Consent and Decision-Making Capacity in Acute Illness

Under the Mental Capacity Act 2005 (UK), every adult is presumed to have capacity unless proven otherwise. When a patient refuses necessary medical treatment and there is reason to doubt their decision-making ability (e.g., severe acute illness, dementia, delusion about working), a decision-specific and time-specific capacity assessment must be conducted before proceeding. Option A is incorrect because emergency common law/doctrine of necessity applies when capacity cannot be assessed or in immediate life-threats where delay causes harm, but a quick formal capacity assessment should be conducted first here. Option B is incorrect because in UK law, family members/next of kin do not have automatic legal authority to sign consent forms for adult patients unless they hold a valid Lasting Power of Attorney (LPA) for Health and Welfare. Option C is incorrect because accepting refusal without assessing capacity in a confused patient risks severe harm.

Teaching point: Before overriding or accepting a treatment refusal in a patient with cognitive impairment, clinicians must perform a decision-specific capacity assessment.

If an adult patient lacks capacity to make a specific medical decision and no Lasting Power of Attorney (LPA) or valid Advance Decision to Refuse Treatment (ADRT) exists, healthcare professionals must act in the patient's best interests under the Mental Capacity Act 2005. Consulting family members (like his daughter) helps determine the patient's past wishes, beliefs, and values to guide the best interests decision. Option A is incorrect because urgent treatment in the best interests of a patient who lacks capacity does not require Court of Protection approval — s.5 of the Mental Capacity Act 2005 provides the legal authority. An application is needed only where there is unresolved disagreement about best interests, genuine doubt, or a finely balanced decision, and for the narrow group of decisions that should always be brought before the court (non-therapeutic sterilisation, or organ or bone marrow donation by a person who lacks capacity). Since An NHS Trust v Y [2018] UKSC 46, even withdrawal of clinically assisted nutrition and hydration from a patient in a prolonged disorder of consciousness does not require court approval where the clinical team and those close to the patient agree that continuing is not in the patient's best interests. Option B is incorrect as withholding life-saving treatment due to lack of consent in an incapacitated patient is unethical and illegal. Option C is incorrect because sedating a patient to obtain 'consent' is invalid; consent cannot be legally obtained from an incapacitated or sedated individual.

Teaching point: When a patient lacks capacity and has no LPA or ADRT, clinicians must provide necessary treatment in the patient's best interests, consulting relatives to ascertain past preferences.

The five core principles of the Mental Capacity Act 2005 begin with the statutory presumption of capacity: a person must be assumed to have capacity unless established otherwise. Option C is incorrect because Principle 3 explicitly states that a person is not to be treated as unable to make a decision merely because they make an unwise decision. Option B is incorrect because capacity is decision-specific and time-specific, not global. Option D is incorrect because capacity cannot be judged based on age, appearance, condition, or an aspect of behavior alone.

Teaching point: Under the Mental Capacity Act 2005, capacity is presumed, decision-specific, and an unwise decision does not automatically equate to a lack of capacity.