Success after CPR
The number of people who survive cardiac arrest following the administration of CPR remains relatively low. For cardiac arrest occurring within hospital, the chance of surviving to hospital discharge varies considerably and depends on many factors, including existing co-morbidities and the cause and circumstances which led to the event. Studies indicate that the average survival to hospital discharge is 15-20% (Sandroni et al 2007; Meaney et al 2010; Girotra et al 2012; Nolan et al 2014).
When cardiac arrest occurs out of hospital and CPR is attempted, average survival to hospital discharge is lower, usually 5-10% (Nolan et al 2007; Berdowski et al 2010; Perkins & Cooke 2012). The probability of success depends on many factors such as underlying cause, how soon CPR is commenced, and the availability of resuscitation equipment and appropriately trained personnel. We should also recognise that the chances of survival after cardiac arrest will be much lower in patients with life-limiting conditions than the unselected populations quoted in the literature above.
Throughout this policy the term "successful" in the context of a clinical decision about CPR, is used to mean CPR which achieves sustainable spontaneous breathing and circulation. However, while success after CPR may be measured clinically by immediate sustainable survival, it is often more meaningfully understood by patients and their relevant others to indicate a return to a quality of life that the patient would find acceptable. Where a patient already has a life-limiting illness, the best that could be hoped for from "successful CPR" is return to that state or more often a reduced level of physical and mental health and function. During CPR, rib fractures and hypoxic brain injury are significant risks. There is a great potential for inflicting distress, harm and suffering in an attempt to prolong some level of survival. The likelihood of success as measured by survival needs to be viewed in this context. Intensive Care is not an option which can change outcome when the cause of arrest was an underlying life-limiting or terminal illness which cannot be improved. In patients with significant life-limiting illness the balance of potential benefits and burdens of any intervention must be considered with the patient and their relevant others before any advance decision can be made.
It is not possible to give guidance for all patients and situations. Individual clinicians should use their knowledge of their patient and natural history of their current underlying health problems to decide what outcomes are likely and when CPR would not work or would lead to outcomes that are not in line with patient wishes. As set out later, though, clinicians must not base their decision on their subjective opinion of the patient's "quality of life".
Email: Elizabeth Gourlay, firstname.lastname@example.org