EVERY FIVE YEARS, THE INTERNATIONAL LIAISON COMMITTEE ON RESUSCITATION (ILCOR) releases new guidelines regarding CPR, BLS, ACLS, and PALS. While some know this fact, few realize that the history behind international standardization of such guidelines has been relatively short. In fact, the ILCOR only first introduced pediatric courses, including pediatric basic life support (BLS) and acute life support (PALS) in 1988.
Since the development of cardiopulmonary resuscitation (CPR) in 1960, the ILCOR has hosted a National Conference on CPR and Emergency Cardiovascular Care (ECC) every five years, with the first conference occurring without planning by National Research Council of the National Academy of Sciences.
The guidelines of today are in stark contrast to the guidelines issues decades ago, but many aspects have remained the same. Meanwhile, the technologies used to increase life expectancy following cardiac arrest or foreign-body airway obstruction (FBAO) have evolved in tandem and grown to reflect key concerns among the public and populations at greatest risk such events.
Rather than starting at the beginning, it is best to work backward through the timeline of guideline changes.
Historical ILCOR Guideline Updates 1995-2020
2015 – 2020 ILCOR Updates
The new guidelines issued in 2015 consider how changing technologies and communication measures impact standards of intervention during a life-threatening event.
Chest Compressions Are a Greater Focus
One of the most significant changes to the guidelines involves chest compressions. The ILCOR opted to increase the focus on compression-only, otherwise known as hands-only, CPR for lay rescuers, which are people without the guidance of professionals. The guidelines call for any available lay rescuers to provide hands-only CPR until appropriate professionals or trained individuals can begin true CPR.
In this case, trained rescuers that arrive should provide two rescue breaths every 30 compressions. Of course, if the first person grows fatigued, individuals should switch positions, and the trained individual should provide direction to the lay rescuer. However, this is only a stepping stone until EMS personnel arrive.
One of the most significant changes to the guidelines involves chest compressions.
Additional changes to the guidelines for chest compressions include the increasing rate of compressions to between 100 and 120 per minute. Furthermore, the compression depth must be at least two inches. However, rescuers should avoid depths beyond 2.4 inches due to the increased risk of injury. Rescuers must also avoid leaning on the chest during recoil to ensure the heart has an opportunity to refill with blood from the lungs.
Creation of Community Lay Rescuer AED Programs and Recommendations for Naloxone Administration
The guidelines also encourage the community to increase the number of public access defibrillator (PAD) programs to treat cases of ventricular fibrillation (VF) resulting in the loss of consciousness. Similarly, the ILCOR recommends bystanders be allowed to administer injections of naloxone for those with suspected opioid overdose. Most often, this recommendation applies to areas with high overdose rates and environments that help people suffering from addiction.
Rescuers May Use Social Media to Contact EMS
A final change involves how people get help. With more people becoming involved with social media and connectivity that may not necessarily have routine access to phone lines, the ILCOR recommends allowing rescuers to be summoned via social media. In other words, people may contact EMS through social media apps when needed.
Algorithm Standards for 2015
In 2000, the algorithm standards evolved to consider possible opioid overdose. However, compression-to-breath rates remained steady at 30:2 for both lay rescuers and professional rescuers. In addition, both lay rescuers and professional rescuers should activate the EMS via a mobile device and obtain an AED. This may involve getting the AED by oneself or sending another person to obtain it.
Additionally, the new algorithm advises rescuers to perform one rescue breath every five to six seconds, about 10 to 12 breaths per minute. This allows rescuers to perform slow, steady breaths, allowing for adequate chest rise.
In keeping with other previous algorithm updates, CPR should be continued during the 2-minute cycle until professional rescuers arrive, using the AED when the device advises a shock.
During ALS, professional rescuers were advised to determine the rhythm’s shockability. For asystole or pulseless rhythms, professional rescuers should perform CPR in 2-minute intervals, giving up to 1 mg of epinephrine or 40 U of vasopressin every three to five minutes.
When the rhythm becomes shockable, give a manual biphasic shock of 120-200 J or a monophasic shock of 360 J. Perform CPR for two minutes, and repeat the process, adding the dosing of epinephrine or vasopressin as described in the algorithm for asystole.
For PALS, the same algorithm applies. However, the use of epinephrine may be withheld at the discretion of the team in accordance with standard best practices for better treatment outcomes.
2010 – 2015 ILCOR Updates
In 2010, the ILCOR added the fifth link to the adult chain of survival, post-cardiac arrest care, but other notable changes were enacted as well.
Immediately Contact EMS and Initiation of CPR
This changed the previous direction to provide care first for adults before contacting EMS. However, the recommendations also emphasize the need for early CPR, even if it is hands-only, and appropriate, high-quality chest compressions. Within the addition of the fifth link, the guidelines advise all lay and trained rescuers used automated external defibrillators (AEDs) when available. Meanwhile, additional care may be necessary following CPR or other interventions to ensure optimal return to health and avoidance of future cardiovascular issues.
Change From ABC to CAB
2010 is also the year in which the mnemonic for remembering the steps to CPR changed to C-A-B. C-A-B stands for compressions, airway, and breaths. Rescuers that do not see any visible signs of circulation, or if they are able to discern the absence of pulse via the carotid artery within 10 seconds, should begin compressions immediately. Compressions were also emphasized to occur at a rate of 30 to two rescue breaths, the first significant change in ventilation rate since 2000.
Algorithm Standards for 2010
2010 was the first year during which simplified BLS algorithms were developed, which would become known as hands-only CPR. The algorithm advised lay rescuers to verify scene safety and activate the EMS. If an AED is available, the rescuer should get and check the rhythm. If a shock is indicated, give the shock, and begin CPR if the person remains unresponsive and without a pulse.
If a shock is not advised, continue with CPR at a rate of 30 compressions to two rescue breaths. The algorithm also advised lay rescuers to continue CPR at intervals of five cycles to one check with an AED. The algorithm also changed steps to C-A-B from A-B-C as explained above. Essentially, if the person is unresponsive and without a pulse, begin compressions immediately at a rate of 100 per minute. After completing 30 compressions, open the airway and perform two rescue breaths.
Continue for five total cycles or approximately two minutes. Recheck the person’s rhythm with an AED. Continue this process using an AED. If the device advises a shock, deliver the shock and await instructions. If the patient has a pulse and is breathing, place him in the recovery position on his left side until EMS arrives. If the patient has a pulse and is not breathing, continue providing rescue breaths every five to six seconds. Remember to recheck the rhythm with the AED every two minutes. If the rhythm changes or if signs of circulation disappear, resume chest compressions in the algorithm-defined ratio of 30:2.
For ALS, the algorithm also advises professional rescuers to use a medical-grade defibrillator up to three times to reverse VF. However, professional rescuers should only perform CPR for 1-minute aftershocks before moving to other steps in the algorithm, including checking electrode placement, securing the airway, obtaining an IV access and giving epinephrine or vasopressin as defined in the 2005 standards. If a non-VF rhythm is present, do not shock, and continue CPR for three minutes before moving to the other steps. However, only epinephrine should be given to patients suffering from a non-VF rhythm.
2005-2010 ILCOR Updates
During this set of guidelines, the ILCOR changed key recommendations on shock frequency with an AED and algorithms, much like standard flow charts, for how rescuers should progress through CPR steps in these ways.
Compression Rate Must Exceed 100 Per Minute.
This was a departure from previous standards. In 2005, the ILCOR recommended all compression rates be changed to a 100 per minute rate regardless of a person’s age. This would help to maximize the circulation and effectivity of CPR. But, these compression guidelines did not change previous standards for compression depth.
Begin Compressions First Before Shock
With the emergence of more AEDs, the 2005 guidelines turned previous assumptions to provide immediate shock upside-down. With these guidelines, rescuers were advised to begin chest compressions prior to using an AED if the AED was not within reach upon finding an unresponsive individual. Furthermore, rescuers were to resume chest compressions immediately after an initial shock, eliminating the standard for a second, immediate shock.
Wait on Checking for a Pulse, and Hold Medications During PALS
Rescuers were also advised to avoid checking for a pulse until five cycles of CPR and breaths had been completed. This reduced delay in resuming compressions, which could increase mortality rates. Among cases of pediatric cardiac arrest or trauma, the ILCOR placed emphasis on using compressions, ventilation, and use of an AED before using epinephrine and other heart-affecting drugs. In addition, automated ventilators were now listed as contraindicated for adults except for those with an advanced airway, such as intubation or those with a tracheostomy.
Lastly, devices were no longer recommended for chest compressions and abdominal decompression to maximize chest recoil during CPR.
Algorithm Standards for 2005
If a person is unresponsive, the 2005 guidelines continued using the 1995 algorithm defining the A-B-C-Ds of CPR. Compressions should stay within the 30 compressions to two breaths ratio identified by earlier guidelines. However, the 2005 algorithm first introduced the rhythm assessment into BLS.
If the person was in VF or pulseless ventricular tachycardia (VT), give one shock. If the person was in a non-shockable rhythm, resume CPR performing five cycles of compressions and rescue breaths until ALS providers arrive. The AED also plays into the algorithm providing audible directions for lay rescuers, depending on the device’s capabilities. However, the algorithm also went through additional changes for use in ALS in both adult and pediatric patients.
ALS algorithm changes in 2005 advised to begin CPR and give oxygen if available. If the rhythm is unshockable, epinephrine and vasopressin may be administered by professional rescuers between every five cycles of CPR. However, professional rescuers have the option of administering 1 mg of atropine every three to five minutes, up to three doses, if the rhythm remained in asystole. After another five cycles, the rhythm sho0uld be rechecked. If no pulse is indicated, the algorithm returns to its starting position.
If the starting position of ALS is with a shockable rhythm, the algorithm advises professional rescuers to continue CPR while the defibrillator charges. A manual biphasic shock may be administered if the device is capable. Alternatively, a monophasic shock of up to 360 J may be administered. If an AED is the only device being used, the shock strength remains stable and controlled by the device.
Professional rescuers may also consider antiarrhythmic medications to give during CPR if the person remains in cardiac arrest. This may include a single 300 mg dose of amiodarone, followed by one additional dose of 150 mg. Or, one to 1.5 mg/kg dose of lidocaine, up to a maximum dose of 3 mg/kg over the event. Upon completing five cycles of CPR, return to the starting point to assess the rhythm’s shockability.
2000 – 2005 ILCOR Updates
The dawn of a new millennium was a time of significant changes to CPR standards.
Stack Electrical Shocks of up to Three Sets
When using manual defibrillators or AEDs, rescuers were advised to perform a series of up to three shocks that could count as a single shock prior to starting chest compressions. At the time, research indicated this would be more successful than beginning chest compressions upon finding an unresponsive individual. However, this guideline would quickly be overturned with the next update to the guidelines.
Call for Help First
Previous guidelines advised rescuers to contact EMS and monitor unresponsive individuals without proper training in CPR or BLS. This set of changes advised rescuers to perform CPR for up to one minute prior to contacting EMS. However, when treating children, rescuers were advised to first determine if there was an FBAO.
Perform Rescue Breathing, and Change the Volume When Using a Bag-Mask to Reflect the Presence of Absence of Oxygen
This was one of the first major changes to impact health professionals and emergency responders. With this change, rescuers were advised to perform rescue breaths with volumes of approximately 10 mL/kg over two seconds without oxygen. If oxygen was connected to the bag-mask, the volume could be reduced to between six and seven mL/kg over one to two seconds.
Pulse Checks Replaced by Looking for Signs of Circulation Among Health Professionals Too.
Due to studies indicating both lay rescuers and health professionals experience trouble recognizing the presence of the absence of a carotid pulse, the ILCOR recommended that rescuers avoid checking for a pulse over extended times. In other words, if a pulse could not be discerned within five seconds, rescuers should look for signs of circulation. If signs indicated poor or stopped circulation, due to cardiac arrests, such as discoloration of the face, lips, and extremities, rescuers should begin CPR.
Compression Rate Becomes 100 Per Minute for Adults.
With increasing evidence to support faster compressions for better care outcomes, the ILCOR recommended the rate of chest compressions be set at 100 per minute for adults. Among younger children, the rate should be increased by increments of 20 for children between the ages of 1 and 8. Meanwhile, infants should receive compressions at a rate of between 120 and 140 per minute.
Compression depths were also advised to be between 1.5 and two inches in depth. Furthermore, the ILCOR recommended the use of mnemonic devices, such as “1 and 2 and 3 and 4 and…” to give the chest an appropriate time to recoil between individual compressions.
Ventilation Ratios Change
The ventilation ratio of compressions to rescue breaths, termed ventilation during this time, was set at 15 to two. In other words, rescuers should provide two rescue breaths for every 15 compressions. Given previous rates were between 80 and 100 compressions per minute, this meant that a person would receive approximately 10 to 12 breaths per minute.
Similarly, rescue cycles were in sets of four, and the ILCOR began to recommend the use of mouth barriers when appropriate to prevent transmission of pathogens during CPR and BLS. However, the frequency that which the cardiac arrest of FABO occurs in private homes and outside of the hospital setting implied that infection risk was minimal.
Guidelines Place a Focus on FBAO.
Rescuers were advised to consider possible FBAO among unresponsive and responsive individuals. The ILCOR was started as an awareness campaign to make the public aware of the universal sign of choking, putting one’s hands around his throat. In adults and children above the age of eight should receive abdominal thrusts if a person is unable to speak when choking is suspected.
Unresponsive individuals that appear to be choking were to receive abdominal thrusts or chest compressions. However, the ILCOR developed a clear preference for straddling the person’s thighs and providing a swift thrust upward below the xiphoid process. Furthermore, rescuers were expected to use a finger sweep and tongue-jaw lift or thrust for unresponsive, unconscious individuals.
However, rescuers that did not see a visible foreign body in the throat when choking were suspected were advised to continue chest compressions and not complete a finger sweep with every set of compressions. Ventilations were also recommended in tandem with the standard of 15 to two breaths.
Algorithm Standards for 2000
The algorithms used for adult BLS and ALS in 2000 did not change dramatically from 1995. However, the algorithm placed greater emphasis on using an AED and contacting EMS earlier upon finding an unresponsive person.
Lay rescuers should check to make sure a person is not choking and open the airway. Next, rescuers should check for breathing, including look for chest rise and fall, listening for the sounds of breathing and feeling for exhaling air when closest to the person’s face.
Like past algorithms, this algorithm advised lay rescuers to use an AED if possible. If a shock is advised, give the shock and resume CPR at a rate of 15 compressions to two breaths. However, each breath should be performed over one to two seconds, allowing for proper chest rise and fall.
Lay rescuers were also advised to check for signs of possible stroke by the algorithm. This included asking a person to smile, raise the arms, recall the year or other common knowledge immediately, if responsive. If a person is unable to perform these tasks, it may indicate a stroke or other ischemic attack, and the person should be transported to the emergency center immediately. Therefore, the 2000 algorithm advised lay rescuers to check for these signs and activate EMS if a person cannot perform such tasks.
If unresponsive, the first step in the algorithm is to check for a pulse. If there is neither a pulse nor breathing, he or she should begin CPR. In addition, this algorithm advised lay rescuers to not worry about checking the pulse. Instead, unresponsive victims should be given CPR if the person lacks signs of circulation, such as poor color or not breathing.
Chest compressions were also to be given at a rate of 100 compressions per minute. While the algorithm recommends at least 80 total compressions, the speed of compression delivery between rescue breaths should be 100 per minute. This enables adequate blood flow.
Unlike the previous algorithm, the 2000 update advised rescuers to perform four cycles of CPR before rechecking the rhythm’s shockability with an AED.
Upon the arrival of EMS, professional rescuers should immediately begin ALS by attaching the defibrillator and assessing the rhythm. If the rhythm is unshockable, continue CPR. However, professional rescuers should establish an advanced airway, intubate the person, and continue CPR via bag-mask and compressions. However, there should be a pause of two seconds between resuming compressions and performing breaths through the bag-mask to allow for securing the mask’s cuff to the patient’s face.
If the rhythm remains shockable, professional rescuers may administer epinephrine or vasopressin. However, for patients in non-shockable rhythms, rescuers have the option of administering epinephrine only, antiarrhythmics or other medications at the discretion of a physician. Upon completing medication administration, continue CPR for three minutes for non-shockable rhythms. Those in shockable rhythms should receive the shock, and if the person still lacks a pulse, perform CPR over one minute while giving appropriate medications.
1995 – 2000 ILCOR Updates
1995 might feel like a world away, but it was a time of advancing medicine and growth in understanding of how to address emergency situations. Furthermore, the rise of AEDs and defibrillators warranted additional changes to response algorithms in determining an appropriate course of action.
The ABCs of CPR Became ABCD
In 1995, the ILCOR recommended the addition of a “D” to the standard ABCs of CPR for defibrillation. This was among the first significant changes since the inception of pediatric BLS and PALS.
Recommendations for Contacting EMS Changed
Prior recommendations were to phone EMS for all cases involving unresponsive children. However, the 1995 guidelines noted this practice increased mortality rates, so it changed to phone fast while still providing care.
Compression Rate Should Be Between 80 and 100 Per Minute
For adults and children, chest compressions should range in pace from 80 to 100 per minute. Furthermore, the guidelines emphasized the need to check for a pulse via the carotid artery prior to beginning compressions. This was overturned in later guidelines that indicated checking for circulation was higher-priority than spending extra time looking for a pulse.
Active Compression-Decompression Resuscitation
Rescuers were advised to perform a decompression action between chest compressions by actively pulling downward on the abdomen of the person in need to ensure the chest recoils. This practice has become obsolete since the 1990s though.
AEDs were first recommended by the ILCOR for determining if VF was occurring in 1995. Furthermore, the ILCOR only advised basic CPR for all individuals that lacked an advanced airway or intubated. Furthermore, lay rescuers were not advised to check for a pulse within this set of guidelines, just signs of circulation, such as coloration of the skin and capillary refill. This guideline would eventually make its way into the guidelines for health professionals as well.
Algorithm Standards in 1995
The algorithm for performing CPR and BLS in 1995 began with the same traditional standard of verifying the scene for safety. If the victim or person was unresponsive, the algorithm advised lay rescuers to shout for help or use a mobile device. Since mobile technology was still relatively new, most lay rescuers would have simply shouted for help and for someone to contact EMS.
The algorithm also created the A-B-C-D standard, which advised lay rescuers to shout for help and begin with checking the airway. The A-B-C Standard, airway, breaths and compressions, define this part of the algorithm. After opening the airway, rescuers should give two to five breaths and begin chest compressions. If an AED is available, place the pads on the unresponsive, pulseless person. Upon completing three cycles of CPR or as soon as the AED arrives.
If a person was not breathing or only gasping, rescuers were advised to check for a pulse over a maximum time of 10 seconds. If the person returns to normal breathing and has a pulse, follow-up care should be performed by contacting EMS.
If the person has a pulse and is not breathing, the person should provide rescue breaths every three to five seconds. If the pulse drops below 60 beats per minute, or if the signs of circulation fade, rescuers should begin compressions.
If EMS has not been contacted yet, rescuers should activate the system after two minutes of performing CPR.
During CPR, rescuers should perform compressions and rescue breaths at a rate of 15:2.
If the AED identifies a shockable rhythm, give one shock. Resume CPR for two minutes, and recheck rhythm with the AED. If the rhythm is unshockable, resume CPR until professional rescuers arrive.
During professional ALS, rescuers will follow a similar algorithm. However, the rate of compressions to breaths is increased to 30:2. Depending on the shockable versus non-shockable rhythm identified by the AED/ professional defibrillator, CPR will continue for two minutes in the same manner as defined for lay rescuers.
Upon regaining circulation and pulse, professional rescuers should complete a 12-lead EK, maintain high oxygenation of 94-98% SpO2, maintain appropriate body temperature and treat the causes of cardiac arrest, such as trauma or illness.
A Quick Thought
The recommendations for CPR, BLS, PALS, and ACLS have changed with history. By knowing where these standards stood over the last 23 years, we can learn and expand our knowledge base going forward. The next set of guidelines will be out in 2020, and we will make sure you have the latest knowledge to serve your communities to the fullest extent possible then and in the interim.