comprehensive management can improve the quality of life of surviving patients. comprehensive management after SCA is important to reduce early death due to hemodynamic instability, and late multi-organ failure and brain injury. This includes: subcritical treatment, optimization of hemodynamics and gas exchange, percutaneous coronary intervention (PCI) when indicated, glycemic control, neurological diagnosis, management and prediction.
Summary
Restoration to pre-SCA quality of life and functional status is the highest goal of the entire CPR process. High-quality CPR is the cornerstone for an optimal prognosis. Therefore, emphasis should be placed on performing high-quality CPR, i.e., adequate frequency and depth of compressions, allowing rebound of the thoracic component, reducing compression interruption time and avoiding hyperinflation. Resuscitators should choose the appropriate CPR method and sequence to treat different patients in different settings. Resuscitators during resuscitation should apply common components individually to the specific treatment of each patient to improve the success rate of CPR.