What Really Happens Inside the Body During CPR? Curious About the Chemistry Behind It

Understanding the Chemistry of CPR

I am curious to know about the background or chemistry that happens during CPR. What happens inside the body when we blow air from the mouth and press the heart?

Regards,
Hansa Vyas

Dear Hansa,

The air we breathe in travels to our lungs where oxygen is picked up by our blood and then pumped by the heart to our tissue and organs. When a person experiences cardiac arrest - whether due to heart failure in adults and the elderly or an injury such as near drowning, electrocution or severe trauma in a child - the heart goes from a normal beat to an arrhythmic pattern called ventricular fibrillation, and eventually ceases to beat altogether.

This prevents oxygen from circulating throughout the body, rapidly killing cells and tissue. In essence, Cardio (heart) Pulmonary (lung) Resuscitation (revive, revitalize) serves as an artificial heartbeat and an artificial respirator.

CPR may not save the victim even when performed properly, but if started within 4 minutes of cardiac arrest and defibrillation is provided within 10 minutes, a person has a 40% chance of survival.



Invented in 1960, CPR is a simple but effective procedure that allows almost anyone to sustain life in the first critical minutes of cardiac arrest. CPR provides oxygenated blood to the brain and the heart long enough to keep vital organs alive until emergency equipment arrives.

To make learning CPR easier, a system was devised that makes remembering it as simple as A-B-C:

Airway

Breathing

Circulation

WHEN TO DIAL 1-0-8

It is critical to remember that dialing 1-0-8 may be the most important step you can take to save a life.

If someone besides you is present, they should dial 1-0-8 immediately. If you're alone with the victim, try to call for help prior to starting CPR on an adult and after a minute on a child. Before we learn what to do in an emergency, we must first emphasize what NOT to do:

DO NOT leave the victim alone.

DO NOT try make the victim drink water.

DO NOT throw water on the victim's face.

DO NOT prompt the victim into a sitting position.

DO NOT try to revive the victim by slapping his face.



Provide 1-0-8 operator with:

Location & phone number

Type of emergency

Victim's condition and age

Always remember to exercise solid common sense. When faced with an emergency situation we may act impulsively and place ourselves in harm's way. Although time should not be wasted, only approach the victim after determining that the scene is safe: always check for cars, fire, gas, downed electrical lines, and any other potential hazards before attempting to perform CPR. . .

Thanks & Besafe

Raghu

Thank you for your valuable input and the link. We must also learn some basics of First Aid, which will be helpful at any time.

With warm regards,
S. Bhaskar
[Phone Number Removed For Privacy Reasons]

Dear Mr. Hansa,

As I will elaborate a bit on what Mr. Raghu has already posted here.

The air we breathe, containing roughly 21% oxygen, reaches the lungs where fine microvascular structures of blood vessels called capillaries are found. Simultaneously, blood from the whole body (referred to as deoxygenated blood) comes to the heart in the right upper chamber, known as the Right Atrium. From the Right Atrium, it is pushed down to the right Ventricle (lower right side of the heart) and then sent to the lungs via four Pulmonary arteries. This means that the lungs now contain deoxygenated blood. Gaseous exchange then takes place in the lungs. Deoxygenated blood contains around 16-17% oxygen and 4-5% CO2, which is eliminated during the exhaling process. Thus, it is a cycle of fresh air with 21% O2 taken in and air with 16-17% O2 being expelled through exhalation.

This process is continuous, and its rate is decreased or increased depending on body actions. If the heart is not functioning, it will be unable to pump blood to all parts of the body that are dependent on oxygen. In the absence of oxygen, vital organs start deteriorating, leading to a standstill in all vital functions. If this situation persists, irreparable damage can occur to brain tissue, ultimately resulting in death.

Any injury or incident that causes respiratory distress or prevents oxygen from entering the lungs or the exchange of gases in the lungs can lead to a heart attack.

There can be a situation where a person is not breathing, but their heartbeat is detected because the heart has a built-in separate powerhouse to run its functions, in addition to the support provided by the brain. Thus, in the event of brain death, the heart can still function due to its own powerhouse. This situation can persist for more than 10 minutes, after which the heart tissue will start to deteriorate, leading to ventricular fibrillation (flutter) and eventual heart failure.

Understanding the concept of defibrillators or automated external defibrillators may be challenging for a non-medical person. Therefore, it is important to know what to do and how to do it to increase the chances of survival for the person.

And here comes CPR -

As previously explained, CPR is the process of reviving the heart and lungs. If an assessment of a cardiac arrest patient is conducted, there will be no breathing and no pulse, as both organs responsible for pulse and breathing are not functioning. CPR is a combination of artificial respiration and chest compression.

Assess the victim; if there is no breathing, provide two mouth-to-mouth breaths, known as rescue breaths. After this, check for the carotid pulse, and if there is no pulse, give 30 chest compressions by pressing the center of the chest at the sternum (chest bone) at a rate of 100 per minute, with a compression depth of 2-2.5 inches.

Following compressions, provide two breaths and then 30 more compressions. Repeat this cycle for a total of 5 cycles of 2 breaths and 30 compressions each. During this process, do not check for pulse or breath.

After completing the cycles, check the pulse again. If there is no pulse, restart with 30 compressions followed by 2 breaths, and repeat for 5 cycles. It is advisable to seek help, as this process is strenuous, and bystanders can assist. Call 108 for emergency services, and continue CPR during transportation until the patient is handed over to doctors or revived.

Learning the process of CPR is essential and can be acquired through training and practice. The process mentioned here follows the latest standard guidelines.

I will continue with further write-ups as provided people respond.

Thank you and regards,

RP Singh (Ravi)

Trainer ACLS

7620958102

Dear friends,

In your life so far, have you ever heard of someone being saved by applying CPR? Now one question remains: We inhale air containing nearly 21% of oxygen. We take up about 4% of it and quite often more depending on our activity, and exhale air containing less than 17% oxygen. While conducting CPR, we are trying to pump in our exhaled air with poor oxygen content. How could we justify this action?

Please...

Regards,
Kesava Pillai

Dear Pillai Sir,

I think now I will enjoy more on this platform since people are coming with very good queries. Especially if a person of your caliber is putting such queries, then it becomes a bound duty of me to clarify. I have come across one of your posts pertaining to your appeal for getting the right utilization of experience from a veteran like you (I am sure I am addressing the right person).

Now let us come to the question.

Yes, I have been involved in this process for the last 18 years. I have participated in almost all major natural calamities that have occurred in this country as a member of the medical care team. So, it is not taboo for those meant for this cause to provide CPR or revive a person. It has happened many times. I can say that the process of CPR is a common situation in operation theaters where surgeries are conducted. It is more common with young children, and we do bring them back to life. In developed countries, it is more widely practiced because of the very fine system employed there, which they follow. I am sure I am able to clear your first question.

Now, let's discuss whether it is feasible to give a patient exhaled air containing roughly 17-18% oxygen. I will say with authority, YES.

In the case of a person experiencing cardiac arrest, there will be no oxygen going to their brains. In such a condition, he or she will receive irreversible brain damage beyond recovery, which may lead to death or brain death. If we provide this so-called 17-18% oxygen through mouth-to-mouth respiration, we can temporarily maintain oxygen saturation and brain tissue perfusion through chest compression. CPR may not be a final remedy, but at least if a patient is brought to the casualty room with CPR ongoing, there are far more chances of survival because we have somewhat maintained the oxygenation of brain tissue.

So, in conclusion, I will say here again that the success of a patient's survival depends on the timely process of CPR and the effective methods used for providing it.

All the information mentioned above is based on my own research and research conducted by the top organizations in the world involved in this cause.

Thanks & Regards,

RP Singh (Ravi)

American Heart Association Certified

ACLS, BLS Trainer, Health Educator

Dear Ravi,

Thanks a lot.

Medical professionals, even paramedics, have to often perform CPR. It is part of their job. They are trained and tuned to perform it. The question I posed is not directed to any medical practitioners like you.

Even if one is just trained in CPR, will they be able to perform it in the middle of today's public? If there is such a casualty and the individual trained in CPR comes forward to perform, will they be permitted? No one will heed them. The one with shouting capability will take control of the situation and shout, "take him to the hospital," and on the way, since critical minutes are lost, the casualty dies.

Even if one is just trained, when faced with their own child needing CPR, they may not dare to perform as they are not accustomed to doing so. The immediate thought is to quickly take the child to the hospital. This is why many famous doctors will not perform surgery on their own spouses and opt to entrust the cases to someone else.

First issue: You are absolutely correct. The immediate priority is to save the casualty.

Our exhaled air contains 17%+ oxygen without exerting much effort. In the case of CPR, we do nothing else but take deep breaths each time to contain more air than required by us. This will provide enough oxygen to revive the casualty. Many individuals attending CPR classes may have doubts about this point, though they mostly remain silent. After the training, they continue to ponder over it. Therefore, I always recommend that this point be explained firsthand.

CPR experience: At Cochin, exactly in Piravom, a bridegroom, about to go to the church for his marriage, had just taken a bath and came out of the bathroom. Suddenly, the power failed. He had arranged for a generator. He attempted to insert bare wires into the generator socket. His long gold chain touched the wire and he was electrocuted. He was put into a decorated car and driven to the hospital where he was pronounced dead. The doctor only said, "If CPR was applied, he would have survived."

In another case, during a girls' football game, lightning struck, and the goalie was thrown about 10 feet unconscious. No breathing, no pulse. The female trainer began CPR on the girl and continued all the way to the hospital until a doctor took over. The girl was saved. The doctor stated, "The lady's CPR saved her, not I." Interestingly, as the girl regained consciousness, the first thing she asked was, "Who won the game?"

Both newspaper clippings are in my collection.

What we need is to popularize the importance of this essential skill.

Regards,

Kesava Pillai.

Dear all,

I wanted to inquire about the question Mr. Kesava had asked. During a discussion, someone mentioned that exhaled air is rich in CO2, which acts as a catalyst or something. However, I disagreed with this statement. Hence, I decided to bring this question to this forum.

Thank you, Mr. Raghu, Dipil, R.P. Singh, and Mr. Pillai, for your replies.

Regards,
Hansa Vyas

Dear Mr. Hansa,

Thank you for your comment.

This is pertaining to what you have just mentioned about the catalytical action of CO2. Actually speaking, it is concerned with the mechanism of breathing and a bit complex phenomenon.

Why do we breathe and how do we breathe?

The rate of breathing depends upon the requirement of oxygen by the body and is sensed through receptors by the Medulla Oblongata. If the level of CO2 in the blood is high, it is sensed by the medulla, which then releases a message to the respiratory muscles to increase the respiratory rate. Similarly, if the oxygen level is high in the blood, it signals for a decrease in the respiratory rate. Thus, CO2 also acts as a catalyst for increasing the rate of respiration.

This is the simplest way I have presented here for people to understand the mechanism of breathing.

It is a highly complex mechanism dependent on the pH of blood and other brain structures, and the brain center reciprocates accordingly.

CO2 acts as a catalyst only when breathing is present, affecting the rate but unable to initiate breathing in the absence of spontaneous respiration. In such cases, the role of CO2 has an adverse effect on the tissues.

Therefore, it is crucial to understand that in cases of no breathing, external means must be used to initiate breathing, such as CPR. Providing oxygen to brain tissue is vital in the absence of breathing, achieved through mouth-to-mouth respiration.

Non-medical individuals should know how to assess whether a victim is breathing or has a pulse. Understand the time required for assessment and the necessary actions for the successful revival of the victim. Knowing whether to check for a pulse first or breathing, and the correct methods for assessment, is essential. Managing injuries to prevent fatalities is not overly complex but requires thorough practice and training.

Regards,

RP Singh (Ravi)
Healthcare Trainer
7620958102

Dear Hansa,

Many thanks for bringing this question to the discussion. Many concepts have become clearer.

@ Keshav Pillai

Dear Sir, thank you for your participation and for sharing your experience.

@ R.P Singh

Dear Sir, thank you for your great explanations. It has helped me to learn more about the topic. Can you please tell me what ratio should be followed if there is one first aider and in the case of two first aiders for imparting CPR? How many cycles of mouth-to-mouth respiration should be followed by chest compressions?

Dear Raghu, great participation and thanks for keeping the forum alive.

Keep up the good work!

Dear ravelove,

Thank you for your explanation. I am from a science biology background, so this is sparking my interest in understanding the hidden processes that our bodies undergo.

Just one more question: will CO2 play any role if a person is unconscious or during CPR?

Thank you all for participating.

Regards,
Ms. Hansa Vyas

Dear Mr. Dipil,

Dear Mr. Hansa,

I am writing here regarding the queries posted by both of you.

Let us understand that the most important part of First Aid is the assessment of the victim since time is crucial. Therefore, the assessment of the victim has to be done methodically and quickly. There is a very thin line between correct assessment and incorrect assessment, and if the assessment is wrong, it can be catastrophic.

During the assessment, only a first aider can learn about these three important stages of the patient/victim/casualty, which are:

1. Unconsciousness
2. Patient with respiratory arrest
3. Cardiac Arrest

Unconsciousness is the stage where breathing and pulse are present, but the patient is not responding to verbal commands, and vital functions (breaths, pulse) may be slightly suppressed. Unconsciousness can occur due to any metabolic disturbance or exposure to extreme temperatures and may be idiopathic (reason unknown).

Such patients should be supported with external oxygen at a rate of 4-6 liters using a Venti mask or nasal prongs. Do not give mouth-to-mouth respiration or chest compressions. Also, provide the recovery position, and if the patient was exposed to low temperatures, cover them with a blanket to preserve body heat. Do not give anything to eat or drink orally.

Respiratory Arrest:
During assessment, if there is no breathing but a pulse is present, give initial 2 breaths and then check for the pulse. If the pulse is present, continue mouth-to-mouth respiration at a rate of 10-12 breaths per minute. Simultaneously, evacuate the patient to the hospital, as such a patient may progress to cardiac arrest.

Cardiac Arrest:
If, upon assessment, there are no breaths (give 2 breaths) and no pulse is found, give compressions. Continue to provide compressions and evacuate the patient with CPR.

I have elaborated on CPR previously; I would like to mention again that if the patient is in a state of Unconsciousness or Cardiac Arrest, the role of CO2 is minimal and falls outside the scope of first aiders. CO2 levels are considered in operating theaters where patients are under anesthesia; there, factors like end tidal volume of CO2 are monitored.

Now, regarding the sequences of CPR ingredients:

CPR consists of mouth-to-mouth respiration and chest compressions.

It is important to note that when CPR is performed, at least two first aiders should be present, as it is a strenuous process that requires assistance.

In the case of one first aider:
- 2 breaths followed by 30 compressions.

In the case of two first aiders:
- 2 breaths followed by 30 compressions.

The sequence of mouth-to-mouth respiration and compressions remains the same. The sequence changes only when the victim is below one year old, in which case, first aiders must follow:
- One First Aider: 2 breaths followed by 30 compressions.
- Two First Aiders: 2 breaths followed by 15 compressions.

These are the latest guidelines, and I hope people will make use of them.

Regards,

RP Singh (Ravi)
Healthcare Trainer
7620958102

Dear Friends,

Please find a PPT attachment for self-CPR. This is a process for a person who is suffering from severe chest pain (Angina pectoris), and this condition arises due to Myocardial Infarction (the most important heart muscle, which works round the clock). If this person is alone and unable to seek help from others, they can sustain their life by following the methods of self-CPR. It involves increasing oxygen intake by deliberately increasing the rate of respiration. The presentation is very brief but precisely explains how one can sustain life.

Thank you.