The medical term for insufficient oxygenation to the brain is referral Anglia. Historically, before recent technology the scientists defined death only when the heartbeat and breathing stopped. Afterward, the idea of brain death was announced in 1959 by French neurologists' Moldable and Gluon. They determined this state as "beyond coma" (D*mice et al. , 2004). Then after around ten years, within the medical community the development of many types of equipment became available which aided in increasing the longevity of individuals with serious injuries to the brain.
Some examples of these devices are ventilators to maintain respiration and heart monitors. These innovations in medicine made the concept of brain death clearer by closely showing the relationship between the respirations or heartbeat and brain. These innovations in the medical field guided the Harvard Medical School Committee to clarify that idea in 1968 (Sass, 2014). After that, it was medically defined as permanent loss of all brain functions, including cerebrum and brain stem due to total death of brain neurons that is caused by decrease of blood flow and oxygenation into the brain (ibid).
This essay will discuss the main brain regions that have immediate cause of brain death and their functions, including the required tests of these regions, both clinical and confirmatory, for instance, the Electroencephalogram. The brain carries two major parts, cerebrum and brain stem. When they have any cause of damaged that might be a final result in brain death. Each one has primary roles in a person's life, because they are responsible for the main operations in human survival, especially the regulation of cardiac and respiratory functions.
The cerebrum is the largest part of the brain and divided into two hemispheres (Fall & Bergman, 1998). There are main functions for he brain cerebrum without them no human can live. It is important to be concerned with functional specialization of different regions of the cerebrum to guide the treatment of the physician and assists them in making the right diagnosis. The cerebrum has a large primary sensory area, which is responsible for general sensation, for example, smell, vision, and hearing.
The motor area is responsible for controlling the skeletal muscles, and the association area of the cortex has operations similar to the sensory areas but more complicated such as behavior, communication and intellect (ibid). Secondly, the brain stem is located in the posterior division of the brain and connected to the spinal cord. Beside that it includes three significant parts; medulla obbligato, pens and mandarin. Each one controls principal performance and it is the pathway of sending and receiving sensory information signals from the body to the brain.
It has other important functions that have a major affect on a person such as regulation of the respiratory system, consciousness, alertness and awareness (Kiering & Barr, 2009). In general, both cerebrum and brain stem damage may end a arson's life because they contain all the regulation centers for all of the most critical functions that are needed to sustain life. There are many criteria to diagnose brain death. Each country has their organization, but there are general rules and guidelines in determining brain death for patients worldwide.
There are important tools to consider when deciding whether the patient is dead or not, before the process of diagnosis of death by the criteria. The first tool is a person who is approaching the protocol of brain death qualified? For example, an ICC physician, an anesthesiologist, an internist, a neurosurgeon or a neuron physician are allowed and qualified to perform the tests because they have studied and trained to diagnose brain death, but a dermatologist or an ophthalmologist they have not done training on that.
Although, they need to know the state of the patient and must be in a coma with ventilator support and the cause of their comatose condition must be rolled out, for instance, Head trauma, Cardiovascular hemorrhage, cerebral Anglia or primary brain tumor. Next, the cause of brain damage must be clarified six hours before tarring brain functions evaluation. Finally, the patient should not be hypothermia and body temperature has to be above 34 C or 32 C in some countries protocol and the person should not be under sedatives, muscle relaxant, anticonvulsant... Etc Drugs for at least the previous five days. When these tools completed correctly the physician can start the diagnosis in following exam steps. The first clinical examination is to confirm that the patient is in a coma and to make sure a patient is not having any seizure activity in the brain. Furthermore, the physician needs to test he absence of motor response by painful stimulation for both hands and feet. It is required to do these evaluation exams on the standard method before starting the brain stem reflexes test because each exam depends on the previous one to give correct final result.
Once the physician has done from the previous evaluation he will start the brain stem reflexes tests, which called the first clinical examination. These are five different exams and begin with papillary response. The light stimulation to test the pupil response by bright beam of light on both eyes, for example, a pen alights. Also, corneal reflex is involuntary blinking and has to be tested via a wisp of cotton wool to touch the cornea. Thirdly, cool-cephalic reflex it does perform by moving the head to a different direction and monitor the retina changes during the head movements.
Fourthly, vestibule-ocular reflex this another test to activated eye movements by injecting both ears about 50 ml of ice-cold water or saline for adult, but children, less than 20 ml may be used. After all, upper and lower airways stimulation is produce either gagging or coughing. Furthermore, this exam's purpose or provoke the pharynx and trachea. For instance, using catheter leads down to reach into the pharynx and the trachea (Saudi center of organ transplantation, 2009). Accordingly, all those brain stem tests should result an absent responses to declare brain stem death.
After finalization of the first examination, it's recommended to not start the second clinical test before 6 hours from the time of first exam end for an adult and after 12 hours for children (above 1 year),24 hours for infants (above 60 days-I year) and 48 hours for neonate (7 days-60 days). Therefore to have enough mime to perform the confirmatory tests, such as Electroencephalogram (EGG) which is a machine that has 21 electrodes connected to the skull to cover all the brain regions and measures the electrical activity of the brain (ibid).
In fact, the EGG and other confirmatory tests are optional in some countries but it is often helpful for the physician to prove that the brain is permanently damaged by having more than one test that confirms his diagnosis and prognosis. The next clinical exam is apneas; it is done to indicate the failure of involuntary respiration. This exam has a specific rotator to perform it, such as an increase the inspired fraction of oxygen without changing the ventilation rate, disconnect the patient from the ventilator for 10 minutes and supply a continuous flow of humidified air.
These procedures are done to detect if there is any attempt for the patient to breathe (ibid). Another test that is sensitive in analyzing the circulation in the brain is transitional Doppler (ETC) this examination detects the velocity of the blood that's circulating in the blood vessels supplying oxygen-rich blood to the brain. It uses ultrasonic waves that are focused onto a beam that is directed at different depths and angles by an experienced operator. The technologist uses sites on the skull where the bone is relatively thin and relatively close to the major vessels whose blood flow velocities are critical.
One major vessel that supplies the brain is the Middle Cerebral Artery (MAC). When the blood flow circulation is compromised to the extent that survivability is not possible the ETC shows reverberating waveforms as the blood ceases to flow in it's normal direction and instead is ineffectually regurgitating back and forth without flow in espouse to the heart contraction. Later there are systolic spikes that indicate some increased pressure in the vessel with heart contraction but without effective flowing of blood through the vessel.
The last signal that is compatible with brain death is a loss of signal entirely indicating no activity in the vessel and no recordable blood flow in the critical vessels of the brain. In conclusion, the concept of brain death has developed with period of the medical field improvements. The absence of a rich uninterrupted supply of oxygen is imperative to supply the brain and maintain unconsciousness and provide for the populations of neurons to continue to function properly.
Trauma, disorders and diseases which impair circulation in the cerebral cortex and brain stem bring about a cascading assortment of symptoms that if not reversed results in death. The protocols and guidelines for brain death determination have been established for the safety of the patient to distinguish between patients who have suffered a life-threatening insult, but who may recover and those unfortunate individuals in whom there is no hope for recovery.