EP375 - Postoperative delirium in older adult patients undergoing colorectal surgery: are we screening enough?

Purpose/Background: Postoperative delirium (POD) is a common complication after colorectal surgery that often goes unrecognized. POD is also associated with poor patient outcomes as well as increased healthcare costs especially in the older adult population. While expert recommendation is that all older adult patients be screened for delirium, there is not widespread multicenter data evaluating delirium screening and detection available for older adults undergoing colorectal surgery. This study aimed to evaluate risk factors for POD screening and delirium screening rates and results in older adults undergoing colorectal surgery.

Methods/Interventions: This retrospective cohort study utilized 2024 ACS National Surgical Quality Improvement Project (NSQIP) data for patients aged 75 and older undergoing inpatient colorectal surgery. The primary outcomes were novel variables: "postoperative delirium screen" and "postoperative delirium screen outcome." Patients were split into delirium screening groups: 'Not screened', 'Positive screen', and 'Negative screen' based on these variables. Covariates included baseline patient factors and comorbidities, surgical factors (including indication and type of colorectal surgery), and older adult-specific factors. Chi-square analysis was performed.

Results/Outcomes: There were 13,729 patients included in the study. The mean age was 81.4 (SD: 4.9). 59.4% of patients were screened for delirium and of these, 12.1% of patients screened positive (7.2% overall in 'Positive screen' group). Baseline patient factors significantly associated with delirium screening group included ASA class (p < 0.0001) and preoperative sepsis (p < 0.0001). Associated surgical factors included case acuity (p < 0.0001), indication for surgery (p < 0.0001), and operation type (p < 0.0001). Associated older adult-specific factors included history of fall (p < 0.0001) and history of dementia (p < 0.0001). Patients with 'non-colon primary neoplasm' were most screened (64.9%) and those with 'trauma', 'anorectal disease', and 'enteritis/colitis' were least commonly screened (0%, 47.5%, and 52.4% respectively). For operation type, patients undergoing open partial colectomy with ostomy were most commonly screened (63.7%) and patients undergoing laparoscopic total colectomy were least commonly screened (46.7%). The highest percentages of 'Positive screen' patients were among those with preoperative ventilator support (32.8%), renal failure (27.0%), open total colectomy (23.9%), ascites (23.2%), oxygen support (23.1%), and dementia (22.6%).

Conclusion/Discussion: Despite expert guidelines recommending universal POD screening for older adult surgical patients, fewer than 60% of older adults undergoing colorectal surgery are being screened. While higher-risk patients (e.g. higher ASA class and preoperative sepsis) are more likely to be screened, significant variability exists based on patient and surgical factors, leaving many at-risk patients unscreened. Given the high overall vulnerability of this population and the substantial consequences of undiagnosed delirium, standardized, routine screening must be utilized in practice. Surgical teams should implement protocols to screen all older adults undergoing colorectal surgery for POD to ensure timely detection and management.

Table 1. Factors associated with delirium screening
Chi-square analysis of baseline patient, surgical, and older adult-specific factors associated with delirium screening based on delirium screening group ('Not Screened', 'Positive Screen', or 'Negative Screen').