The most recent version of the AHA basic life support (BLS) algorithm appears in the following table or can be accessed here. Important practices described in the CPR-ECC Guidelines are summarized below.
●Chest compressions – Chest compressions are the most important element of cardiopulmonary resuscitation (CPR). Interruptions in chest compressions during CPR, no matter how brief, result in unacceptable declines in coronary and cerebral perfusion pressure. The CPR mantra is: “push hard and push fast (but not too hard nor too fast) on the center of the chest.” The critical performance standards for CPR include:
•Maintain the rate of chest compression at 100 to 120 compressions per minute
•Compress the chest at least 5 cm (2 inches) but no more than 6 cm (2.5 inches) with each down-stroke
•Allow the chest to recoil completely between each down-stroke
•Minimize the frequency and duration of any interruptions
●Compression-only CPR (CO-CPR) – The appropriate use of CO-CPR is as follows:
•When multiple trained personnel are present, the simultaneous performance of continuous excellent chest compressions and proper ventilation with a 30:2 compression to ventilation ratio is recommended for the management of sudden cardiac arrest (SCA).
•If a sole lay rescuer is present or multiple lay rescuers are reluctant to perform mouth-to-mouth ventilation, the CPR-ECC Guidelines encourage the performance of CPR using chest compressions alone. Lay rescuers should not interrupt chest compressions to palpate for pulses and should continue CPR until an automated external defibrillator (AED) is ready to defibrillate, EMS personnel assume care, or the patient wakes up. Note that CO-CPR is not recommended for children or arrest of noncardiac origin (eg, near drowning).
●Ventilations – As pulselessness persists in patients with sudden cardiac arrest (SCA), the importance of performing ventilations increases. The CPR-ECC Guidelines suggest a compression to ventilation ratio of 30:2. Each ventilation should be delivered over no more than one second while compressions are withheld during this time. Ventilations must not be delivered with excessive force; only enough tidal volume to confirm chest rise should be given. Avoid excessive ventilation from high rates or increased volumes, which can compromise cardiac output. The effective use of a bag-mask-ventilator is a learned procedure, is best done with two people, and requires practice to maintain proficiency.
●Compression-ventilation ratio – In adults, the CPR-ECC Guidelines recommend that CPR be performed at a ratio of 30 excellent compressions to two ventilations until an advanced airway has been placed. There is mounting evidence that early tracheal intubation results in worse outcomes; however, following placement of an advanced airway, excellent compressions are performed continuously, and asynchronous ventilations are delivered approximately 6 to 8 times per minute.
●Defibrillation – Early defibrillation is critical to the survival of patients with ventricular fibrillation. The CPR-ECC Guidelines recommend a single defibrillation in all shocking sequences. In adults, we suggest defibrillation using the highest available energy (generally 200 J with a biphasic defibrillator and 360 J with a monophasic defibrillator) (Grade 2C). Compressions should not be stopped until the defibrillator has been fully charged.
●Phases of resuscitation – There are three phases of sudden cardiac arrest. The electrical phase comprises the first 4 to 5 minutes and requires immediate defibrillation. The hemodynamic phase spans approximately minutes 4 to 10 following SCA. Patients in the hemodynamic phase benefit from excellent chest compressions to generate adequate cerebral and coronary perfusion and immediate defibrillation. The metabolic phase occurs following approximately 10 minutes of pulselessness; few patients who reach this phase survive.
●Instruction – All health care providers should receive standardized training in CPR and be familiar with the operation of AEDs.
