Risk Factors and Mechanisms of Postoperative Delirium After Intracranial Neurosurgical Procedures

Postoperative delirium (POD) is a condition characterized by cerebral dysfunction or failure and associated with high morbidity and mortality, prolonged intensive care unit and hospital stay, increased costs and long-term disability. The risk factors can be divided into three categories: preoperative, intraoperative, and postoperative. POD is underrecognized, underdiagnosed, and undertreated condition which can lead to potentially life-threatening conditions. Prevention and treatment of POD include adequate perioperative pain control, maintenance of optimal blood pressure, water-electrolyte balance, hypoglycemia, hyperglycemia, sleep hygiene. Despite POD has been extensively studied in various types of surgery, there is not enough evidence on POD in intracranial neurosurgery. Patients undergoing open craniotomy might be at particular risk because on top of the above-mentioned factors, they also can have a direct neurosurgical brain injury. Future research on the POD in neurosurgical patients after intracranial interventions is needed. A bibliographic search was performed in the MEDLINE and PubMed virtual library. The following descriptors were used: POD, neurosurgery, anesthesia and POD, postoperative pain management and POD, water and electrolyte imbalance and POD, neurochemistry of POD. We included in this review original and review articles in the English language. Majority of non-neurosurgical patients have multiple risk factors for POD (preoperative, intraoperative, and postoperative); patients undergoing intracranial neurosurgery might have additional risks associated with neurosurgical pathology (brain tumor, cerebral hemorrhage, and severe traumatic brain injury) as well as neurosurgery-induced brain injury can also appear to be a contributing factor.