Rationale: The extreme increase of obesity in the last years had led to this study. There is no consensus about how to anaesthetise morbidly obese patients. The amounts of narcotics given vary widely and rather depend on the anaesthetist than on the pharmacokinetics and dynamics in the morbidly obese patient. Reason for this is that it is not clear in what extend the pharmacokinetics and dynamics are affected in the morbidly obese patient.