Capacity in Critical Care

Kate Rimmer

The issue of mental capacity in the critical care environment can be fraught with difficulty and can cause anxiety to staff working in these environments.  It is important for all staff involved in the care of the critically ill to understand the law in relation to capacity and consent and have knowledge of the process of making a capacity assessment. 

Many patients in critical care environments will lack capacity, and so are unable to decide for themselves when considering procedures and treatment options.  They are often too ill to understand the options being considered, with significant physiological and biochemical derangement, sedation and delirium being common.  It is therefore important that in all cases a proper assessment of capacity is undertaken when treatment decisions are required.  Further information on consent in critical care can be found in this post.

The Mental Capacity Act 2005 (MCA) is the legal framework that outlines how capacity is assessed in adults in England and Wales.  In Scotland the Adults with Incapacity (Scotland) Act 2000 provides a similar framework.  The main guiding principles of the MCA are that:

  • All adult patients must be presumed to have capacity
  • All practical steps must be taken to help a patient to make a decision
  • An unwise decision does not mean that the patient lacks capacity
  • Any decision made on behalf of someone who lacks capacity must be made in their best interests
  • If a treatment or procedure is to be done in the patients best interests, it must be the least restrictive option

Any patient with capacity can at any time refuse specific treatments, and that these decisions must be respected.

A patient is deemed to lack capacity if they have:

  1. a disturbance in the functioning of their mind or brain, and
  2. this disturbance renders them unable to make the decision required of them. 

It is important to remember that capacity is decision specific, so at any time a patient may have capacity for some decisions but not for other more complex ones.  It is also important to remember that capacity may fluctuate due to the clinical condition of the patient, and that consent given when a patient has capacity is valid even if the patient subsequently loses capacity.

In circumstances when a patient lacks capacity, the medical team must make a treatment decision in the best interests of the patient.  This should include not only considering what is medically the best treatment option, but also consideration must be given to what the patient would likely want to be done in the given situation.  This will include considering treatment decisions they may have made in the past, and any advance statements or advanced decisions.  It must also consider any wishes the patient may have expressed to family members or staff when they still had capacity.  The MCA Code of Practice contains a best interests checklist for guidance, to ensure that a broad approach considering all aspects of a patient’s life is taken when making a best interest decision.   

Some people may have made written advanced statements before becoming unwell, giving the medical team an idea of what would and wouldn’t be acceptable to the patient in the event of losing capacity.  Some patients also make a formal advanced decision to refuse a specific treatment in certain circumstances.  These decisions are legally binding, and must be written and signed as witnessed by an independent person to apply to refusing life-saving treatment; for example invasive ventilation or cardiopulmonary resuscitation

If a decision to treat is made in the best interests of a patient who lacks capacity, there are a few points to consider.  The least restrictive option for treatment must be undertaken, meaning that only what is necessary should be done, with the aim of interfering as little as possible in the patients’ rights and freedoms.  If it is possible to delay a procedure or treatment until a time when it would be expected that the patient could be involved in the decision, then this should be done.  The patient should be involved as much as possible in all care decisions, even if the final decision will be a best interests decision. 

When there are disputes between relatives and medical staff about what the best course of action is for a patient who lacks capacity, it is prudent to consult the hospital’s legal department early for advice.  Where no resolution is possible, the courts may be consulted.  If appropriate, the court can appoint a deputy to attend the hospital and make an assessment, considering all the needs of the patient and the issues as understood by both the family and healthcare team.  The deputy then reports back to the court, and the court would then make a legal ruling on how to proceed.

It is sometimes very difficult to determine whether a patient in critical care has capacity.  In situations where there is uncertainty, involving colleagues can be very helpful.  In cases where a patient lacks capacity, by taking each decision individually, involving the patient as much as possible, and seeking any information from family members, friends and staff that may aid the best interests decision, it is usually possible to determine what is best for a patient and to plan their care accordingly.

This post does not constitute nor replace formal legal advice.  

Kate is a Consultant Anaesthetist at the Royal Victoria Infirmary, Newcastle.  She has a Masters degree in medical law, with an interest is consent and capacity.