What does it mean to be clinically dead (deceased)?

From the Guidelines

Being dead means that an individual has sustained either irreversible cessation of circulatory and respiratory functions or irreversible cessation of all functions of the entire brain, including the brain stem, as defined by the Uniform Determination of Death Act 1. This definition is based on the most recent and highest quality evidence available, which emphasizes the importance of clinical examination in determining brain death.

Key Points to Consider

• The determination of death is typically confirmed when there is irreversible cessation of heartbeat and breathing (cardiopulmonary death) or when there is irreversible cessation of all brain function, including the brainstem (brain death) 1.
• The clinical diagnosis of brain death in a patient receiving or who has received neuromuscular blocking agents (NMBAs) should not be made unless the patient has a train-of-four (TOF) of 4/4 as measured using peripheral nerve stimulation (PNS) at the maximum current 1.
• The presence of NMBA-produced paralysis prevents assessment of the physical examination-based criteria for determining brain death, and therefore, their continued use during a brain death examination cannot be justified 1.

Important Considerations

• The American Academy of Neurology lists the first criterion for determining brain death as establishing an irreversible and proximate cause of coma, and the absence of central nervous system–depressant drugs and NMBAs 1.
• The physical examination is an integral part of brain death determination and must be performed with precision, but may be difficult to do in a paralyzed patient, which could lead to a breach of the “Dead Donor Rule” 1.
• Confirmation of brain death through such means as electroencephalogram, transcranial Doppler, or cerebral perfusion scans has not been recommended as a replacement for the clinical brain death examination 1.

From the Research

Definition of Death

• The concept of death has raised lasting questions about what it means to be dead, with implications for organ transplantation and end-of-life care 2.
• Death can be defined in terms of the biological failure of the organism to maintain integrated functioning, or on the basis of severe neurological injury even when biological functions remain intact 2.
• Some experts consider death to be essentially a social construct that can be defined in different ways, based on human judgment 2.

Biological and Physiological Changes

• Physiological changes that occur at the end stage of life can alter the pharmacokinetics of medications used for symptom control in palliative care 3.
• The interaction of drugs with the physiology of dying is complex, and pharmacological treatment is probably best assessed in a multi-disciplinary setting 3.

Palliative Care and Symptom Management

• A variety of medications are used for symptom control in palliative care, including morphine, midazolam, and haloperidol 3, 4, 5.
• These medications can help alleviate common symptoms such as pain, anxiety, dyspnea, nausea and vomiting, and respiratory tract secretions 4, 6.
• Anticipatory prescribing of medications such as analgesics, anti-emetics, anxiolytics, and anti-secretory medications can help ensure that patients have access to necessary medications in the last hours to days of life 6.