Learning Outcome

• What is meant by brain death?
• List out the causes 
• Mention the risk factors
• Illustrate the assessment
• What is the evaluation process?
• Recall the medical management
• Point out the nursing management

Introduction

Brain death is both a legal and clinical term. The term has been present in medical literature and texts for many years, but as part of the National Conference of Commissioners on Uniform State Laws in 1980, the Uniform Determination of Death Act (UDDA) was drafted'; this was later adopted by the American Medical Association and the American Bar Association. The act was drafted in response to medical advances in life support in the late 1970s that allowed for complete respiratory and circulatory support despite the complete cessation of brain function. This reads as follows "Determination of Death: An individual who has sustained either (1) irreversible cessation of circulatory and respiratory functions, or (2) irreversible cessation of all functions of the entire brain, including the brain stem, is dead. A determination of death must be made under accepted medical standards."

Unfortunately, the UDDA did not go on to establish what "accepted medical standards' were, only that they existed. The American Academy of Neurology (AAN) initially published the most current standards in 1995 and then updated them in 2010.[1]

Based on the published standards, three findings must be present to establish brain death; the AAN defines them as "coma (with a known cause), the absence of brainstem reflexes, and apnea."[2][3][4]

Nursing Diagnosis

• Anticipatory grieving of the family is related to the loss of physiological well-being, as evidenced by changes in all the regular activity patterns.
• Compromised family coping related to unrealistic expectations as evidenced by the inability to accept the patient's degrading health.
• Ineffective tissue perfusion is related to decreased blood volume as evidenced by compression of vital areas within the brainstem.
• Decreased cardiac output related to altered stroke volume as evidenced by tachycardia, hypotension, and decreased peripheral pulse.

Causes

Brain death occurs after the destruction of enough neuronal cells in the brain that there is both an irreversible loss of consciousness (coma) and the absence of brainstem reflexes, including the inability of the lungs to inhale and exhale without external positive pressure support (apnea).[3]

In adults and children, the precipitant of brain death is either from an intracranial or extracranial cause. First, we have to establish an acute and irreversible cause. Intracranial injuries leading to brain death in adults are most commonly caused by traumatic brain injury or subarachnoid hemorrhage. In children, the most common cause is non-accidental trauma. The extracranial cause of brain death is most commonly cardiopulmonary arrest with inadequate cardiopulmonary resuscitation.[5]

We have to exclude the presence of any drugs or poisoning in the system. This can be accomplished by history, drug screen, etc. A thorough lab testing is performed to exclude severe endocrine, acid-base, and electrolyte disturbances.

The usual causes include:

• Severe head injury
• Brain tumors causing brain swelling may lead to brain death
• Blockage of blood vessels due to blood clots
• Infections like encephalitis and meningitis may lead to brain death

Risk Factors

The processes that lead to brain death are in order of frequency: cardiopulmonary arrest, traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage.

For extracranial causes of brain death, in patients with cardiopulmonary arrest, 8.9% of those initially resuscitated will progress to brain death. In patients presenting with traumatic brain injury, 2.8 to 6.1% will die of brain death.

Among the intracranial etiologies of brain death, 8.5 to 10.7% of patients presenting with subarachnoid hemorrhage will progress to brain death, compared to 6.1 to 9.6% of those with intracerebral hemorrhage.[6][7]

By definition, brain death carries 100% mortality.

Assessment

Once the decision to proceed with the brain death determination has been made, three conditions must be present: coma, the absence of brainstem reflexes, and apnea.

Coma should be evaluated by ensuring a lack of responsiveness to noxious stimuli; no eye or motor reflex should be present in response to stimuli. Additionally, the cause of the coma should be identified by neuroimaging, history, and physical or laboratory testing. 

The following brainstem reflexes should be tested in the physical exam of a patient deemed for brain death evaluation; they all must be absent for a patient to be diagnosed as brain dead:

• The pupillary reflex to light – must be fixed at a mid-position, usually around 4 to 9 mm, and must not respond to light
• Oculocephalic reflex – performed by rapidly turning the head
• Oculovestibular reflex (cold caloric) – absence when the head is held at 30 degrees and cold water is instilled in the ear canal
• Corneal reflex – stimulate with a swab.
• Gag reflex – stimulate posterior pharynx
• Cough reflex – stimulate with endotracheal suctioning
• The facial movement to noxious stimuli – apply noxious pressure to the supraorbital ridge; there should be no facial muscle response
• Any external injuries causing blood loss

Evaluation

Before deciding to proceed with the diagnosis of brain death, several conditions must be evaluated and met:

• Ensure no recent neuromuscular blocking agents have been administered (must wait five times the drug half-life).
• Drug screen to ensure no central nervous system (CNS) depressants are present. 
• Normal core temperature must be present >36 C
• Normal systolic blood pressure >100 mmHg; vasopressors may be administered if necessary. 
• No severe electrolyte, acid-base, or endocrine disturbance
• Neurologic examination, in most US states, 1 attending physician exam is sufficient; however, some states require 2. 

If the above conditions are present, and there is an identified cause of coma and complete lack of brainstem reflex, the examiner may proceed with apnea testing. 

Apnea testing is performed by the following procedure as recommended by the AAN:

• Preoxygenate for at least 10 minutes with 100% FiO2 to a PaO2 >200mmHg
• Reduce ventilator frequency to 10 breaths per minute. 
• Reduce positive end-expiratory pressure to 5 cm H2O.
• If SPO2 remains >95%, obtain baseline blood gas. 
• Disconnect the patient from the ventilator, and preserve oxygenation with oxygen delivered through insufflation tubing given at 100% FiO2 at 6L/min near the level of the carina through the endotracheal tube. 
• Look for respiratory movements for 8 to 10 minutes.
• If no respiratory drive is observed, repeat blood gas at approximately 8 minutes. 
• If no respiratory movements are observed, and PCO2 is >60mmHg, the apnea test result is positive. 

If the above list is complete, and coma, the absence of brainstem reflexes, and a positive apnea test are present, the diagnosis of brain death can be made. This procedure is validated and supported by several professional organizations. 

Although not required for the diagnosis of brain death, hospitals frequently have additional ancillary tests available to confirm the diagnosis of brain death. These include electroencephalogram (EEG), cerebral angiography, nuclear scan, transcranial doppler, computed tomogram angiogram (CTA), and magnetic resonance imaging (MRI)/ magnetic resonance angiogram (MRA). These tests are used when apnea testing is inconclusive, or patients are too unstable to proceed with apnea testing.[2][8] 

In the case of cerebral angiography, no intracerebral filling is noted in the carotid or vertebral arteries at the skull entry-level, and blood flow in the external carotid artery is maintained. In the case of EEG, no electrographic reactivity is noticed after intense stimuli, either somatosensory or audiovisual.[9] It is crucial to understand that there is no need to establish the death of every neuron in the brain to demonstrate brain death. For example, some neuroendocrine function is preserved even after death in the brain stem and cerebral hemispheres.[10] MRI of the brain is not yet accepted as an ancillary test for brain death determination.

Medical Management

Once brain death has been diagnosed, the patient is clinically and legally declared deceased at the time of death after testing. At this time, depending on family and patient preference, cardiopulmonary support should be withdrawn, or arrangements for organ harvest should begin. Adequate documentation of all criteria of the diagnosis of brain death must be included in the patient's medical record. It is recommended that some form of checklist be used to ensure the completeness of testing.[5]

Nursing Management

• Provide proper suctioning of the endotracheal/tracheostomy tube to remove secretions from the airway. This also helps to prevent blockage of endotracheal or tracheostomy tubes.
• Clean all the body parts, especially the face, back, and perineal area.
• Provide dressing to open wounds (if any) and cover them with gauze pieces.
• Every patient goes through a different situation despite having the same diagnosis. Nurses should manage the patients accordingly.
• Visualization of patient treatment and prognosis, as well as counseling daily, may slowly help family members cope with the patient's degrading health status.
• Change the patient's position every 2 hours to prevent bedsores.
• Check the intravenous cannula sites for redness and swelling.
• Make sure that the "Do not attempt resuscitation order" (DNR) is in place
• Provide emotional and psychological support to the family and relatives of the patient, as they may deny seeing their loved ones in the end stage.
• Find out and inform the organ donation center as soon as a patient is declared brain dead.
• Respect the patient's cultural and religious backgrounds.
• Record and report all the procedures that are done for the patient throughout the hospital stay.

When To Seek Help

If the patient develops hypotension, there will be reduced urine output and extreme variations in heart rate.

Outcome Identification

The prognosis of the brain-dead patient is dismal and will result in physical death very soon, even with all the support and resuscitation.

Monitoring

• Glasgow Coma Scale (GCS) score and pupillary reflex.
• Variations in vital signs and ECG changes.

Coordination of Care

The designation of brain death will often involve a multidisciplinary team. Nurses, physicians, social workers, and clergy will play a vital role in working with families throughout the evaluation and once the diagnosis is made. Subspecialists, such as neurology, neurosurgery, and radiology, may be required to aid in interpreting ancillary testing if the clinical diagnosis is inadequate. While the diagnosis is considered, an interprofessional team specially trained in organ procurement should be involved; these specialty teams should handle all aspects of care only once the diagnosis of brain death has been made to ensure adequate protection for the team that cared for the patient until death.

Health Teaching and Health Promotion

The diagnosis of brain death is difficult for families to accept. However, there is research to support asking the family to witness the clinical evaluation of brain death will help them understand the diagnosis. Multiple meetings with more than one provider, clergy, social workers, or other ancillary staff may be necessary for the family's acceptance of the diagnosis.[11]

Risk Management

• Promote circulation to protect the donating organs.
• Keep the body in proper alignment, as some patients are prone to develop bedsores.
• Avoid any injury while extracting tubes or performing any procedure.
• Avoid infection in any wound or surgical site.

Discharge Planning

Proper documentation should be in place regarding the declaration of brain death and ensure that a death certificate is prepared per the protocol.

Pearls and Other issues

Requirements for the diagnosis of brain death: 

• Coma with an identified cause
• The absence of brainstem reflexes
• Apnea

The diagnosis is best made by closely following the American Academy of Neurology guidelines.