[Medical advance directives as instruments of patient self-determination].

Medical advance directives and durable powers of attorney for health care increasingly gain importance and recognition as instruments of patient self-determination. This article explores the various possibilities for advance directives as well as their ethical legal background. Furthermore, results of a current patient and population survey are presented, showing how (potential) patients think about the possibilities of advance directives. Finally, practical recommendations on how to deal with medical advance directives are given.