Efficacy of Erector Spinae Plane Block on Postoperative Delirium in Patients Undergoing Lumbar Spine Surgery

Postoperative delirium (PD) and postoperative cognitive dysfunction (POCD) are extremely common in geriatric surgical patients. After elective major joint replacement or other types of major surgery, about 5% to 15% of elders develop delirium and 25% to 40% and 12% to 15% developearly or late POCD. PDand POCD are associated with prolonged length of stay, discharge to a place other than home and higher 1 year mortality. In addition, delirium is associated with an accelerated trajectory of cognitive decline to dementia (1). The etiologies of both PD and POCD remain unknown. Controversy exists over whether delirium is a marker or risk factor for subsequent persistent cognitive impairment . The PD is an acute impairment of cognitive and or spatial/temporal perception,that can be diagnosed at the bedside with dedicated diagnostic tools. It has an acute onset and a fluctuating course, and therefore can be missed if not systematically tested. It is defined by three principal characteristics: altered consciousness; changes in cognitive abilities; recent and rapid onset . The POCD affects global cognitive functions for several months/years after surgery and anesthesia, diagnosis requires detailed neuropsychological testing.

Surgical interventions have been associated with severe pain and discomfort in the immediate perioperative period. Surgical anesthesia and the perioperative analgesic regimen aim toward complete intra-operative amnesia, profound analgesia, effective control of autonomic responses and rapid emergence. However, anesthesia, analgesia and sedation all utilize medications that might be implicated in the development of central nervous system (CNS) dysfunction. Elderly patients are more sensitive to the CNS effects of barbiturates, inhalationalanesthetics, benzodiazepines and opioids. Some medications frequently associated with delirium with or without POCD include opioids, anxiolytics, antidepressants, and corticosteroids.

There are studies regarding the effect of erektor spina field block on postoperative pain in vertebra surgery.The investigators will compare the effect on postoperative delirium of patients who underwent erector spina plane block after spinal surgery with those who did not.