Disclaimer: This article is intended solely for informational and educational purposes only. It does not constitute medical advice.

Older adults make up a growing share of the surgical population, and many arrive in preoperative clinics with cognitive changes that have never been formally recognized. Preoperative cognitive decline, whether established dementia or subtle, undiagnosed impairment, is independently associated with longer-term postoperative cognitive impairment. With cognitive dysfunctions being a major concern in older surgical patients, it is essential for clinicians to evaluate cognitive health before surgery to more accurately assess patient risk and ensure complete care preparations. 

Preoperative cognitive impairment is more prevalent than most surgical teams appreciate, and it is clinically important, as it can help identify patients who need more safeguards in their anesthesia, surgery, recovery, and follow-up care. In one large cohort of elective noncardiac surgical patients aged 70 and older, roughly one in five screened positive for cognitive impairment on the Mini-Cog, despite having no prior diagnosis of dementia.1 Data from the 2025 American Society of Anesthesiologists Practice Advisory reveals two striking trends among older elective noncardiac surgery patients: around 37% of patents without any prior history of neurocognitive diagnosis were found to have significant impairment during preoperative screening.2 In short, a large fraction of vulnerable patients go unnoticed without a screening. 

The association between baseline cognition and postoperative cognitive impairment is robust. In one study, patients with preoperative cognitive decline developed delirium at nearly three times the rate of unimpaired patients, along with more complications and longer hospital stays.1 A systematic review and meta-analysis of 53 studies encompassing nearly 200,000 patients found that preoperative cognitive decline roughly quadrupled the odds of postoperative delirium and was also associated with higher one-year mortality, discharge to assisted care, readmissions, and complications. 

The relationship extends beyond acute delirium to durable postoperative cognitive impairment. Presurgical cognitive impairment has been independently associated with both postoperative delirium and postoperative cognitive impairment at three months, and patients with both presurgical impairment and postoperative delirium carried the highest risk of long-term postoperative cognitive impairment, suggesting these conditions compound one another.4 Longer term, postoperative delirium has been associated with a roughly 40% acceleration in cognitive decline over six years of follow-up, though whether delirium causes decline or reveals preclinical brain disease remains uncertain.5 

These findings reframe cognitive decline as a vital sign worth measuring before surgery. Professional bodies now endorse routine preoperative cognitive screening in older adults without a known diagnosis, using brief validated tools such as the Mini-Cog, which combines three-item recall with clock drawing and has been validated in the surgical population.6 Documenting a baseline also gives the team a reference point for interpreting postoperative mental status changes. 

Ultimately, identification enables mitigation. While no single pharmacologic or anesthetic intervention has proven decisively protective, multicomponent strategies show promise. One strategy can be avoiding medications with a higher risk of postoperative delirium like benzodiazepines, antipsychotics, and anticholinergics in patients 65 and older. Another can be incorporating prehabilitation and structured programs emphasizing orientation, cognitive stimulation, and early mobilization.7,8 

References 

1. Weiss Y, Zac L, Refaeli E, Ben-Yishai S, Zegerman A, Cohen B, Matot I. Preoperative Cognitive Impairment and Postoperative Delirium in Elderly Surgical Patients: A Retrospective Large Cohort Study (The CIPOD Study). Ann Surg. 2023 Jul 1;278(1):59-64. doi: 10.1097/SLA.0000000000005657. Epub 2022 Aug 1. PMID: 35913053.
2. Sieber F, McIsaac DI, Deiner S, Azefor T, Berger M, Hughes C, Leung JM, Maldon J, McSwain JR, Neuman MD, Russell MM, Tang V, Whitlock E, Whittington R, Marbella AM, Agarkar M, Ramirez S, Dyer A, Friel Blanck J, Uhl S, Grant MD, Domino KB. 2025 American Society of Anesthesiologists Practice Advisory for Perioperative Care of Older Adults Scheduled for Inpatient Surgery. Anesthesiology. 2025 Jan 1;142(1):22-51. doi: 10.1097/ALN.0000000000005172. PMID: 39655991. 
3. Chen L, Au E, Saripella A, Kapoor P, Yan E, Wong J, Tang-Wai DF, Gold D, Riazi S, Suen C, He D, Englesakis M, Nagappa M, Chung F. Postoperative outcomes in older surgical patients with preoperative cognitive impairment: A systematic review and meta-analysis. J Clin Anesth. 2022 Sep;80:110883. doi: 10.1016/j.jclinane.2022.110883. Epub 2022 May 24. PMID: 35623265. 
4. Knaak C, Brockhaus WR, Spies C, Borchers F, Piper SK, Radtke FM, Lachmann G. Presurgical cognitive impairment is associated with postoperative delirium and postoperative cognitive dysfunction. Minerva Anestesiol. 2020 Apr;86(4):394-403. doi: 10.23736/S0375-9393.20.13903-8. Epub 2020 Jan 28. PMID: 32000470. 
5. Kunicki ZJ, Ngo LH, Marcantonio ER, Tommet D, Feng Y, Fong TG, Schmitt EM, Travison TG, Jones RN, Inouye SK. Six-Year Cognitive Trajectory in Older Adults Following Major Surgery and Delirium. JAMA Intern Med. 2023 May 1;183(5):442-450. doi: 10.1001/jamainternmed.2023.0144. PMID: 36939716; PMCID: PMC10028541. 
6. Coleman J, Finlayson E, Katlic M, et al. Geriatric Surgery Verification Program Standards. Chicago (IL): American College of Surgeons; 2019. 
7. Vacas S, Cole DJ, Cannesson M. Cognitive Decline Associated With Anesthesia and Surgery in Older Patients. JAMA. 2021 Aug 2:10.1001/jama.2021.4773. doi: 10.1001/jama.2021.4773. Epub ahead of print. PMID: 34338712; PMCID: PMC8807795. 
8. Peden CJ, Miller TR, Deiner SG, Eckenhoff RG, Fleisher LA; Members of the Perioperative Brain Health Expert Panel. Improving perioperative brain health: an expert consensus review of key actions for the perioperative care team. Br J Anaesth. 2021 Feb;126(2):423-432. doi: 10.1016/j.bja.2020.10.037. Epub 2021 Jan 4. PMID: 33413977.