“Life is pleasant, death is peaceful. It is the transition that is troublesome.” - Issac Asimov
After suffering severe brain injury in a motorcycle accident, Sameer had been unconscious for three weeks. His relatives would patiently sit outside the ICU for days together, anxiously waiting for any updates. The wait became increasingly tiresome, as Sameer remained in a deep coma. All of his brain functions had stopped, but he was still connected to the ventilator – and his heart was still beating. The family finally asked the doctor: “Is he really alive? If not, can we take him off the ventilator?”
Sameer’s family has just asked a very important question: Was he dead? The ECG monitor showed a beating heart pattern, and the ventilator kept pushing air in and out of his lungs. At what point does a person really die? Does the ECG have to show a flat line, as shown dramatically in the movies? Can the doctor switch off the ventilator?
Such scenarios are commonplace in every major hospital in the present day. This article is written to clarify the situation about brain death, and to help differentiate between coma, persistent vegetative state and brain death.
Evolution of death
Till the 1950’s, there was hardly any confusion about when exactly a person died. Once breathing ceased, there was no more oxygen delivered to the heart. The heart would stop, blood supply to the brain would stop, and that was it. Alternatively, the heart would stop first, oxygen supply to the rest of the body including the brain would stop, and the person would be dead in a matter of minutes. In other words, we died when we were no longer breathing and the heart stopped.
With advancement of medical technology, ventilators arrived. These machines could deliver air and oxygen into the lungs, even when the person was not able to breathe on his own. Breathing never stopped as long as the device was plugged in, even in patients whose brain had stopped working. From being a single event, death suddenly became a process.
Why does the heart still go on in a ventilated patient? The heart is not wholly controlled by the brain. It has its own pacemaker and electrical network, but needs a steady supply of oxygen. Being largely an independent organ, it continues to pump blood as long as it receives oxygen - whether it is through normal breathing or through artificial breathing, and can continue beating for several days even after brain-death.
This creates confusion about when the person actually dies. As one can no longer use the cessation of breathing as the point of death, when does the person really die? Is it when the brain stopped functioning completely, or when the heart stopped beating?
What is the difference between coma, persistent vegetative state and brain death?
Technically speaking, the brain has two departments: The cortex (first floor) and the brainstem (the ground floor). The cortex, which looks like a large soft cauliflower boxed inside the skull, carries out the conscious functions of thinking, memory, emotion, speech, control of limb movements, and the five senses including vision, taste, smell, hearing and touch. The cortex is very delicate: even a few minutes without oxygen supply can cause damage, which becomes permanent if prolonged.
The brainstem - practically the thick stalk of the cauliflower - is located at the bottom chamber of the skull, its tail extending into the upper part of our neck. It performs largely involuntary (automatic) functions such as breathing, temperature and blood pressure regulation, and is also the delicate corridor through which tightly packed bundles of nerves travel, connecting the brain to the rest of the body. The brainstem is less dependent on oxygen than the cortex, therefore gets damaged only in more severe cases of hypoxia.
To understand this better, let us consider the case of a man who suffers hypoxic brain damage following a cardiac arrest and is then placed on a ventilator after resuscitation. The level of injury can vary depending on how long the brain went without oxygen.
When the first floor (cortex) is non-functional, the person enters into a coma, like a power-cut affecting only the top floor of a house. He is no longer able to respond to any of the five senses, and is unable to comprehend or speak. The person is neither awake nor aware. However, the intact ground floor (the brainstem) ensures that automatic functions like breathing, digestion and circulation continue. With time, if the initial hypoxic injury was mild, the cortex might recover its function, and the person wakes up from the coma.
When such a recovery of the cortex does not happen even after a month, it is called a persistent vegetative state. Although he does not respond to any external stimuli, chances are he will be able to breathe without a ventilator, and have normal digestive process, as his brainstem (the ground floor of the brain) is still working. He will have sleep-wake cycles and may even seem awake at times when he opens his eyes (albeit without purpose), but he is not aware. Further recovery after three months in this condition is exceedingly rare. He may live like this for years, as long as he receives nutrition through a feeding tube, and basic nursing care. Persistent vegetative state is not brain-death.
In contrast, if the damage was so severe that the ground floor (brainstem) also became non-functional, the person remains in a deep coma and in addition, he is no longer able to breathe or maintain other automatic functions like circulation. There is prolonged power-cut on both floors of the house, which means there is no chance of survival. This is called brain-death. Such a person may have a beating heart when the ventilator is operational, but this also eventually fails.
In technical language, brain death is the triad of irreversible coma (of known cause), absence of brain-stem reflexes and irreversible apnea.
In most developed countries, brainstem death or whole-brain death is now accepted as the point of death.
How is brainstem death declared?
After confirming that there is no reversible process to account for brain dysfunction, doctors perform a set of tests at the patient’s bedside to ascertain the function of the brainstem. Among these tests, the most important is the ‘Apnea test’ which checks the patient’s ability to breathe on his own. The test measures the blood concentration of carbondioxide while the ventilator is temporarily disconnected. If the person does not take spontaneous breaths in spite of rising CO2 levels, the Apnea test is positive, confirming brainstem death.
What is the importance of a precise definition of death in India?
All over the world, health care is expensive, and it is widely agreed that futile treatment measures are best minimized. In contrast to places like the UK with a National Health Service, in India, advanced health care is largely delivered by the private sector - and patients pay out-of-pocket for most of their medical expenses. With a low per-capita income and a large population, there is a resource crunch; there aren’t enough ventilators or critical care facilities to accommodate the needs of large numbers of patients. It follows that such life-support measures be given only to those patients who will actually benefit. In fact, there is a view that the term ‘life-support’ cannot be used in brain-dead patients, as they are not technically alive. It is not only expensive, but also unethical to keep a dead body on a ventilator for days together - a common occurrence still.
Having a uniform definition of death will help doctors and families alike while taking decisions about discontinuing artificial support measures. It also brings a sense of closure and calm in an otherwise dreary situation, by removing the uncertainty factor.
What is the situation in India at this time?
Unfortunately, in India, a uniform definition of death does not exist.
According to the Indian Penal Code, IPC 1860, section 46, the word ‘death’ denotes the death of a human being unless the contrary appears from the context.
The Registration of Births and Deaths Act, 1969, section 29(b) defines death as the permanent disappearance of all evidence of life at any time after live-birth has taken place.
A more recent definition was included in the Human Organ Transplantation Act 1994, where brainstem death was accepted as the point of death, prior to harvesting organs for transplantation. Many experts are however concerned that this definition exists only within the purview of organ transplantation. Ideally, the determination of death should have nothing to do with whether organ donation is planned or not.
It should be noted that ICU’s with such advanced facilities that can keep a brain-dead patient’s organs in good working condition (for transplantation) are relatively scarce - restricted to a few large hospitals in major cities. At the same time, most of the brain-dead patients in India are located in less-equipped hospitals scattered across the country; many of them are not potential organ donors due to various limitations. Brainstem death is not yet officially included under the general definition of death in India. As a result, doctors working in such smaller hospitals, fearing legal consequences, are reluctant to discontinue artificial support measures in this vast majority of brain-dead patients.
To make matters worse, not everyone is supportive of the concept of brain death - largely due to ignorance among the general public about this entity. This leads to non-uniformity of care, prolonged hospital stays, unnecessary expenses and aggravation for the patients’ families.
More recently, the Aruna Shanbaug judgment by the Supreme Court of India in 2011 recognized brain death as equivalent to death, to some extent reducing the legal ambiguity. However, assertive legislation is yet to happen in India. In contrast, in the US, the Uniform determination of death act was passed as early as in 1981.
Lobbying has been going on to persuade lawmakers to wake up to this basic issue. health care legislation needs to be updated to keep up with scientific progress, bearing in mind the socioeconomic and cultural milieu unique to each country.
In summary, a uniform definition of death is much-needed, for every nation.
(The author is a senior consultant gastroenterologist and deputy medical director, Sunrise group of hospitals)