Mr. JF is a 57 year old man with a past medical history of hypertension who was found unresponsive by a family member. Emergency Medical Services found the patient to be unresponsive and hypertensive. Upon arrival to the Emergency Room at Grady Memorial Hospital, the patient was in respiratory distress. He was a very difficult intubation, and a tracheal tube for breathing was eventually placed. On Computed Tomography (CT) of the head, he was found to have bilateral posterior cerebellar artery (PCA) infarcts and uncal herniation.
Whether as a physician in the emergency room, in the trauma bay, in the medical intensive care unit, or on the neurology service, we already have or will encounter a situation such as this at some point during our careers. Many difficult decisions need to be made immediately, and others will need to be made over the next few hours and days. As with many patients, these decisions will be critical to the patient’s prognosis for survival, the family’s perception of the patient’s prognosis, as well as their perception of the care given to the patient. The comatose state, vegetative state, and brain death are issues that are discussed by those outside of medicine. These topics have quite a bit of confusion among the general public, and it is quite apparent in the with the Terri Schindler-Schiavo case.
According to
www.terrisfight.org, Ms. Schindler-Schiavo “is in a locked-in state”. Furthermore “though she is responsive to stimuli, interacts with her environment and her loved ones and is capable of communicating in limited ways, she is a disabled and vulnerable adult - requiring protection, therapy and the route to recovery.”1
Her case has spawned debate on television, on Internet forums, and even a new “Terri’s Law”- the term given to the decision of Florida governor Jeb Bush to restore tube feedings to Ms. Schindler-Schiavo. It is important for us as physicians to dispel any misconceptions our patients’ families may have. It is also important for us to respect and honor the decisions of our patients’ families.
Brain Death, a definition:
The levels of consciousness can be thought of as a continuum: from alert, oriented, and active in a meaningful way with other individuals to absolute absence of alertness, orientation, or activity.
Coma, from the Greek word “koma”, literally means deep sleep 1. The comatose state is one of pathologic unconsciousness. The comatose patient is unaware of his/her surroundings, and is unable to be aroused. There are many anatomical and metabolic reasons for a person to be in a coma, which are outside the scope of this paper. However, all of the different reasons for coma affect the cerebral cortex and/or the reticular activating system. The cerebral cortex, which is composed of the right and left hemispheres, controls voluntary movement and sensation. It is also responsible for thought, reasoning, and memory. The reticular activating system is not located in a particular area of the brain, but rather it is a collection of different portions of the brain, including the thalamus, brainstem, and medulla. Together, the cerebral cortex and the reticular activating system are responsible for consciousness.2, 3
A comatose patient may or may not make a meaningful recovery. One comatose patient may regain consciousness, as well as regain all abilities present prior to the coma, whereas another comatose patient may regain consciousness, but with impairment of some or all abilities. Yet another comatose patient may remain in a coma. This third scenario is termed a persistent vegetative state. A persistent vegetative state is also characterized by unawareness, but patients have normal sleep-wake cycles and are arousable. A fourth comatose patient may progress to brain death.
Brain death can be defined as “an unresponsiveness and lack of receptivity, the absence of movement, and breathing, the absence of brain-stem reflexes, and coma whose cause has been identified”4. In the brain dead state, a patient is completely relying upon medical interventions to keep the heart beating and the lungs respiring.
Mimickers of brain death: hypothermia, drug intoxication, “locked in” syndrome.
There is an old saying that a dead body must be a warm body. Hypothermia is a condition that occurs when body temperature falls below 35 degrees Celsius. It may occur when a person is subjected to extremely cold temperatures, or if there is a pathological condition affecting the temperature regulating portion of the brain, found in the hypothalamus. As the core temperature of the body drops below 35 degrees Celsius, coordination will begin to be lost. The skin may become pale, muscles may become rigid, and shivering may occur in an attempt to maintain and perhaps raise core temperature. Heart rate, respiratory rate, and blood pressure may begin to rise in this early stage of hypothermia. As the core temperature continues to drop, speech may become slurred and confusion may begin to set in. As the core temperature of the body drops below 32 degrees Celsius, the response to light is lost (i.e. no pupillary response). Although they rose in the early stage of hypothermia, heart rate, respiratory rate, and blood pressure will begin to plummet once core temperature falls below 32 degrees Celsius. As the core temperature drops below 28 degrees Celsius, brain-stem reflexes are lost. It is imperative to remember that people can survive the extreme cold, and all of these deficits are potentially reversible.5
A chart used by EMS.
Somewhere between twenty-five to forty percent of hospital admissions are related to substance abuse and its sequelae, and ten to sixteen percent of outpatients seen in primary care practice are suffering from addiction related problems. Roughly ten percent of Americans, report misuse of sedatives in their lifetime. Approximately five to ten of primary care patients meet clinical criteria for major depression. Approximately ten percent meet criteria for minor depression. Antidepressant has increased dramatically within the last ten years with the advent of selective serotonin reuptake inhibitors (SSRIs), the television commercials and advertisements of pharmaceutical companies, leading to the increased awareness and recognition of depression by the general public. Sixty-two percent of Americans age eighteen and over have had alcohol in the past year. Thirty-two percent of those had five or more drinks on the same occasion at least once in the past year. Needless to say, sedatives, antidepressants, and alcohol are commonly used, misused, and abused in today’s American society. When used in combination, the effects can be deleterious, even fatal. Barbiturates, other sedatives, antidepressants, even alcohol can mimic brain death when present at extreme or toxic levels. However, certain portions of brain-stem function remain intact, such as the pupillary response to light.6, 7, 8, 9, 10, 11, 12, 13
Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating polyneuropathy of unknown origin, characterized by progressive muscle weakness and areflexia. It appears that GBS, also known as ascending paralysis, was first described by James Wardrop in 1834. It was more fully described by Jean Baptiste Octave Landry de Thézillat in 1859, and for a time was known as Landry’s ascending paralysis. In 1916, the landmark study was undertaken by Guillain, Barré, and Strohl. The name "Guillain-Barré Syndrome" was first used in 1927 and persists to this day. GBS occurs in both men and women, affecting people of all ages. It has an annual incidence of 0.6 to 2.4 cases per 100,000; and is now the most common cause of acute flaccid paralysis in healthy people. 14, 15, 16, 17
Though spontaneous remission is the typical outcome, GBS can progress to involve cranial and peripheral nerves, resulting in a “Locked-In Syndrome” (LIS). The term LIS was introduced by Plum and Posner in 1966 and is used to define a clinical picture characterized by a total paralysis of voluntary motor functions with preservation of vertical eye movements combined with synergetic elevation of the upper eyelids when looking upwards. This syndrome is usually associated with a bilateral ventral pontine lesion.18, 19, 20
Brain death is a completely irreversible condition, whereas hypothermia, drug intoxication, and locked-in syndrome are potentially reversible.
Determination of brain death:
One must use his/her clinical neurological skills to find and document coma, the complete absence of brain-stem reflexes, and apnea. The clinical criteria consist of: coma, absence of motor responses to pain, absence of pupillary responses to light, absence of corneal reflexes, absence of caloric responses, absence of gag reflex, absence of coughing in response to tracheal suctioning, absence of sucking and rooting reflexes, and absence of respiratory drive at a PaCO2 that is 60 mm Hg or 20 mm Hg above normal base-line values (i.e. failed apnea test). 21
A physician should refer to the rules, regulations, and criteria of the particular hospital in order to establish brain death in a patient. It is of note, “that it is not the physician’s role to diagnosis death, but rather to diagnose life.”22
What to do if uncertainty remains about brain death?
If uncertainy remains, so-called confirmatory tests can be ordered: electroencephalography (EEG), transcranial Doppler ultrasonography, cerebral angiography, and/or cerebral scintigraphy. None of these technological modalities should be used alone in determining brain death, but rather their interpretation should be combined with the objective findings of the physical exam.
An EEG is a non-invasive procedure in which electrodes are placed on the head of the patient. The electrical output and activity of the brain is recorded and read on a monitor. In brain death, a lack of reactivity to stimuli needs to be demonstrated on EEG.23
Transcranial Doppler ultrasonography is another non-invasive procedure. However, this modality uses sound waves to detect direction, velocity, and direction of blood flow.
A cerebral angiography test is an invasive procedure where a radiopaque substance is injected into the arteries so that the blood vessels will be prominent on X-ray. In brain death, no filling of the cerebrum should be detected in the carotid or vertebral arteries on cerebral angiography.24
Cerebral scintigraphy uses a radionucleotide, generally technetium bound to another molecule, to determine perfusion of the cerebral perfusion. There should be absence of cerebral and brain stem activity on cerebral scintigraphy in order for brain death to be determined.
Conclusion:
The subject of brain death is a hot button issue in today’s society. Care should be taken by the physicians, and the rest of the health care team in establishing brain death. The cause of the patient’s coma must first be determined. Mimickers of brain death need to be ruled out. A careful physical and neurological exam will lead the physician to diagnose life, or determine a state of brain death. If the objective physical exam does not fit all clinical criteria of brain death, there are a number of confirmatory tests which can be done. The results of any test performed should be used in conjunction with the physical exam. In the end, it is important for the physicians: 1. to answer any questions of the patient’s family, 2. to dispel any misconceptions about the patient’s condition, and 3. to honor the decisions of the family, even if it goes against what the physicians would choose to do.
Upon neurological exam, Mr. JF was found to have absence of all brain stem reflexes. He failed the apnea test. However, he did have a reproducible triple reflex with plantar stimulation. An EEG was obtained, which was found to be severely abnormal, but not isoelectric. The medical ICU team was informed of the findings. The family, taking everything into account, decided to withdraw care.
Schiavo's feeding tube has been removed...
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Originally Posted by RISKYB
