Beyond Cognitive Screening: Establishing an Interprofessional Perioperative Brain Health Initiative.

OBJECTIVE: Perioperative neurocognitive disorder (PND) is now recognized as the most common postoperative complication in older surgical patients. Current multidisciplinary guidelines recommend simple cognitive screening of older adults before surgery. Patients identified at risk should have input from an interprofessional team with expertise caring for older surgical patients. Data suggest these recommendations are infrequently met. We set out to test feasibility of routine cognitive screening in a busy preoperative assessment clinic and establish a perioperative pathway with multidisciplinary support for patients identified at risk. METHODS: We undertook a prospective quality improvement study. A cohort of 1,803 older surgical patients scheduled for preoperative evaluation was screened with the Mini-Cog© test. As the project developed, we began confirmatory neurocognitive testing by occupational therapists for those patients flagged at risk. Patients confirmed at risk were referred for further evaluation by a geriatrician and geriatric pharmacist. Alerts were developed to flag patients at risk through their in-patient journey, and a multidisciplinary team developed a comprehensive care pathway. RESULTS: We demonstrated that implementing routine cognitive screening can be done in a busy clinic, regardless of prior experience. The prevalence of preoperative cognitive impairment was 21% in our older patients undergoing inpatient surgery, rising to 36% in those older than 85 years. When the Mini-Cog results were not known to providers, they were unable to identify cognitive impairment in half of the patients, supporting the use of a validated screening test. We established an interprofessional team and pooled relevant recommendations into an age-friendly perioperative care pathway for patients at increased cognitive risk. CONCLUSION: Cognitive screening must be done to reliably identify older surgical patients at risk of PND. Demonstrating the prevalence of cognitive impairment in older surgical patients can provide impetus to develop a multidisciplinary team and care pathway with the aim of reducing the incidence of PNDs. J Am Geriatr Soc 68:2359-2364, 2020.

Radial basis function for fast voltage stability assessment using Phasor Measurement Units.

A simple method, based on Machine Learning Radial Basis Functions, RBF, is developed for estimating voltage stability margins in power systems. A reduced set of magnitude and angles of bus voltage phasors is used as input. Observability optimization technique for locating Phasor Measurement Units, PMUs, is applied. A RBF is designed and used for fast calculation of voltage stability margins for online applications with PMUs. The method allows estimating active local and global power margins in normal operation and under contingencies. Optimized placement of PMUs leads to a minimum number of these devices to estimate the margins, but is shown that it is not a matter of PMUs quantity but of PMUs location for decreasing training time or having success in estimation convergence. Compared with previous work, the most significant enhancement is that our RBF learns from PMU data. To test the proposed method, validations in the IEEE 14-bus system and in a real electrical network are done.