Cardiopulmonary resuscitation

From Free net encyclopedia

(Redirected from CPR)

CPR redirects here. For other meanings of CPR see CPR (disambiguation)

Image:CardiopulmonaryResuscitationAdult.jpg Cardiopulmonary resuscitation (CPR) is an emergency first aid protocol for an unconscious person on whom both breathing and pulse cannot be detected.

The medical term for a patient whose heart has stopped is cardiac arrest (also referred to as cardiorespiratory arrest), in which case CPR is used. If the patient still has a pulse, but is not breathing, this is called respiratory arrest and Rescue breathing is used. In many first aid certifications, the CPR protocol is also used for an unconscious and choking patient.

The most common treatable cause of cardiac arrest outside of a hospital is a heart attack leading to a heart rhythm disturbance. Cardiac arrest may be caused by a number of events, including drowning, drug overdoses, poisoning, electrocution and many other conditions.

Many countries have official guidelines on how CPR should be provided, and these naturally override the general description of CPR in this article.

Beginning in 2004, some jurisdictions began receiving automated CPR machines such as the AutoPulse, which will do the necessary chest compressions automatically and allow the first responders to attend to other needs for the affected patient.

In 2005, new CPR guidelines were published with input from the American Heart Association, the Canadian Heart and Stroke Foundation and European Resuscitation Council, with the primary goal of simplifying CPR for laypersons and healthcare providers alike.

1 Importance
2 Effectiveness
3 CPR training
4 History
5 Myths and popular culture
6 References
7 See also
8 External links

[edit]

Importance

Heart action and respiratory effort are absolute requirements in transporting oxygen to the tissues. The main organ to suffer from oxygen starvation is the brain, which may sustain damage after four minutes and irreversible damage after about seven minutes. The heart also rapidly loses the ability to maintain a normal rhythm. Following cardiac arrest, effective CPR enables enough oxygen to reach the brain to delay brain death, and allows the heart to remain responsive to defibrillation attempts.

CPR is commonly taught to the general public as these may be the only ones present in the crucial few minutes before emergency personnel are available. If administered properly it can save lives but when done badly or inappropriately it can interfere with life saving operations later. Sometimes CPR should not be attempted, particularly if other persons are injured and need immediate help. CPR takes a lot of effort and may keep care providers from helping others. See triage.

[edit]

Effectiveness

CPR is almost never effective if started more than 15 minutes after collapse because permanent brain damage has probably already occurred. A notable exception is cardiac arrest occurring with exposure to very cold temperatures. A patient cannot be pronounced dead before he has been brought back to a normal temperature by appropriate means: Hypothermia seems to protect the victim by slowing down metabolic and physiologic processes, greatly decreasing the oxygen needed by tissues. There are cases where CPR, defibrillation, and advanced warming techniques have revived hypothermia victims after over 30 minutes or longer.

In respiratory arrest, when the victim still has a heartbeat (such as in drowning, choking, or drug overdose with opioids or sedatives) Rescue breathing (rather than CPR) should be used.

Used alone, few patients (estimates vary, but many organizations stress that CPR does not "bring anyone back", it simply preserves the body for defibrillation and advanced life support) will make a complete recovery, and those that do survive often develop serious complications. If CPR is begun within several minutes of cardiac arrest and defibrillation arrives shortly thereafter, a patient's chances of recovery rise to approximately 80%.

[edit]

CPR training

CPR is a practical skill and needs professional instruction followed up by regular practice on a resuscitation mannequin to gain and maintain full competency. Training is available through many commercial, volunteer and government organizations worldwide.

CPR training is not confined to the medical professionals. To be effective, CPR must be applied almost immediately after a patient's heart has stopped. Early CPR on the scene of an incident is essential to the prevention of brain damage during a cardiac arrest. Blood flow and air supply to the brain and other major organs is maintained until a defibrillator and professional medical help arrives. Almost anyone is able to perform CPR with training, and health organizations advocate the development of CPR skills throughout the general public.

[edit]

History

CPR has been known in theory, if not practice, for many hundreds, if not thousands, of years; some claim it is even described in the Bible, discerning a superficial similarity to CPR in a passage from the Books of Kings (II 4:34), wherein the Hebrew prophet Elisha warms a dead boy's body and "places his mouth over his". However it wasn't until the middle of the 20th century that the wider medical community started to recognise and promote it as a key part of resuscitation following cardiac arrest. Peter Safar wrote the book ABC of resuscitation in 1957. In the US, it was first promoted as a technique for the public to learn in the 1970s. Early marketing efforts oversold the effectiveness of CPR in rescuing heart attack and other victims, and this misperception continues even today.

[edit]

Myths and popular culture

CPR is often portrayed in movies and television as being highly effective in resuscitating a person who is not breathing and has no circulation. A 1996 study by the New England Journal of Medicine showed that CPR success rates in television shows was 75% [1]. The reality is that CPR administered outside hospitals has a near 0% success rate on its own, and is most importantly used to sustain oxygen supply to the brain until specialized medical equipment and personnel can reach the scene (see defibrillator). Several medical studies have indicated that CPR is inaccurately portrayed in the media: it is commonly described on television and movies as the definitive treatment of cardiac arrest and leads the general public to believe that CPR alone can have an extraordinary resuscitation save rate.

The truth remains that while CPR is an integral part of the resuscitation process, it cannot be used to replace other resuscitative adjuncts such as defibrillation, airway management and intravenous drug therapy. The most common myth associated with CPR is that it restarts the heart. It does not. The rhythmic breathing and chest compressions provide some amount of air and circulation to a victim, allowing more time for help to arrive. During cardiac arrest the heart enters into one of 8 spasmic rhythm types. The heart in these stages is still beating, but ineffectively. A defibrillator is needed to "shock" the heart. This takes a current across the heart, allowing for more regular electrical activity and a resuscitation of regular beating. CPR only acts as a substitute pumping to circulate blood when the heart itself cannot. Very few victims regain regular heatbeat solely by CPR. If someone "regains" signs of circulation after only bystander CPR was performed, it is usually because the victim was not actually in true cardiac arrest.

Many rescuers who have performed CPR — healthcare provider and layperson alike — have indicated their surprise about what it is really like to perform CPR. Some note that they were unprepared for cartilage separation (considered to be normal in some cases) during chest compression, and believed that they were performing CPR incorrectly (when they were not). In order to perform CPR, chest compressions must go very deep and it is not uncommon to crack ribs. Others note that they were shocked when patients vomited, a stark contrast to the clean environment CPR was taught to them in classes (although in modern American Red Cross classes pupils are warned about the possibility of vomiting and the importance of using barriers, such as gloves, against bodily fluids - especially blood). In some cases, rescuers blamed themselves when patients were not resuscitated, believing it was their fault for doing "CPR incorrectly" or "not doing CPR well enough". It is considered important to educate the general public and healthcare professionals that CPR is never guaranteed to save someone's life. Even if CPR is performed perfectly, the person in cardiac arrest may still not be resuscitated. The American Heart Association notes that "some hearts are too sick to be saved" and reflects the reality that CPR is not a cure-all but merely an important part of the resuscitation process.

[edit]

References

Weisfeldt ML. Public access defibrillation: good or great? BMJ USA 2004;328:E271-E272. Fulltext. PMID 14988214.
Resuscitation Guidelines 2005. Resuscitation Council (UK), 2005. ISBN 1903812100. Online version.
Ganong WF. Review of Medical Physiology 19th ed. Appleton & Lange, 1999. ISBN 0838584497

[edit]