Postoperative Cognitive Disorder

Abstract

POCD is a severe, potentially long-term complication after surgical procedures. POCD is mainly seen among older patients. Hospitalization for medical illness, extent of surgery and a systemic inflammatory response might contribute to POCD. Incidence rates have been reported between 19 – 40% in the first week and approximately 10% for 3 months or longer in patients over 60 and may be nearly twice as high in patients over 70 years old. POCD is associated with major consequences for the individual patient and their caregivers including delayed long term recovery, reduced quality of life and increased mortality (death rate). Multiple risk factors have been identified however, the exact cause is still unknown. Grandma was never the same after her operational many of us have experienced this problem following surgery in an older, sicker loved one. In an aging population, this statement describes difficulties that can afflict older people after major surgery. In the case of emergency or life-saving surgery, the risk of cognitive impairment may be acceptable. However, much of the elective surgery in older patients is to improve quality of life and a risk of cognitive impairment might be problematic. Let’s distinguish between delirium and cognitive dysfunction. Delirium is well defined and is characterized by an acute onset, reduced awareness of the environment and a  Summary  86 disturbance of attention. Although the condition will develop quickly, it will wax and wane during the course of a day. Delirium is often labeled with an underlying cause (i.e., drug induced or associated with a medical condition. Emergence delirium is a phenomena related to the time when a patient is arousing from anesthesia and is seen predominantly in pediatric patients. In this circumstance it is associated with pre-operative anxiety and may be attenuated by preparing the child prior to surgery and the administration of a sedative prior to surgery. Post-operative delirium is not related to the time of awakening from anesthesia (emergence). These patients may be alert, initially, but develop fluctuating mental status between the 1st and 3rd days after surgery. Post-operative delirium is not benign. Elderly patients undergoing repair of a hip fracture who develop post-operative delirium have a greater chance of dying, developing dementia, and requiring placement in a facility for long term care. Post-operative cognitive dysfunction is more difficult to define. In a general sense, POCD refers to deterioration in cognition that occurs in the time period after surgery. To truly diagnose POCD one would need to have tested the patient preoperatively (baseline) and determined how much of a decline occurred after surgery. Perhaps a more understandable term would be post-operative cognitive decline.