Life support

Life support refers to the treatments and techniques performed in an emergency in order to support life after the failure of one or more vital organs. Healthcare providers and emergency medical technicians are generally certified to perform basic and advanced life support procedures; however, basic life support is sometimes provided at the scene of an emergency by family members or bystanders before emergency services arrive. In the case of cardiac injuries, cardiopulmonary resuscitation is initiated by bystanders or family members 25% of the time. Basic life support techniques, such as performing CPR on a victim of cardiac arrest, can double or even triple that patient's chance of survival.^[1] Other types of basic life support include relief from choking (which can be done by using the Heimlich maneuver), staunching of bleeding by direct compression and elevation above the heart (and if necessary, pressure on arterial pressure points and the use of a manufactured or improvised tourniquet), first aid, and the use of an automated external defibrillator.

The purpose of basic life support (abbreviated BLS) is to save lives in a variety of different situations that require immediate attention. These situations can include, but are not limited to, cardiac arrest, stroke, drowning, choking, accidental injuries, violence, severe allergic reactions, burns, hypothermia, birth complications, drug overdose, and alcohol intoxication. The most common emergency that requires BLS is cerebral hypoxia, a shortage of oxygen to the brain due to heart or respiratory failure. A victim of cerebral hypoxia may die within 8–10 minutes without basic life support procedures. BLS is the lowest level of emergency care, followed by advanced life support and critical care.^[2]

Bioethics

As technology continues to advance within the medical field, so do the options available for healthcare. Out of respect for the patient's autonomy, patients and their families are able to make their own decisions about life-sustaining treatment or whether to hasten death.^[3] When patients and their families are forced to make decisions concerning life support as a form of end-of-life or emergency treatment, ethical dilemmas often arise. When a patient is terminally ill or seriously injured, medical interventions can save or prolong the life of the patient. Because such treatment is available, families are often faced with the moral question of whether or not to treat the patient. Between 60 and 70% of seriously ill patients will not be able to decide for themselves whether or not they want to limit treatments, including life support measures. This leaves these difficult decisions up to loved ones and family members.

Patients and family members who wish to limit the treatment provided to the patient may complete a do not resuscitate (DNR) or do not intubate (DNI) order with their doctor. These orders state that the patient does not wish to receive these forms of life support. Generally, DNRs and DNIs are justified for patients who might not benefit from CPR, who would result in permanent damage from CPR or patients who have a poor quality of life prior to CPR or intubation and do not wish to prolong the dying process.

Another type of life support that presents ethical arguments is the placement of a feeding tube. Decisions about hydration and nutrition are generally the most ethically challenging when it comes to end-of-life care. In 1990, the US Supreme Court ruled that artificial nutrition and hydration are not different from other life-supporting treatments. Because of this, artificial nutrition and hydration can be refused by a patient or their family. A person cannot live without food and water, and because of this, it has been argued that withholding food and water is similar to the act of killing the patient or even allowing the person to die.^[4] This type of voluntary death is referred to as passive euthanasia.^[5]

Techniques

There are many therapies and techniques that may be used by clinicians to achieve the goal of sustaining life. Some examples include:

• Feeding tube
• Total parenteral nutrition
• Mechanical ventilation
• Heart/Lung bypass
• Urinary catheterization
• Dialysis
• Cardiopulmonary resuscitation
• Defibrillation
• Artificial pacemaker
• Life extension
• Life support system for human spaceflight.^[6]

These techniques are applied most commonly in the Emergency Department, Intensive Care Unit and, Operating Rooms. As various life support technologies have improved and evolved they are used increasingly outside of the hospital environment. For example, a patient who requires a ventilator for survival is commonly discharged home with these devices. Another example includes the now-ubiquitous presence of automated external defibrillators in public venues which allow lay people to deliver life support in a prehospital environment.

The ultimate goals of life support depend on the specific patient situation. Typically, life support is used to sustain life while the underlying injury or illness is being treated or evaluated for prognosis. Life support techniques may also be used indefinitely if the underlying medical condition cannot be corrected, but a reasonable quality of life can still be expected.

Gallery

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  Dialysis center for patients with severe chronic kidney disease

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  Hemodialysis machine Bellco Formula

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  Endotracheal tube of an emergency ventilator system

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  An iron lung

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  Ventilator "Evita4" on an ICU

References