VANCOUVER, BC—In elderly patients with cognitive dysfunction undergoing surgery for hip fracture, perioperative application of the rivastigmine patch reduced incidence and average severity of postoperative delirium, according to a prospective randomized study reported in a poster presentation at the 68th AAN Annual Meeting.

The study examined the effects of rivastigmine, an acetylcholinesterase inhibitor, in elderly patients at risk for dementia scheduled to undergo surgery for femoral neck fracture.

Prior to surgery, Young Chul Youn, MD, PhD, of the department of neurology at Chung-Ang University Hospital, Seoul, South Korea, and colleagues randomly assigned 62 patients to treatment with the rivastigmine patch (n=31), which was applied from 3 days before to 7 days postoperatively, or to no patch (control group; n=31).

Both groups were compared for incidence and severity of delirium on postoperative Days 2, 3, or 7, and multivariate analysis was performed to identify factors associated with postoperative delirium, Dr. Youn and colleagues reported.

They found that 5 of 31 patients in the rivastigmine group had postoperative delirium, compared with 14 in the control group (P=0.013).

The hazard ratio for postoperative delirium among patients in the rivastigmine patch group, after multivariate statistical adjustment for Korean-language Mini-Mental State Examination (K-MMSE) score, age, and sex, was 0.187 (95% CI: 0.051–0.686).

“The mean severity of delirium using the Delirium Rating Scale [was] 2.2 vs. 6.2 [for control-group participants],” (P=0.001), the researchers reported.“However, once delirium developed, the patch did not decrease the severity of delirium.”