All About CPR: Cardiopulmonary Resuscitation

Podcast Transcript

For most of human history, when a person’s heart stopped, that was considered the end.

Then, through centuries of trial and error, strange experiments, and medical breakthroughs, doctors discovered that death was not always instantaneous.

A stopped heart could sometimes be restarted, and ordinary people could be taught how to help save a life.

The result was one of the most important emergency procedures ever developed.

Learn more about the history and science of CPR on this episode of Everything Everywhere Daily.

CPR, or cardiopulmonary resuscitation, is one of those medical techniques that feels timeless, but in its modern form, it is surprisingly recent. For most of human history, sudden cardiac arrest was essentially considered final.

People tried many methods to revive the apparently dead, but they were usually improvised, poorly understood, and often ineffective. Before we get into the history of CPR, we should understand what it is.

Modern CPR is a lifesaving procedure that is used when a person’s heart stops beating or when they stop breathing.

CPR involves giving a person chest compressions. These compressions involve pushing down on the center of a person’s chest to a depth of 2 inches. Depending on the number of people present and the individual’s training, these compressions can be given continuously or with two breaths every 30 compressions.

Even though CPR may break ribs and require chest pounding, it is an effective and immediate intervention that significantly increases survival odds.

CPR is important because it manually pumps the heart, allowing blood to continue to flow throughout the body. This helps prevent immediate damage to important organs, such as the brain, because they aren’t cut off from the blood supply.

The practice is typically performed using two techniques: conventional CPR and compression-only CPR.

Conventional CPR is usually performed by those formally trained in CPR, such as medical professionals. This version sees the rescuer completing chest compressions and mouth-to-mouth breathing at a 30:2 ratio. This means 30 compressions to two breaths.

Adding rescue breaths is important in CPR as it keeps air in the person’s lungs. This helps prevent oxygen desaturation, which can harm the body’s organs.

Compression-only CPR is usually used by the general public when they witness a cardiac emergency. In this situation, the person only performs chest compressions without breathing. During this method, chest compressions are continuous.

Compression-only CPR is recommended when the rescuer sees someone collapse outside of a hospital setting and there might be potential health risks from engaging in mouth-to-mouth resuscitation without a barrier. It is recommended to complete these compressions to the beat of “Staying Alive” by the Bee Gees.

The origins of CPR can be traced back to the Ancient Egyptians. While they did not practice CPR, Egyptians are our earliest examples of artificial resuscitation. Historians have found literary records of methods for reviving the “apparently dead.” One of these methods was to pound on the person’s heart and give them “the breath of life.”

Despite the Egyptian example, the first recorded instance of early CPR wouldn’t occur until 15th-century Persia. A physician named Burhan-ud-din Kermani used a method that involved expanding a person’s abdomen by moving their arms, followed by compressing the person’s chest.

Although some physicians were using Kermani’s resuscitation method, for the most part, it did not catch on. This is unfortunate because if CPR had become more widely adopted earlier, the field of early medicine would likely have progressed faster.

Instead, doctors commonly used the flagellation method. This involves a rescuer whipping the victim with items like stinging nettles, a wet cloth, or their hands. The goal was to shock the victim into responding.

Another common method to resuscitate victims around this time was to apply burning dry excrement, hot water, or embers to the body. The idea was that when a person passes, their body goes cold. By warming the body, the doctors had hoped to bring the person back to life by raising their body temperature.

In 1530, a Swiss Physician named Paracelsus invented something called the Bellow Method. It was well known by this point that when a person dies, they stop breathing. Paracelsus decided to see if putting air into a victim’s lungs would help resuscitate them.

To do this, Paracelsus placed a seal over the victim’s mouth, and a fireplace bellows into the victim’s nostrils. The tool was normally used to push a controlled stream of oxygen into a fireplace when compressed.

In this theory, the lungs were the fire, and the bellows blew a controlled stream of air into their bodies. Unfortunately, this method rarely worked as they literally used the same tool they used for their fireplace. This meant it caused more damage to the victims’ lungs by pushing ash and cinders into them.

The next major development would not occur until 1667. British scientist Robert Hooke theorized that a continuous supply of fresh air could keep a person’s lungs alive. He proved his findings by opening a dog’s thorax and pumping air in and out of its lungs. The dog lived, and that probably wouldn’t fly today.

This idea was further proven when a surgeon named William Tossach successfully resuscitated a coal miner by breathing air into his mouth. While this event did not occur until 1732, it was likely inspired by Hooke’s prior findings.

In 1740, the Académie des Sciences in Paris declared that mouth-to-mouth resuscitation was the best method when attempting to save drowning victims. Other medical hubs, such as London, England, continued to recommend the Bellows Method for resuscitation until 1829.

In the 1700s, two other methods of proto-CPR were developed.

The first method was inversion. This involved hanging the victim by their feet on a rope. Once hung, the rescuer would pull it up and down. The goal was to expel any water from the lungs while simultaneously applying pressure to the chest.

The other development was known as the barrel method. This one is much more self-explanatory. The victim was laid over a barrel by the rescuers and rolled back and forth. The goal of the method was to aid breathing by simulating lung mechanics through the addition and release of pressure.

In the 1800s, early CPR methods continued to be developed. The most notable of these were made in the 1850s and were known as the Hall and Silvester Methods.

Dr. Marshall Hall, a British physician, developed a technique that involved rolling a victim from their side onto their back while simultaneously applying manual pressure to the thorax.

Dr. Henry Silvester introduced a technique where the victim was positioned on their back with their arms stretched above their head. Rescuers would then cross the individual’s arms over their chest rhythmically. This alternating movement of raising and crossing the arms provided the steady, repetitive pressure needed to help the lungs expel air.

Critical changes began to occur in the 20th century. One of the most notable findings was made by a doctor named George Crile. In his research, he found that chest compressions could restore a person’s blood circulation. This was initially done through experiments on dogs, and was later repeated on humans.

With new medical breakthroughs, CPR practices took a drastic turn in the 1950s.

Two Doctors, James Elam and Peter Safar, showed that expired air from someone performing a resuscitation contained enough oxygen to keep another person alive.

This method was further expanded by Doctors William Kouwenhoven, Guy Knickerbocker, and James Jude at Johns Hopkins, who combined it with chest compressions. This was the birth of modern CPR.

Formal training in modern CPR by the American Heart Association began in 1960 and was officially endorsed by the organization in 1963.

The term ‘CPR’ was also coined in 1960. The name comes from the two systems the act aims to support: the cardiovascular and pulmonary (aka respiratory) systems.

By 1966, CPR was being taught to both professionals and the general public. However, early training was not very effective. In the first three months of training, fewer than half of the participants passed a performance evaluation. This, combined with the fact that death rates for people performing CPR outside of hospitals are high, led to a better training program being developed.

The American Red Cross collaborated with over 30 national organizations to develop national guidelines for teaching and practicing CPR. One of the most notable of these was recommending the practice of CPR on mannequins.

Fast forward to today, and CPR is performed with proven techniques and guidance. Up to 65% of all Americans have trained in the practice at least once in their lives.

In addition to CPR, defibrillators are commonly used in tandem. A defibrillator is a device that administers an electric shock to the victim to help restore the victim’s heart rate to its natural rhythm.

The first successful use of defibrillators was in 1947 by Claude Beck; however, it involved surgically opening the chest and delivering the shock directly to the heart.

The closed-chest version was proven successful in the 1950s by the previously mentioned Dr. William Kouwenhoven. He found that as long as circulation was continued, through a method like CPR, a defibrillator could be used to shock the heart from the outside of the body.

The original defibrillator was large and heavy, so methods were developed to miniaturize it. The goal was for the tool to be usable by anyone, not just experts.

Through careful development, defibrillators were made to be more practical. The modern versions are lighter and more mobile. They store enough energy to administer shocks to the heart to restore the heart rate.

Defibrillators, such as automated external defibrillators (AEDs), are incredibly effective at saving lives after a cardiac event. The device can be used on adults and children and is FDA-approved.

The likelihood of survival after administering an AED can be anywhere from 10% to 70% when used immediately. The odds of survival drop by 10% for each minute delayed in administering treatment during a cardiac emergency.

Because of their effectiveness, changes have been made to ensure that CPR and AED knowledge is everywhere.

Most US states require schools to teach CPR to both students and teachers. This helps drastically increase the number of people prepared to administer CPR when needed.

AEDs have also been implemented in many public places. This change was mainly done as part of an operation called Project Adam.

In 1999, a 17-year-old Wisconsin student named Adam Lemel tragically collapsed and passed away while playing basketball. This event led to the creation of a namesake project dedicated to his memory.

As sad as it is, Adam’s death was one in a series of deaths. In southern Wisconsin, multiple children had passed away from ventricular fibrillation, where the heart quivers rather than pumping blood.

A cardiac event can be treated with an AED, which helps restore the heart to its normal rhythm. If an AED had been present in Adam’s case, his likelihood of survival would have drastically increased.

Enacted on July 1, 2001, Project Adam was established to facilitate the nationwide implementation of AEDs within school systems.

The initiative focuses on enhancing awareness of sudden cardiac arrest in educational settings, while ensuring that these institutions possess both the necessary equipment and the training to respond effectively during emergencies.

I’m just a podcaster, and this is just a podcast, so nothing I’ve covered in this episode should be considered medical training. If you are interested in learning CPR, and everyone should be, the easiest way to do so is to sign up for a training course with your local Red Cross organization.

It is easy to enroll in online training sessions. Many courses include an online session and an in-person skills assessment. These sessions are fairly short, depending on the class and skill level, and are valid for two years.

CPR is one of the often overlooked medical advancements of the 20th century. Unlike other advancements, it doesn’t require a hospital or a doctor. It is something that can be performed by anyone.