Antipsychotics and anesthetic drugs

Psychiatric illness is common, affecting up to 10% of the population, with around 1% diagnosed with a major psychiatric disorder. An increased mortality rate in the postoperative period for schizophrenic patients receiving chronic antipsychotic therapy has been demonstrated. According to the Diagnostic and Statistical Manual of Disease, schizophrenia-associated psychotic disorders are characterized by disturbances in emotional, behavioral and cognitive arenas, impeding on nearly every aspect of life functioning in the form of thought disorders, delusions and hallucinations. Chronic schizophrenic patients lack pain sensitivity, and have pituitary-adrenal and autonomic nerve dysfunction, abnormalities of the immune system, and water intoxication. These alterations may influence postoperative outcome. Psychotropic drugs often given in combination with each other or with other non-psychiatric drugs generally exert profound effects on the central and peripheral neurotransmitter and ionic mechanisms. The increased complications are associated with physical disorders, antipsychotic or hazardous health behaviour and interactions between antipsychotics and anaesthetic drugs. Adverse responses during anaesthesia include arrhythmias, hypotension, prolonged narcosis or coma, hyperpyrexia, post-operative ileus and post-operative confusion. Although drug interaction probably remains the most potentially serious problem current evidence suggests that psychiatric medication need not be discontinued prior to anesthesia.