A medicolegal perspective on the impact of the Mental Capacity Act on critical care practice

A Medicolegal Perspective on the Impact of the Mental Capacity Act on Critical Care Practice 

The Mental Capacity Act (MCA) 2005 came into force across England and Wales in April 2007. The aim of the Act is to set out in law the procedures to be followed to establish whether an individual has mantal capacity. This is especially relevant for patients who have capacity now but want to make preparations for a time when they may lack it, or who lack the capacity to make decisions for themselves. Rather than introducing new measures, the MCA provides a statutory framework for procedures that have always been deemed best practice. However, the Act has raised some issues that healthcare professionals working in critical care need to be aware of.  

The guiding principle of the MCA is that every adult has the right to make his or her own decisions and must be assumed to have the capacity to do so unless proven otherwise. Therefore, it is vital to establish whether a patient has capacity. This is defined as a person’s ability to understand information about the decision, retain that information, use the information as part of the decision-making process, and communicate their decision. In the critical care setting, a lack of capacity is obvious in a patient who is unconscious or heavily sedated. However, most cases are not this clear-cut and a formal assessment is required. This assessment is decision-specific, so that a patient who lacks capacity for complex decisions may be deemed to have it for simpler ones. Capacity may also fluctuate, so re-assessment of mental capacity may be required as treatment progresses. In this scenario, it may be necessary to delay decisions until the patient is able to participate.   

Before concluding that a patient lacks capacity, it is important that as much support as possible is offered to allow the patient to continue to make their own decisions. Information should be presented in a way that is appropriate for the individual patient and circumstances. For example, even if a patient cannot speak, communication may still be possible with non-verbal means through gestures or the use of a letter board. However, this may not always be possible in the critical care setting. In particular, the need for urgent treatment may significantly reduce the time available for interaction with a patient with fluctuating capacity. This is particularly relevant, as the stressful environment means that even patients with full capacity often need more time to understand and retain information. Where there is any doubt about a patient’s capacity, ultimate responsibility for assessment lies with the senior treating clinician.  

An assessment of the reason for the patient’s incapacity should also be made and documented. Conditions such as electrolyte imbalance, may lead to unconsciousness and compromise capacity. However, once treated, the patient may regain capacity and may be able to participate in future decisions. The presence of psychiatric illness does not necessarily mean that capacity is lacking, but is clearly a result of the patient’s underlying mental state. This is of importance when decisions of treatment are made and may be refused. 

If after mental capacity assessment, there is a ‘reasonable belief’ that a patient lacks capacity, decisions can be made on their behalf. This must always be done in line with the patient’s best interests, regardless of the decision-maker or the magnitude of the decision. Thus, decisions concerning the care of a critically ill patient who lacks capacity are legitimised by the MCA, although the Act cannot be used as a defence against negligence. The ‘best interests’ principle can only be overridden by a valid advanced directive refusing specific medical treatment made while the patient still had capacity, in which case the patient’s explicit wishes take precedence.   

Patients may also appoint a Lasting Power of Attorney (LPA) to make decisions on their behalf. Clinicians must adhere to the wishes of the LPA unless there are concerns that they are not acting in the best interests of the patient. Where patients have made no forward provision to communicate their wishes, and do not have any other available representative, such as a family member or friend, an Independent Mental Capacity Advocate (IMCA) may need to be appointed. One disadvantage of an IMCA is that they are generally only available during office hours, which may not coincide with the time a decision needs to be made. In these circumstances, medical staff may act in the patient’s best interests without input from the IMCA.  

One important aspect of the MCA is that it preserves a patient’s right to make ‘bad’ decisions. However, this is based on the assumption that the decision is not compromised by lack of capacity. For example, a confused patient who removes a tracheostomy tube could have the tube replaced against their apparent wishes, as this would be in their best interests. Conversely, the decision of a patient with full capacity to refuse aggressive therapy for a spinal cord injury or treatment of a known malignancy (cancer) would be legitimate, albeit probably unwise.  

The MCA has helped to remove ambiguity from existing best practices concerning patients who lack capacity and provides additional protection for the clinicians who are treating them. However, one unresolved issue is the identification and following of wishes expressed when the patient still had capacity. Clear documentation of assessments of capacity and procedures undertaken in patient’s best interests is vital if litigation is to be avoided.