Presurgical Screening Improves Risk Prediction for Delirium in Elective Surgery of Older Patients: The PAWEL RISK Study

Abstract

Introduction: The number of elective surgeries for patients who are over 70 years of age is continuously growing. At the same time, postoperative delirium (POD) is common in older patients (5–60%) depending on predisposing risk factors, such as multimorbidity, cognitive impairment, neurodegenerative disorders and other dementing disorders, and precipitating factors, such as duration of surgery. Knowledge of individual risk profiles prior to elective surgery may help to identify patients at increased risk for development of POD. In this study, clinical and cognitive risk factors for POD were investigated in patients undergoing various elective cardiac and non-cardiac surgeries.Methods: The PAWEL study is a prospective, interventional trial on delirium prevention. At baseline, 880 inpatients at five surgical centers were recruited for sub-sample PAWEL-R. Multimodal assessments included clinical renal function, medication, American Society of Anesthesiologists (ASA) Physical Status Classification System, geriatric and cognitive assessments, which comprised the Montreal Cognitive Assessment Scale (MoCA), Trail-making Test, and Digit Span backward. Delirium incidence was monitored postoperatively by the Confusion Assessment Method (CAM) and a chart review for up to a week or until discharge. Multivariate regression models and Chi-square Automatic Interaction Detectors (CHAID) analyses were performed using delirium incidence as the primary outcome.Results: Eighteen risk factors were investigated in elective cardiovascular and orthopedic or general surgery. A total of 208 out of 880 patients (24%) developed POD. A global regression model that included all risk variables predicted delirium incidence with high accuracy (AUC = 0.81; 95% CI 0.77, 0.85). A simpler model (clinical and cognitive variables; model CLIN-COG) of 10 factors that only included surgery type, multimorbidity, renal failure, polypharmacy, ASA, cut-to-suture time, and cognition (MoCA, Digit Span backward, and preexisting dementia), however, exhibited similar predictive accuracy (AUC = 0.80; 95% CI 0.76, 0.84).Conclusion: The risk of developing POD can be estimated by preoperative assessments, such as ASA classification, expected cut-to-suture time, and short cognitive screenings. This rather efficient approach predicted POD risk over all types of surgery. Thus, a basic risk assessment including a cognitive screen can help to stratify patients at low, medium, or high POD risk to provide targeted prevention and/or management strategies for patients at risk.

Prospective Analysis Between Neutrophil-to-Lymphocyte Ratio on Admission and Development of Delirium Among Older Hospitalized Patients With COVID-19

“…Our study has limitations. First, we did not include additional important covariates in our models, such as type of respiratory support, cognitive impairment measures ( Eschweiler et al, 2021 ; Mychajliw et al, 2021 ) or use of other medications, due to limited data availability. We adjusted for the use of chloroquine, dexamethasone and for presence of critical illness, defined as being admitted to an ICU or having two or more recorded blood oxygen saturation measurements less than 90% while on a reservoir mask or on non-invasive mechanical ventilation, which is a proxy of the use of sedative and analgesic agents.…”

The relationship between pre-surgery self-rated health and changes in functional and mental health in older adults: insights from a prospective observational study

“…Moreover, patients were excluded when they deceased to follow-up ( n = 19), resulting in 1,580 patients that were included in our analyses. This also included 185 individuals of the PAWEL-RISK sub-sample without 12 months post-assessment [ 41 ]. They were included in our analyses on the total sample to use all available information of the pre-surgery assessment but were excluded in our completers analyses.…”

Development and validation of a post-operative delirium prediction model for patients undergoing abdominal surgery: A retrospective, observational, single-center study

“…Based on past literature and theory, it is presumed that POD evolves and manifests as a result of a combination of the predisposing and precipitating factors [26,27]: As mentioned before, advanced age, pre-history of cognitive de ciencies, previous episodes of dementia, psychological or emotional disruptions, multiple or speci c comorbidities such as cerebrovascular events and alcohol abuse have been identi ed as common predisposing risk factors. Nevertheless, other studies have identi ed higher ASA physical status, non-elective surgery and higher postoperative pain scores as risk factors for the development of POD [28][29][30][31][32][33][34][35].…”