7C: A Guide to the International ACLS Algorithms

Summary/Overview

The ILCOR algorithm presents the actions to take and decisions to face for all people who appear to be in cardiac arrest–unconscious, unresponsive, without signs of life. The victim is not breathing normally, and no rescuer can feel a carotid pulse within 10 to 15 seconds. Since 1992 the resuscitation community has examined and reconfirmed the wisdom of most recommendations formulated by international groups through the 1990s. Sophisticated clinical trials provided high-level evidence on which

Fig. 1: ILCOR Universal/International ACLS Algorithm

Fig. 1, the ILCOR Universal/International ACLS Algorithm, and Fig. 2, the Comprehensive ECC Algorithm, are groundbreaking efforts to unify and simplify the essential information of adult ACLS. They demonstrate the integration of the steps of BLS, early defibrillation, and ACLS.

The ILCOR algorithm (Fig. 1) shows how simply the overall approach can be presented, with minimum elaboration of separate steps. The Comprehensive ECC Algorithm (Fig. 2) provides more details, particularly to support the

Fig. 2: Comprehensive ECC Algorithm

Both the ILCOR Universal Algorithm and the Comprehensive ECC Algorithm (Fig. 2) convey the concept that all cardiac arrest victims are in 1 of 2 ‘rhythms’: VF/VT rhythms and non-VF rhythms.

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  Non-VF comprises asystole and PEA, which are treated alike.

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  Therefore, there is no critical need to separate the subjects into VF, pulseless VT, PEA, or asystole.

All cardiac arrest victims receive the same 4 treatments

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  CPR

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  Tracheal intubation

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  Vasoconstrictors

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  Antiarrhythmics

The only distinguishing treatment for

Newly Recommended Agent:Vasopressin for VF/VT

People knowledgeable about the ACLS recommendations during the 1990s will immediately notice that the recommendations for the requisite vasoconstrictor, epinephrine, have changed. The first 3 algorithms–the ILCOR Universal Algorithm, the Comprehensive ECC Algorithm, and Ventricular Fibrillation–each contain the same recommendation for vasopressin as an adrenergic agent equivalent to epinephrine for VF/VT cardiac arrest.

This is one of the most important new recommendations in the International

Primary and Secondary ABCD Surveys

In some locations, particularly in courses for ACLS providers, the learners are taught a memory aid called the Primary and Secondary ABCD Surveys. These 8 steps apply to all cardiovascular-cardiopulmonary emergencies. Course directors crafted the ABCD surveys to help ACLS providers remember the specific action steps. By memorizing the 2 surveys, ACLS students learn specific actions in a specific sequence. The surveys use the familiar mnemonic of the first 4 letters of the alphabet, and they

Fig. 3: VF/Pulseless VT

Fig. 3 covers the treatment of VF/pulseless VT in more depth than Fig. 1, Fig. 2. Fig. 3 was created as a teaching aid to convey specific details about the Primary and Secondary ABCD Surveys. The treatments outlined in Fig. 1, Fig. 2, Fig. 3 are identical: CPR, defibrillation if VF/VT, advanced airway control, intravenous access, rhythm-appropriate medications.

Always Assume VF (Figs. 1–3)

Note that Fig. 1, the ILCOR Universal ACLS Algorithm, Fig. 2, the ECC Comprehensive Algorithm, and Fig. 3, the Ventricular Fibrillation/Pulseless VT Algorithm, state this precept unequivocally: rescuers must assume that all adult sudden cardiac arrests are caused by VF/pulseless VT. All training efforts therefore place a strong emphasis on immediate recognition and treatment of VF/pulseless VT. Proper treatment with early defibrillatory shocks allows VF/pulseless VT to provide the majority of

Energy Levels for Shock and Defibrillation Waveforms

The appearance of biphasic waveform defibrillators has generated great enthusiasm in the resuscitation community. Reaching EMS organizations in 1996, the first biphasic defibrillator approved for market shocked at only 1 energy level, approximately 170 J. Competitive market forces stirred up considerable controversy over the efficacy of biphasic waveform shocks in general and nonescalating energy levels in particular. This unseemly chapter in the history of medical device manufacturers has been

CPR, VF, and Defibrillation

After 3 unsuccessful attempts to achieve defibrillation, the first 3 algorithms instruct rescuers to provide approximately 1 minute of CPR. This produces some reoxygenation of the blood and some circulation of this blood to the heart and brain. The precise effect of this minute of CPR on refractory VF is unclear.

Stimulated by the 1999 publication of a retrospective analysis of out-of-hospital cardiac arrest data from the Seattle, Washington, EMS system, the Evidence Evaluation Conference

Diminishing Roles for Drugs in VF Arrest

The ILCOR Universal Algorithm, the Comprehensive ECC Algorithm, and similar comments in Fig. 3 relegate adrenergic agents, antiarrhythmic agents, and buffer therapy to secondary roles for both VF and non-VF patients. This secondary role applies to time-honored agents such as epinephrine, lidocaine, procainamide, and buffer agents and to newly available agents such as amiodarone. Meticulous, systematic review reveals that relevant, valid, and credible evidence to confirm a benefit due to these

New Class of Recommendation for Epinephrine and Lidocaine: Indeterminate

An immense amount of animal research and lower-level human research exists on epinephrine in cardiac arrest. These projects are remarkable in the homogeneity of results–the findings are consistently and invariably positive. But almost no valid, consistent, and relevant human evidence exists to support epinephrine over placebo in human cardiac arrest. Clinical researchers have not conducted prospective, placebo-controlled, clinical trials in humans on this topic. Consequently, the international,

Fig. 4: Pulseless Electrical Activity

The absence of a detectable pulse and the presence of some type of electrical activity other than VT or VF defines this group of arrhythmias. When electrical activity is organized and no pulse is detectable, clinicians traditionally have used the term electromechanical dissociation (EMD). This term, however, is too specific and narrow. Strictly speaking, EMD means that organized electrical depolarization occurs throughout the myocardium, but no synchronous shortening of the myocardial fiber

Fig. 5: Asystole: The Silent Heart Algorithm

Patients in cardiac arrest discovered on the defibrillator's monitor screen to be in asystole have a dismal rate of survival–usually as low as 1 or 2 people out of 100 cardiac arrests. During a resuscitation attempt, brief periods of an organized complex may appear on the monitor screen, but spontaneous circulation rarely emerges. As with PEA, the only hope for resuscitation of a person in asystole is to identify and treat a reversible cause.

Fig. 5, the Asystole Algorithm, outlines an approach

When to Stop?

Is it possible to state a specific time interval beyond which rescuers have never resuscitated patients? Does every resuscitation attempt have to continue for that length of time to guarantee that every salvageable person will be identified and saved? As outlined in the algorithm notes, the resuscitation team must make a conscientious and competent effort to give patients ‘a trial of CPR and ACLS,’ provided that the person had not expressed a decision to forego resuscitative efforts. The final