Longitudinal Cohort Study - for the Treatment of Acute Postoperative Pain and Postoperative Delirium, Postoperative Cognitive Dysfunctions, and Chronic Pain.

There are strong evidence-based recommendations for an appropriate assessment and treatment of postoperative pain. Due to the complex and subjective nature of pain, an adequate pain therapy is an extremely challenging task, and the under- or overdosing of analgesics are common. An inadequate pain therapy leads to patient dissatisfaction, post-operative nausea and vomiting (PONV), inadequate nutrition, lack of mobilization, and an increased risk for the development of further complications, such as postoperative delirium (POD). Other long-term consequences of an insufficient postoperative analgesia include the chronification of pain and post-traumatic stress disorder (PTSD). Conversely, excessive opioid therapy may be associated with increased risk of POD. Subsequently, patients with POD have an increased risk for the consecutive development of postoperative cognitive dysfunction (POCD). The latter is marked by a progressive and permanent loss of cognitive abilities, which can ultimately lead to dementia. The use of patient-controlled analgesia (PCA) systems, which allow patients to self-administer analgesics, has been an improvement in the prevention of under- and overdosage of analgesics. Currently, there are two systems available: Conventional i.v. PCA with patients being dependent on an i.v. line and a PCA-pump and a patient-controlled, non-invasive administration of sufentanil sublingual tablets (ZALVISO®). The aim of this investigation is to study patient controlled analgesia systems and to examine the incidence of POD, POCD and postoperative pain.