Incidence of Postoperative Delirium and its Association with Intraoperative Blood Pressure Fluctuation in Elderly Undergoing Oncosurgery: A Prospective Cohort Study

Abstract

Introduction: Postoperative Delirium (POD) is one of the most common complications in geriatric surgical patients. POD has immense implication because it can initiate a cascade of deleterious events leading to functional decline, reduced cognitive function, prolonged hospitalisation, and death. The risk factors for POD include increased age, cognitive, visual or sensory impairment, functional dependence, infection, and electrolyte abnormalities. Published literature on POD in patients aged >60 years undergoing oncosurgeries are few. According to the American Geriatric Society, evidence for recommendation of intraoperative risk factors is lacking. The relation between intraoperative haemodynamics and postoperative pain with POD is controversial, as studies provide differences in evidence. Hence this relation needs to be studied further. Aim: To find the incidence of POD in patients >60 years of age undergoing oncosurgery, and its association with intraoperative hypotension and blood pressure fluctuations. The secondary objective was to assess the relation of POD with postoperative pain. Materials and Methods: The present study was prospective cohort study which was carried on 50 patients aged >60 years undergoing cancer surgery. Intraoperative hypotension and blood pressure fluctuations were measured based on predefined criteria. Postoperative pain and total opioid consumption were also noted. Delirium was assessed with the short Confusion Assessment Method (short CAM), on the first three postoperative days. The association between hypotension and intraoperative blood pressure fluctuations with POD were analysed with Fisher exact test and MannWhitney U test. Association of pain scores and total dose of opioid with POD was performed using Student’s t-test and Mann-Whitney U test. Results: The mean age of the study population was 69.5±2.8 years. The mean preoperative Addenbrook’s Cognitive Examination (ACE) score was 83.78. The incidence of POD was 22%. There was a significant association between intraoperative blood pressure fluctuation and POD. The mean BP variance ranged from 126.89 to 111.13 mm Hg. Increased age and more co-morbidities ≥3 (present in 58%) showed an association with POD. Conclusion: The incidence of POD was high (22%) among the elderly requiring oncosurgery. Intraoperative blood pressure fluctuation as well as hypotension was associated with increased risk of POD. Hence in elderly patients, tight blood pressure control is advisable during surgery.