The association between intraoperative hypotension and postoperative delirium- a retrospective cohort analysis.

BACKGROUND: Intraoperative hypotension might contribute to the development of postoperative delirium through inadequate cerebral perfusion. However, evidence regarding the association between intraoperative hypotension and postoperative delirium is equivocal. We therefore tested the hypothesis that in patients>70 years having elective non-cardiac surgery, intraoperative hypotension is associated with postoperative delirium. METHODS: We conducted a retrospective cohort analysis of patients >70 years who underwent elective non-cardiac surgery in a single tertiary academic center between 2020 and 2021. Intraoperative hypotension was quantified as the area under a mean arterial pressure (MAP) threshold of 65 mmHg. Postoperative delirium was defined as a collapsed composite outcome including positive 4A's test during the initial 2 postoperative days, and/or delirium identification using the Chart-based Delirium Identification Instrument. The association between hypotension and postoperative delirium was assessed using multivariable logistic regression, adjusting for potential confounding variables. Several sensitivity analyses were performed using similar regression models. RESULTS: In total, 2352 patients were included (median age 76 years, 1112 (47%) women, 1166 (50%) ASA score≥3, and 698 (31%) having high-risk surgeries). The median [IQR] intraoperative AUC of MAP<65 mmHg was 28 [0,103] mmHg. min. The overall incidence of postoperative delirium was 14% (327/2352). After adjustment for potential confounding variables, hypotension was not associated with postoperative delirium. Compared to the 1st quartile of AUC of MAP<65 mmHg, patients in the 2nd, 3rd, and 4th quartiles did not have more postoperative delirium, with adjusted odds ratio (aOR) of 0.94 (95% confidence interval (CI) 0.64-1.36; P=0.73), 0.95 (0.66-1.36; P=0.78), and 0.95 (0.65-1.36; P=0.78), respectively. Intraoperative hypotension was also not associated with postoperative delirium in any of the sensitivity and sub-group analyses performed. CONCLUSIONS: To the extent of hypotension observed in our cohort, our results suggest that intraoperative hypotension is not associated with postoperative delirium in elderly patients having elective non-cardiac surgery.

Preoperative cognitive impairment and postoperative delirium among Holocaust survivors who achieved longevity.

BACKGROUND: Holocaust survivors (HS) experience higher rates of physiological and psychological morbidities, increasing their vulnerability to perioperative complications. Limited information exists regarding their perioperative neurocognitive disorders. This study aimed to assess the rates of preoperative cognitive impairment, postoperative delirium, and other complications among HS aged 75+ undergoing elective surgery. METHODS: This is a single-center retrospective cohort study that analyzed prospectively collected data. All surgical patients born before 1945 who underwent elective noncardiac surgery at a tertiary hospital in Israel during 2020-2021 were included. The HS group was identified through the hospital's information system. Preoperative cognitive impairment was assessed using the Mini-Cog test. Postoperative delirium was defined as a combined outcome, which included a positive 4A's-Test (4AT) result during the postanesthesia care unit stay up to the second postoperative day, a positive 3-Minute Diagnostic Confusion Assessment Method (3D-CAM) test administered by the geriatric team, and identification through the medical records using the Chart-based Delirium Identification Instrument (CHART-DEL). We used multivariable regression to assess the risk factors for postoperative delirium. RESULTS: Out of 1332 eligible patients, 422 (32%) were HS, while the others served as controls. Both groups had a similar rate of preoperative cognitive impairment (24%, p = 0.89) and postoperative delirium (16%, p = 0.95). HS exhibited a higher risk of the composite adverse events (24% vs. 20%, p = 0.05, aOR [95% CI] 1.3 [1.0-1.7]), driven mainly by falls during hospitalization (4% vs. 2%, p = 0.03, aOR 2.1 [1.1-4.1]). HS patients were more likely to be childless (33% vs. 11%, p = 0.001) and had higher rates of chronic antidepressant and benzodiazepine use. CONCLUSIONS: HS achieving longevity do not face increased risks of preoperative cognitive impairment and postoperative delirium. However, special care is still warranted due to their elevated rate of other complications during hospitalization.

The association between midazolam premedication and postoperative delirium - a retrospective cohort study.

STUDY OBJECTIVE: To evaluate the association between midazolam premedication and postoperative delirium in a large retrospective cohort of patients ≥70 years. DESIGN: Retrospective cohort study. SETTING: A single tertiary academic medical center. PATIENTS: Patients ≥70 years having elective non-cardiac surgery under general anesthesia from 2020 to 2021. INTERVENTIONS: Midazolam premedication, defined as intravenous midazolam administration prior to induction of general anesthesia. MEASUREMENTS: The primary outcome, postoperative delirium, was a collapsed composite outcome including at least one of the following: a positive 4A's test during post-anesthesia care unit stay and/or the initial 2 postoperative days; physician or nursing records reporting new-onset confusion as captured by the CHART-DEL instrument; or a positive 3D-CAM test. The association between midazolam premedication and postoperative delirium was assessed using multivariable logistic regression, adjusting for potential confounding variables. As secondary analysis, we investigated the association between midazolam premedication and a composite of other postoperative complications. Several sensitivity analyses were performed using similar regression models. MAIN RESULTS: In total, 1973 patients were analyzed (median age 75 years, 47% women, 50% ASA score ≥ 3, 32% high risk surgery). The overall incidence of postoperative delirium was 15.3% (302/1973). Midazolam premedication was administered to 782 (40%) patients (median [IQR] dose 2 [1,2] mg). After adjustment for potential confounding variables, midazolam premedication was not associated with increased odds of postoperative delirium, with adjusted odds ratio of 1.09 (95% confidence interval 0.82-1.45; P = 0.538). Midazolam premedication was also not associated with the composite of other postoperative complications. Furthermore, no association was found between midazolam premedication and postoperative delirium in any of the sensitivity analyses preformed. CONCLUSIONS: Our results suggest that low doses of midazolam can be safely used to pre-medicate elective surgical patients 70 years or older before non-cardiac surgery, without significant effect on the risk of developing postoperative delirium.

Preoperative Cognitive Impairment and Postoperative Delirium in Elderly Surgical Patients: A Retrospective Large Cohort Study (The CIPOD Study).

OBJECTIVE: To test the hypothesis that in surgical patients ≥70 years, preoperative cognitive impairment is independently associated with postoperative delirium. BACKGROUND: Postoperative delirium is common among elderly surgical patients and is associated with longer hospitalization and significant morbidity. Some evidence suggest that baseline cognitive impairment is an important risk factor. Routine screening for both preoperative cognitive impairment and postoperative delirium is recommended for older surgical patients. As of 2019, we implemented such routine perioperative screening in all elective surgical patients ≥70 years. METHODS: Retrospective single-center analysis of prospectively collected data between January and December 2020. All elective noncardiac surgical patients ≥70 years without pre-existing dementia were included. Postoperative delirium, defined as 4A's test score ≥4, was evaluated in the postanesthesia care unit and during the initial 2 postoperative days. Patients' electronic records were also reviewed for delirium symptoms and other adverse outcomes. RESULTS: Of 1518 eligible patients, 1338 (88%) were screened preoperatively [mean (SD) age 77 (6) years], of whom 21% (n=279) had cognitive impairment (Mini-Cog score ≤2). Postoperative delirium occurred in 15% (199/1338). Patients with cognitive impairment had more postoperative delirium [30% vs. 11%, adjusted odds ratio (95% confidence interval) 3.3 (2.3-4.7)]. They also had a higher incidence of a composite of postoperative complications [20% vs. 12%, adjusted odds ratio: 1.8 (1.2-2.5)], and median 1-day longer hospital stay [median (interquartile range): 6 (3,12) vs. 5 (3,9) days]. CONCLUSIONS: One-fifth of elective surgical patients ≥70 years present to surgery with preoperative cognitive impairment. These patients are at increased risk of postoperative delirium and major adverse outcomes.