Journal Club Express - Postoperative delirium in total knee and hip arthroplasty patients

Professor Monty Mythen presents Journal Club Express. Postoperative delirium in total knee and hip arthroplasty patients: a study of perioperative modifiable risk factors DOI: 10.1016/j.bja.2017.12.046 -- S. M. Weinstein et al. Br J Anaesth 2018; 120(5): 999-1008 This is an American single center retrospective study with 41,766 patients undergoing hip and knee arthroplasties over a seven year period.  They showed that 22.1% patients developed post operative delirium according to the ICD 9 definition of delirium.  Delirium occurs more in patients with multiple co-morbidities, older age, higher baseline creatinine, lower haemoglobins and longer patients stays. They looked at the type of anaesthetic as well as the use of opioids, ketamine and benzodiazepines.  They found the rates of delirium were higher in the knee arthroplasty group compared with the hip arthroplasty group. Those that received a neuroaxial block had a lower rate of delirium; Spinal:  OR 0.55 (CI 0.37-0.83), Epidural:  OR 0.59 (CI  0.38-0.93), CSE:  OR0.56 (CI 0.40-0.80).  There was a high risk with the use of postoperative benzodiazepines (OR 2.47 CI 2.04-2.97) and ketamine infusion ()R 10.59 CI 5.26-19.91) as well as intraoperative ketamine (OR 1.27 CI 1.01-1.59)  and opioids (OR 10.59 CI 5.26-19.91).