Incidence of and Risk Factors for Emergence Delirium and Postoperative Delirium in Neurosurgical Patients- A Prospective Cohort Study

Background: Delirium after surgery is a spectrum of clinical syndrome constituting emergence delirium (ED) and/or postoperative delirium (POD). Objectives: The primary objective of this study was to evaluate the incidence of ED and POD in patients after neurosurgical procedures. The secondary objectives were to examine the relationship between ED and POD and identify perioperative risk factors of ED and POD. Materials and Methods: This is a prospective cohort study conducted at the National Institute of Mental Health and Neurosciences. After obtaining the ethics committee approval, consecutive adult patients scheduled for elective neurosurgical procedures from February 2018 to November 2018 were included. We excluded children, patients with preoperative Glasgow Coma score <15, and patients with preoperative delirium. ED was assessed using Riker's Sedation-Agitation Score and POD was assessed using Confusion Assessment Method. Data collection included patient demographics, details of anesthetics and analgesics, and neurosurgical details. Results: The incidence of ED and POD was 41% (N = 82/200) and 20% (N = 40/200), respectively. The occurrence of ED and POD coexisting as a continuous spectrum was 15%. Patients undergoing spine surgeries were found to have 44% less risk of ED than after cranial surgeries (P = 0.032). Presence of ED was associated with 1.8 times higher risk of POD (P < 0.001) and male gender was associated with 2.5 times higher risk of POD (P = 0.005). Conclusions: Incidences of ED and POD are higher after neurosurgery as compared with that reported in nonneurosurgical population previously.