The Mental Capacity Act 2005--implications for anaesthesia and critical care.

The Mental Capacity Act 2005 is due to come into force in April 2007. The Act provides a protective statutory framework for decision-making on behalf of incompetent adults, representing, in the main, a codification of the common law that had already developed in this area. For example, 'advance decisions' are now given formal statutory recognition. Importantly, the Act creates a new specialist 'Court of Protection' to manage the Act's enforcement, and an office of 'Public Guardian' to act as registering authority for new 'Lasting Powers of Attorney' and 'court-appointed deputies', both of which will be able to make proxy decisions about medical treatment for adult patients without capacity. There is also considerable regulation concerning the participation of adults without capacity in research. Given that their practice routinely involves the medical treatment of adults who lack legal capacity, anaesthetists and intensivists should familiarise themselves with the Act's key precepts.