Cardiopulmonary Resuscitation (CPR) involves chest compressions and rescue breaths designed to artificially maintain blood flow and oxygen delivery to the brain and other vital organs when the heart has stopped beating. CPR is recognized globally as a foundational life-saving measure in cases of cardiac or respiratory arrest. While the instinct is to begin compressions upon finding someone unresponsive and without a pulse, CPR is not always appropriate. Specific circumstances, guided by legal instructions or physical reality, indicate that initiating or continuing resuscitation efforts would be inappropriate or medically futile.
Understanding Pre-Existing Medical Orders
A person’s right to determine their own medical treatment forms the basis for legal instruments that prohibit CPR. This concept of patient autonomy allows individuals to refuse medical interventions, including life-sustaining measures. The most common legal instruction is a Do Not Resuscitate (DNR) order, which instructs medical personnel not to attempt CPR in the event of cardiac or respiratory arrest. These orders result from informed consent, where the patient or their legally designated surrogate has discussed the likely outcomes of resuscitation with a healthcare provider.
The legal weight of a DNR order means that medical professionals and emergency medical services (EMS) are legally bound to withhold compressions and ventilations. For patients with serious chronic illnesses, these preferences may be documented on portable forms like Physician Orders for Life-Sustaining Treatment (POLST). These forms are designed to be immediately accessible and transferable across healthcare settings, honoring the patient’s wishes. The presence of a valid, authenticated order makes initiating CPR a violation of the patient’s legal and ethical rights.
Physical Indicators That Prevent Starting CPR
When a person exhibits certain definitive signs, biological death has already occurred, rendering any resuscitation attempt medically futile. These physical indicators confirm the body has been without circulation and oxygen for an extended period, making the restoration of life impossible. One such sign is rigor mortis, the stiffening of the muscles caused by chemical changes after death, which begins within two to four hours.
If a body is found completely rigid, CPR cannot be performed effectively. Another reliable sign is dependent lividity (livor mortis), which appears as a purplish-red discoloration of the skin where blood settles due to gravity. Lividity usually becomes noticeable within 30 minutes to three hours after death and becomes fixed after about 12 hours. Furthermore, obvious signs of massive, non-survivable trauma, such as decapitation or complete separation of the torso, immediately confirm that resuscitation is impossible.
When to Stop Resuscitation Efforts
The decision to terminate CPR differs between lay rescuers and professional medical teams based on training, resources, and specific protocols. For an untrained bystander, the criteria for stopping are based on physical limitations or scene safety. A lay rescuer should cease compressions if they become physically exhausted and are no longer able to deliver high-quality chest compressions.
Resuscitation efforts must also be stopped if the scene becomes unsafe, such as due to an active fire, traffic hazard, or exposure to dangerous chemicals, as rescuer safety takes precedence. For professional emergency medical providers, the criteria for termination of resuscitation (TOR) are significantly more detailed and protocol-driven. Efforts are stopped immediately if the patient achieves Return of Spontaneous Circulation (ROSC), meaning the heart has successfully restarted a sustained, effective rhythm. If ROSC is not achieved, protocols often rely on a combination of time and clinical findings.
These guidelines suggest considering termination when the arrest was not witnessed by EMS, no shocks were delivered by a defibrillator, and there has been no ROSC after a prolonged period of high-quality CPR (often 20 to 30 minutes). Advanced Life Support (ALS) teams use specific physiological markers to guide their decision-making. Persistent asystole (“flatline”) or Pulseless Electrical Activity (PEA) after aggressive treatment may indicate a non-survivable event. The presence of specific injuries incompatible with survival, such as catastrophic brain trauma, can also lead to a physician-ordered termination of efforts.