Treatment of Postoperative Delirium
Modern classification defines postoperative delirium as an acute disturbance of consciousness with reduced ability to focus, sustain or shift attention, which is accompanied by changes in perception. The etiology of postoperative delirium is not fully understood and is likely multifactorial. Reduced activity of gamma-aminobutyric acid, abnormal metabolism of melatonin and serotonin along with noradrenaline hyperproduction leads to increased release of interleukin-1 (IL-1) and IL-6, which results in damage to neurons and cerebral hypoperfusion that is a possible pathogenetic mechanism. Postoperative delirium occurs in patients undergoing surgical procedures and anesthesia, usually within 1-3 days. The incidence of postoperative delirium is 10-24 % in all hospitalized patients, and 37-46 % in surgical patients. In the intensive care units, the incidence of postoperative delirium is reported to be 87 %. In general, the incidence of delirium in the postoperative period varies widely: from 9 to 87 %, depending on the patient’s age and type of operation. The degree of operational stress to some extent affects the development of delirium. In addition, reduced intellectual ability in the preoperative period and chronic illnesses are independent predictors of postoperative delirium in elderly people. Today, among the methods of medical treatment and prevention of postoperative delirium, the use of haloperidol and chlorpromazine is proved. There is a sufficient number of individual and multicenter studies confirming the efficacy of first-generation antipsychotics. Sufficient evidence base allows the use of these drugs, when studying new drugs, as a standard and in terms of their well-known and provided clinical effect. Despite the pathognomonic role of acetylcholinesterase in creating conditions for postoperative delirium, the clinical efficacy of acetylcholinesterase inhibitors remains controversial. Today, the positive impact of rivastigmine, donepezil and galantamine on the incidence of delirium is not proven during their use both in preoperative and postoperative period. That is, the search for new drugs and prevention schemes remains very topical issue of anesthesiology today.