In surgical intensive care patients, analgosedation with SK/P showed some advantages over SK/M with respect to control and quality. The endocrine stress response was reduced by both regimens in course of time. Altogether higher levels of ADH and noradrenaline during SK/M-analgosedation let expect higher cardiocirculatory stability and possible reduction of catecholamine demand. Due to ketamine-typical beta-activity, a reliable assessment of sedation by the pEEG is not possible.