Perioperative Factors Associated With Postoperative Delirium in Patients Undergoing Noncardiac Surgery

Abstract

ImportancePostoperative delirium (POD) is a common and serious complication after surgery. Various predisposing factors are associated with POD, but their magnitude and importance using an individual patient data (IPD) meta-analysis have not been assessed.ObjectiveTo identify perioperative factors associated with POD and assess their relative prognostic value among adults undergoing noncardiac surgery.Data SourcesMEDLINE, EMBASE, and CINAHL from inception to May 2020.Study SelectionStudies were included that (1) enrolled adult patients undergoing noncardiac surgery, (2) assessed perioperative risk factors for POD, and (3) measured the incidence of delirium (measured using a validated approach). Data were analyzed in 2020.Data Extraction and SynthesisIndividual patient data were pooled from 21 studies and 1-stage meta-analysis was performed using multilevel mixed-effects logistic regression after a multivariable imputation via chained equations model to impute missing data.Main Outcomes and MeasuresThe end point of interest was POD diagnosed up to 10 days after a procedure. A wide range of perioperative risk factors was considered as potentially associated with POD.ResultsA total of 192 studies met the eligibility criteria, and IPD were acquired from 21 studies that enrolled 8382 patients. Almost 1 in 5 patients developed POD (18%), and an increased risk of POD was associated with American Society of Anesthesiologists (ASA) status 4 (odds ratio [OR], 2.43; 95% CI, 1.42-4.14), older age (OR for 65-85 years, 2.67; 95% CI, 2.16-3.29; OR for >85 years, 6.24; 95% CI, 4.65-8.37), low body mass index (OR for body mass index <18.5, 2.25; 95% CI, 1.64-3.09), history of delirium (OR, 3.9; 95% CI, 2.69-5.66), preoperative cognitive impairment (OR, 3.99; 95% CI, 2.94-5.43), and preoperative C-reactive protein levels (OR for 5-10 mg/dL, 2.35; 95% CI, 1.59-3.50; OR for >10 mg/dL, 3.56; 95% CI, 2.46-5.17). Completing a college degree or higher was associated with a decreased likelihood of developing POD (OR 0.45; 95% CI, 0.28-0.72).Conclusions and RelevanceIn this systematic review and meta-analysis of individual patient data, several important factors associated with POD were found that may help identify patients at high risk and may have utility in clinical practice to inform patients and caregivers about the expected risk of developing delirium after surgery. Future studies should explore strategies to reduce delirium after surgery.

Triglyceride-glucose index predicts postoperative delirium in elderly patients with type 2 diabetes mellitus: a retrospective cohort study

“…Specifically, the E-value reflects the minimum strength of association that an unmeasured confounder would need to have with both the exposure and outcome, above and beyond the measured confounders, to fully explain away a specific estimated effect [ 16 ]. And reported ORs of identified risk factors for POD were compared with the E-value in present study [ 17 – 20 ]. Additional sensitivity analysis has also been conducted using the original, non-imputed data to detect if the results of TyG index as a binary variable are affected by imputing missing values.…”

Opioid use and subsequent delirium risk in patients with advanced cancer in palliative care: a multicenter registry study

“…The etiology of delirium in these patients is typically multifactorial, and our prior research identified several risk factors for delirium in patients with cancer, including old age, absence of chemotherapy during hospitalization, hearing impairment, underweight status, current opioid use, and history of delirium and other psychiatric disorders 9 . Opioid prescriptions, in particular, have been identified in various studies as potential triggers of delirium, observed across different surgical and disease groups, including those with neurological injury, pain, infection, fever, and hypotension 4 , 10 , 11 . However, previous studies exploring the association between opioid use and delirium in patients with advanced cancer showed controversy and limited cohort size 12 – 15 .…”

Predicting Postoperative Delirium in Older Patients: a multicenter retrospective cohort study

“…The Type and length of surgery and anesthesia are indispensable for POD prediction 18,27 . Although preoperative neuropsychological assessments, like the Mini-Mental State Examination (MMSE) and others [28][29][30] , help identify at-risk patients for early risk mitigation [31][32][33] , these evaluations…”

“…The Type and length of surgery and anesthesia are indispensable for POD prediction 18,27 . Although preoperative neuropsychological assessments, like the Mini-Mental State Examination (MMSE) and others 28–30 , help identify at-risk patients for early risk mitigation 31–33 , these evaluations are not yet incorporated in clinical routine despite experts’ recommendations 34 . The early identification of POD risk factors enables clinicians to proactively mitigate the occurrence of POD 35 and might affect patient’s decision before non-emergent surgery.…”