Postoperative delirium

Incidence and risk factors of postoperative delirium in elderly surgical patients 2023

Postoperative delirium has the potential to impact individuals of all age groups, with a significant emphasis on the elderly population. Its presence leads to an increase in surgical morbidity and mortality rates, as well as a notable prolongation of hospital stays. However, there is a lack of research regarding the prevalence, risk factors, and implications of postoperative delirium in developing nations like Ethiopia, which affects both patients and healthcare institutions. An observational study was conducted at hospitals in the South Gondar Zone to diagnose postoperative delirium in the Post-Anesthesia Care Unit (PACU) using the Nursing Delirium Screening Scale. Both bivariable and multivariable logistic regression techniques were employed to analyze the association between independent factors and postoperative delirium. The strength of the association was indicated by the odds ratio with a 95% confidence interval (CI). Any p-values below 0.05 were considered statistically significant. The incidence of postoperative delirium was determined to be 41%. In the multivariate logistic regression analysis, several factors were identified as significantly associated with postoperative delirium. These factors include an age of 75 or older (AOR, 11.24; 95% CI, 4.74-26.65), ASA-PS IV (AOR, 3.25; 95% CI, 1.81-5.85), severe functional impairment of activities of daily living (AOR, 3.29; 95% CI, 1.06-10.20), premedication with benzodiazepine (AOR, 4.61; 95% CI, 2.48-8.57), intraoperative estimated blood loss exceeding 1000 ml (AOR, 2.74; 95% CI, 1.50-4.98), and intraoperative ketamine use (AOR, 3.84; 95% CI, 2.21-6.68). Additionally, postoperative delirium was found to significantly prolong the duration of stay in the post-anesthesia care unit (PACU) and the length of hospital stay (p-value < 0.05). Patients aged 75 or older, ASA-PS IV, experiencing severe functional impairment of ADL, patients premedicated with benzodiazepine, patients with intraoperative estimated blood loss exceeding 1000 ml, and intraoperative ketamine use were identified as risk factors for post-operative delirium.

Risk factors of delirium after cardiac surgery: a systematic review and meta-analysis

BACKGROUND

Post-operative delirium (POD) is a relatively common occurrence following surgical procedures, particularly cardiac surgeries. Given that the majority of pharmacologic treatments for delirium have demonstrated inadequate efficacy, it is of great importance to identify risk factors to prevent delirium or reduce its complications. Consequently, in this systematic review and meta-analysis, we identified risk factors of POD after cardiac surgery.

METHOD

A comprehensive search of the literature was conducted using the databases Scopus, PubMed, and Web of Science from the inception to April 22, 2024. The objective was to identify prospective cohorts that had assessed the risk factors associated with POD in patients undergoing cardiac surgery using multivariate regression.

RESULTS

Of the 3,166 studies that were initially screened, 23 were included in the review. Nine risk factors were evaluated including age (OR 1.06, 95% CI (1.04, 1.08), p < 0.001), pre-operative depression (OR 3.71, 95% CI (2.45, 5.62), p < 0.001), post-operative atrial fibrillation (AF) (OR 2.39, 95% CI (1.79, 3.21), p < 0.001), hypertension (HTN) (OR 1.64, 95% CI (0.75, 3.56), p = 0.212), age ≥ 65 (OR 3.32, 95% CI (2.40, 4.60), p < 0.001), pre-operative AF (OR 4.43, 95% CI (2.56, 7.69), p < 0.001), diabetes mellitus (OR 2.16, 95% CI (1.39, 3.35), p = 0.001), combined coronary artery bypass graft (CABG) + valve surgery (OR 2.73, 95% CI (1.66, 4.49), p < 0.001), and cardiopulmonary bypass (CPB) time (OR 1.02, 95% CI (1.01, 1.04), p = 0.001).

CONCLUSIONS

A total of nine risk factors were evaluated, from which eight were found to have a statistically significant effect on the risk of developing POD. These factors can be employed to more effectively identify at-risk patients and to prevent the occurrence of POD. Furthermore, this approach can facilitate earlier diagnosis and more effective patient care.

Sex-Specific Validity of the PRE-DELIRIC Model and the E-PRE-DELIRIC Model for Predicting Delirium in Patients After Cardiac Surgery

BACKGROUND

Several risk prediction models are used in intensive care units (ICUs) to detect delirium risk.

OBJECTIVE

The aim of this study was to compare the sex-specific validity of the Prediction of Delirium in ICU patients (PRE-DELIRIC) and Early Prediction of Delirium in ICU patients (E-PRE-DELIRIC) models for predicting delirium in ICU patients after cardiac surgery.

METHODS

Retrospective data from electronic medical records of ICU patients who underwent cardiac surgery between January 2019 and December 2022 were examined. Both models were evaluated using sensitivity, specificity, and positive and negative predictive values based on the highest Youden index for female and male patients. Receiver operating characteristic curve analysis was performed.

RESULTS

Delirium incidence was 30.7% and 27.5% in female and male patients, respectively. In the PRE-DELIRIC model, the highest Youden index scores for female and male patients were 67.00 and 57.54, respectively, with sensitivities and specificities of 61% and 88%, and 72% and 79%, respectively. In the E-PRE-DELIRIC model, the highest scores for female and male patients were 14.25 and 14.05, with sensitivities and specificities of 78% and 50%, and 70% and 53%, respectively. The area under the curve of the PRE-DELIRIC model for female and male patients was 0.77 and 0.78, respectively, and that of the E-PRE-DELIRIC model was 0.67 and 0.63, respectively.

CONCLUSIONS

The PRE-DELIRIC model showed higher specificity and was more reliable for male patients, whereas the E-PRE-DELIRIC model demonstrated better sensitivity for female patients due to its inclusion of more female-sensitive factors. A combined approach is recommended for improved reliability and validity in delirium risk assessment in clinical settings.

Risk Factors and Pain Management in the Incidence of Postoperative Delirium in Elderly Patients: A Retrospective Study

Background: Postoperative delirium (POD) is a common surgical complication that increases hospital stay duration, hospitalization costs, readmission rates and mortality. This study aims to describe the incidence of POD in an elderly patient population and to investigate pain assessment as a risk factor for postoperative confusion. Additionally, we aim to determine a predictive model for POD. Methods: We conducted a retrospective, observational, single-center study at La Timone Hospital between September 2020 and September 2021. We included patients aged 65 or older, admitted for scheduled or emergency surgical care, with an expected postoperative stay of three days or more and no history of dementia. Data were collected in three stages of hospitalization: preoperative, perioperative, and postoperative. Preoperative data included medical history and lifestyle; perioperative data included surgical and anesthesia characteristics, and postoperative data were collected. Results: Of the 531 patients admitted for surgical care, we analyzed 109 patients. Among these, 24 (22%) experienced a POD episode within the first three postoperative days. Age, preoperative cognitive impairments, preoperative sensory deficits, and long-term benzodiazepine use were identified as risk factors for POD. A significant difference in pain levels was also observed for all NRS scores during the first three postoperative days. After multivariate analysis, we retained two predictive models for POD. Conclusions: This study identified risk factors for POD and proposed predictive models based on these factors. Two models were particularly notable for their potential use in anesthesia consultations and patient follow-up services to quickly detect patients at risk of POD.

Pharmacological Prevention of Postoperative Delirium in Adults: A Review of Recent Literature

PURPOSE OF REVIEW

Postoperative delirium (POD) is a common complication that has important implications for surgical patients, often leading to both short- and long-term cognitive deficits, worse outcomes, and increased healthcare costs. Given these implications, there may be a benefit in reducing the incidence of POD. Pharmacologic interventions may have the potential to reduce the risk of a patient developing POD.

RECENT FINDINGS

Recently studied therapies include dexmedetomidine, propofol, haloperidol, ketamine, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, acetaminophen, melatonin/ramelteon, corticosteroids, midazolam, physostigmine, and neostigmine. In addition, the implementation of regional anesthesia and reduction of overall anesthetic depth have been examined. Of these therapies, dexmedetomidine has been studied the most and has the most supporting evidence for prevention of POD, but current studies lack clarity on optimal dosing and timing of dexmedetomidine administration. Acetaminophen, corticosteroids, and melatonin/ramelteon are other plausible medications that have potential for reducing POD incidence, but they all require further investigation. Reduction of anesthetic depth and regional anesthetics are options for anesthetic management that show promise but still lack enough supporting evidence in recent literature to receive a strong recommendation. Future research should focus on identifying optimal strategies for the implementation of the pharmacological options listed, including doses and timing of administration. Attention should be given to dexmedetomidine given its promise demonstrated by recent literature.

Projection of visual material on postoperative delirium in patients undergoing cardiac surgery: A double blind randomized clinical trial

BACKGROUND

Postoperative delirium is a neurobehavioral disorder that can appear after surgery. It is characterized by an altered level of consciousness and impaired cognitive function. The aim of this study was to evaluate the impact of visual projection of images of relatives or loved ones in patients undergoing cardiac surgery in the immediate postoperative period, and its influence on the incidence and development of postoperative delirium.

METHODS

A randomized, double-blind clinical trial was designed in the immediate postoperative period of adult patients undergoing cardiac surgery. Consolidated Statement of Reporting Trials guidelines were followed. A control group (CG) and an intervention group (IG) were established. In the IG, the patients underwent a visual projection, while the usual unit treatment was carried out with the CG. Sociodemographic, anthropometric, anesthetic, and surgical variables were also recorded. The postoperative delirium assessment scale used was the confusion assessment method for diagnosing delirium in intensive care unit patients.

RESULTS

Information was collected from 104 patients undergoing cardiac surgery. Most of the patients included in the study were men (66.35%) and the most performed surgical intervention was aortic valve replacement (34.62%). In the CG, positive patients in postoperative delirium increased from 19.23% to 25%, while in the IG they decreased from 5.77% to 1.92%. The logistic regression analysis presents a prediction model where the variables that influence the model are gender and group membership, meaning that being female and belonging to the IG significantly reduce the presence of delirium.

CONCLUSION

The projection of visual material reduced the incidence of postoperative delirium in patients undergoing cardiac surgery, although it cannot be established that it is effective as a treatment once the pathology is already established.

Association of preoperative frailty with risk of postoperative delirium in older patients undergoing craniotomy: a prospective cohort study

BACKGROUND

Preoperative frailty is a risk factor associated with postoperative delirium (POD), which has attracted more attention from clinicians, but no research has shown that it is related to elderly patients undergoing craniotomy. Therefore, the aim of this study was to determine the effect of preoperative frailty on POD in older patients, especially those who underwent craniotomy.

METHODS

From October 2022 to May 2023, older patients who underwent elective craniotomy were collected. Assess the occurrence of frailty using the FRAIL scale one day before surgery. Evaluate the occurrence of POD using the Confusion Assessment Method (CAM) within three days after surgery. Participants were divided into two groups, one group being POD, Logistic regression analysis was used to find the risk variables for POD, and the predictive value of preoperative frailty to POD was determined by using the operating characteristic curve of the subjects.

RESULTS

A total of 300 patients were included in this study, among whom 83 patients (27.7%) exhibited preoperative frailty and 69 patients (23.0%) experienced POD. The results of the multivariate logistic regression analysis indicate that preoperative frailty (OR: 8.816, 95% CI: 3.972-19.572), preoperative hypoalbuminemia (OR: 0.893, 95% CI: 0.811-0.984), low BMI (OR: 0.793, 95% CI: 0.698-0.901), and prolonged operative duration (OR: 1.007, 95% CI: 1.004-1.010) are independent risk factors for POD in older patients who underwent craniotomy. We constructed a risk prediction model using these factors, which had an area under the ROC curve of 0.908 (95% CI: 0.869-0.947, P < 0.001). Preoperative frailty enhanced the discriminative ability of the prediction model by 0.037. POD was associated with a longer length of hospital stay and higher hospitalization costs.

CONCLUSIONS

Preoperative frailty is an independent risk factor for POD in older patients undergoing elective craniotomy and can predict the occurrence of POD to a certain extent. In addition, early identification of patients at risk of malnutrition and appropriate surgical planning can reduce the incidence of POD.

Prevalence and risk factors of postoperative delirium in tumor patients after free flap reconstruction: A systematic review and meta-analysis of case-control studies

BACKGROUND

Postoperative delirium is a severe complication of flap transplantation surgery, adversely affecting surgical prognoses. The intricate pathophysiology of postoperative delirium renders the elucidation of its risk factors challenging. This research aims to delineate the prevalence and the specific risk factors of postoperative delirium in patients with cancer undergoing free flap reconstruction through a systematic review and meta-analysis to enlighten proactive prevention measures.

METHODS

The researchers systematically queried both the international and Chinese databases. Searches were performed for publications from inception until September 14, 2023, using the terms "free tissue flaps," "delirium," "neoplasms," and "risk factors." Data synthesis and statistical analysis were conducted using Stata SE (version 15.0) to calculate the combined effect size for identified risk factors. Reported outcomes included weighted mean differences or odds ratios with their respective 95% confidence intervals.

RESULTS

Twelve case-control studies were included (ntotal = 3,256). Among them, 515 patients developed postoperative delirium after free flap surgery, compared with 2,741 patients who did not. The outcomes suggest that the risk factors include but are not limited to age, male, late neoplasm staging, use of hypnotic or antipsychotic, history of background diseases, psychiatric review, tracheotomy, and impaired wound healing. In contrast, early neoplasm staging and others are the protective factors with statistical significance. Multivariate analysis further identified significant correlations between preoperative albumin, perioperative blood transfusion, sleep disturbance, postoperative visual analog scale, postoperative albumin, smoking, and the appearance of postoperative delirium.

CONCLUSION

The determined risk factors were grouped into preoperative, intraoperative, and postoperative categories substantiated by current data to present instructions for postoperative delirium prevention.

Incidence and related risk factors for postoperative delirium following revision total knee arthroplasty: a retrospective nationwide inpatient sample database study

BACKGROUND

Postoperative delirium (POD) is a common surgical complication. However, the incidence and risk factors associated with postoperative delirium after revision total knee arthroplasty (rTKA) have not been comprehensively explored through extensive national databases.

METHODS

Utilizing the National Inpatient Sample (NIS), the largest comprehensive U.S. hospital healthcare database, we undertook a retrospective investigation involving 127,400 patients who underwent rTKA between 2010 and 2019. We assessed various aspects, including patient demographics, hospital characteristics, pre-existing medical conditions, and perioperative complications.

RESULTS

The overall incidence of postoperative delirium (POD) in patients undergoing rTKA between 2010 and 2019 was 0.97%. The highest incidence rate of 1.31% was recorded in 2013. Notably, this patient cohort demonstrated advanced age, increased burden of co-morbidities, prolonged hospital stays, increased hospitalization costs, and elevated in-hospital mortality rates (P < 0.001). Moreover, non-elective admissions, non-private insurance payments, and a preference for teaching hospitals were commonly observed among these patients. During their hospitalization, individuals who developed delirium subsequent to rTKA were more prone to experiencing certain perioperative complications. These complications encompassed medical issues like acute myocardial infarction, continuous invasive mechanical ventilation, postoperative shock, sepsis, stroke and other medical problems. Additionally, surgical complications including hemorrhage / seroma / hematoma, irrigation and debridement, prosthetic joint infection, periprosthetic fracture, and wound dehiscence / nonunion were noted. Several risk factors were found to be linked with the development of POD. These included advanced age (≥ 75 years), alcohol abuse, coagulation disorders, congestive heart failure, depression, fluid and electrolyte imbalances, and more. Conversely, female sex, having private insurance, and undergoing elective hospitalization emerged as protective factors against POD.

CONCLUSION

Our findings suggest that the general prevalence of POD in rTKA is relatively low according to NIS. There was a significant connection between the POD of rTKA and advanced age, prolonged length of stay (LOS), more in-patients' costs, higher in-hospital mortality rate, increased comorbidities, postoperative medical complications and postoperative surgical complications. This study helps to understand the risk factors associated with POD to improve poor outcomes.

Machine learning with clinical and intraoperative biosignal data for predicting postoperative delirium after cardiac surgery

Early identification of patients at high risk of delirium is crucial for its prevention. Our study aimed to develop machine learning models to predict delirium after cardiac surgery using intraoperative biosignals and clinical data. We introduced a novel approach to extract relevant features from continuously measured intraoperative biosignals. These features reflect the patient's overall or baseline status, the extent of unfavorable conditions encountered intraoperatively, and beat-to-beat variability within the data. We developed a soft voting ensemble machine learning model using retrospective data from 1,912 patients. The model was then prospectively validated with data from 202 additional patients, achieving a high performance with an area under the receiver operating characteristic curve of 0.887 and an accuracy of 0.881. According to the SHapley Additive exPlanation method, several intraoperative biosignal features had high feature importance, suggesting that intraoperative patient management plays a crucial role in preventing delirium after cardiac surgery.

The Association of Cerebral Oxygen Desaturation with Postoperative Cognitive Dysfunction in Older Patients: A Review

Postoperative cognitive dysfunction (POCD) is a neurological complication associated with surgery and anesthesia that is commonly observed in older patients, and it can significantly affect patient prognosis and survival. Therefore, predicting and preventing POCD is important. Regional cerebral oxygen saturation (rSO2) reflects cerebral perfusion and oxygenation, and decreased intraoperative cerebral oxygen saturation has been reported to increase the risk of POCD. In this review, we elucidated the important relationship between the decline in rSO2 and risk of POCD in older patients. We also emphasized the importance of monitoring rSO2 during surgery to predict and prevent adverse perioperative cognitive outcomes. The findings reveal that incorporating intraoperative rSO2 monitoring into clinical practice has potential benefits, such as protecting cognitive function, reducing perioperative adverse outcomes, and ultimately improving the overall quality of life of older adults.

A Novel Preoperative Electroencephalogram-Derived Index to Predict Early Postoperative Delirium in Elderly Patients After Hip Fracture Surgeries: Development of a Prediction Model

Introduction

It is appealing to accurately predict postoperative delirium (POD) before surgeries. In this study, it was hypothesized that a novel electroencephalogram-derived index, the delirium index (DELi), could extract latent information regarding the predisposing factors of POD preoperatively. This study was aimed at developing a concise model that incorporated this DELi score to predict the early POD of elderly patients after hip surgeries.

Materials and Methods

Elderly patients scheduled for elective hip fracture surgeries were prospectively enrolled in a tertiary care hospital from November 2020 to June 2022. DELi scores and patient characteristics (age, sex, types of fracture and surgery, the time interval between fracture and surgery, cognitive function assessed using the Montreal Cognitive Assessment (MoCA), and frailty status assessed using the FRAIL scale) were collected preoperatively as candidate predictors. POD diagnosed using the confusion assessment method (CAM) was the outcome. Least absolute shrinkage and selection operator (LASSO) regression analysis was used to select predictors. Then, these predictors were entered into a backward logistical regression analysis to develop a prediction model. Discrimination, calibration and clinical utility were validated using the bootstrapping method.

Results

All data (144 qualified patients of 170) were used for development. POD was observed in 71 patients (49.3%). Preoperative DELi scores predicted early POD (the area under the curve (AUC) = .786, 95% confidence interval (CI): .712, .860, in internal validation). A nomogram with MoCA, FRAIL scale and DELi score was constructed with excellent discrimination (AUC = .920, 95% CI: .876, .963, in internal validation), accredited calibration (P = .733, Hosmer‒Lemeshow test), and a wide range of threshold probabilities (5% to 95%).

Conclusions

Preoperative DELi scores predicted the early POD of elderly patients after hip surgeries. A concise prediction model was developed and demonstrated excellent discrimination.

Association Between Preoperative Long-Term Poor Sleep Quality and Postoperative Delirium in Elderly Patients Undergoing Cardiac Surgery: A Multi-Center Observational Study

BACKGROUND

Delirium is a common complication in elderly patients after cardiac surgery, and sleep disorders have been suggested as a potential risk factor. However, few studies have explored the link between long-term preoperative poor sleep quality and postoperative delirium (POD) in this population. This study aimed to investigate the association between preoperative sleep quality and POD in elderly cardiac surgery patients.

METHODS

The study enrolled 194 patients aged 60 years or older who underwent cardiac surgery. The Pittsburgh Sleep Quality Index (PSQI) objectively assessed preoperative sleep quality, while the Confusion Assessment Method screened for POD. The measurable outcomes encompassed the identification of risk factors associated with POD, while the secondary outcomes focused on factors influencing levels of consciousness. The statistical analysis is logistic regression analysis.

RESULTS

Patients with POD had a higher prevalence of preoperative sleep disorders and higher PSQI scores than those without delirium (12.9 ± 5.1 vs 7.8 ± 3.4, P = .007). Logistic regression analysis demonstrated that the number of months with high PSQI scores and age were significantly associated with POD. The predictive ability of the number of months with high PSQI scores for POD was .762 (95% CI: .671-.854). Multivariate linear regression analysis revealed that preoperative sleep disorder was a significant predictor of exacerbation of POD (P < .05).

CONCLUSION

This study suggests that long-term poor preoperative sleep quality, as assessed by the PSQI, is associated with an increased risk of POD in elderly patients undergoing cardiac surgery.

Development and internal validation of a nomogram to predict temporary acute agitated delirium after surgery for chronic subdural hematoma in elderly patients: an analysis of the clinical database

Background

This study aimed to develop a nomogram for predicting temporary acute agitated delirium after surgery in patients with chronic subdural hematoma (CSH) without neurological compromise and hospitalized in the neurosurgery.

Methods

We included 289 patients with chronic subdural hematoma (CSH) from the medical information system of Yuebei People's Hospital of Shaoguan City, Guangdong Province, and collected 16 clinical indicators within 24 h of admission. We used the least absolute shrinkage and selection operator (LASSO) regression to identify risk factors. We established a multivariate logistic regression model and constructed a nomogram. We performed internal validation by 1,000 bootstrap samples; we plotted a receiver operating curve (ROC) and calculated the area under the curve (AUC), sensitivity, and specificity. We also evaluated the calibration of our model by the calibration curve and the Hosmer-Lemeshow goodness-of-fit test (HL test). We performed a decision curve analysis (DCA) and a clinical impact curve (CIC) to assess the net clinical benefit of our model.

Results

The nomogram included alcoholism history, hepatic insufficiency, verbal rating scale for postoperative pain (VRS), pre-hospital modified Rankin Scale (mRS), and preoperative hematoma thickness as predictors. Our model showed satisfactory diagnostic performance with an AUC value of 0.8474 in the validation set. The calibration curve and the HL test showed good agreement between predicted and observed outcomes (p = 0.9288). The DCA and CIC showed that our model had a high predictive ability for the occurrence of postoperative delirium in patients with CSDH.

Conclusion

We identified alcoholism, liver dysfunction, pre-hospital mRS, preoperative hematoma thickness, and postoperative VRS pain as predictors of postoperative delirium in chronic subdural hematoma patients. We developed and validated a multivariate logistic regression model and a nomogram.

Non-pharmacological interventions for delirium in the pediatric population: a systematic review with narrative synthesis

BACKGROUND

Delirium is a serious complication experienced by hospitalized children. Therefore, preventive management strategies are recommended for these patients. However, comprehensive analyses of delirium interventions in children remain insufficient. Specifically, this systematic review aimed to summarize non-pharmacological interventions for pediatric delirium, addressing the urgent need for a comprehensive understanding of effective strategies. We also explored frequently measured outcome variables to contribute evidence for future research on delirium outcomes in children.

METHODS

This systematic review searched articles from PubMed, Web of Science, Cumulative Index to Nursing and Allied Health Literature, and Excerpta Medica databases. The eligibility criteria were formed under the population, intervention, comparator, outcome, and study design framework. Studies were included if they involved (1) children aged under 18 years receiving hospital care, (2) non-pharmacological delirium interventions, (3) comparators involving no intervention or pharmacological delirium interventions, and (4) outcomes measuring the effectiveness of non-pharmacological delirium interventions. Only peer-reviewed articles published in English were included.

RESULTS

Overall, 16 studies were analyzed; of them, 9 assessed non-pharmacological interventions for emergence delirium and 7 assessed interventions for pediatric delirium. The intervention types were grouped as follows: educational (n = 5), multicomponent (n = 6), and technology-assisted (n = 5). Along with pediatric and emergence delirium, the most frequently measured outcome variables were pain, patient anxiety, parental anxiety, pediatric intensive care unit length of stay, agitation, analgesic consumption, and postoperative maladaptive behavior.

CONCLUSIONS

Non-pharmacological interventions for children are effective treatments without associated complications. However, determining the most effective non-pharmacological delirium intervention for hospitalized children based on current data remains challenging.

A machine learning-based prediction model for postoperative delirium in cardiac valve surgery using electronic health records

BACKGROUND

Previous models for predicting delirium after cardiac surgery remained inadequate. This study aimed to develop and validate a machine learning-based prediction model for postoperative delirium (POD) in cardiac valve surgery patients.

METHODS

The electronic medical information of the cardiac surgical intensive care unit (CSICU) was extracted from a tertiary and major referral hospital in southern China over 1 year, from June 2019 to June 2020. A total of 507 patients admitted to the CSICU after cardiac valve surgery were included in this study. Seven classical machine learning algorithms (Random Forest Classifier, Logistic Regression, Support Vector Machine Classifier, K-nearest Neighbors Classifier, Gaussian Naive Bayes, Gradient Boosting Decision Tree, and Perceptron.) were used to develop delirium prediction models under full (q = 31) and selected (q = 19) feature sets, respectively.

RESULT

The Random Forest classifier performs exceptionally well in both feature datasets, with an Area Under the Curve (AUC) of 0.92 for the full feature dataset and an AUC of 0.86 for the selected feature dataset. Additionally, it achieves a relatively lower Expected Calibration Error (ECE) and the highest Average Precision (AP), with an AP of 0.80 for the full feature dataset and an AP of 0.73 for the selected feature dataset. To further evaluate the best-performing Random Forest classifier, SHAP (Shapley Additive Explanations) was used, and the importance matrix plot, scatter plots, and summary plots were generated.

CONCLUSIONS

We established machine learning-based prediction models to predict POD in patients undergoing cardiac valve surgery. The random forest model has the best predictive performance in prediction and can help improve the prognosis of patients with POD.

EEG pre-burst suppression: characterization and inverse association with preoperative cognitive function in older adults

The most common complication in older surgical patients is postoperative delirium (POD). POD is associated with preoperative cognitive impairment and longer durations of intraoperative burst suppression (BSup) - electroencephalography (EEG) with repeated periods of suppression (very low-voltage brain activity). However, BSup has modest sensitivity for predicting POD. We hypothesized that a brain state of lowered EEG power immediately precedes BSup, which we have termed "pre-burst suppression" (preBSup). Further, we hypothesized that even patients without BSup experience these preBSup transient reductions in EEG power, and that preBSup (like BSup) would be associated with preoperative cognitive function and delirium risk. Data included 83 32-channel intraoperative EEG recordings of the first hour of surgery from 2 prospective cohort studies of patients ≥age 60 scheduled for ≥2-h non-cardiac, non-neurologic surgery under general anesthesia (maintained with a potent inhaled anesthetic or a propofol infusion). Among patients with BSup, we defined preBSup as the difference in 3-35 Hz power (dB) during the 1-s preceding BSup relative to the average 3-35 Hz power of their intraoperative EEG recording. We then recorded the percentage of time that each patient spent in preBSup, including those without BSup. Next, we characterized the association between percentage of time in preBSup and (1) percentage of time in BSup, (2) preoperative cognitive function, and (3) POD incidence. The percentage of time in preBSup and BSup were correlated (Spearman's ρ [95% CI]: 0.52 [0.34, 0.66], p < 0.001). The percentage of time in BSup, preBSup, or their combination were each inversely associated with preoperative cognitive function (β [95% CI]: -0.10 [-0.19, -0.01], p = 0.024; -0.04 [-0.06, -0.01], p = 0.009; -0.04 [-0.06, -0.01], p = 0.003, respectively). Consistent with prior literature, BSup was significantly associated with POD (odds ratio [95% CI]: 1.34 [1.01, 1.78], p = 0.043), though this association did not hold for preBSup (odds ratio [95% CI]: 1.04 [0.95, 1.14], p = 0.421). While all patients had ≥1 preBSup instance, only 20.5% of patients had ≥1 BSup instance. These exploratory findings suggest that future studies are warranted to further study the extent to which preBSup, even in the absence of BSup, can identify patients with impaired preoperative cognition and/or POD risk.

Dynamic predictive scores for cardiac surgery-associated agitated delirium: a single-center retrospective observational study

BACKGROUND

Prevention, screening, and early treatment are the aims of postoperative delirium management. The scoring system is an objective and effective tool to stratify potential delirium risk for patients undergoing cardiac surgery.

METHODS

Patients who underwent cardiac surgery between January 1, 2012, and January 1, 2019, were enrolled in our retrospective study. The patients were divided into a derivation cohort (n = 45,744) and a validation cohort (n = 11,436). The AD predictive systems were formulated using multivariate logistic regression analysis at three time points: preoperation, ICU admittance, and 24 h after ICU admittance.

RESULTS

The prevalence of AD after cardiac surgery in the whole cohort was 3.6% (2,085/57,180). The dynamic scoring system included preoperative LVEF ≤ 45%, serum creatinine > 100 µmol/L, emergency surgery, coronary artery disease, hemorrhage volume > 600 mL, intraoperative platelet or plasma use, and postoperative LVEF ≤ 45%. The area under the receiver operating characteristic curve (AUC) values for AD prediction were 0.68 (preoperative), 0.74 (on the day of ICU admission), and 0.75 (postoperative). The Hosmer‒Lemeshow test indicated that the calibration of the preoperative prediction model was poor (P = 0.01), whereas that of the pre- and intraoperative prediction model (P = 0.49) and the pre, intra- and postoperative prediction model (P = 0.35) was good.

CONCLUSIONS

Using perioperative data, we developed a dynamic scoring system for predicting the risk of AD following cardiac surgery. The dynamic scoring system may improve the early recognition of and the interventions for AD.

Risk for post-operative delirium related to comorbidities in older adult cardiac patients: An integrative review

BACKGROUND

Delirium is defined as a sudden onset of confusion due to disruption in normal brain functioning. Although it is highly prevalent in post-operative patients, most significantly the older adult population, limited information exists explaining why its onset occurs.

PURPOSE

This integrative review aimed to synthesise specific comorbidities that can contribute to the development of post-operative delirium in older adult cardiac surgical patients.

METHODS

PRISMA statement was used to report the identification, selection, appraisal and synthesis of articles and the PRISMA diagram reports the selection process. The Johns Hopkins Evidence-Based Practice Tools were used as guide in literature review, critical analysis, levelling of evidence and quality rating. PubMed, ProQuest, CINAHL plus, EMBASE, MEDLINE, Ovid Nursing Collection and Cochrane databases were searched from 2015 to 2020.

RESULTS

The initial search yielded 1529 articles. Following the removal of duplicates and screening, 14 articles were included for this review. The following comorbidities were identified in the studies: Diabetes mellitus, atrial fibrillation, depression, impaired olfaction, pre-existing cerebrovascular disease, pre-existing cardiovascular disease, insomnia and frailty.

CONCLUSION

There was a strong indication of the development of post-operative delirium among older adult cardiac surgical patients with comorbidities.

RELEVANCE TO CLINICAL PRACTICE

Awareness of the impact of comorbidities in developing post-operative delirium may help healthcare providers to plan and implement proper care management among older adult cardiac surgical patients with comorbidities.

Peri-Operative Risk Factors Associated with Post-Operative Cognitive Dysfunction (POCD): An Umbrella Review of Meta-Analyses of Observational Studies

This umbrella review aimed to systematically identify the peri-operative risk factors associated with post-operative cognitive dysfunction (POCD) using meta-analyses of observational studies. To date, no review has synthesised nor assessed the strength of the available evidence examining risk factors for POCD. Database searches from journal inception to December 2022 consisted of systematic reviews with meta-analyses that included observational studies examining pre-, intra- and post-operative risk factors for POCD. A total of 330 papers were initially screened. Eleven meta-analyses were included in this umbrella review, which consisted of 73 risk factors in a total population of 67,622 participants. Most pertained to pre-operative risk factors (74%) that were predominantly examined using prospective designs and in cardiac-related surgeries (71%). Overall, 31 of the 73 factors (42%) were associated with a higher risk of POCD. However, there was no convincing (class I) or highly suggestive (class II) evidence for associations between risk factors and POCD, and suggestive evidence (class III) was limited to two risk factors (pre-operative age and pre-operative diabetes). Given that the overall strength of the evidence is limited, further large-scale studies that examine risk factors across various surgery types are recommended.

Risk factors and prognosis of postoperative delirium in nonagenarians with hip fracture

Hip fractures in nonagenarians is one of the great challenges for patients of this age, the family and the larger society. The purpose of this study was to investigate the risk factors and prognosis of postoperative delirium in nonagenarians with hip fracture. 199 Eligible patients were enrolled. Confusion Assessment Method (CAM) were used to identify the delirium. Logistic regressions were used to investigate the effect of 18 pre-existing conditions on postoperative delirium. Prognosis of postoperative delirium in nonagenarians with hip fracture were also be evaluated. The results indicated the following: (1) the prevalence of postoperative delirium among nonagenarians with hip fracture was 28.1% (56 of 199); (2) coexisting disease ≥ 4 (OR = 5.355, 95% CI = 1.394-9.074, P = 0.007), longer admission to operating time (OR = 1.514, 95% CI = 1.247-1.837, P = 0.000), and general anesthesia (OR = 2.086, 95% CI = 1.804-7.968, P = 0.032) were independent risk factors for postoperative delirium in nonagenarians with hip fracture; (3) nonagenarians with postoperative delirium had a predominantly high burden of perioperative complications, long length of stay, and postoperative mortality at 30 days follow-up and 1 year follow-up than the patients without postoperative delirium. The results could enable clinicians to improve outcome after operation in nonagenarians with hip fracture.

General anesthetic binding mode via hydration with weak affinity and molecular discrimination: General anesthetic dissolution in interfacial water of the common binding site of GABAA receptor

The GABAA receptor (GABAAR) is a target channel for the loss of awareness of general anesthesia. General anesthetic (GA) spans a wide range of chemical structures, such as monatomic molecules, barbital acids, phenols, ethers, and alkanes. GA has a weak binding affinity, and the affinity has a characteristic that correlates with the solubility in olive oil rather than the molecular shape. The GA binding site of GABAAR is common to GAs and exists in the transmembrane domain of the GABAAR intersubunit. In this study, the mechanism of GA binding, which allows binding of various GAs with intersubunit selectivity, was elucidated from the hydration analysis of the binding site. Regardless of the diverse GA chemical structures, a strong correlation was observed between the binding free energy and total dehydration number of the binding process. The GA binding free energy was more involved in the binding dehydration and showed molecular recognition that allowed for the binding of various GA structures via binding site hydration. We regarded the GA substitution for the interfacial water molecule of the binding site as a dissolution into the interfacial hydration layer. The elucidation of the GA binding mechanism mediated by hydration at the GABAAR common binding site provides a rationale for the combined use of anesthetics in medical practice and its combination adjustments via drug interactions.

Surgical Pharmacy for Optimizing Medication Therapy Management Services within Enhanced Recovery after Surgery (ERAS®) Programs

Drug-related problems (DRPs) are common among surgical patients, especially older patients with polypharmacy and underlying diseases. DRPs can potentially lead to morbidity, mortality, and increased treatment costs. The enhanced recovery after surgery (ERAS) system has shown great advantages in managing surgical patients. Medication therapy management for surgical patients (established as "surgical pharmacy" by Guangdong Province Pharmaceutical Association (GDPA)) is an important part of the ERAS system. Improper medication therapy management can lead to serious consequences and even death. In order to reduce DRPs further, and promote the rapid recovery of surgical patients, the need for pharmacists in the ERAS program is even more pressing. However, the medication therapy management services of surgical pharmacy and how surgical pharmacists should participate in ERAS programs are still unclear worldwide. Therefore, this article reviews the main perioperative medical management strategies and precautions from several aspects, including antimicrobial agents, antithrombotic agents, pain medication, nutritional therapy, blood glucose monitoring, blood pressure treatment, fluid management, treatment of nausea and vomiting, and management of postoperative delirium. Additionally, the way surgical pharmacists participate in perioperative medication management, and the relevant medication pathways are explored for optimizing medication therapy management services within the ERAS programs. This study will greatly assist surgical pharmacists' work, contributing to surgeons accepting that pharmacists have an important role in the multidisciplinary team, benefitting medical workers in treating, counseling, and advocating for their patients, and further improving the effectiveness, safety and economy of medication therapy for patients and promoting patient recovery.

Transcutaneous Electrical Acupoint Stimulation for Preventing Postoperative Delirium: A Meta-Analysis

Objective

This meta-analysis of randomized controlled trials (RCTs) aims to evaluate the efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) for postoperative delirium (POD) in surgical patients.

Methods

Based on database searches of the Wanfang, China National Knowledge Infrastructure (CNKI), VIP, Chinese Biology Medicine (CBM), PubMed, Cochrane Library, and Web of Science, relevant RCTs published before December 30, 2022, were extracted. Outcome indicators included the incidence of POD, changes in Confusion Assessment Method (CAM) scores, Visual Analogue Scale (VAS) scores, and the intraoperative consumption of anesthetics. Data were pooled and analyzed by Review Manager 5.3, and publication bias detection was conducted using Stata 17.0.

Results

A meta-analysis containing 715 experimental and 717 control participants from 12 RCTs was performed. The overall results showed that TEAS had obvious superiority with a lower incidence of POD on any day during the postoperative 1 week. In subgroup analyses, the CAM scores on the third postoperative day were significantly lower in the TEAS group than in the control group (MD = -0.52, 95% CI: -1.02 to -0.03, P = 0.04), the VAS scores on the first postoperative day were significantly lower in the TEAS group than in the control group (MD = -0.19, 95% CI: -0.36 to -0.02, P = 0.03), the consumption of propofol and remifentanil were both significantly lower in the TEAS group compared with the control group (MD = -23.1, 95% CI: -37.27 to -8.94, P = 0.001; MD = -105.69, 95% CI: -174.20 to -37.19, P = 0.002). No serious adverse events of TEAS were reported in any of the referenced studies.

Conclusion

TEAS has an obvious curative effect in preventing POD and pain in the earlier stage of surgical patients. It could be a promising assisted anesthesia technique in the future.

Two-stage prediction model for postoperative delirium in patients in the intensive care unit after cardiac surgery

OBJECTIVES

Postoperative delirium is a common severe complication in patients in the intensive care unit after cardiac surgery. We developed a two-stage prediction model and quantified the risk of developing postoperative delirium to assist in early prevention before and after surgery.

METHODS

We conducted a prospective cohort study and consecutively recruited adult patients after cardiac surgery. The Confusion Assessment Method for patients in the intensive care unit was used to diagnose delirium 5 days postoperatively. The stage I model was constructed using patient demographics, health conditions and laboratory results obtained preoperatively, whereas the stage II model was built on both pre- and postoperative predictors. The model was validated internally using the bootstrap method and externally using data from an external cohort.

RESULTS

The two-stage model was developed with 654 patients and was externally validated with 214 patients undergoing cardiac surgery. The stage I model contained 6 predictors, whereas the stage II model included 10 predictors. The stage I model had an area under the receiver operating characteristic curve of 0.76 (95% confidence interval: 0.68-0.81), and the stage II model's area under the receiver operating characteristic curve increased to 0.85 [95% confidence interval (CI): 0.81-0.89]. The external validation resulted in an area under the curve of 0.76 (95% CI: 0.67-0.86) for the stage I model and 0.78 (95% CI: 0.69-0.86) for the stage II model.

CONCLUSIONS

The two-stage model assisted medical staff in identifying patients at high risk for postoperative delirium before and 24 h after cardiac surgery. This model showed good discriminative power and predictive accuracy and can be easily accessed in clinical settings.

TRIAL REGISTRATION

The study was registered with the US National Institutes of Health ClinicalTrials.gov (NCT03704324; registered 11 October 2018).

Instruments to Identify Delirium in Patients Recovering From Anesthesia: A Scoping Review

PURPOSE

To identify the validated instruments used for screening and detecting postoperative delirium (POD) during Post Anesthesia Recovery (PAR) period, and the incidence and associated risk factors with POD.

DESIGN

A scoping review.

METHODS

The study search occurred in May 2021 in the PubMed, Embase, Scopus, CINAHL, Web of Science and LILACS databases. Primary studies that used validated instruments for screening and detecting POD in the PAR period were included.

FINDINGS

A total of 38 articles were included. The most used instruments were CAM-ICU, Nu-DESC, and RASS. The instruments that screened and detected delirium earliest were the Nu-DESC and CAM-ICU. POD incidence was up to 20% in more than half of the included studies. Cardiovascular comorbidities, chronic kidney disease, low functional reserve, chronic obstructive pulmonary disease and postoperative pain were among the primary risk factors.

CONCLUSION

The instrumentsshowing the greatest accuracy for screening and detecting POD in the PAR period were the Nu-DESC and CAM-ICU.

Prediction models for postoperative delirium after cardiac surgery: Systematic review and critical appraisal

BACKGROUND

Many studies have developed or validated prediction models to estimate the risk of delirium after cardiac surgery, but the quality of the model development and model applicability remain unknown.

OBJECTIVES

To systematically review and critically evaluate currently available prediction models for delirium after cardiac surgery.

DATA SOURCES

PubMed, EMBASE, and MEDLINE were systematically searched. This systematic review was registered in PROSPERO (Registration ID: CRD42021251226).

STUDY SELECTION

Prospective or retrospective cohort studies were considered eligible if they developed or validated prediction models or scoring systems for delirium in the ICU. We included studies involving adults (age ≥18 years) undergoing cardiac surgery and excluded studies that did not validate a prediction model.

DATA EXTRACTION

Data extraction was independently performed by two authors using a standardized data extraction form based on the Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies checklist. Quality of the models was assessed with the Prediction Model Risk of Bias Assessment Tool (PROBAST).

DATA SYNTHESIS

Of 5469 screened studies, 13 studies described 10 prediction models. The postoperative delirium incidence varied from 11.3 % to 51.6 %. The most frequently used predictors were age and cognitive impairment. The reported areas under the curve or C-statistics were between of 0.74 and 0.91 in the derivation set. The reported AUCs in the external validation set were between 0.54 and 0.90. All the studies had a high risk of bias, mainly owing to poor reporting of the outcome domain and analysis domain; 10 studies were of high concern regarding applicability.

CONCLUSIONS

The current models for predicting postoperative delirium in the ICU after cardiac surgery had a high risk of bias according to the PROBAST. Future studies should focus on improving current prediction models or developing new models with rigorous methodology.

Postoperative Delirium after Reconstructive Surgery in the Head and Neck Region

Postoperative delirium (POD) is an acute and serious complication following extended surgery. The aim of this study was to identify possible risk factors and scores associated with POD in patients undergoing reconstructive head and neck surgery. A collective of 225 patients was retrospectively evaluated after receiving reconstructive surgery in the head and neck region, between 2013 to 2018. The incidence of POD was examined with regards to distinct patient-specific clinical as well as perioperative parameters. Uni- and multivariate statistics were performed for data analysis. POD occurred in 49 patients (21.8%) and was strongly associated with an increased age-adjusted Charlson Comorbidity Index (ACCI) and a prolonged stay in the ICU (p = 0.009 and p = 0.000, respectively). Analogous, binary logistic regression analysis revealed time in the ICU (p < 0.001), an increased ACCI (p = 0.022) and a Nutritional Risk Screening (NRS) score ≠ 0 (p = 0.005) as significant predictors for a diagnosis of POD. In contrast, the extent of reconstructive surgery in terms of parameters such as type of transplant or duration of surgery did not correlate with the occurrence of POD. The extension of reconstructive interventions in the head and neck region is not decisive for the development of postoperative delirium, whereas patient-specific parameters such as age and comorbidities, as well as nutritional parameters, represent predictors of POD occurrence.

The effects of anesthesia methods and anesthetics on postoperative delirium in the elderly patients: A systematic review and network meta-analysis

Study objective

Postoperative delirium (POD) is one of the serious postoperative complications in elderly patients, which is always related to long-term mortality. Anesthesia is often considered a risk factor for POD. This systematic review and network meta-analysis (NMA) aimed to assess the impact of different anesthesia methods and anesthetics on POD.

Measurements

We searched for studies published in PubMed, Embase, Web of Science, Scopus, and Cochrane Library (CENTRAL) from inception to 18 March 2022. RevMan 5.3 and CINeMA 2.0.0 were used to assess the risk of bias and confidence. Data analysis using STATA 17.0 and R 4.1.2. STATA 17.0 was used to calculate the surface under the cumulative ranking curve (SUCRA) and provide network plots with CINeMA 2.0.0. NMA was performed with R 4.1.2 software gemtc packages in RStudio.

Main results

This NMA included 19 RCTs with 5,406 patients. In the pairwise meta-analysis results, only regional anesthesia (RA) with general anesthesia (GA) vs. GA (Log OR: –1.08; 95% CI: –1.54, –0.63) were statistically different in POD incidence. In the NMA results, there was no statistical difference between anesthesia methods, and psoas compartment block (PCB) with bupivacaine was superior to the desflurane, propofol, sevoflurane, and spinal anesthesia with bupivacaine of POD occurrence.

Conclusion

Our study indicated that RA and GA had no significant effect on POD, and there was no difference between anesthesia methods. Pairwise meta-analysis showed that, except for RA with GA vs. GA, the rest of the results were not statistically different. Besides, PCB with bupivacaine may benefit to reduce POD incidence.

Systematic review registration

https://www.crd.york.ac.uk/prospero/dis play_record.php?ID=CRD42022319499, identifier PROSPERO 2022 CRD42022319499.

Forecasting Postoperative Delirium in Older Adult Patients with Fast-and-Frugal Decision Trees

Postoperative delirium (POD) is associated with increased complication and mortality rates, particularly among older adult patients. However, guideline recommendations for POD detection and management are poorly implemented. Fast-and-frugal trees (FFTrees), which are simple prediction algorithms, may be useful in this context. We compared the capacity of simple FFTrees with two more complex models—namely, unconstrained classification trees (UDTs) and logistic regression (LogReg)—for the prediction of POD among older surgical patients in the perioperative setting. Models were trained and tested on the European BioCog project clinical dataset. Based on the entire dataset, two different FFTrees were developed for the pre-operative and postoperative settings. Within the pre-operative setting, FFTrees outperformed the more complex UDT algorithm with respect to predictive balanced accuracy, nearing the prediction level of the logistic regression. Within the postoperative setting, FFTrees outperformed both complex models. Applying the best-performing algorithms to the full datasets, we proposed an FFTree using four cues (Charlson Comorbidity Index (CCI), site of surgery, physical status and frailty status) for the pre-operative setting and an FFTree containing only three cues (duration of anesthesia, age and CCI) for the postoperative setting. Given that both FFTrees contained considerably fewer criteria, which can be easily memorized and applied by health professionals in daily routine, FFTrees could help identify patients requiring intensified POD screening.

Depression is associated with delirium after cardiac surgery-a population-based cohort study

OBJECTIVES

Depression is common in patients with cardiac disease, and preoperative depression is associated with worse outcomes after cardiac surgery. Depression is also correlated with postoperative delirium (POD) after major surgery. However, the association between preoperative depression and POD after cardiac surgery is sparsely studied. The aim of this study was to investigate depression as a predictor for POD in cardiac surgery patients.

METHODS

This population-based cohort study included 1133 cardiac surgery patients in Stockholm 2013-2016. Depression was defined by the Patient Health Questionnaire-9, and POD was evaluated by assessing medical records for symptoms of POD according to Diagnostic and Statistical Manual of Mental Disorders criteria. The association between depression and POD was determined through multivariable logistic regression analysis.

RESULTS

A total of 162 (14%) individuals reported depressive symptoms preoperatively. The incidence of POD was 26% and highest among elderly patients. Among patients with depression, 34% developed POD. In the group of non-depressed patients, 24% developed POD. The overall adjusted odds of delirium were 2.19 times higher in individuals with depressive symptoms compared to controls (95% confidence interval 1.43-3.34). The onset of delirium was most common on Days 0-2 after surgery.

CONCLUSIONS

This unique population-based study in patients undergoing cardiac surgery shows that preoperative depression is associated with POD in a large proportion of treated patients. The findings support the need for improved preoperative screening for depression, especially in younger patients, and enhanced clinical surveillance in the early postoperative period for all patients.

Silent cerebral ischemia detected by magnetic resonance imaging can predict postoperative delirium after total arch replacement for aneurysm

Objective

To identify whether preoperative magnetic resonance imaging findings of the brain can predict postoperative delirium in patients who undergo arch replacement for aneurysms.

Methods

Overall, 193 patients who underwent aortic replacement for the first time at a single institution between April 2014 and September 2020 were enrolled in this retrospective study. After we excluded patients with acute aortic dissection, no preoperative magnetic resonance imaging findings of the brain, and postoperative cerebral infarction, 50 patients were included and divided into 2 groups, according to their confusion scale results: postoperative delirium (group D) and nonpostoperative delirium (group ND). Preoperative magnetic resonance imaging findings of the brain were classified into lacunar stroke, periventricular hyperintensity, and deep subcortical white matter hyperintensity groups; the latter 2 groups were further classified based on the Fazekas scale, grade 0 to 3.

Results

There were 23 patients (46%) in group D and 27 (54%) in group ND. The mean age was significantly greater in group D than in group ND (75 vs 70 years; P = .007). The mean operative time was significantly longer in group D than in group ND (447 vs 384 minutes; P = .024). As for preoperative magnetic resonance imaging findings of the brain, there were significantly more lacunar stroke cases in group D than in group ND (P = .027). In multivariable logistic regression with stepwise selection, high-grade periventricular hyperintensity was significantly related to postoperative delirium (odds ratio, 9.38; 95% confidence interval, 1.55-56.56; P = .015).

Conclusions

Silent cerebral ischemia detected by preoperative magnetic resonance imaging of the brain was a significant risk factor for postoperative delirium.

The Effect of Intraoperative Cerebral Oximetry Monitoring on Postoperative Cognitive Dysfunction and ICU Stay in Adult Patients Undergoing Cardiac Surgery: An Updated Systematic Review and Meta-Analysis

Aim

Determining whether intraoperative cerebral oximetry monitoring-guided intervention reduces the risk of postoperative cognitive dysfunction remains controversial. The objective of this study was to conduct an up-to-date meta-analysis to comprehensively assess the effects of regional cerebral oxygen saturation (rSO₂) monitoring-guided intervention on cognitive outcomes after cardiac surgery.

Methods

PubMed, EMBASE, Ovid, and Cochrane Library databases were systematically searched using the related keywords for cardiac surgical randomized-controlled trials (RCTs) published from their inception to July 31, 2021. The primary outcome was postoperative delirium (POD). The secondary outcomes were postoperative cognitive decline (POCD) and other major postoperative outcomes. The odds ratio (OR) or weighted mean differences (WMDs) with 95% confidence interval (CI) were used to pool the data. The random-effect model was used for the potential clinical inconsistency. We performed meta-regression and subgroup analyses to assess the possible influence of rSO₂ monitoring-guided intervention on clinical outcomes.

Results

In total, 12 RCTs with 1,868 cardiac surgical patients were included. Compared with controls, the incidences of POD (n = 6 trials; OR, 0.28; 95% CI, 0.09–0.84; p = 0.02; I² = 81%) and POCD (n = 5 trials; OR, 0.38; 95% CI, 0.16–0.93; p = 0.03; I² = 78%) were significantly lower in the intervention group. Cerebral oximetry desaturation also showed a positive association with the incidence of POD (n = 5 trials; OR, 2.02; 95% CI, 1.25–3.24; p = 0.004; I² = 81%). The duration of intensive care unit (ICU) stay was markedly shorter in the intervention group than in the control group (n = 10 trials; WMD, −0.22 days; 95% CI, −0.44 to −0.00; p = 0.05; I² = 74%). Univariate meta-regression analyses showed that the major sources of heterogeneity were age (p = 0.03), body mass index (BMI, p = 0.05), and the proportion of congenital heart disease (CHD, p = 0.02) for POD, age (p = 0.04) for POCD, diabetes mellitus (DM, p = 0.07), cerebrovascular accident (CVA, p = 0.02), and chronic obstructive pulmonary disease (COPD, p = 0.09) for ICU stay. Subsequent subgroup analyses also confirmed these results.

Conclusion

Available evidence from the present study suggests that an intraoperative cerebral oximetry desaturation is associated with an increased POD risk, and the rSO₂ monitoring-guided intervention is correlated with a lower risk of POD and POCD, and a shorter ICU stay in adults undergoing cardiac surgery. These clinical benefits may be limited in patients with older age, diabetes status, high BMI, non-CHD, non-COPD, or a previous cardiovascular accident.

Systematic Review Registration: [PROSPREO], identifier: [CRD42021252654].

A Non-Linear Relationship between Preoperative Total Bilirubin Level and Postoperative Delirium Incidence after Liver Transplantation

This study aimed to explore the correlation between preoperative total bilirubin (TBil) level and postoperative delirium (POD) in orthotopic liver transplantation (OLT). All the OLT consecutively performed between April 2019 and March 2021 were retrospectively reviewed with data retrieved from a prospectively collected database. Logistic regression model and generalized additive model were used to identify both linear and non-linear relationships between TBil and POD. A two-piecewise regression model was performed to calculate the saturation effect. Subgroup analyses were performed using stratified logistic regression models. A total of 402 recipients were enrolled. After fully adjusted for covariates, TBil was indicated to have a non-linear relationship with POD. The two-piecewise regression model showed the inflection point was 20 mg/dL. On the left side of the inflection point, the incidence of POD increased by 5% per 1 mg/dL increment of TBil (p = 0.026). On the right side of the inflection point, the effect size had no statistical significance (OR, 0.97; 95% CI, 0.90–1.05; p = 0.482). The relationship between preoperative TBil level and POD incidence is non-linear in OLT recipients. The incidence of POD is positively correlated with TBil level when it is below 20 mg/dL. A saturation effect is observed when TBil level reaches 20 mg/dL.

Presurgical diffusion metrics of the thalamus and thalamic nuclei in postoperative delirium: A prospective two-centre cohort study in older patients

BACKGROUND

The thalamus seems to be important in the development of postoperative delirium (POD) as previously revealed by volumetric and diffusion magnetic resonance imaging. In this observational cohort study, we aimed to further investigate the impact of the microstructural integrity of the thalamus and thalamic nuclei on the incidence of POD by applying diffusion kurtosis imaging (DKI).

METHODS

Older patients without dementia (≥65 years) who were scheduled for major elective surgery received preoperative DKI at two study centres. The DKI metrics fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK) and free water (FW) were calculated for the thalamus and - as secondary outcome - for eight predefined thalamic nuclei and regions. Low FA and MK and, conversely, high MD and FW, indicate aspects of microstructural abnormality. To assess patients' POD status, the Nursing Delirium Screening Scale (Nu-DESC), Richmond Agitation Sedation Scale (RASS), Confusion Assessment Method (CAM) and Confusion Assessment Method for the Intensive Care Unit score (CAM-ICU) and chart review were applied twice a day after surgery for the duration of seven days or until discharge. For each metric and each nucleus, logistic regression was performed to assess the risk of POD.

RESULTS

This analysis included the diffusion scans of 325 patients, of whom 53 (16.3 %) developed POD. Independently of age, sex and study centre, thalamic MD was statistically significantly associated with POD [OR 1.65 per SD increment (95 %CI 1.17 - 2.34) p = 0.004]. FA (p = 0.84), MK (p = 0.41) and FW (p = 0.06) were not significantly associated with POD in the examined sample. Exploration of thalamic nuclei also indicated that only the MD in certain areas of the thalamus was associated with POD. MD was increased in bilateral hemispheres, pulvinar nuclei, mediodorsal nuclei and the left anterior nucleus.

CONCLUSIONS

Microstructural abnormalities of the thalamus and thalamic nuclei, as reflected by increased MD, appear to predispose to POD. These findings affirm the thalamus as a region of interest in POD research.

The effect of type 2 diabetes mellitus on perioperative neurocognitive disorders in patients undergoing elective noncardiac surgery under general anesthesia. A prospective cohort study

Background and Aims:

Preliminary evidence suggests a possible relationship between type 2 diabetes mellitus (T2DM) and perioperative neurocognitive disorders (NCD). We sought to investigate whether patients with T2DM, undergoing elective noncardiac surgery under general anesthesia, are at increased risk of perioperative NCD.

Material and Methods:

A prospective cohort study was designed. One-hundred and forty-four patients with T2DM and 144 healthy controls were recruited. Controls were matched for sex, age, type of operation, and educational background. Postoperative delirium (POD), delayed neurocognitive recovery and postoperative NCD were evaluated.

Results:

Two hundred twenty-eight patients were analyzed. Compared to controls, patients with T2DM were diagnosed with higher rates of NCD preoperatively (n = 96 vs. n = 26, P < 0.05) and higher POD up to 4 days postoperatively (n = 204 vs. n = 68, P < 0.05). Increased rates of delayed neurocognitive recovery and postoperative NCD were recorded in patients with T2DM up to 9 months postoperatively (n = 473 vs. n = 192, P < 0.05). Insulin-dependent patients had higher rates of POD on the second (n = 38 vs. n = 24, P < 0.05) and third day (n = 27 vs. n = 16, P < 0.05) when compared to noninsulin-dependent patients. Logistic multivariable analysis revealed that patients with T2DM are at increased risk for postoperative cognitive disorders.

Conclusion:

Patients with type 2 diabetes mellitus appear to be at a higher risk of perioperative NCDs up to 9 months after elective noncardiac surgery under general anesthesia.

A scientometric study of publications on delirium from 2001 to 2020

AIM

This study aims to evaluate the publications on delirium by using bibliometric analysis.

METHODOLOGY

The Scopus database was evaluated for publications on delirium, during the period of 2001-20. The search results were analyzed for the origin of country, origin of institution, authorship, collaborations, type of article, source of funding, and number of citations.

RESULTS

The searches of Scopus database yielded 22,941 publications, originating from 139 countries. Compared to the decade of 2001-2010, the number of publications on delirium doubled in the decade of 2011-2020. The majority of the papers were research articles (58.26%), and the papers were cited for mean number of 20.53 times. Only a small proportion of the papers were based on funding (13.14%). Maximum number of papers emerged from United States of America. In terms of institutional affiliations, among the authors from top 20 institutes, 15 were from United States, 2 from Netherlands and 1 each from Canada, Germany and United Kingdom. In terms of authors, the research productivity of the top 20 most productive authors varied from 172 to 612 publications with 12 authors belonging to United States, 2 from Italy and 1 each from Canada, Greece, India, Ireland, Netherland and the United Kingdom. The maximum number of papers were published in Journal of the American Geriatric Society and based on the number of citations the New England Journal of Medicine was the most impactful journal.

CONCLUSION

Over the years number of publications on delirium have increased, majority of the publications have emerged from United States.

Diagnosis and Risk Factors for Delirium in Elderly Patients in the Emergency Rooms and Intensive Care Unit of the National Geriatric Hospital Emergency Department: A Cross-Sectional Observational Study

Purpose

To diagnose delirium and identify risk factors for its development in elderly patients in the emergency department (ED) and intensive care units (ICU) at the National Geriatric Hospital (Vietnam).

Patients and Methods

A cross-sectional observational study was conducted with a convenience sample of non-surgical patients admitted to ED and ICU at Hanoi National Geriatric Hospital in Vietnam. In total, 163 patients met the selection criteria and were included in the study. Screening involved using the Confusion Assessment Method (CAM) and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). The diagnosis was established according to the DSM-5 and ICD-10 codes.

Results

Delirium was found in a total of 106 (63.1%) patients. The factors significantly affecting its development were vision impairment (OR, 3.3; 95% CI, 1.5 to 7.4, P=0.003), hearing impairment (OR, 3.6; 95% CI, 1.77 to 7.36, P=0.0001), acute or chronic kidney failure (OR, 7.1; 95% CI, 2.05 to 6.39, P<0.001), respiratory disorders (OR, 2.7; 95% CI, 1.4 to 5.2, P=0.004), and malnutrition (OR, 9.17; 95% CI, 3.43–24.5, P=0.0001). The list also include the fall risk factors (OR, 12.2; 95% CI, 4.1–36.3, P=0.0001), frailty (OR, 8.35; 95% CI, 3.4–20.6, P=0.0001), activities of daily living (OR, 8.35; 95% CI, 3.4–20.6, P=0.0001), hyponatremia (OR, 2.48; 95% CI, 1.07 to 5.75, P=0.001), hypernatremia (OR, 13.1; 95% CI, 1.67 to 2.5, P=0.001), and treatment interventions. In addition, delirium was linked to the duration of ICU admission (OR, 6.53; 95% CI, 4.5–25.5, P < 0.0001).

Conclusion

The CAM/CAM-ICU diagnostic algorithm makes it possible to diagnose delirium successfully. The present study confirmed the role of several premorbid and triggering factors in the occurrence of delirium in elderly patients in ED and ICU. There is a need for further research into risk factors for delirium in elderly patients.

Related Factors and Treatment of Postoperative Delirium in Old Adult Patients: An Integrative Review

“Postoperative delirium” is defined as delirium occurring in the hospital up to one week after a procedure or before discharge (whichever occurs first) that meets the DSM-5 diagnostic criteria. Objectives: To describe the risk factors related to this pathology and identify effective non-pharmacological forms of treatment. An integrative review of the available literature was performed. The search results considered included all quantitative studies published between 2011 and 2019 in both English and Spanish. A total of 117 studies were selected. Advanced age was identified as the principal risk factor for postoperative delirium. Nursing interventions appear to be the key to preventing or reducing the seriousness of delirium after an anaesthetic episode. The aetiology of postoperative delirium remains unknown, and no treatment exists to eliminate this pathology. The role of nursing staff is fundamental in the prevention, diagnosis, and management of the pathology.

Management of post-operative delirium following stereoelectroencephalography electrode placement for drug resistant epilepsy: Lessons learned from two case reports

•

Post-operative delirium poses unique challenges in neurosurgical patients.

•

Substance use is a modifiable risk factor for post-operative delirium after SEEG.

•

SEEG patients have increased risk of harm when experiencing post-operative delirium.

Post-operative delirium (POD) represents a unique challenge in the care of any surgical patient but is especially challenging in neurosurgical inpatient management due to a host of potentially significant predisposing factors. Patients undergoing stereoencephalography (SEEG) for diagnosis of drug resistant epilepsy are at unique risk due to safety concerns, yet POD has been underdiscussed in this population. Patients should be counseled pre-operatively about their risk and subsequent steps be taken post-operatively. We present two cases of POD status-post SEEG and propose a mechanism by which future post-operative care be coordinated by the physician, patient, and patient’s family.

Association of Pain With Atrial Fibrillation and Delirium After Cardiac Surgery: A DECADE Sub-Study

OBJECTIVE

The authors aimed to evaluate the effects of postoperative pain on the incidence of atrial fibrillation and delirium in patients having surgery with cardiopulmonary bypass (CPB).

DESIGN

Post hoc analysis of the (An investigator-initiated, multicentre, double-blind trial (ClinicalTrials NCT02004613) (DECADE)), a randomized, placebo-controlled trial.

SETTING

Tertiary, academic hospital.

PARTICIPANTS

Six hundred five adults from the DECADE enrolled at Cleveland Clinic Main Campus, who had had surgery with CPB.

INTERVENTIONS

Dexmedetomidine versus placebo started before surgical incision and postoperatively was maintained until 24 hours.

MEASUREMENTS

Primary outcomes were atrial fibrillation, diagnosed by clinicians in the intensive care unit (ICU), presence of delirium assessed with the Confusion Assessment Method for the ICU, data on pain scores, and opioid consumption, occurring between ICU admission and the earlier of postoperative day five or hospital discharge.

RESULTS

Postoperative pain levels were similar among patients with or without atrial fibrillation. Two hundred six (34%) patients had atrial fibrillation and ninety-two (15%) had delirium before hospital discharge within the first five postoperative days. The risk of atrial fibrillation was not significantly different between groups (hazard ratio: 1.09; 97.5% confidence interval [CI]: 0.99, 1.20, p = 0.039); there were no associations between postoperative pain and the risk of postoperative delirium (hazard ratio: 0.96; 97.5% CI: 0.84-1.11; p = 0.57). Postoperative opioid consumption was neither significantly associated with postoperative atrial fibrillation nor delirium.

CONCLUSIONS

Atrial fibrillation and delirium was not associated with pain after cardiac surgery. Opioid use was not associated with atrial fibrillation and delirium. Because both atrial fibrillation and delirium have a multifactorial nature, further studies should be focused on other plausible mechanisms.

Perioperative dexmedetomidine administration to prevent delirium in adults after non-cardiac surgery: A systematic review and meta-analysis

STUDY OBJECTIVE

To evaluate the efficacy of perioperative dexmedetomidine (DEX) administration for preventing delirium in adults after non-cardiac surgery.

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

INTERVENTIONS

Perioperative administration of DEX to prevent delirium in adults following non-cardiac surgery.

MEASUREMENTS

The incidence of postoperative delirium (POD).

METHODS

The databases of PubMed, Embase and Cochrane Central Register were searched from inception to Mar 4, 2021 for all available RCTs that assessed DEX for POD in adults after non-cardiac surgery. Risk ratio (RR) with a 95% confidence interval (CI) was calculated for dichotomous data. Standardized mean difference (SMD) was calculated for continuous data. Risk of bias was assessed using the second version of the Cochrane risk-of-bias tool for RCTs (RoB 2.0), and the level of certainty for main outcomes were assessed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology.

MAIN RESULTS

Thirteen studies, including the meta-analysis with a total of 4015 patients (DEX group: 2050 patients; placebo group: 1965 patients), showed that DEX significantly reduced the incidence of POD in adults after non-cardiac surgery compared with control group (RR: 0.60; 95%CI: 0.46 to 0.77, P = 0.0001, I² = 55%, GRADE = moderate). Meanwhile, there was a statistical difference by the subgroup analysis between the mean age ≥ 65 years group and the mean age<65 years group. There were no statistical differences in length of hospital stay following surgery (SMD: -0.36; 95%CI: -0.80 to 0.07, P = 0.1, I² = 97%, GRADE = low) and all-cause mortality rate (RR:0.57; 95%CI: 0.25 to 1.28, P < 0.17, I² = 0%, GRADE = moderate) compared with placebo group. However, Meta-analysis showed that DEX administration significantly resulted in intraoperative bradycardia when compared with placebo group (RR: 1.39; 95%CI: 1.14 to 1.69, P = 0.0009, I² = 0%, GRADE = high), and as well as intraoperative hypotension (RR: 1.25; 95%CI: 1.11 to 1.42, P = 0.0004, I² = 0%, GRADE = high).

CONCLUSION

This systematic review and meta-analysis suggests that perioperative administration of DEX could significantly reduce the incidence of POD in patients elder than 65 years following non-cardiac surgery. However, there was no definite evidence that perioperative DEX could reduce the incidence of POD in patients younger than 65 years of age after non-cardiac surgery. In addition, perioperative DEX administration was associated with an elevated risk of bradycardia and hypotension.

Risk factors of postoperative delirium after cardiac surgery: a meta-analysis

Background

Postoperative delirium is a frequent event after cardiac surgery. This meta-analysis aimed to identify relevant risk factors.

Method

In this meta-analysis, all original researches regarding patients undergoing mixed types of cardiac surgery (excluding transcatheter procedures) and postoperative delirium were evaluated for inclusion. On July 28th 2020, we searched PubMed, Embase, Web of Science and Scopus. Data about name of first author, year of publication, inclusion and exclusion criteria, research design, setting, method of delirium assessment, incidence of delirium, odds ratio (OR) and corresponding 95% confidence interval (CI) of risk factors, and other information relevant was collected. OR and 95% CI were used as metrics for summarized results. Random effects model was applied.

Results

Fourteen reports were included with a total sample size of 13,286. The incidence of delirium ranged from 4.1 to 54.9%. Eight risk factors were identified including aging, diabetes, preoperative depression, mild cognitive impairment, carotid artery stenosis, NYHA functional class III or IV, time of mechanical ventilation and length of intensive care unit stay.

Conclusion

In this study several risk factors associated with postoperative delirium after cardiac surgery were identified. Utilizing the information may allow us to identifying patients at high risk of developing postoperative delirium prior to delirium onset.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01496-w.

Cardiac Delirium Index for Predicting the Occurrence of Postoperative Delirium in Adult Patients After Coronary Artery Bypass Grafting

Background

Postoperative delirium (POD) is a serious complication of cardiac surgery. It is an acute neuropsychiatric syndrome. The aim of this study was to analyze the CARDEL Index, composed of advancing age, preoperative glycated hemoglobin and the platelet-to-WBC ratio (PWR) previously described and calculated, using a different patient database, to assess its usefulness as a marker for predicting postoperative delirium after coronary artery by-pass grafting (CABG).

Methods

A retrospective analysis of 1098 patients who underwent, isolated CABG procedures between 2017 and 2019 was performed.

Results

Within the study group, 164/1098 (14.93%) patients were diagnosed with delirium. Preoperative inflammatory parameters were elevated in patients with delirium: White Blood Cell count (p=0.003), Neutrophil count (p=0.016) and C-reactive protein (p<0.001). A decrease in preoperative PWR was shown in patients with delirium (p=0.008). Delirious patients spent more time mechanically ventilated (p<0.001) and had longer hospitalization times (p=0.002). Mortality at 1 year was significantly higher in patients with POD (p<0.001). The CARDEL Index in this study group for POD detection has the largest area under the curve (AUC) of 0.664 (p<0.001) and a cut-off value of 8.08.

Conclusion

CARDEL Index may be treated as a potentially valuable tool for delirium prediction in patients after CABG.

Postoperative delirium - treatment and prevention

PURPOSE OF REVIEW

Postoperative delirium (POD) is one of the most severe complications after surgery.The consequences are dramatic: longer hospitalization, a doubling of mortality and almost all cases develop permanent, yet subtle, cognitive deficits specific to everyday life. Actually, no global guideline with standardized concepts of management exists. Advances in prevention, diagnosis and treatment can improve recognition and risk stratification of delirium and its consequences.

RECENT FINDINGS

Management of POD is a multiprofessional approach and consists of different parts: First, the detection of high-risk patients with a validated tool, preventive nonpharmacological concepts and an intraoperative anesthetic management plan that is individualized to the older patient (e.g. avoiding large swings in blood pressure, vigilance in maintaining normothermia, ensuring adequate analgesia and monitoring of anesthetic depth). In addition to preventive standards, treatment and diagnostic concepts must also be available, both pharmaceutical and nonpharmacological.

SUMMARY

Not every POD can be prevented. It is important to detect patients with high risk for POD and have standardized concepts of management. The most important predisposing risk factors are a higher age, preexisting cognitive deficits, multimorbidity and an associated prodelirious polypharmacy. In view of demographic change, the implementation of multidisciplinary approaches to pharmacological and nonpharmacological POD management is highly recommended.

Incidence and risk factors of delirium after percutaneous coronary intervention in individuals hospitalised for acute myocardial infarction: protocol for a systematic review and meta-analysis

INTRODUCTION

Delirium in the postoperative period is a wide-reaching problem that affects important clinical outcomes. The incidence and risk factors of delirium in individuals with acute myocardial infarction (AMI) after primary percutaneous coronary intervention (PCI) has not been completely determined and no relevant systematic review and meta-analysis of incidence or risk factors exists. Hence, we aim to conduct a systematic review and meta-analysis to ascertain the incidence and risk factors of delirium among AMI patients undergoing PCI.

METHODS AND ANALYSES

We will undertake a comprehensive literature search among PubMed, EMBASE, Cochrane Library, PsycINFO, CINAHL and Google Scholar from their inception to the search date. Prospective cohort and cross-sectional studies that described the incidence or at least one risk factor of delirium will be eligible for inclusion. The primary outcome will be the incidence of postoperative delirium. The quality of included studies will be assessed using a risk of bias tool for prevalence studies and the Cochrane guidelines. Heterogeneity of the estimates across studies will be assessed. Incidence and risk factors associated with delirium will be extracted. Incidence data will be pooled. Each risk factor reported in the included studies will be recorded together with its statistical significance; narrative and meta-analytical approaches will be employed. The systematic review and meta-analysis will be presented according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

ETHICS AND DISSEMINATION

This proposed systematic review and meta-analysis is based on published data, and thus there is no requirement for ethics approval. The study will provide an up to date and accurate incidence and risk factors of delirium after PCI among patients with AMI, which is necessary for future research in this area. The findings of this study will be disseminated through publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020184388.

Association between postoperative changes in the gut microbiota and pseudopsia after cardiac surgery: prospective observational study

Background

Delirium after cardiac surgery affects mortality, but the mechanism remains unclear. Previous studies have reported gut microbiota are associated with brain activity. Systemic inflammation and antibiotics can damage the gut microbiota after cardiac surgery. We aimed to investigate changes in the gut microbiota and the association between the gut microbiota and delirium after cardiac surgery.

Methods

Twenty-one patients who underwent cardiac surgery were enrolled. Microbiota counts and fecal organic acid concentrations were measured in fecal samples harvested before surgery, just after surgery, and before discharge. To quantify the microbiota, we extracted total RNA fractions and examined gut microbiota composition using 16S and 23S rRNA-targeted quantitative-reverse Transcription-PCR. Postoperative delirium, insomnia, and pseudopsia were assessed for 1 week. Postoperative total bacterial counts changed significantly from 10.2 ± 0.2 log₁₀ cells/g of feces to 9.8 ± 0.5 in the first postoperative samples (p = 0.003) and 10.0 ± 0.4 in the samples before discharge (p = 0.039). Fecal pH was 6.9 ± 0.6 before surgery and 7.4 ± 0.7 in the first postoperative samples (p = 0.001). Postoperative Staphylococcus and Pseudomonas counts were significantly higher in patients with postoperative pseudopsia than in patients without pseudopsia (3.2 ± 1.3 vs. 5.4 ± 0.9; p = 0.012 and 1.7 ± 0.8 vs. 4.6 ± 2.7; p = 0.001).

Conclusions

Total bacterial counts were significantly lower after surgery and until discharge. Fecal pH was significantly higher than preoperative levels. Staphylococcus and Pseudomonas counts were significantly higher in patients with postoperative pseudopsia.