Low body temperatures, as sometimes seen in near-drownings, prolong the time the brain survives. The heart also rapidly loses the ability to maintain a normal rhythm. Therefore, in general CPR is effective only if performed within seven minutes of the stoppage of blood flow. Typically if blood flow ceases for one to two hours, then body cells die. 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. Blood circulation and oxygenation are required to transport oxygen to the tissues. Pathophysiology ĬPR is used on people in cardiac arrest in order to oxygenate the blood and maintain a cardiac output to keep vital organs alive.
Correcting the underlying cause such as a tension pneumothorax or pericardial tamponade may help. In those with cardiac arrest due to trauma, CPR is considered futile but still recommended. : S643 If a person still has a pulse but is not breathing ( respiratory arrest) artificial ventilations 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. 6.5 Survival differences, based on prior illness, age or locationĬPR 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.4.5 Mobile apps for providing CPR instructions.4.4 Devices for providing automatic CPR.
ĬPR 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. It is recommended in those who are unresponsive with no breathing or abnormal breathing, for example, agonal respirations. Cardiopulmonary resuscitation ( CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation 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.