Postoperative Delirium In Older Patients Research Articles

Development of an individualized model for predicting postoperative delirium in elderly patients with hepatocellular carcinoma.

Postoperative delirium (POD) is a common complication in older patients with hepatocellular carcinoma (HCC) that adversely impacts clinical outcomes. We aimed to evaluate the risk factors for POD and to construct a predictive nomogram. Data for a total of 1481 older patients (training set: n=1109; validation set: n=372) who received liver resection for HCC were retrospectively retrieved from two prospective databases. The receiver operating characteristic (ROC) curve, calibration plot, and decision curve analysis (DCA) were used to evaluate the performance. The rate of POD was 13.3% (148/1109) in the training set and 16.4% (61/372) in the validation set. Multivariate analysis of the training set revealed that factors including age, history of cerebrovascular disease, American Society of Anesthesiologists (ASA) classification, albumin level, and surgical approach had significant effects on POD. The area under the ROC curves (AUC) for the nomogram, incorporating the aforementioned predictors, was 0.798 (95% CI 0.752-0.843) and 0.808 (95% CI 0.754-0.861) for the training and validation sets, respectively. The calibration curves of both sets showed a degree of agreement between the nomogram and the actual probability. DCA demonstrated that the newly established nomogram was highly effective for clinical decision-making. We developed and validated a nomogram with high sensitivity to assist clinicians in estimating the individual risk of POD in older patients with HCC.

Development and validation of a nomogram to predict postoperative delirium in older patients after major abdominal surgery: a retrospective case-control study

BackgroundPostoperative delirium is a common complication in older patients, with poor long-term outcomes. This study aimed to investigate risk factors and develop a predictive model for postoperative delirium in older patients after major abdominal surgery.MethodsThis study retrospectively recruited 7577 patients aged ≥ 65 years who underwent major abdominal surgery between January 2014 and December 2018 in a single hospital in Beijing, China. Patients were divided into a training cohort (n = 5303) and a validation cohort (n = 2224) for univariate and multivariate logistic regression analyses and to build a nomogram. Data were collected for 43 perioperative variables, including demographics, medical history, preoperative laboratory results, imaging, and anesthesia information.ResultsAge, chronic obstructive pulmonary disease, white blood cell count, glucose, total protein, creatinine, emergency surgery, and anesthesia time were associated with postoperative delirium in multivariate analysis. We developed a nomogram based on the above 8 variables. The nomogram achieved areas under the curve of 0.731 and 0.735 for the training and validation cohorts, respectively. The discriminatory ability of the nomogram was further assessed by dividing the cases into three risk groups (low-risk, nomogram score < 175; medium-risk, nomogram score 175~199; high-risk, nomogram score > 199; P < 0.001). Decision curve analysis revealed that the nomogram provided a good net clinical benefit.ConclusionsWe developed a nomogram that could predict postoperative delirium with high accuracy and stability in older patients after major abdominal surgery.

Association between increased systemic immune-inflammation index and postoperative delirium in older intertrochanteric fracture patients

Background and purposeThe systemic immune-inflammation index (SII), a novel inflammation index derived from the counts of circulating platelets, neutrophils and lymphocytes, has been studied in the treatment of acute cancer and ischemic stroke (AIS). However, the clinical value of the SII in postoperative delirium patients has not been further investigated. The purpose of our research was to study the incidence and preoperative risk factors for postoperative delirium (POD) and verify whether the SII could serve as a potential marker for POD in older intertrochanteric fracture patients. Finally, we created a novel nomogram for predicting POD in older patients with intertrochanteric fractures.MethodsWe enrolled elderly patients with intertrochanteric fractures who underwent proximal femoral nail antirotation (PFNA) between February 2021 and April 2023. Univariate and multivariate logistic analyses were subsequently performed to confirm the risk factors and construct a nomogram model.Calibration curve and clinical decision curve analysis (DCA) were used to assess the model’s fitting performance. The performance of the nomogram was evaluated for discrimination, calibration, and clinical utility.ResultsA total of 293 patients were eligible for inclusion in the study, 25.6% (75/293) of whom had POD. The POD patients had higher SII values than the non-POD patients. The SII was strongly correlated with POD in older intertrochanteric fracture patients, and the optimal cutoff value was 752.6 × 109. Multivariate analysis revealed that age, diabetes, total albumin, SII > 752.6 × 109 and a CRP > 20.25 mg/L were independent risk factors for POD patients. By incorporating these 5 factors, the model achieved a concordance index of 0.745 (95% CI, 0.683–0.808) and had a well-fitted calibration curve and good clinical application value.ConclusionThe SII is a simple and valuable biomarker for POD, and the new nomogram model can be used to accurately predict the occurrence of POD. They can be utilized in clinical practice to identify those at high risk of POD in older intertrochanteric fracture patients.

The Association of Preoperative Diabetes With Postoperative Delirium in Older Patients Undergoing Major Orthopedic Surgery: A Prospective Matched Cohort Study.

Postoperative delirium (POD) is a common form of postoperative brain dysfunction, especially in the elderly. However, its risk factors remain largely to be determined. This study aimed to investigate whether (1) preoperative diabetes is associated with POD after elective orthopedic surgery and (2) intraoperative frontal alpha power is a mediator of the association between preoperative diabetes and POD. This was a prospective matched cohort study of patients aged 60 years or more, with a preoperative diabetes who underwent elective orthopedic surgery. Nondiabetic patients were matched 1:1 to diabetic patients in terms of age, sex, and type of surgery. Primary outcome was occurrence of POD, assessed using the 3-minute Diagnostic Confusion Assessment Method (3D-CAM) once daily from 6 pm to 8 pm during the postoperative days 1-7 or until discharge. Secondary outcome was the severity of POD which was assessed for all participants using the short form of the CAM-Severity. Frontal electroencephalogram (EEG) was recorded starting before induction of anesthesia and lasting until discharge from the operating room. Intraoperative alpha power was calculated using multitaper spectral analyses. Mediation analysis was used to estimate the proportion of the association between preoperative diabetes and POD that could be explained by intraoperative alpha power. A total of 138 pairs of eligible patients successfully matched 1:1. After enrollment, 6 patients in the diabetes group and 4 patients in the nondiabetes group were excluded due to unavailability of raw EEG data. The final analysis included 132 participants with preoperative diabetes and 134 participants without preoperative diabetes, with a median age of 68 years and 72.6% of patients were female. The incidence of POD was 16.7% (22/132) in patients with preoperative diabetes vs 6.0% (8/134) in patients without preoperative diabetes. Preoperative diabetes was associated with increased odds of POD after adjustment of age, sex, body mass index, education level, hypertension, arrhythmia, coronary heart disease, and history of stroke (odds ratio, 3.2; 95% confidence interval [CI], 1.4-8.0; P = .009). The intraoperative alpha power accounted for an estimated 20% (95% CI, 2.6-60%; P = .021) of the association between diabetes and POD. This study suggests that preoperative diabetes is associated with an increased risk of POD in older patients undergoing major orthopedic surgery, and that low intraoperative alpha power partially mediates such association.

Association of preoperative frailty with the risk of postoperative delirium in older patients undergoing hip fracture surgery: a prospective cohort study

ObjectiveThis study aimed to explore the correlation between preoperative frailty and the risk of postoperative delirium (POD) in older patients undergoing hip fracture surgery.MethodsIn total, 148 patients with hip fractures who were admitted to Tsinghua Changgung Hospital (Beijing, China) between January 2022 and January 2023 were involved in this study. Preoperative frailty scales were assessed, of which the CAM scale was postoperatively administered every morning and evening on days 1, 2, 3, 5, and 7. Binary logistic regression analysis was conducted to determine the correlation between preoperative frailty and the risk of POD.ResultsAmong 148 older patients with hip fractures, 71 (48.0%) were identified as preoperative frail and 77 (52.0%) as non-frail. The overall incidence of POD on day 7 was 24.3% (36/148), and preoperative frailty was associated with a significantly higher risk of POD compared with non-frailty (42.3% vs. 7.8%, P < 0.001). The binary logistic regression analysis revealed that preoperative frailty was noted as an independent risk factor for the risk of POD in older patients undergoing hip fracture surgery (P = 0.002).ConclusionPreoperative frailty increased the risk of POD in older patients undergoing hip fracture surgery.DiscussionPreoperative assessment of frailty in geriatric hip surgery can timely identify potential risks and provide interventions targeting frailty factors to reduce the incidence of POD in older patients undergoing hip fracture surgery. The findings suggested that preoperative frailty could increase the risk of POD in older patients undergoing hip fracture surgery. Further research is necessary to determine whether perioperative interventions aimed at enhancing frailty can mitigate the risk of POD and improve prognosis in older patients undergoing hip fracture surgery.

Random forest algorithm for predicting postoperative delirium in older patients.

In this study, we were aimed to identify important variables via machine learning algorithms and predict postoperative delirium (POD) occurrence in older patients. This study was to make the secondary analysis of data from a randomized controlled trial. The Boruta function was used to screen relevant basic characteristic variables. Four models including Logistic Regression (LR), K-Nearest Neighbor (KNN), the Classification and Regression Tree (CART), and Random Forest (RF) were established from the data set using repeated cross validation, hyper-parameter optimization, and Smote technique (Synthetic minority over-sampling technique, Smote), with the calculation of confusion matrix parameters and the plotting of Receiver operating characteristic curve (ROC), Precision recall curve (PRC), and partial dependence graph for further analysis and evaluation. The basic characteristic variables resulting from Boruta screening included grouping, preoperative Mini-Mental State Examination(MMSE), CHARLSON score, preoperative HCT, preoperative serum creatinine, intraoperative bleeding volume, intraoperative urine volume, anesthesia duration, operation duration, postoperative morphine dosage, intensive care unit (ICU) duration, tracheal intubation duration, and 7-day postoperative rest and move pain score (median and max; VAS-Rest-M, VAS-Move-M, VAS-Rest-Max, and VAS-Move-Max). And Random Forest (RF) showed the best performance in the testing set among the 4 models with Accuracy: 0.9878; Matthews correlation coefficient (MCC): 0.8763; Area under ROC curve (AUC-ROC): 1.0; Area under the PRC Curve (AUC-PRC): 1.0. A high-performance algorithm was established and verified in this study demonstrating the degree of POD risk changes in perioperative elderly patients. And the major risk factors for the development of POD were CREA and VAS-Move-Max.

Functional intervention following cardiac surgery to prevent postoperative delirium in older patients (FEEL WELL study)

BackgroundPostoperative delirium is a common complication in patients after cardiac surgery, especially in older patients, and can manifest as a disturbance of attention and consciousness. It can lead to increased postoperative morbidity, prolonged need for care, and mortality. The presented study investigates whether the occurrence of postoperative delirium after cardiac surgery can be prevented by a multisensory stimulation. It was conducted as a prospective, randomized, controlled, non-pharmacological intervention study in the years 2021 and 2022 at the University Hospital Bonn in Germany. A total of 186 patients over 65 years with elective cardiac surgery were enrolled. Patients were randomized either to the intervention or control group. In both groups, postoperative delirium was assessed with the 3-min diagnostic interview for confusion assessment method on the first 5 days after surgery and pain was assessed using the Numeric Rating Scale. Multisensory stimulation was performed 20 min a day for the first three postoperative days in the intervention group.ResultsThe incidence of postoperative delirium was 22.6% in the intervention group and 49.5% in the control group (p < 0.001). Duration of postoperative delirium was significantly shorter in the intervention group (p < 0.001). Stay in the intensive care unit was significantly longer in the control group (p = 0.006). In the regression model non-intervention, high pain scores, advanced age, and prolonged mechanical ventilation were associated with postoperative delirium (p = 0.007; p = 0.032; p = 0.006; p = 0.006, respectively).ConclusionsResults of the study imply that a multisensory stimulation done on the first 3 days after planned cardiac surgery can reduce the incidence and duration of postoperative delirium in older patients. Influence of the treatment on the incidence of delirium in other patient groups, the length of stay in the intensive care unit, and patients´ postoperative pain should be confirmed in further clinical studies.Trial registration: DRKS, DRKS00026909. Registered 28 October 2021, Retrospectively registered, https://drks.de/search/de/trial/DRKS00026909.

Dexmedetomidine Infusion Versus Placebo During Light or Deep Anesthesia on Postoperative Delirium in Older Patients Undergoing Major Noncardiac Surgery: A Pilot Randomized Factorial Trial.

Postoperative delirium (POD) is common among older surgical patients and may be affected by dexmedetomidine and depth of anesthesia. We designed this pilot study to assess the feasibility of comparing dexmedetomidine with normal saline during light versus deep anesthesia on POD in older patients undergoing major noncardiac surgery. In this pilot randomized factorial study, 80 patients aged 60 years or older undergoing major noncardiac surgery were randomized (1:1:1:1) to receive dexmedetomidine infusion 0.5 μg/kg/h or normal saline placebo during light (bispectral index [BIS] target 55) or deep (BIS target 40) anesthesia. Feasibility end points included consent rate and dropout rate, timely enrollment, blinded study drug administration throughout surgery, no inadvertent unmasking, achieving BIS target throughout >70% of surgery duration, and the process of twice-daily POD screening. In addition, we estimated the POD incidences in the 2 control groups (placebo and deep anesthesia) and treatment effects of dexmedetomidine and light anesthesia. Between November 1, 2021, and June 30, 2022, 78 patients completed the trial (mean [standard deviation, SD] age, 69.6 [4.6] years; 48 male patients [62%]; dexmedetomidine-deep, n = 19; dexmedetomidine-light, n = 20; placebo-deep, n = 19; placebo-light, n = 20). This study had a high consent rate (86%) and a low dropout rate (2.5%). Average recruitment was 5 patients at each center per month. Dexmedetomidine and normal saline were administered in a blinded fashion in all patients. Unmasking did not occur in either group. Approximately 99% of patients received the scheduled study drug infusion throughout the surgery. Approximately 81% of patients achieved the BIS targets throughout >70% of the surgery duration. The scheduled twice-daily POD screening was completed without exception. Overall, 10 of the 78 patients (13%; 95% confidence interval [CI], 7%-22%) developed POD. For the 2 reference groups, POD was observed in 7 of the 39 patients (17.9%; 95% CI, 9%-32.7%) in the placebo group and 7 of the 38 patients (18.4%; 95% CI, 9.2%-33.4%) in the deep anesthesia group. Regarding the treatment effects on POD, the estimated between-group difference was -10% (95% CI, -28% to 7%) for dexmedetomidine versus placebo, and -11% (95% CI, -28% to 6%) for light versus deep anesthesia. The findings of this pilot study demonstrate the feasibility of assessing dexmedetomidine versus placebo during light versus deep anesthesia on POD among older patients undergoing major noncardiac surgery, and justify a multicenter randomized factorial trial.

Association between Plasma Ascorbic Acid Levels and Postoperative Delirium in Older Patients Undergoing Cardiovascular Surgery: A Prospective Observational Study.

The incidence of delirium is high in older patients undergoing cardiovascular surgery with cardiopulmonary bypass (CPB). Intraoperative tissue hypoperfusion and re-reperfusion injury, which generate reactive oxygen species (ROS), are suggested to induce delirium. Ascorbic acid is an excellent antioxidant and may reduce organ damage by inhibiting the production of ROS. This prospective observational study aimed to measure pre- and postoperative plasma ascorbic acid levels and examine their association with delirium. Patients older than 70 years of age scheduled for elective cardiovascular surgery using CPB were enrolled. From September 2020 to December 2021, we enrolled 100 patients, and the data of 98 patients were analyzed. In total, 31 patients developed delirium, while 67 did not. Preoperative plasma ascorbic acid levels did not differ between the non-delirium and delirium groups (6.0 ± 2.2 vs. 5.5 ± 2.4 µg/mL, p = 0.3). Postoperative plasma ascorbic acid levels were significantly different between the groups (2.8 [2.3-3.5] vs. 2.3 [1.6-3.3] µg/mL, p = 0.037). In patients who undergo cardiovascular surgery with CPB, lower postoperative plasma ascorbic acid levels may be associated with the development of delirium.

Interrater reliability and concurrent validity of 4AT for the detection of postoperative delirium: A prospective cohort study

Interrater reliability and concurrent validity of 4AT for the detection of postoperative delirium: A prospective cohort study Abstract. Background: Numerous tools for detecting postoperative delirium are available. Guidelines recommend the 4 A's Test (4AT). However, there is little evidence on the validity and reliability of the German version of 4AT. Aim: To assess the interrater reliability of the German version of 4AT test for the detection of postoperative delirium in general surgical and orthopedic-traumatological patients, and the concurrent validity with the Delirium Observation Screening Scale (DOS). Methods: The present work is part of a prospective cohort study with a sample of 202 inpatients (≥ 65 years) who underwent surgery. The interrater reliability of the 4AT (intraclass coefficients) was determined with a subsample of 33 subjects who were rated by two nurses. Concurrent validity between the DOS scale and the 4AT was calculated using Pearson's correlation coefficient. Results: Interrater reliability for the 4AT total score and dichotomized total score were 0.92 (95% CI 0.84-0.96) and 0.98 (95% CI 0.95-0.98), respectively. The correlation between DOS and 4AT (Pearson) was 0.54 (p < 0.001). Conclusions: The 4A test can be used by nurses as a screening instrument for the detection of postoperative delirium in older patients on general surgery and orthopedic traumatology wards. In case of positive 4AT results further assessment by nurse experts or physicians is required.

Effect of Repeated Intranasal Administration of Different Doses of Insulin on Postoperative Delirium, Serum τ and Aβ Protein in Elderly Patients Undergoing Radical Esophageal Cancer Surgery.

Postoperative delirium is common after general anesthesia in older patients. However, there are currently no effective preventive measures. This study investigated the effect of repeated intranasal administration of different insulin doses before surgery on postoperative delirium in older patients with esophageal cancer, and the possible mechanism for its efficacy. In this randomized, placebo-controlled, double-blind, parallel-group study, 90 older patients were randomly assigned to either a Control (normal saline), Insulin 1 (20 U/0.5 mL intranasal insulin), or Insulin 2 (30 U/0.75 mL intranasal insulin) group. Delirium was assessed on postoperative days 1 (T2), 2 (T3), and 3 (T4) using the Confusion Assessment Method for the Intensive Care Unit. Serum τ and Aβ protein levels were measured at T0 (before insulin/saline administration), T1 (end of surgery), T2, T3 and T4. The Insulin 2 group had a significantly lower prevalence of delirium compared to the Control and Insulin 1 groups three days after surgery. Compared to baseline, τ and Aβ protein levels increased significantly at T1-T4. Compared to the Control group, the Insulin 1 and 2 groups had significantly lower τ and Aβ protein levels at T1-T4, and the Insulin 2 group had significantly lower levels than the Insulin 1 group at T1-T2. The administration of 30 U of intranasal insulin twice daily, from 2 days preoperatively until 10 minutes preanesthesia on the day of surgery, can significantly reduce postoperative delirium in older patients undergoing radical esophagectomy. It can also decrease postoperative τ and Aβ protein expression without causing hypoglycemia. This study was registered at the Chinese Clinical Trial Registry (www.chictr.org.cn, with the unique identifier: ChiCTR2100054245; December 11, 2021).

Association between preoperative anxiety and postoperative delirium in older patients: a systematic review and meta-analysis

BackgroundPostoperative delirium (POD) is a common postoperative complication associated with multiple adverse consequences on patient outcomes and higher medical expenses. Preoperative anxiety has been suggested as a possible precipitating factor for the development of POD. As such, we aimed to explore the association between preoperative anxiety and POD in older surgical patients.MethodsElectronic databases including MEDLINE (via PubMed), EMBASE (via Embase.com), Web of Science Core Collection, Cumulative Index to Nursing and Allied Health Literature (CINAHL Complete; via EBSCOhost) and clinical trial registries were systematically searched to identify prospective studies examining preoperative anxiety as a risk factor for POD in older surgical patients. We used Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies to assess the quality of included studies. The association between preoperative anxiety and POD was summarized with odds ratios (ORs) and 95% confidence intervals (CIs) using DerSimonian-Laird random-effects meta-analysis.ResultsEleven studies were included (1691 participants; mean age ranging between 63.1–82.3 years). Five studies used a theoretical definition for preoperative anxiety, with the Anxiety subscale of Hospital Anxiety and Depression Scale (HADS-A) as the instrument being most often used. When using dichotomized measures and within the HADS-A subgroup analysis, preoperative anxiety was significantly associated with POD (OR = 2.17, 95%CI: 1.01–4.68, I2 = 54%, Tau2 = 0.4, n = 5; OR = 3.23, 95%CI: 1.70–6.13, I2 = 0, Tau2 = 0, n = 4; respectively). No association was observed when using continuous measurements (OR = 0.99, 95%CI: 0.93–1.05, I2 = 0, Tau2 = 0, n = 4), nor in the subgroup analysis of STAI-6 (six-item version of state scale of Spielberger State-Trait Anxiety Inventory, OR = 1.07, 95%CI: 0.93–1.24, I2 = 0, Tau2 = 0, n = 2). We found the overall quality of included studies to be moderate to good.ConclusionsAn unclear association between preoperative anxiety and POD in older surgical patients was found in our study. Given the ambiguity in conceptualization and measurement instruments used for preoperative anxiety, more research is warranted in which a greater emphasis should be placed on how preoperative anxiety is operationalized and measured.

Association between preoperative anxiety and postoperative delirium in older patients: A systematic review and meta-analysis

Association between preoperative anxiety and postoperative delirium in older patients: A systematic review and meta-analysis

Preoperative serum ribose concentrations may be associated with postoperative delirium in older patients with a hip fracture

BackgroundPostoperative delirium (POD) is a common postoperative neurocognitive complication, especially in older patients. However, satisfactory biomarkers for predicting individual risks of POD have not been confirmed. D-ribose involvement in protein glycation and aggregation plays a pivotal role in age-related neurodegenerative disorders such as Alzheimer’s disease. ObjectivesThis study aimed to determine whether serum D-ribose concentrations contribute to the early diagnosis of POD. We also discuss the probable mechanisms underlying the development of POD. Methods110 older patients with hip fracture who had undergone internal fixation or hip replacement under general anesthesia and had completed our assessments were selected. Preoperative venous blood (4 ml) was collected before the induction of anesthesia. Postoperative venous blood was obtained at 07:00 and 20:00 h on postoperative day 1 and at 20:00 h on postoperative day 2. On the first 2 postoperative days, the patients were assessed twice daily (at 8:00 and 20:00 h on each day) using the Confusion Assessment Method-Chinese Revision. Results15 patients were finally diagnosed with POD. We also included 15 patients without POD who were matched with the recruited patients with POD (1:1) on the basis of age, sex, body mass index and the Mini-Mental State Examination score. Serum ribose concentrations were measured by high-performance liquid chromatography. The demographic characteristics of the groups were matched. Preoperative serum ribose concentrations were significantly higher in patients with POD than in those without POD (p < 0.05) and were also an independent risk factor for POD. Moreover, when the preoperative serum ribose concentration doubled, the risk of POD increased by 1.672 times. ConclusionsThese results indicate that the serum D-ribose concentration may be a potential predictive molecular biomarker for POD, and provide useful information for further pathological mechanism studies.

Desflurane is risk factor for postoperative delirium in older patients' independent from intraoperative burst suppression duration.

Postoperative Delirium (POD) is the most frequent neurocognitive complication after general anesthesia in older patients. The development of POD is associated with prolonged periods of burst suppression activity in the intraoperative electroencephalogram (EEG). The risk to present burst suppression activity depends not only on the age of the patient but is also more frequent during propofol anesthesia as compared to inhalative anesthesia. The aim of our study is to determine, if the risk to develop POD differs depending on the anesthetic agent given and if this correlates with a longer duration of intraoperative burst suppression. In this secondary analysis of the SuDoCo trail [ISRCTN 36437985] 1277 patients, older than 60 years undergoing general anesthesia were included. We preprocessed and analyzed the raw EEG files from each patient and evaluated the intraoperative burst suppression duration. In a logistic regression analysis, we assessed the impact of burst suppression duration and anesthetic agent used for maintenance on the risk to develop POD. 18.7% of patients developed POD. Burst suppression duration was prolonged in POD patients (POD 27.5 min ± 21.3 min vs. NoPOD 21.4 ± 16.2 min, p < 0.001), for each minute of prolonged intraoperative burst suppression activity the risk to develop POD increased by 1.1% (OR 1.011, CI 95% 1.000-1.022, p = 0.046). Burst suppression duration was prolonged under propofol anesthesia as compared to sevoflurane and desflurane anesthesia (propofol 32.5 ± 20.3 min, sevoflurane 17.1 ± 12.6 min and desflurane 20.1 ± 16.0 min, p < 0.001). However, patients receiving desflurane anesthesia had a 1.8fold higher risk to develop POD, as compared to propofol anesthesia (OR 1.766, CI 95% 1.049-2.974, p = 0.032). We found a significantly increased risk to develop POD after desflurane anesthesia in older patients, even though burst suppression duration was shorter under desflurane anesthesia as compared to propofol anesthesia. Our finding might help to explain some discrepancies in studies analyzing the impact of burst suppression duration and EEG-guided anesthesia on the risk to develop POD.

Predictors of Postoperative Delirium in Older Patients Undergoing Elective Spine Surgery.

This prospective study was conducted to investigate the prevalence and predictors of postoperative delirium (POD) in a cohort of patients aged ≥65 years who were scheduled to undergo elective spine surgery. Patients aged ≥65 years who were scheduled to undergo elective spine surgery from February 2018 to May 2019 were prospectively recruited for this study. Delirium was diagnosed according to the Confusion Assessment Method algorithm. Candidate predictors included patient characteristics, comorbidities, surgical time, blood loss, preoperative laboratory parameters, and preoperative cognitive function, as assessed by the Mini-Cog test. These variables were compared between patients with and without POD. Multivariate logistic regression was performed to identify the independent predictors of POD. For the continuous variables, a receiver operating characteristic curve was used to determine the optimal cutoff value for predicting POD. Of the 106 patients included in the study, 12 (11.3%) patients developed POD, with a median time to onset of 3 d and median duration of 2 d. After adjusting for confounders, the occurrence of POD was independently associated with older age, a higher blood urea nitrogen (BUN) concentration, and a lower Mini-Cog score. The optimal cutoff point of the Mini-Cog score for predicting the occurrence of POD was ≤3. POD was a common complication after spine surgery, showing an incidence of 11.3% in this study. Older age, a higher BUN concentration, and impaired cognition, as defined by the Mini-Cog, were independent predictors of POD. The current results may be useful for early identification of patients at risk of POD and facilitation of targeted interventions for preventing POD or mitigating its severity.

Intraoperative allogeneic transfusion is associated with postoperative delirium in older patients after total knee and hip arthroplasty.

To determine whether intraoperative transfusion of allogeneic or autologous blood is associated with an increased incidence of postoperative delirium (POD) after total knee arthroplasty (TKA) and total hip arthroplasty (THA). The medical records of 1,143 older (≥65 years old) patients who received an intraoperative blood transfusion while undergoing total knee or hip arthroplasty at the First Medical Center of Chinese PLA General Hospital from 2014 to 2019 were reviewed; of these patients, 742 (64.92%) received allogeneic blood, while 401 (35.08%) received autologous blood. Patients who received autologous transfusion were paired with those received allogeneic transfusion using 1:1 propensity score matching method. The primary outcome was POD. The secondary outcomes were postoperative complications, including heart failure, deep vein thrombosis, myocardial infarction, stroke, and lung infection. Multivariable nominal logistic regression was used to identify any independent associations between intraoperative blood transfusions and POD, and secondary postoperative complications, respectively. Postoperative delirium occurred in 6.6% (49/742) of patients who had received an allogeneic blood transfusion and in 2.0% (8/401) of patients who had received an autologous blood transfusion. It is noteworthy that the multivariable logistic regression demonstrated a significant association between intraoperative allogeneic blood transfusion and POD (odds ratio [OR]: 4.11; 95% confidence interval [CI]: 1.95-9.77; p < 0.001). After PSM, Allogeneic transfusion was also the strongest predictor for POD (OR: 4.43; 95% CI: 2.09-10.58; p < 0.001). In the patients who had received THA or TKA, intraoperative allogeneic blood transfusions were associated with an increased risk of POD.

Preoperative anxiety as an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation.

Anxiety is common in older patients suffering from lumbar disc herniation. Postoperative delirium is related to poor prognosis. But the relationship between preoperative anxiety and postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation is not clear. The study aimed to investigate if preoperative anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation. The medical records of 1290 patients undergoing elective surgery for lumbar disc herniation at a single institution from 2016 through 2021 were reviewed. Of 863 eligible patients, 225 (26.1%) patients had been diagnosed with anxiety by a board-certified psychiatrist and constituted the Anxiety group; the remaining 638 patients constituted the no-anxiety group. The demographics, baseline, operative variable and postoperative complications were collected and compared between the two groups. The primary outcome of this study was the incidence of delirium, according to the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition, during a hospital stay after surgery for lumbar disc herniation. The relationship between anxiety and postoperative delirium was determined through multivariate logistic regression analysis. The demographics and comorbidity were similar between the two groups, except for age, sex, alcohol use and cerebrovascular disease. The operative variables were different between the two groups. The incidence of postoperative complications other than postoperative delirium was also similar between the two groups. In total, 86 patients (9.97%) had an episode of postoperative delirium, with anxiety group patients experiencing approximately a twofold higher rate (15.6% vs 7.99%). In a multivariate logistic regression analysis, anxiety was an independent predictor of postoperative delirium in older patients undergoing elective surgery for lumbar disc herniation (OR 2.228, 95% CI 1.494-3.416, p = 0.009). This study suggests that anxiety is an independent risk factor of postoperative delirium among older patients undergoing elective surgery for lumbar disc herniation. Preoperative anxiety assessment can help to identify older patients at high risk of postoperative delirium and facilitate perioperative management of older patients undergoing elective surgery for lumbar disc herniation.

Dose-dependent relationship between intra-procedural hypoxaemia or hypocapnia and postoperative delirium in older patients

BackgroundPrevious studies indicated an association between impaired cerebral perfusion and post-procedural neurological disorders. We investigated whether intra-procedural hypoxaemia or hypocapnia are associated with delirium after surgery. MethodsInpatients ≥60 yr of age undergoing anaesthesia for surgical or interventional procedures between 2009 and 2020 at an academic healthcare network in the USA (Massachusetts) were included in this hospital registry study. The primary exposure was intra-procedural hypoxaemia, defined as peripheral oxygen saturation <90% for >2 cohering min. The co-primary exposure was hypocapnia during general anaesthesia, defined as end-tidal carbon dioxide pressure ≤25 mm Hg for >5 cohering min. The primary outcome was delirium within 7 days after surgery. ResultsOf 71 717 included patients, 1702 (2.4%) developed postoperative delirium, and hypoxaemia was detected in 2532 (3.5%). Of 42 894 patients undergoing general anaesthesia, 532 (1.2%) experienced hypocapnia. The occurrence of either hypoxaemia (adjusted odds ratio [ORadj]=1.71; 95% confidence interval [CI], 1.40–2.07; P<0.001) or hypocapnia (ORadj=1.77; 95% CI, 1.30–2.41; P<0.001) was associated with a higher risk of delirium within 7 days. Both associations were dependent on the magnitude, and increased with event duration (ORadj=1.03; 95% CI, 1.02–1.04; P<0.001 and ORadj=1.01; 95% CI, 1.00–1.01; P=0.005, for each minute increase in the longest continuous episode, respectively). There was no association between occurrence of hypercapnia and postoperative delirium (ORadj=1.24; 95% CI, 0.90–1.71; P=0.181). ConclusionsIntra-procedural hypoxaemia and hypocapnia were dose-dependently associated with a higher risk of postoperative delirium. These findings support maintaining normal gas exchange to avoid postoperative neurological disorders.

Lower preoperative serum uric acid level may be a risk factor for postoperative delirium in older patients undergoing hip fracture surgery: a matched retrospective case-control study

BackgroundPostoperative delirium (POD) is a common complication after hip fracture surgery that is associated with various short- and long-term outcomes. The mechanism of POD may be associated with the oxidative stress process. Uric acid has been shown to provide a neuroprotective effect in various neurodegenerative diseases through its antioxidant properties. However, it is unclear whether lower preoperative serum uric acid levels are associated with the development of POD after hip fracture surgery. Therefore, this study assessed the association of lower preoperative uric acid levels in patients with POD during hospitalization.MethodsThis is a matched retrospective case-control study that included 96 older patients (≥65 y) who underwent hip fracture surgery. POD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Patients diagnosed with POD (cases) were matched 1:1 with patients without POD (controls) on the basis of age, sex, and anesthesia type. The relationship between preoperative uric acid and POD was analyzed by multivariable analysis.ResultsThe POD and non-POD groups each had 48 patients. In the univariate analysis, lower log preoperative serum uric acid value, higher neutrophil-to-lymphocyte ratio, and cerebrovascular disease were more likely in patients with POD than in those with no POD. Multivariable conditional logistic regression analysis showed that lower log preoperative serum uric acid (adjusted odds ratio [aOR], 0.028; confidence interval [CI], 0.001–0.844; p = 0.040), higher neutrophil-to-lymphocyte ratio (aOR, 1.314; 95% CI, 1.053–1.638; p = 0.015), and increased surgery duration (aOR, 1.034; 95% CI, 1.004–1.065; p = 0.024) were associated with increased risk of POD.ConclusionsLower preoperative serum uric acid levels may be an independent risk factor for POD after adjustment for possible confounding factors. However, large prospective studies are needed to confirm this finding.