Prolonged disorders of consciousness (PDOC); history and update.

The diagnosis and management of patients with prolonged disorders of consciousness is an area of expertise acquired by rehabilitation specialists starting in 1992 with the Bland case. There were few developments until 2010. Change accelerated, culminating in 2018 with a Supreme Court ruling that removed the requirement to involve the Court of Protection in every case. (here) Following this change, further guidance was published in 2018 (here) and 2020 (here). This update summarises the critical differences. More importantly, I draw on my experience of giving more than 50 second opinions before withdrawing active treatment, usually gastrostomy feeding and hydration. The main message is that patients in a prolonged disorder of consciousness are simply at one end of a spectrum of impairment and disability seen after brain damage and are not a separate category. The Mental Capacity Act (2005) principles should guide management and the best interests process. (here) As I wrote in 2018, “This represents the culmination of a paradigm shift over the past six years, moving from a focus on a patient’s diagnosis and level of awareness to a focus on the patient’s best interests. some parts of existing guidance are not needed or appropriate because they emphasise clinical assessment more than the best interests process.” (here)

Prolonged Disorders of Consciousness
History and Context.

In 1972, Bryan Jennett and Fred Plum published “Persistent vegetative state after brain damage. A syndrome in search of a name.” (here) The adjective persistent did not carry as much implied prognostic information as the word used later, permanent, and indeed was analogous to the adjective now used, prolonged. Both persistent and prolonged are descriptive; permanent give a prognosis.

In 1989, Tony Bland suffered severe hypoxic brain damage when crushed in the Hillsborough football stadium disaster and, in 1992, the Court of Appeal decided that his gastrostomy feeding could be withdrawn. The House of Lords upheld the decision in February 1993. (here) The reasoning, in brief, was:

  • gastrostomy feeding is a medical treatment
  • medical treatment should not be given if judged futile
  • Tony Bland has no awareness, and never will have
  • Therefore,
    • he cannot benefit, the treatment is futile, and treatment should be stopped.

The judges required all cases to come to court until “the medical profession” developed guidelines and standards of practice. Although they expected that to be soon, it never happened.

Then, in 2005, the Mental Capacity Act was passed. This Act required all decisions about patients who could not decide to be made in their best interests. Unfortunately, this Act is notable for the failure of clinical services to adhere to it. (here) Indeed, although the Act set out a process for people lacking capacity, most people did not use it, and all cases of people thought to be in the so-called vegetative state were still required to go to court.

In addition, increasing scrutiny of the responses seen in people thought to be in a vegetative state highlighted the spectrum of responsiveness seen, culminating, in 2002, in the definition of a minimally conscious state. (here) The legal basis for stopping treatments only applied to people who were unequivocally completely and permanently unaware. Consequently, in people considered to be in a minimally conscious state, the argument of futility was invalid.

In 1998, a case of a person who was not “four square” in the vegetative state was taken to court, and the judge considered the patient’s interests and held that “On the facts, it was in the interests of the patient that the life-sustaining treatment presently being artificially administered be discontinued, and therefore the declarations sought would be made.” (here) This judgement was before the minimally conscious state was formally recognised in 2002 and before Parliament passed the Mental Capacity Act in 2005.

Then, in 2012, The Honourable Mr Justice Baker heard a case of a person in a minimally conscious state. He considered the situation in light of the Mental Capacity Act and decided not to permit withdrawal of treatment. (here) Then, in 2015, in the case of someone in a minimally conscious state, Mr Justice Hayden decided that it was no longer in their best interests to continue with clinically assisted nutrition and hydration. (here)

I was involved in the case in 2015, and I argued that one could not draw any line between the vegetative state and the minimally conscious state. Mr Justice Hayden did not accept this. Subsequently, I published a paper (here) that gave the evidence behind my opinion, which is now accepted. This realisation is made concrete by the widespread use of the term, a prolonged disorder of consciousness.

A further case occurred in 2016, the Briggs case. (here) Mr Justice Charles decided that the clinical team could stop feeding and nutrition. He gave a clear, meaningful summary of the decision to be made: “The test I must apply is not whether Mr Briggs should live or die. Rather it is whether it is in his best interests for him to continue to receive life-sustaining medical treatment that he could have refused consent to if he had the capacity to make that decision.”

Understanding that “this is not a life-or-death decision” is vital. Instead, the decision concerns “whether the patient wishes to continue living as he is for many years” because, if not, then the clinical team should not continue medical treatment.

Finally, in 2018, the Supreme Court heard a case where the patient had, by that time, died. (here) The Supreme Court established that:

  • decisions were made on best interests grounds, not according to any arbitrary classification
  • any decision required a second, independent opinion with at least one of the two doctors being a ‘recognised expert in prolonged disorders of consciousness
  • published guidance (which was still being developed) should be followed
  • decisions did not need to go to court if there was no disagreement or significant uncertainty

Following this decision and change in the legal guidance (the most recent direction is here), I and a small number of other experts have been seeing patients more frequently. I have seen about 50-60 people as a formal second opinion since 2018. This number is a tiny proportion of the number entering a prolonged disorder of consciousness each year, estimated as over 1,500 each year. (here)

I will now discuss some common misunderstandings.

Prolonged disorders of consciousness:
Waiting for six or 12 months.

When judges made decisions about continuing gastrostomy hydration on the grounds of futility, one had to wait until the prospect of improvement was very small. The usual limits were after three (in the US) or six (in the UK) months after hypoglycaemic or hypoxic brain damage and 12 months for most other causes.

When deciding on a person’s best interests, the question is quite different and is not based on futility. The question you are asking is, “Would the patient wish to continue active medical treatment if the best likely outcome is [whatever the best predicted outcome is]?” 

Putting it another way, you should consider is, “Will this person ever reach the minimum level of function and quality of life that they would find sufficient to warrant continuing active medical treatment?”. If not, then they would not wish to continue active treatment.

Different people will attach differing importance to various factors, though the differences are probably not that great. It is helpful to consider the following domains:

  • autonomy. The ability to influence decisions on what happens. For example, choosing what to eat, when to get up, or what to watch on television.
  • function and activities. The ability to achieve wanted goals. For example, being able to turn a radio on or off, being able to scratch an itch, or being able to take a drink.
  • social interaction. The ability to interact as a person with another person including but not restricted to using direct language communication. For example, giving signs of recognition of a specific person, waving goodbye, answering a question correctly.
  • experience. This covers feelings, both sensory (pain, comfort) and emotional (pleasure, distress).
  • accommodation. Where the person lives and who with. The usual choice is between residential care or sheltered care and being in the community alone or with others, with additional care and support as needed.

Whether to continue or limit active medical treatment is a decision that clinicians can make at any time. Once the estimated best prognosis is approaching or below what the patient would consider an acceptable, worthwhile outcome, you must consider whether active treatments are still in a person’s best interests. Clinicians may make this decision as early as the first few days or weeks, and doctors routinely make such decisions in intensive care units.

I have been involved with several patients with a prolonged disorder of consciousness where decisions have been made within eight weeks.

Giving a prognosis is always a more significant concern than diagnosing a prolonged disorder of consciousness. The ‘trajectory of change’, how much change has occurred over a period of observation, is a valuable factor to consider.

The Wessex Head Injury Matrix and the Coma Recovery Scale – Revised are two practical measures for someone unconscious because they are relatively quick and easy to do on a repeated basis. There is always fluctuation, and one needs to look at the trend over time and not just two or three measures. Measuring two or three times a week over four weeks helps detect change or lack of change, especially in the first few weeks.

In summary, you should consider starting, continuing, and stopping treatment from the outset; there is no reason to wait any fixed time before deciding to limit or withdraw active treatment. Once the prognosis is sufficiently sure to know that the person would not value even the best likely outcome, the clinical team must consider topping active treatment. The time after onset is not a material factor.

Prolonged disorder of consciousness
Extent of awareness.

When decisions were made based on treatment futility, it was essential to determine the presence of any awareness, however limited. Now that decisions are based on a person’s best interests, the level of awareness is not a specific, relevant factor. Thus, in a patient lacking capacity to make healthcare decisions, the best interests process is the same, whatever the clinical state.

The guidance that a certain number of formal assessments of awareness using standardised measures is no longer directly relevant. Formal assessments will be necessary and may be helpful in two circumstances:

  • to establish the trajectory of change in the early weeks or months after onset. This is a means of establishing prognosis, and the actual level of awareness is not relevant.
  • on the rare occasion when the information given suggests that a person with minimal awareness would wish to continue treatment, but would not wish to if completely unaware.

In principle, one might also use detailed testing to ‘prove’ that someone had absolutely no awareness so that treatment was indeed futile because there is no legal or ethical requirement to offer a patient a futile treatment. In practice, this distinction is not possible. Moreover, a clinical team would only use this approach to stop treatment against a family’s wishes when it would be contested and probably fail.

The most important way to evaluate a person’s level of awareness, not mentioned in the guidance, is a routine clinical observation by staff familiar with observing unconscious patients. Relatives can also provide much useful, important information. (here) and (here) Both these methods need an experienced clinician to interpret the data.

This less structured approach has advantages. It is simple, collects data as part of daily routine, and covers different settings and interactions. Further, family members may elicit different responses. (here) Thirdly, especially if comments are recorded, one can also observe behaviours that suggest what the person might be experiencing. It is difficult to know what someone is consciously experiencing, but observing changes associated with pain or pleasure is essential.

A form and protocol for informal observations are available here, and research on the form would be welcome.

In summary, teams should focus much less on assessing awareness and instead should (a) record and review clinical observations made during routine care and interactions and (b) divert the resource (time and effort) to collecting information about best interests.

Prolonged disorder of consciousness
Best interests.

It is remarkable when reviewing notes to give a second opinion how little information is recorded about factors that will inform the decision-making process. There are notable exceptions, but often there is nothing until a family member suggests limiting treatment.

Many patients have no recorded best interests meetings or decisions for months or years after onset. Others have a statement that a decision was made “in the patient’s best interests” with no record of who made the decision, what factors were considered, what reasoning explained the decision or who else was present.

This lack of recorded information contrasts with efforts to measure the level of awareness, although these are not universal.

Teams talk to family members from the outset of any severe brain damage. Teams also record that they have spoken to the family and, sometimes, the content of information imparted.

Unfortunately, teams seem not to listen and/or record what they hear. Teams very rarely seem to look for information about the patient. For example, notes rarely record the patient’s previous lifestyle and interests, how they viewed illness and healthcare, what their interests were, what was important to them in life and whether they had ever given an opinion on what treatment they would want if they had severe brain damage.

This information is vital for the best interests process. Even if recorded, it is usually buried in a massive number of other clinical notes and is effectively not visible.

The clinical team needs to establish some background information about the patients and what factors they might consider when making a decision. The policy should ensure that the data are accumulated and updated from the outset, and ensure that other clinicians can easily find it when necessary.

In summary, all clinical teams caring for unconscious patients for more than a few days must start to ask about and record information about the patient’s interests and ambitions and all other factors that will help the clinical team make decisions in the patient’s best interest interests.


Clinical teams should manage patients with a prolonged disorder of consciousness just like they manage all other severely disabled patients. These patients are not qualitatively different. Patients have a spectrum of disabilities and problems, with complete unawareness at one end and minor impairments with no functional consequences at the other end. There are no valid boundaries within that spectrum – just as there are no boundaries in a rainbow.

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