ABSTRACT
Sleep is a state of ‘suspended consciousness’, a temporary interruption of sensorimotor interaction with the environment. Clinically, the distinguishing feature of sleep, in contrast to coma, is the ease with which the sleeping subject can be roused to awareness of the external world. Between alertness and coma are a variety of altered states of consciousness. Palliative sedation refers to the intentional clinical practice of suppressing consciousness to control refractory symptoms during the last days or hours of life, in a manner that is ethically acceptable to the patient, family and healthcare providers. The intractable symptoms, which have proven non-responsive to all other interventions, are contained by the induction and the continuance of deep sedation. Deep sedation may need to be maintained until death; the duration is usually in the range of 1–6 days. Trial releases of deep sedation can be orchestrated, if required, by withholding the dose or administering flumazenil. The dosage necessary to induce deep sedation is variable.
