Postoperative delirium: why, what, and how to confront it at your institution

Priority areas for outcomes improvement among older adults undergoing inpatient general surgery inclusive of geriatric-pertinent complications

BACKGROUND

Comprehensive studies on priority areas for improving geriatric surgery outcomes, inclusive of geriatric-pertinent data, are limited.

METHODS

The ACS NSQIP geriatric database (2014-2018) was used to abstract older adults (≥65 years) undergoing inpatient general surgery procedures. Thirty-day complication, functional decline, and mortality rates were analyzed, with a focus on two geriatric-pertinent complications: delirium and new/worsening pressure ulcers.

RESULTS

There were 9062 patients; 41.9% were ≥75 years. Mean age was 73.9 years. The majority of patients were female (54.0%), White (77.7%), and had independent functional status before surgery (94.0%). Overall 30-day complication, functional decline, and mortality rates were 33.6%, 34.5%, and 3.5%, respectively; failure to the rescue rate was 9.7%. Including geriatric-pertinent complications increased the overall complication rate by 20.4%. Delirium emerged as the leading complication (11.9%), followed by bleeding (11.1%), and wound-related complications (10.1%); these three accounted for 53.7% of complications. Delirium and pressure ulcers were associated with a >50% rate of postoperative functional decline (52.0% and 71.4%, respectively); pressure ulcers were also notable for a 25.5% failure to the rescue rate. Both were also among complications most likely to occur following the 3 most common procedures (colorectal surgery, pancreatic resections, and exploratory laparotomy), which overall accounted for approximately 79.6% of complications, 73.4% of patients experiencing functional decline, and 82.3% of mortality.

CONCLUSIONS

Delirium is the leading complication among older adults undergoing inpatient surgery. Overall, a small number of complications and procedure groups account for most surgical morbidity and mortality among older adults and thus constitute priority areas for outcomes improvement.

The way towards ethical anesthesia care: no aim - no game - no fame or blame?

PURPOSE OF REVIEW

This review explores the intricacies of ethical anesthesia, exploring the necessity for precision anesthesia and its impact on patient-reported outcomes. The primary objective is to advocate for a defined aim, promoting the implementation of rules and feedback systems. The ultimate goal is to enhance precision anesthesia care, ensuring patient safety through the implementation of a teamwork and the integration of feedback mechanisms.

RECENT FINDINGS

Recent strategies in the field of anesthesia have evolved from intraoperative monitorization to a wider perioperative patient-centered precision care. Nonetheless, implementing this approach encounters significant obstacles. The article explores the evidence supporting the need for a defined aim and applicable rules for precision anesthesia's effectiveness. The implementation of the safety culture is underlined. The review delves into the teamwork description with structured feedback systems.

SUMMARY

Anesthesia is a multifaceted discipline that involves various stakeholders. The primary focus is delivering personalized precision care. This review underscores the importance of establishing clear aims, defined rules, and fostering effective and well tolerated teamwork with accurate feedback for improving patient-reported outcomes. The Safe Brain Initiative approach, emphasizing algorithmic monitoring and systematic follow-up, is crucial in implementing a fundamental and standardized reporting approach within patient-centered anesthesia care practice.

Development of postoperative delirium prediction models in patients undergoing cardiovascular surgery using machine learning algorithms

Associations between delirium and postoperative adverse events in cardiovascular surgery have been reported and the preoperative identification of high-risk patients of delirium is needed to implement focused interventions. We aimed to develop and validate machine learning models to predict post-cardiovascular surgery delirium. Patients aged ≥ 40 years who underwent cardiovascular surgery at a single hospital were prospectively enrolled. Preoperative and intraoperative factors were assessed. Each patient was evaluated for postoperative delirium 7 days after surgery. We developed machine learning models using the Bernoulli naive Bayes, Support vector machine, Random forest, Extra-trees, and XGBoost algorithms. Stratified fivefold cross-validation was performed for each developed model. Of the 87 patients, 24 (27.6%) developed postoperative delirium. Age, use of psychotropic drugs, cognitive function (Mini-Cog < 4), index of activities of daily living (Barthel Index < 100), history of stroke or cerebral hemorrhage, and eGFR (estimated glomerular filtration rate) < 60 were selected to develop delirium prediction models. The Extra-trees model had the best area under the receiver operating characteristic curve (0.76 [standard deviation 0.11]; sensitivity: 0.63; specificity: 0.78). XGBoost showed the highest sensitivity (AUROC, 0.75 [0.07]; sensitivity: 0.67; specificity: 0.79). Machine learning algorithms could predict post-cardiovascular delirium using preoperative data.Trial registration: UMIN-CTR (ID; UMIN000049390).

Association of general anesthesia exposure with risk of postoperative delirium in patients receiving transcatheter aortic valve replacement: a meta-analysis and systematic review

The aim of this meta-analysis was to assess the association of general anesthesia (GA) exposure with the risk of POD in this patient population. Databases including Medline, EMBASE, Cochrane library, and Google Scholar were searched from inception to December 2022. Analysis of 17 studies published between 2015 and 2021 involving 10,678 individuals revealed an association of GA exposure with an elevated risk of POD [odd ratio (OR) = 1.846, 95% CI 1.329 to 2.563, p = 0.0003, I2 = 68.4%, 10,678 patients]. Subgroup analysis of the diagnostic methods also demonstrated a positive correlation between GA exposure and POD risk when validated methods were used for POD diagnosis (OR = 2.199, 95% CI 1.46 to 3.31, p = 0.0002). Meta-regression analyses showed no significant impact of age, male proportion, and sample size on the correlation between GA and the risk of POD. The reported overall incidence of POD from the included studies regardless of the type of anesthesia was between 0.8 and 27%. Our meta-analysis showed a pooled incidence of 10.3% (95% CI 7% to 15%). This meta-analysis suggested an association of general anesthesia with an elevated risk of postoperative delirium, implying the necessity of implementing appropriate prophylactic strategies against this complication when general anesthesia was used in this clinical setting.

Association between preoperative on-site CCU visits and postoperative delirium in patients undergoing cardiac surgery: A retrospective cohort study

BACKGROUND

Postoperative delirium (POD) is a common complication after cardiac surgery (CS), with symptoms like attention disorders and even delays patients' recovery.

AIMS

To evaluate the impact of preoperative on-site visits in the cardiac care unit (CCU) on POD after CS.

STUDY DESIGN

Patients admitted to the CCU with extracorporeal CS were included in the visiting or non-visiting group according to whether they were on visiting week. The visiting group received a preoperative visit from a nurse-led multidisciplinary visiting team (including CCU nurses and physicians) 1 week before surgery in addition to standard care. The non-visiting group received standard care like unstructured information from the CS team and anesthesiologists and so on. The Confusion Assessment Method for the ICU (CAM-ICU) and the Intensive Care Delirium Screening Checklist (ICDSC) were used to evaluate the POD severity. The incidence, occurrence and duration of POD, as well as the CCU length of stay, postoperative mechanical ventilation duration and length of hospital stay were compared between the two groups.

RESULTS

A total of 735 participants (369 in the visited group and 366 in the unvisited group) were included in this study. Preoperative on-site visits were associated with a decreased POD incidence (odds ratio [OR]: 0.524, 95% CI: 0.336-0.817), an improved POD severity (OR: 0.578, 95% CI: 0.359-0.932) and a shortening POD duration (OR: 0.972, 95% CI: 0.951-0.994). There was a significant difference between the visiting and non-visiting groups in the mechanical ventilation duration (OR: 0.987, 95% CI: 0.978-0.996).

CONCLUSIONS

Preoperative on-site visits are associated with a reduction in the incidence, duration, and severity of POD, as well as the mechanical ventilation duration of patients.

RELEVANCE TO CLINICAL PRACTICE

This study found that preoperative on-site visits were associated with the onset, duration, severity and duration of mechanical ventilation of POD. Although many factors influence the occurrence of POD, a multidisciplinary visiting team led by a nurse (including CCU nurses and physicians) can provide early nursing interventions through preoperative visits, better obtain postoperative cooperation from patients, establish a good nurse-patient relationship and provide better health services to patients. In a realistic CCU setting, nurses and physicians can act as educators, assessing patients before surgery, enhancing preoperative education, improving patient familiarity with the CCU environment and teaching sign language communication skills when patients are mechanically ventilated. These findings can therefore provide the basis for effective clinical care to prevent postoperative POD.

Hydrogen Gas Treatment Improves Postoperative Delirium and Cognitive Dysfunction in Elderly Noncardiac Patients

Purpose: Postoperative delirium is a state of acute brain dysfunction characterized by fluctuating mental status that affects millions of patients each year. We used prophylactic inhalation of hydrogen gas in elderly patients undergoing elective surgery to compare their occurrence of postoperative delirium with that of controls. Methods: A total of 184 patients aged ≥ 65 years were enrolled and randomized into either a control group or a hydrogen inhalation group. The quality of sleep was assessed 1 day before and 1, 3, and 7 days after surgery at 8 A.M. The Confusion Assessment Method (CAM) was used as a screening tool for delirium and assessed the patients’ state of consciousness 1−7 days after surgery. Results: Postoperative delirium occurred in 17 (24%) of 70 patients without hydrogen inhalation and in 10 (12%) of 83 patients after hydrogen inhalation. The incidence of delirium was decreased in the hydrogen group. No significant differences were found between length of stay in hospital after surgery and sleep quality at 1, 3, and 7 days postoperatively between the two groups. The numerical rating scale (NRS) pain scores were higher in the hydrogen group (4.08 ± 1.77) than the control group (3.54 ± 1.77) on day 1 (p < 0.05); however, the mean difference between the two groups was small (1 to 1.6). There were no significant differences on day 3 and 7. The postoperative C-reactive protein level was significantly lower in the hydrogen group than the control group. Conclusions: This study suggests that hydrogen inhalation can prevent postoperative delirium in elderly noncardiac patients by reducing the inflammatory response.

Effect of Perioperative Dexmedetomidine Infusion on Postoperative Delirium in Elderly Patients Undergoing Oral and Maxillofacial Surgery: A Randomized Controlled Clinical Trial

Purpose

The aim of the study was to determine whether perioperative dexmedetomidine administration can improve postoperative delirium in elderly patients undergoing oral and maxillofacial surgery.

Patients and Methods

This was a prospective double-blind randomized controlled clinical trial conducted in Cangzhou Central Hospital from December 2021 to March 2022. Patients aged 65 and older underwent oral and maxillofacial surgery under general anesthesia. Eligible patients were randomly assigned to dexmedetomidine or control group. Dexmedetomidine was injected intravenously from 10 min before induction of anesthesia to 30 min before the end of surgery in dexmedetomidine group, while patients in the control group were given normal saline at the same rate during the same time period. The primary measurement indicators were the incidence and duration of delirium in the first five days after surgery. The secondary measurement indicators were Visual Analogue Score (VAS) for the first 24 hours following surgery, subjective sleep quality score within 24 hours postoperatively and intraoperative adverse reactions.

Results

One hundred and twenty patients were randomly assigned. Baseline characteristics were similar between two groups. The incidence and duration of postoperative delirium did not differ statistically between two groups (all P > 0.05). Compared with control group, VAS scores in dexmedetomidine group were significantly lower at 6, 12, and 24 hours after surgery (all P < 0.05); moreover, Richards-Campbell Sleep Questionnaire (RCSQ) results were significantly improved 1 day after surgery in dexmedetomidine group (P < 0.05). Dexmedetomidine-related adverse reactions were similar in both groups (P > 0.05).

Conclusion

Intravenous infusion of dexmedetomidine 10 min before induction of anesthesia to half an hour before the end of surgery did not improve postoperative delirium in elderly patients undergoing oral and maxillofacial surgery; however, dexmedetomidine may be associated with decreased postoperative pain and improved postoperative sleep quality.

Postoperative delirium prediction using machine learning models and preoperative electronic health record data

Background

Accurate, pragmatic risk stratification for postoperative delirium (POD) is necessary to target preventative resources toward high-risk patients. Machine learning (ML) offers a novel approach to leveraging electronic health record (EHR) data for POD prediction. We sought to develop and internally validate a ML-derived POD risk prediction model using preoperative risk features, and to compare its performance to models developed with traditional logistic regression.

Methods

This was a retrospective analysis of preoperative EHR data from 24,885 adults undergoing a procedure requiring anesthesia care, recovering in the main post-anesthesia care unit, and staying in the hospital at least overnight between December 2016 and December 2019 at either of two hospitals in a tertiary care health system. One hundred fifteen preoperative risk features including demographics, comorbidities, nursing assessments, surgery type, and other preoperative EHR data were used to predict postoperative delirium (POD), defined as any instance of Nursing Delirium Screening Scale ≥2 or positive Confusion Assessment Method for the Intensive Care Unit within the first 7 postoperative days. Two ML models (Neural Network and XGBoost), two traditional logistic regression models (“clinician-guided” and “ML hybrid”), and a previously described delirium risk stratification tool (AWOL-S) were evaluated using the area under the receiver operating characteristic curve (AUC-ROC), sensitivity, specificity, positive likelihood ratio, and positive predictive value. Model calibration was assessed with a calibration curve. Patients with no POD assessments charted or at least 20% of input variables missing were excluded.

Results

POD incidence was 5.3%. The AUC-ROC for Neural Net was 0.841 [95% CI 0. 816–0.863] and for XGBoost was 0.851 [95% CI 0.827–0.874], which was significantly better than the clinician-guided (AUC-ROC 0.763 [0.734–0.793], p < 0.001) and ML hybrid (AUC-ROC 0.824 [0.800–0.849], p < 0.001) regression models and AWOL-S (AUC-ROC 0.762 [95% CI 0.713–0.812], p < 0.001). Neural Net, XGBoost, and ML hybrid models demonstrated excellent calibration, while calibration of the clinician-guided and AWOL-S models was moderate; they tended to overestimate delirium risk in those already at highest risk.

Conclusion

Using pragmatically collected EHR data, two ML models predicted POD in a broad perioperative population with high discrimination. Optimal application of the models would provide automated, real-time delirium risk stratification to improve perioperative management of surgical patients at risk for POD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01543-y.

Feasibility of low-dose dexmedetomidine for prevention of postoperative delirium after intracranial operations: a pilot randomized controlled trial

Background

Clinical trials have shown that dexmedetomidine might decrease the occurrence of postoperative delirium after major surgery, but neurosurgical patients were excluded from these studies. We aimed to determine the feasibility of conducting a full-scale randomized controlled trial of the effect of prophylactic low-dose dexmedetomidine on postoperative delirium in patients after elective intracranial operation for brain tumors.

Methods

In this single-center, parallel-arm pilot randomized controlled trial, adult patients who underwent an elective intracranial operation for brain tumors were recruited. Dexmedetomidine (0.1 μg/kg/hour) or placebo was continuously infused from intensive care unit (ICU) admission on the day of surgery until 08:00 AM on postoperative day one. Adverse events during the study-drug administration were recorded. The primary feasibility endpoint was the occurrence of study-drug interruption. Delirium was assessed twice daily with the Confusion Assessment Method for the ICU during the first five postoperative days. The assessable rate of delirium evaluation was documented.

Results

Sixty participants were randomly assigned to receive either dexmedetomidine (n = 30) or placebo (n = 30). The study-drug was stopped in two patients (6.7%) in the placebo group due to desaturation after new-onset unconsciousness and an unplanned reoperation for hematoma evacuation and in one patient (3.3%) in the dexmedetomidine group due to unplanned discharge from the ICU. The absolute difference (95% confidence interval) of study-drug interruption between the two groups was 3.3% (− 18.6 to 12.0%), with a noninferiority P value of 0.009. During the study-drug infusion, no bradycardia occurred, and hypotension occurred in one patient (3.3%) in the dexmedetomidine group. Dexmedetomidine tended to decrease the incidence of tachycardia (10.0% vs. 23.3%) and hypertension (3.3% vs. 23.3%). Respiratory depression, desaturation, and unconsciousness occurred in the same patient with study-drug interruption in the placebo group (3.3%). Delirium was evaluated 600 times, of which 590 (98.3%) attempts were assessable except in one patient in the placebo group who remained in a coma after an unplanned reoperation.

Conclusions

The low rate of study-drug interruption and high assessable rate of delirium evaluation supported a fully powered trial to determine the effectiveness of low-dose dexmedetomidine on postoperative delirium in patients after intracranial operation for brain tumors.

Trial registration

The trial was registered at ClinicalTrials.gov (NCT04494828) on 31/07/2020.

The degree of frailty as a translational measure of health in aging

Frailty is a multiply determined, age-related state of increased risk for adverse health outcomes. We review how the degree of frailty conditions the development of late-life diseases and modifies their expression. The risks for frailty range from subcellular damage to social determinants. These risks are often synergistic-circumstances that favor damage also make repair less likely. We explore how age-related damage and decline in repair result in cellular and molecular deficits that scale up to tissue, organ and system levels, where they are jointly expressed as frailty. The degree of frailty can help to explain the distinction between carrying damage and expressing its usual clinical manifestations. Studying people-and animals-who live with frailty, including them in clinical trials and measuring the impact of the degree of frailty are ways to better understand the diseases of old age and to establish best practices for the care of older adults.

Current status of perioperative hypnotics, role of benzodiazepines, and the case for remimazolam: a narrative review

Anaesthesiologists and non-anaesthesiologist sedationists have a limited set of available i.v. hypnotics, further reduced by the withdrawal of thiopental in the USA and its near disappearance in Europe. Meanwhile, demand for sedation increases and new clinical groups are using what traditionally are anaesthesiologists' drugs. Improved understanding of the determinants of perioperative morbidity and mortality has spotlighted hypotension as a potent cause of patient harm, and practice must be adjusted to respect this. High-dose propofol sedation may be harmful, and a critical reappraisal of drug choices and doses is needed. The development of remimazolam, initially for procedural sedation, allows reconsideration of benzodiazepines as the hypnotic component of a general anaesthetic even if their characterisation as i.v. anaesthetics is questionable. Early data suggest that a combination of remimazolam and remifentanil can induce and maintain anaesthesia. Further work is needed to define use cases for this technique and to determine the impact on patient outcomes.

Preoperative Cognitive Impairment and the Prevalence of Postoperative Delirium in Elderly Cancer Patients-A Prospective Observational Study

Preoperative cognitive impairment (PCI) in cancer patients includes a broad spectrum of neurocognitive changes produced by complex interplay of patient, tumoural and treatment-related factors. Reduced preoperative cognitive reserve can favour the emergence of postoperative delirium (POD). The study aims to document PCI prevalence and to assess the relationship with POD in elderly cancer patients. The prospective observational study included consecutive patients scheduled for elective surgery; PCI was assessed with Mini-Cog test and defined at a score ≤ 3, POD was screened using Nursing Delirium Screening Scale (Nu-DESC) and defined at a score ≥ 2. Data on education, American Society of Anesthesiologists (ASA) score, preoperative medications, substance use, comorbidities, sensorial deficits, surgery and anaesthesia type, anaesthetic drugs, Mini-Cog score, postoperative pain, Nu-DESC were collected. In total, 131 patients were enrolled, mean age 72.1 ± 5.9 years. PCI prevalence was 51.9% (n = 68). POD prevalence was 19.8% (n = 26), with significantly higher value in PCI patients (27.9% vs. 11.1%, p = 0.016). In multivariate analysis, Mini-Cog score ≤ 3 (OR = 2.6, p = 0.027), clock draw (OR: 2.9, p = 0.013), preoperative renal dysfunction (OR = 2.6, p = 0.012), morphine (OR = 2.7, p = 0.007), metoclopramide (OR = 6.6, p = 0.006), and high pain score (OR = 1.8, p = 0.018) had a significant association with POD development. In this sample of elderly patients, PCI had a high prevalence and predicted the emergence of POD. Incorporating Mini-Cog test into the preoperative evaluation of onco-geriatric patients seems valuable and feasible.

Use of Processed Electroencephalography in the Clinical Setting

Purpose of Review

Processed electroencephalography (pEEG) is widely used in clinical practice. Few clinicians utilize the full potential of these devices. This brief review will address the improvements in patient management available from the utilization of all pEEG data.

Recent Findings

Anesthesiologists easily learn to recognize raw pEEG patterns that are consistent with an appropriate level of hypnotic effect. Power distribution within the waveform can be displayed in a visual format that identifies signatures of the principal anesthetic hypnotics. Opinion on the benefit of pEEG data in the mitigation of postoperative neurological impairment remains divided.

Summary

Looking beyond the index number can aid clinical decision making and improve confidence in the benefits of this monitoring modality.