CPR

CPR - Cardiopulmonary resuscitation is an emergency procedure for people in cardiac arrest or, in some circumstances, respiratory arrest. CPR is performed both in hospitals and in pre-hospital settings.

CPR involves physical interventions to create artificial circulation through rhythmic pressing on the patient's chest to manually pump blood through the heart, called chest compressions, and usually also involves the rescuer exhaling into the patient (or using a device to simulate this) to ventilate the lungs and pass oxygen in to the blood, called artificial respiration. Some protocols now downplay the importance of the artificial respirations, and focus on the chest compressions only (CCR).

Despite its name, CPR is unlikely to restart the heart; its main purpose is to maintain a flow of oxygenated blood to the brain and the heart, which are both the most essential organs to life and the most vulnerable to damage from lack of oxygen (hypoxia). Effective CPR helps by delaying tissue death and extending the brief window of opportunity for a successful resuscitation without permanent brain damage. Advanced life support, including intravenous drugs and defibrillation (the administration of an electric shock to the heart) is usually needed to restore a viable or "perfusing" heart rhythm-one which will support life. This only works for patients in certain heart rhythms, namely ventricular fibrillation or pulseless ventricular tachycardia, rather than the 'flat line' asystolic patient, although CPR can help induce a shockable rhythm in an asystolic patient.

Indications

Blood circulation and oxygenation are absolute requirements in transporting oxygen to the tissues. The brain may sustain damage after blood flow has been stopped for about four minutes and irreversible damage after about seven minutes. If blood flow ceases for one to two hours, the cells of the body die unless they get an adequately gradual blood flow, (provided by cooling and gradual warming, rarely, in nature (such as in a cold stream of water) or by an advanced medical team). Because of that CPR is generally only effective 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 death, and allows the heart to remain responsive to defibrillation attempts.

If the patient still has a pulse, but is not breathing, this is called respiratory arrest and artificial respiration is more appropriate. However, since people often have difficulty detecting a pulse, CPR may be used in both cases, especially when taught as first aid.

source: wikipedia.org