Estimates of Geriatric Delirium Frequency in Noncardiac Surgeries and Its Evaluation Across the Years: A Systematic Review and Meta-Analysis

Abstract

Objectives: Delirium is an acute neuropsychiatric syndrome associated with poor outcomes. Older adults undergoing surgery have a higher risk of manifesting perioperative delirium, particularly those having associated comorbidities. It remains unclear whether delirium frequency varies across surgical settings and if it has remained stable across the years. We conducted a systematic review to (1) determine the overall frequency of delirium in older people undergoing noncardiac surgery; (2) explore factors explaining the variability of the estimates; and (3) determine the changing of the estimates over the past 2 decades. Design: Systematic review and meta-analysis. Literature search was performed in MEDLINE, PubMed, ISI Web of Science, EBSCO, ISRCTN registry, ScienceDirect, and Embase in January 2020 for studies published from 1995 to 2020. Setting: Noncardiac surgical settings. Participants: Forty-nine studies were included with a total of 26,865 patients screened for delirium. Methods: We included observational and controlled trials reporting incidence, prevalence, or proportion of delirium in adults aged !60 years undergoing any noncardiac surgery requiring hospitalization. Data extracted included sample size, reported delirium frequencies, surgery type, anesthesia type, delirium diagnosis method, length of hospitalization, and year of assessment. (PROSPERO registration no.: CRD42020160045). Results: We found an overall pooled frequency of preoperative delirium of 17.9% and postoperative delirium (POD) of 23.8%. The POD estimates increased between 1995 and 2020 at an average rate of 3% per year. Pooled estimates of POD were significantly higher in studies not excluding patients with lower cognitive performance before surgery (28% vs 16%) and when general anesthesia was used in comparison to local, spinal, or epidural anesthesia (28% vs 20%). Conclusions and Implications: Type of anesthesia and preoperative cognitive status were significant moderators of delirium frequency. POD in noncardiac surgery has been increasing across the years, suggesting that more resources should be allocated to delirium prevention and management.

Postoperative Delirium in Older Patients: A Systematic Review of Assessment and Incidence of Postoperative Delirium

“…Our findings support an earlier study that specifically estimated the frequency of delirium in older patients who had noncardiac surgeries, where the POD incidence is 23.8% (Silva et al, 2020). The incidence of POD has been investigated in relation to relevant health indicators presurgery such as sleep disruption in the general population (> 18 years old).…”

Lack of Association Between Perioperative Medication and Postoperative Delirium in Hip Fracture Patients in an Orthogeriatric Care Pathway

“…The wide variance in postoperative delirium incidence between our cohort and the literature 4,22 is probably a result of the considerable heterogeneity in definitions and methods used to identify postoperative delirium, the study populations, and the settings. By selecting only studies specific to older patients with hip fracture surgery [23][24][25] , the incidences were comparable (30% to 42%).…”

“…Baseline characteristics are reported in Table 1. The mean (SD) age was 87 (6) years, 383 (78%) patients were female; the median Cumulative Illness Rating Scale score was 9 [IQR 6-12], median number of drugs per day was 5 [3][4][5][6][7][8], and 15% were living in a nursing home before the hip fracture. Patients with postoperative delirium were older, had more comorbidities (especially dementia), were less autonomous and more frequently lived in a nursing home than patients without postoperative delirium.…”

“…In older people, a common but avoidable complication in the first postoperative days after hip fracture surgery is postoperative delirium, characterized by an acute onset and fluctuating course of inattention and either disorganized thinking or altered level of consciousness. A specialized geriatric intervention can lead to a 30% reduction in risk of postoperative delirium [1][2][3][4] . Postoperative delirium, which is distressing to patients, family members and clinicians, is associated with poor cognitive and functional recovery, increased use of health care resources, and increased mortality 1,5 .…”

Perioperative neurocognitive disorders: A narrative review focusing on diagnosis, prevention, and treatment

“…In general adult patients, the incidence of postoperative delirium is 2.5%–4.5% 4,5 . In patients aged 60 years or above, the incidence of postoperative delirium is increased to 12.0%–23.8% 6,7 . The type and complexity of surgery also greatly affect the occurrence of delirium.…”