Out of Hospital CPR in COVID Era: A Journey from Look, Listen, Feel to Cover, Look, Feel

Introduction

Currently, we are facing one of the most challenging times that human race has endured. Though equipped better with medical, scientific and technological support, COVID-19 has managed to bring a fast-moving world to standstill. The repercussions of this are evident, especially in the health, education and economics sectors. Health care workers have been constantly working in this pandemic to save as many lives as possible.¹ Though there is literature and guidelines set for performing cardiopulmonary resuscitation in hospital, not much literature is available for performing out of hospital cardiopulmonary resuscitation in the wake of emergencies. The current article is an attempt to fill this gap.

JeevaRaksha, a collaboration of Swami Vivekananda youth movement, Rajiv Gandhi University of Health Sciences, and the University of Utah has made it its primary focus to increase the survival rate of medical emergencies, both occurring out and in hospital by training not only the doctors, allied health science professionals, and students, but also by getting into the community and training layman as well.

Jeeva Raksha, after reviewing the different definitions given by veteran bodies in the field, defined cardiopulmonary resuscitation as an emergency, lifesaving procedure done in the wake of cardiac and, or pulmonary arrest, to maintain the blood flow and oxygenation to vital organs, till the return of spontaneous circulation through continuous cardiac compression.

Since its introduction by Dr. Kowenhovenin in the early 1960s, closed cardiac massage has made its place along with external defibrillators and mouth to mouth resuscitation in the guidelines issued by authoritative bodies across the globe including American Heart Association (AHA) and different National conferences to date.^2,3 JeevaRaksha has formulated an evidence-based, population-tailored cardiopulmonary resuscitation (CPR) program with cardiac compressions and early delivery of defibrillation at its center for India. Given the current situation, the following guidelines must be kept in mind when dealing with emergencies, especially outside the hospital settings.

Scene Safety: Assess the scene of emergency for safety of both the rescuer and the patient eg: water, fire, electric cables, traffic, etc. If any threat is present in the scene, neutralization of it becomes a priority, keeping two major things in mind:

a) do not harm,

b) don’t become the next casualty. For eg: if a live wire is present, then the main supply to the live wire must be switched off. Do not start resuscitation before securing the area. Ensure that the victim’s nose and mouth are covered and that the rescuer/ rescuers are wearing a mask.⁴

Once the scene safety has been ensured, then perform a primary assessment. It should be done in the following manner:

• Assess the level of consciousness using Awake Verbal Pain Unresponsive scale (AVPU):⁵ Awake-check if the victim is awake and oriented, maintaining a social distance. Verbal- if the victim is not awake, then call out to him/her. A tap on the clavicle may be used along with the verbal cue. Pain- If the victim is not responding to the verbal cue, then a painful stimulus may be given as a trapezius pinch, which delivers good enough painful stimulus, not hurting or bruising the victim. If there is no response to verbal and painful stimuli, then the victim is reckoned to be unresponsive.⁵ In such a scenario, move on to these following steps: 
• Look: Watch the chest of the patient for any movement during inspiration and expiration 
• Feel: Feel for the carotid pulse in the carotid triangle (Figure 1)

If the patient has no effective respiration and pulse and if the patient is unresponsive, then it can be confirmed that the victim is in cardiac arrest. In such a scenario, the following recommendations are made:

• Call for help (108 in outside hospital cases and code blue for in-hospital patients) 
• Early CPR
• Early defibrillation 
• Early transport to hospital⁶

Many researchers have already established that effective compression and early defibrillation are the determining factors that directly affect survival rates. Every minute of delay in CPR and defibrillation reduces a patient’s chance of survival by up to 10%.⁷

During an episode of out of hospital cardiac arrest (OHCA), the major components that determine the survival rate of the victim is the oxygen and substrate delivery to the vital organs. To ensure this, adequate amount of blood flow should be established to the vital organs through effective cardiac compressions.⁶ Return to spontaneous circulation after cardiac attack depends on the myocardial oxygen delivery and myocardial perfusion during CPR.

The pressure difference between aortic diastolic and right atrial diastolic pressure during the relaxation phase of the cardiac compression is called the cardiac perfusion pressure (CPP), which is the major factor that determines the myocardial perfusion during CPR.⁶ Five major factors are directly linked to the CPP. These are chest compression rate, chest compression depth, chest compression fraction, chest recoil, and ventilation. As evidence emerges for COVID-19 to be an airborne infection,⁸ the ventilation component with AMBU bag takes a back seat as it is an aerosol generating procedure, shifting the focus mainly to the chest compression depth, rate, recoil, and chest compression fraction. ⁶

Chest compression fraction (CCF) may be defined as the time fraction in cardiac arrest that is spent administrating effective cardiac compressions. To maximize the CCF, it is recommended that the compressions are continuous instead of 30:2 (compressions and ventilation) as recommended by AHA.⁶ In continuous chest compressions, we are not only maximizing the CCF, but also postponing the need for ventilation which is an aerosolgenerating technique; thus, minimizing the chances of exposing the rescuer to possible exposure to coronavirus. It is recommended to perform a primary assessment after two minutes of continuous compressions, which should be completed under 10 sec and repeated only every two minutes to maximize the chest compression fraction.⁶

Chest compression rate or frequency of chest compressions is defined as the compressions delivered by the rescuer in one minute. It is recommended to be kept in 100-120 bpm as a lower rate than 100 bpm affects the return of spontaneous circulation negatively, while higher than 120 bpm reduces the coronary perfusion and the percentage of compressions that attains the target depth.⁶ The rate can be instructed to the rescuers as the rhythm of the famous song “chaiyya chaiyya” from the movie Dil se, as it clocks in 98 beats per minute and is extremely popular with the Indian population.

There seems to be a debate among researchers when it comes to the depth of the compression. AHA recommends a 2-inch depth to be sufficient. Due to the size difference in population, the recommended chest compression depth is at least one-third of the anterior-posterior diameter of the chest of the patient. In recommending a fraction, the victim dependent factors that affect the depth of compression like higher body mass index (BMI) are eliminated. The same formula is applicable for all the age groups and holds correct provided the victim is on a flat surface that resists any movement due to the compression, thus contributing to the pressures created during compression.⁶

Ensuring a full chest recoil is important as it can affect both the cardiac pump which is responsible for the circulation as well as the pulmonary pump which is responsible for the ventilation.⁹ If the pressure is not released fully during the relaxation phase, then the venous return decreases, in turn affecting the cardiac output and risking the efficacy of the cardiac pump.

As we are recommending against any ventilatory efforts outside the hospital (in-hospital scenarios with proper personal protective equipment (PPE) for the rescuers, the ventilation should be addressed using an endotracheal tube),⁴ the compliance of chest recoil in the COVID era becomes the center of focus in delivering an effective chest compression. The difference between the intrathoracic pressure created during the compression phase and the atmospheric pressure acts as the only driving force for ventilation. An effective compression of 1/3rd the chest wall height can create up to 33% of vital capacity.⁹

The only four situations when chest compression should be stopped:

1. After every 2 minutes for a pulse check (Not more than 10 seconds to check the pulse)

2. When the defibrillator is assessing rhythm

3. When a shock is delivered by a defibrillator (peri shock pause)

4. If patient pushes you away or there is pulse palpable on checking or the team leader decides to discontinue resuscitation

The recommended position of the rescuer (Figure 2)

1. Heel of one hand in the center of the chest on the lower half of sternum, with the other hand on top

2. Straight arms, locked elbows, and shoulders in line with patient’s midline¹⁰

3. Back extended

Compressions in Infants and Children

The mortality rate of out of hospital cardiac arrest in infants and children is estimated to be 90%. Out of this, 50% to 60% are infants i.e less than one year of age and majority falling under 6 months of age. The same protocol is to be followed in case the victim is an infant or a child i.e scene safety, faces of both the rescuer and the victim covered, but there are changes in hand placement, frequency and indication of initiation of CPR. For the chest compressions to be effective, it has to be delivered at a frequency of 120 compressions per minute. If the infant is unconscious and has a heart rate less than 60 beats per minute, it is taken as an indication for initiating CPR. For the compression to be effective, the depth of compression should be at least 1/3rd of the chest wall. The hand placement is different in infants. If the chest circumference is smaller, then side by side thumb placement over the midpoint between two nipples is preferred for chest compression. A double finger method where the index and the middle fingers are placed at the midpoint between the nipples may be considered if the chest circumference is greater. In children, a single hand placed two finger width above xiphoid process is considered apt.³

Early Defibrillation

Early defibrillation is the other factor that affects the higher survival rate as most adults who suffer from a cardiac arrest are often in either ventricular fibrillation or pulseless ventricular tachycardia.¹¹ It is mandatory to have an automated external defibrillator (AED) available in common places that expect greater than 250 people above the age of 50 years using the location for more than 16 hours a day, incidence of cardiac arrest event at the location recurring every few years, high risk location with the presence of high risk individuals, gyms with more than 2500 members on an annual basis etc.¹¹

The machine will determine if the victim has a shockable rhythm. The electrode placements are well pictured on the machine itself (Figure 3). One electrode should be placed just below the right clavicle and the other electrode should be placed in the anterior axillary line at the lower coastal in such a way that the heart is oriented in the pathway connecting the two electrodes.

As mentioned prior in this article, the chest compressions should be stopped and the rescuer should remove his hands when the machine is analyzing the heart rhythm of the victim. If the rescuer’s hands are in contact with the chest of the victim or the AED, the AED may interpret the electrical impulse from the rescuer’s hand as a sinus rhythm. Once the rhythm is analyzed and the machine is charging, the compressions are to be continued to achieve a high chest compression fraction. When the comments from the machine come in cueing its readiness to shock, the team leader/ rescuer should ensure that no one is in touch with the victim’s body, and once clearance is confirmed, shock may be delivered. Once the shock is delivered, continue chest compressions for two minutes before assessing the victim for a palpable pulse.¹²

Two Rescuer

CPR When two rescuers are present at the scene, person 1 who takes up the position of the team leader does scene safety, ensures infection control (make sure the victim and the team members are masked), assess patient, and start CPR, while the second person (person 2) calls for help and then assumes the hovering position (Figure 4).¹⁰ With clear countdown by the person who is performing the CPR, the swapping may be done. This may be done every two minutes so that longer effective CPR is delivered to the victim. A flow chart for one person rescue and operating AED is presented in Figure 5 and 6, respectively

Conclusion

The survival rate of OHCA heavily depended on the first responder and the quality of CPR he or she delivers. In spite of this,the out of hospital CPR remains a fairly neglected topic. Seeing the current pandemic situation the above said alterations to the delivery of CPR will not only ensure an increased survival rate of OHCA victims but makes it safe for both the victim and the responder.

Conflict of interest

No.