Cardio Pulmonary Resuscitation
Cardiopulmonary resuscitation, commonly known as CPR, is an emergency procedure performed in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It is indicated in those who are unresponsive with no breathing or abnormal breathing.
According to the International Liaison Committee on Resuscitation guidelines, CPR involves chest compressions for adults between 5 cm (2.0 in) and 6 cm (2.4 in) deep and at a rate of at least 100 to 120 per minute. The rescuer may also provide breaths by either exhaling into the subject’s mouth or nose or using a device that pushes air into the subject’s lungs. This process of externally providing ventilation is termed artificial respiration.
CPR alone is unlikely to restart the heart. Its main purpose is to restore partial flow of oxygenated blood to the brain and heart. The objective is to delay tissue death and to extend the brief window of opportunity for a successful resuscitation without permanent brain damage. Administration of an electric shock to the subject’s heart, termed defibrillation, is usually needed in order to restore a viable or “perfusing” heart rhythm. Defibrillation is effective only for certain heart rhythms, namely ventricular fibrillation or pulseless ventricular tachycardia, rather than asystole orpulseless electrical activity. CPR may succeed in inducing a heart rhythm that may be shockable. In general, CPR is continued until the person has a return of spontaneous circulation (ROSC) or is declared dead.
CPR is indicated for:
- Any person unresponsive with no breathing or
- Breathing only in occasional agonal gasps, as it is most likely that they are in cardiac arrest.
If a person still has a pulse but is not breathing (respiratory arrest) artificial respirations may be more appropriate, but, due to the difficulty people have in accurately assessing the presence or absence of a pulse, CPR guidelines recommend that lay persons should not be instructed to check the pulse, while giving healthcare professionals the option to check a pulse. In those with cardiac arrest due to trauma, CPR is considered futile but still recommended. Correcting the underlying cause such as a pneumothorax or pericardial tamponade may help.
CPR serves as the foundation of successful cardiopulmonary resuscitation, preserving the body for defibrillation and advanced life support. Even in the case of a “non-shockable” rhythm, such as Pulseless Electrical Activity (PEA) where defibrillation is not indicated, effective CPR is no less important. Used alone, CPR will result in few complete recoveries, though the outcome without CPR is almost uniformly fatal.
Studies have shown that immediate CPR followed by defibrillation within 3–5 minutes of sudden VF cardiac arrest dramatically improves survival.
While CPR is a last resort intervention, without which a person without a pulse will all but certainly die, the physical nature of how CPR is performed does lead to complications that may need to be rectified.
Common complications due to CPR are:
- Rib fractures
- Sternal fractures
- Bleeding in the anterior mediastinum
- Heart contusion
- Upper airway complications
- Damage to the abdominal viscus – lacerations of the liver and spleen, fat emboli
- Pulmonary complications – pneumothorax, hemothorax, lung contusions.
- The most common injuries sustained from CPR are rib fractures and sternal fractures.
CPR training: CPR is being administered while a second rescuer prepares for defibrillation.
In 2010, the American Heart Association and International Liaison Committee on Resuscitation updated their CPR guidelines. The importance of high quality CPR (sufficient rate and depth without excessively ventilating) was emphasized.
The order of interventions was changed for all age groups except newborns from airway, breathing, chest compressions (ABC) to chest compressions, airway, breathing (CAB). An exception to this recommendation is for those believed to be in a respiratory arrest (drowning, etc.). The most important aspect of CPR are: few interruptions of chest compressions, a sufficient speed and depth of compressions, completely relaxing pressure between compressions, and not ventilating too much. It is unclear if a few minutes of CPR before defibrillation results in different outcomes than immediate defibrillation.
A universal compression to ventilation ratio of 30:2 is recommended by the AHA. With children, if at least 2 trained rescuers are present a ratio of 15:2 is preferred. In newborns a rate of 3:1 is recommended unless a cardiac cause is known in which case a 15:2 ratio is reasonable. If an advanced airway such as an endotracheal tube or laryngeal mask airway is in place, artificial ventilation should occur without pauses in compressions at a rate of 8–10 per minute.
The recommended order of interventions is chest compressions, airway, breathing or CAB in most situations, with a compression rate of at least 100 per minute in all groups. Recommended compression depth in adults and children is at least 5 cm (2 inches) and in infants it is 4 centimeters (1.6 in).
In adults, rescuers should use two hands for the chest compressions, while in children they should use one, and with infants two fingers (index and middle fingers).
Compression-only (hands-only or cardio cerebral resuscitation) CPR is a technique that involves chest compressions without artificial respiration. It is recommended as the method of choice for the untrained rescuer or those who are not proficient because it is easier to perform and instructions are easier to give over a phone.
In adults with out-of-hospital cardiac arrest, compression-only CPR by the lay public has a higher success rate than standard CPR. The exceptions are cases of drownings, drug overdose and arrest in children. Children who receive compression-only CPR have the same outcomes as those having received no CPR. The method of delivering chest compressions remains the same, as does the rate (at least 100 per minute). It is hoped that the use of compression-only delivery will increase the chances of the lay public delivering CPR.
Prone CPR / Reverse CPR
Standard CPR is performed with the person in supine position. Prone CPR or reverse CPR is CPR performed on a person lying on their chest, by turning the head to the side and compressing the back. Due to the head’s being turned, the risk of vomiting and complications caused by aspiration pneumonia maybe reduced.
The American Heart Association’s current guideline recommends to perform CPR in the supine position, and limits prone CPR to situations where the patient cannot be turned.
CPR is used on people in cardiac arrest in order to oxygenate the blood and maintain a cardiac output to keep vital organs alive. Blood circulation and oxygenation are required to transport oxygen to the tissues. The physiology of CPR involves generating a pressure gradient between the arterial and venous vascular beds; CPR achieves this via multiple mechanisms The brain may sustain damage after blood flow has been stopped for about four minutes and irreversible damage after about seven minutes. Typically if blood flow ceases for one to two hours, then body cells die. Therefore, in general CPR is effective only if performed within seven minutes of the stoppage of blood flow. The heart also rapidly loses the ability to maintain a normal rhythm. Low body temperatures, as sometimes seen in near-drownings, prolong the time the brain survives. Following cardiac arrest, effective CPR enables enough oxygen to reach the brain to delay brain stem death, and allows the heart to remain responsive to defibrillation attempts.
Cardiopulmonary resuscitation (CPR) is a lifesaving technique useful in many emergencies, including heart attack or near drowning, in which someone’s breathing or heartbeat has stopped. The American Heart Association recommends that everyone — untrained bystanders and medical personnel alike — begin CPR with chest compressions.
It’s far better to do something than to do nothing at all if you’re fearful that your knowledge or abilities aren’t 100 percent complete. Remember, the difference between your doing something and doing nothing could be someone’s life.
Here’s advice from the American Heart Association:
- Untrained. If you’re not trained in CPR, then provide hands-only CPR. That means uninterrupted chest compressions of about 100 a minute until paramedics arrive (described in more detail below). You don’t need to try rescue breathing.
- Trained and ready to go. If you’re well-trained and confident in your ability, begin with chest compressions instead of first checking the airway and doing rescue breathing. Start CPR with 30 chest compressions before checking the airway and giving rescue breaths.
- Trained but rusty. If you’ve previously received CPR training but you’re not confident in your abilities, then just do chest compressions at a rate of about 100 a minute. (Details described below.)
The above advice applies to adults, children and infants needing CPR, but not newborns.
CPR can keep oxygenated blood flowing to the brain and other vital organs until more definitive medical treatment can restore a normal heart rhythm.
When the heart stops, the lack of oxygenated blood can cause brain damage in only a few minutes. A person may die within eight to 10 minutes.
Before starting CPR, check:
- Is the person conscious or unconscious?
- If the person appears unconscious, tap or shake his or her shoulder and ask loudly, “Are you OK?”
- If the person doesn’t respond and two people are available, one should call for help or the local emergency number and one should begin CPR. If you are alone and have immediate access to a telephone, call for help before beginning CPR — unless you think the person has become unresponsive because of suffocation (such as from drowning). In this special case, begin CPR for one minute and then call for help or the local emergency number.
- If an AED is immediately available, deliver one shock if instructed by the device, then begin CPR.
Remember to spell C-A-B
The American Heart Association uses the acronym of CAB — compressions, airway, breathing — to help people remember the order to perform the steps of CPR.
Compressions: Restore blood circulation
- Put the person on his or her back on a firm surface.
- Kneel next to the person’s neck and shoulders.
- Place the heel of one hand over the center of the person’s chest, between the nipples. Place your other hand on top of the first hand. Keep your elbows straight and position your shoulders directly above your hands.
- Use your upper body weight (not just your arms) as you push straight down on (compress) the chest at least 2 inches (approximately 5 centimeters). Push hard at a rate of about 100 compressions a minute.
- If you haven’t been trained in CPR, continue chest compressions until there are signs of movement or until emergency medical personnel take over. If you have been trained in CPR, go on to checking the airway and rescue breathing.
Airway: Clear the airway
- If you’re trained in CPR and you’ve performed 30 chest compressions, open the person’s airway using the head-tilt, chin-lift maneuver. Put your palm on the person’s forehead and gently tilt the head back. Then with the other hand, gently lift the chin forward to open the airway.
- Check for normal breathing, taking no more than five or 10 seconds. Look for chest motion, listen for normal breath sounds, and feel for the person’s breath on your cheek and ear. Gasping is not considered to be normal breathing. If the person isn’t breathing normally and you are trained in CPR, begin mouth-to-mouth breathing. If you believe the person is unconscious from a heart attack and you haven’t been trained in emergency procedures, skip mouth-to-mouth breathing and continue chest compressions.
Breathing: Breathe for the person
Rescue breathing can be mouth-to-mouth breathing or mouth-to-nose breathing if the mouth is seriously injured or can’t be opened.
- With the airway open (using the head-tilt, chin-lift maneuver), pinch the nostrils shut for mouth-to-mouth breathing and cover the person’s mouth with yours, making a seal.
- Prepare to give two rescue breaths. Give the first rescue breath — lasting one second — and watch to see if the chest rises. If it does rise, give the second breath. If the chest doesn’t rise, repeat the head-tilt, chin-lift maneuver and then give the second breath. Thirty chest compressions followed by two rescue breaths is considered one cycle.
- Resume chest compressions to restore circulation.
- If the person has not begun moving after five cycles (about two minutes) and an automated external defibrillator (AED) is available, apply it and follow the prompts. Administer one shock, then resume CPR — starting with chest compressions — for two more minutes before administering a second shock. If you’re not trained to use an AED, a 911 or other emergency medical operator may be able to guide you in its use. If an AED isn’t available, go to step 5 below.
- Continue CPR until there are signs of movement or emergency medical personnel take over.
To perform CPR on a child
The procedure for giving CPR to a child age 1 through 8 is essentially the same as that for an adult. The differences are as follows:
- If you’re alone, perform five cycles of compressions and breaths on the child — this should take about two minutes — before calling help or local emergency number or using an AED.
- Use only one hand to perform chest compressions.
- Breathe more gently.
- Use the same compression-breath rate as is used for adults: 30 compressions followed by two breaths. This is one cycle. Following the two breaths, immediately begin the next cycle of compressions and breaths.
- After five cycles (about two minutes) of CPR, if there is no response and an AED is available, apply it and follow the prompts. Use pediatric pads if available, for children ages 1 through 8. If pediatric pads aren’t available, use adult pads. Do not use an AED for children younger than age 1. Administer one shock, then resume CPR — starting with chest compressions — for two more minutes before administering a second shock.
Continue until the child moves or help arrives.
To perform CPR on a baby
Most cardiac arrests in babies occur from lack of oxygen, such as from drowning or choking. If you know the baby has an airway obstruction, perform first aid for choking. If you don’t know why the baby isn’t breathing, perform CPR.
To begin, examine the situation. Stroke the baby and watch for a response, such as movement, but don’t shake the baby.
If there’s no response, follow the CAB procedures below and time the call for help as follows:
- If you’re the only rescuer and CPR is needed, do CPR for two minutes — about five cycles — before calling help or local emergency number.
- If another person is available, have that person call for help immediately while you attend to the baby.
Airway: Clear the airway
- After 30 compressions, gently tip the head back by lifting the chin with one hand and pushing down on the forehead with the other hand.
- In no more than 10 seconds, put your ear near the baby’s mouth and check for breathing: Look for chest motion, listen for breath sounds, and feel for breath on your cheek and ear.
Breathing: Breathe for the baby
- Cover the baby’s mouth and nose with your mouth.
- Prepare to give two rescue breaths. Use the strength of your cheeks to deliver gentle puffs of air (instead of deep breaths from your lungs) to slowly breathe into the baby’s mouth one time, taking one second for the breath. Watch to see if the baby’s chest rises. If it does, give a second rescue breath. If the chest does not rise, repeat the head-tilt, chin-lift maneuver and then give the second breath.
- If the baby’s chest still doesn’t rise, examine the mouth to make sure no foreign material is inside. If an object is seen, sweep it out with your finger. If the airway seems blocked, perform first aid for a choking baby.
- Give two breaths after every 30 chest compressions.
- Perform CPR for about two minutes before calling for help unless someone else can make the call while you attend to the baby.
- Continue CPR until you see signs of life or until medical personnel arrive.