Understanding Cough CPR

Cough CPR has been advertised as a possible quick-fix mechanism for managing cardiac arrest. Social media has made waves on this as a layperson’s effort to tackle cardiac dysfunction while waiting on the arrival of paramedics. However, many “therapies” circulate within mainstream media, and not all of them are good. Cough CPR is one such “life-saving” measure still being questioned for its potential to navigate through potential cardiac arrest.

While it can save someone’s life by maintaining blood circulation for a short time following cardiac arrest, this is only beneficial if proper medical assistance is provided swiftly.

There might be some reasoning for performing cough CPR. But currently, success rates and scientific evidence are lacking.

What Is Cough CPR?

Cough CPR is self-administered cardiopulmonary resuscitation via coughing every one to three seconds before unconsciousness occurs. It can be considered in cases of ventricular fibrillation and pulseless arrhythmia.

It was first discovered in a cardiology lab in 1976, where three patients, who experienced ventricular fibrillation while undergoing coronary angiography, kept themselves conscious for around 30 seconds by coughing forcefully, aiding in resuscitation. The cardiologists involved tentatively suggested coughing as a form of internal CPR which may have been used in situations where an arrhythmic heartbeat is spotted before it arrests.

Since then, cough CPR has grown in popularity online as a supposed life-saving technique, despite being disparaged by both the American Heart Association and the British Heart Foundation, among others.

Patients are advised to watch out for signs of impending cardiac arrest, including chest discomfort, changes in consciousness, and difficulty breathing. Ideally, in such a scenario, the first thing to do would be to call 911 and then initiate manual CPR if the patient is unconscious. But, if the patient is alone, cough CPR can be attempted as soon as signs of an impending cardiac arrest are spotted, hopefully keeping them conscious and alive long enough to call 911 or have someone else notice.

During cough CPR, individuals undergoing symptoms of possible cardiac discomfort are told to take a deep breath and then cough vigorously for a prolonged duration. This cycle is to be repeated every few seconds. The primary benefit of cough CPR is to enable blood flow to the brain enough to maintain consciousness.

However, cough CPR can no longer happen when the patient loses consciousness, and manual CPR should be immediately initiated.

How Does Cough CPR Work?

In a study among healthy participants, it was noted that forceful rhythmic coughing had the potential to change intra-thoracic and intra-abdominal pressures. These changing pressures resulted in the blood in the pulmonary veins being forced into the heart and blood from the abdominal splanchnic region (which acts as a circulatory reservoir) being pushed to the brain and other tissues.

During an episode of vigorous coughing, muscles of the diaphragm and abdomen contract in unison. Thus, the contractions push blood to the extremities via the splanchnic vasculature. For the coughing to be effective as CPR, it should start at total lung capacity, which is required to enable sufficient cardiovascular push to the extremities and brain.

The study found that coughing provides two essential functions:

• Ventilation of the airways and clearance of foreign substances
• Facilitation of cardiovascular flow without external compressions

Understanding such physiology within normal subjects who do not have any underlying health conditions is important to know how it functions. However, these results fail to factor in the state of mind, such as fear and panic, during inevitable cardiac arrest.

Is Cough CPR Effective?

Research into cough CPR has indicated the most benefit is attained from cough CPR when it is conducted within supervised settings, similar to the original discovery. This is primarily due to the guided indications on how and when to cough following a prolonged and deep breath to maximize lung capacity and oxygen intake.

Studies have noted if breathing is shallow, there is insufficient time given for splanchnic vasculature to refill. Capillary refill coupled with the forceful act of coughing is a crucial duo to enable a few minutes of consciousness during unstable arrhythmia before clinical intervention by trained personnel.

The information available within mainstream media can be misleading about the actual benefits of cough CPR within normal settings. Messaging can indicate that cough CPR can “save lives” or prevent imminent “heart attack.” In reality, both statements are false. This is why the American Heart Association has taken a stance against teaching cough CPR within standard layperson CPR training.

Facilitating the right information starts with educating the public on the difference between a heart attack and cardiac arrest. It is crucial to understand that general discomfort experienced in the chest can be due to limitations in the perfusion of the heart tissue in what is often termed a heart attack. However, this doesn’t indicate a heart moving toward an inevitable arrest. States of cardiac dysrhythmia can quickly progress to arrest and eventual death, which is where manual CPR becomes vital to initiate sinus rhythm.

Within research settings, cough CPR has been proven effective, converting ventricular tachycardia to normal sinus rhythm when guided forceful coughs were performed. However, this study also showed that if cough CPR was not able to be conducted as required, an external shock was required to maintain cardiac rhythm.

Similarly, other clinical scenarios where cough CPR was shown to be effective have been during procedures such as cardiac catheterization. In such clinical settings, if dysrhythmias were noted, they could be managed during their initial stages via cough CPR. Such studies continue to document that resuscitation is possible for about 30 seconds to a minute if the patient is compliant with the instructions on coughing.

Weighing the Potentials and Limitations of Cough CPR

Cough CPR has indeed been proven to be beneficial within clinical settings, especially under the guidance of trained medical professionals. Coughing increases the pressure required to facilitate circulation to the extremities and brain, and also possible to reattain sinus rhythm for a short duration. This must be followed by medical intervention to stabilize the patient and maintain sinus rhythm. Cough CPR has been proven to be effective for about 30 seconds to a couple of minutes when performed correctly.

One of the foremost limitations of cough CPR is timing. Studies have indicated that cough CPR is effective when conducted at the initial signs of possible hemodynamic compromise following arrhythmia. Used like this, it gives time for interventions such as intubation and mechanical CPR when these resources become available for the patient.

But most laypeople on their own are unlikely to understand signs indicating life-threatening rhythm changes. They may attribute it to heartburn, tiredness, or something else less serious than an impending cardiac arrest. Thus cough CPR may be delayed, performed incorrectly, or performed solely without seeking any further medical help, thus proving ineffective in most situations when people are alone.

The first step when a patient does experience chest discomfort must be to call 911. And in the event of loss of consciousness, traditional CPR should be initiated immediately via bystander intervention if possible. Cough CPR should ideally not be a part of basic life training courses, as it is often a futile attempt outside a clinical setting.

Conclusion

With cough CPR, an individual is expected to take deep breaths, then cough for a few seconds, keeping the coughs and breaths both deep and vigorous. The premise of the breath is to increase oxygen supply which can also then facilitate stronger coughs. The strength of the cough increases the pressure required to enable cardiovascular circulation to both the extremities and the brain. The original researchers still hold that coughing during pre-cardiac-arrest dysrhythmia can be a life-saving technique.

While in theory, and a few studies, have indicated its benefits, in reality, this is not the scenario. If not performed correctly, there is little to no benefit of cough CPR. Additionally, in cases of infarction where the heart is otherwise still functioning within a normal rhythm, there are no benefits of cough CPR.

This is why globally, cough CPR is not advocated as a life-saving method for cardiac resuscitation. Standard CPR protocols and immediate contact with emergency medical services are mandatory.

As a healthcare professional, you should try to understand cough CPR both from a physiological standpoint with its potential uses and as a case study of the spread of well-intentioned misinformation. This will help you educate your patients more effectively if cardiac arrest is fear or risk for them. Here at Hyfe, we aim to understand the nuances of cough in clinical settings and if there are any benefits to the mechanism of coughing. Hyfe is doing extensive studies on respiratory health and finding links on how technology and acoustic epidemiology can bridge the knowledge gap for better outcomes. You can read more about how Hyfe’s innovative contribution to the field of respiratory health helps both health professionals and patients in tracking and monitoring cough here: www.hyfe.ai