Are we pulling the plug too early on coma patients with severe traumatic brain injury?

"Pulling the plug" on a patient is a colloquial expression that refers to the decision to withdraw life-sustaining treatment from a patient who is critically ill or in a coma. This usually involves discontinuing medical interventions that are keeping the patient alive, such as mechanical ventilation, feeding tubes, dialysis, or other life-support systems. Without such support the patient will die.

A coma is a state of prolonged unconsciousness where a person is unresponsive to their environment and cannot be awakened. This condition can result from various causes, including traumatic brain injuries, strokes, infections, lack of oxygen, or drug overdose. During a coma, a patient may exhibit minimal brain activity and no voluntary movements, though basic (unconscious) life functions such as breathing and circulation continue. The severity and cause of the coma significantly influence the patient's prognosis and potential for recovery.

The presence of some brain activity distinguishes coma from death (brain dead). Brain activity in a patient in a coma is typically measured using electroencephalography (EEG).  EEG involves placing electrodes on the patient's scalp to detect electrical activity in the brain. It provides information about the brain's overall electrical activity and can help identify patterns associated with different states of consciousness.

Severe traumatic brain injury (TBI) occurs when there is significant damage to the brain due to an external force, such as a blow to the head, a fall, or an accident. This damage can disrupt normal brain function, leading to a loss of consciousness. Severe TBI often leads to brain swelling and increased intracranial pressure, which can compress brain tissues and impair critical functions, contributing to a comatose state. In addition severe TBI may give rise to diffuse axonal injury (DAI) which involves widespread damage to the brain's axons (e.g. from shearing during the physical trauma), the nerve fibers that transmit signals between neurons. This can disrupt communication within the brain, also contributing to the coma.

Recovery is possible from TBI-induced coma and coma in general but it is highly uncertain and varies significantly from patient to patient. Factors such as the extent of brain damage, the specific areas of the brain affected, and the duration of the coma play crucial roles. The process is typically gradual, with patients often progressing through stages such as a minimally conscious state and post-coma unresponsiveness. Rehabilitation plays a crucial role in recovery and often involves physical therapy, occupational therapy, and speech therapy to help regain lost functions. Predicting the prognosis can be challenging, but early signs of recovery and responsiveness are generally positive indicators. While some patients may regain significant functions and independence, others may face long-term disabilities.

With respect to TBI coma patients, families and medical teams face difficult decisions regarding life-sustaining treatments and the long-term care of the patient. Customarily, prognosis discussions and decisions on life support withdrawal are made within 72 hours with many doctors predicting grim outcomes. This raises the crucial question of whether families are pulling the plug too early.

In a new study, researchers reviewed cases of 1392 unresponsive patients with severe traumatic brain injuries, comparing outcomes of 80 patients who had life support withdrawn and 80 who did not. The two cohorts were roughly matched in terms of their injury severity. 

While all those who had life support withdrawn died, many of those who stayed on life support underwent a partial gradual recovery. Those who died tended to die quickly, i.e. within 6 days. Overall at 6 months, 45% survived, and at 12 months 42% who continued life support recovered enough to have some degree of independence. A few even returned to their former lives. However, these unusual cases were the rare exceptions; the majority of survivors suffered from lasting disabilities, with many ending up living in nursing homes.

Given the possibility of at least limited recovery in a good number of patients (~40%), and dramatic recovery in a few, then why are we pulling the plug so quickly? A New York Times article reporting on the new results highlights the custom of the doctor "sitting down with family members within 72 hours of the patient’s admission to intensive care to discuss the patient’s prognosis, and whether they want to keep their loved one alive, or to remove life support." But what is so special about 72 hours?

There is nothing scientific about making a decision within 72 hours, Dr. Claude Hemphill of the University of California, San Francisco, said. That time frame has become a convention because, he said, “these people look very sick when they come in.” As a consequence, he added, “many physicians have felt compelled to make a decision early.”

The decision to be made is excruciatingly difficult:

“Families are asked what sort of life the patient would accept. There may be no easy answer. While healthy people may say that a life with a severe disability would be completely unacceptable, researchers speak of the “disability paradox”: Often when people become disabled, they report still having meaningful lives.”

One possibility would be to wait 6 days, and see if the patient survives. At that point, the patient is more likely to survive, and the three extra days would give the family more time to think about their decision.