Preoperative medication use and postoperative delirium: a systematic review

Differences of anticholinergic drug burden between older hospitalized patients with and without delirium: a systematic review and meta-analysis based on prospective cohort studies

OBJECTIVES

This review aims to comprehensively summarize the differences in anticholinergic drug burden (ADB) scores between older hospitalized patients with and without delirium.

METHODS

We searched PubMed, Embase, Web of Science, Cochrane Library and CINAHL EBSCOhost databases to identify prospective cohort studies exploring the relationship between ADB and the occurrence of delirium in older hospitalized patients. The primary outcome of the review was the mean ADB scores for the delirium and non-delirium groups, and the secondary outcome was the scores for the subsyndromal and non-delirium groups. The standardized mean difference (SMD) and corresponding 95% confidence intervals (95% CI) were incorporated using a fixed-effect method. Moreover, we performed subgroup analysis according to the admission type, age, the ADB scale type and the ADB classification.

RESULTS

Nine prospective cohort studies involving 3791 older patients with a median age of 75.1 (71.6-83.9) were included. The ADB score was significantly higher in the delirium group than in the non-delirium group (SMD = 0.21, 95%CI 0.13-0.28). In subgroup analysis, the age subgroup was split into < 75 and ≥ 75 according to the median age of the older people. There were significant differences in ADB scores between older people with delirium and those without delirium in various subgroups: surgical (SMD = 0.20, 95%CI 0.12-0.28), internal medicine (SMD = 0.64, 95%CI 0.25-1.02), age < 75 (SMD = 0.17, 95%CI 0.08-0.26), age ≥ 75 (SMD = 0.27, 95%CI 0.15-0.39), ADS scale (SMD = 0.13, 95%CI 0.13-0.40), ARS scale (SMD = 0.15, 95%CI 0.03-0.26), ACB scale (SMD = 0.13, 95%CI 0.01-0.25), pre-admission ADB (SMD = 0.24, 95%CI 0.05-0.43) and ADB during hospitalization (SMD = 0.20, 95%CI 0.12-0.27).

CONCLUSIONS

We found a quantitative relationship between ADB and delirium in older patients admitted for internal medicine and surgery. And this relationship remained significant in different age, ADB scale type and ADB classification subgroups. However, the actual difference in ADB scores between patients with delirium and without delirium was small. More high-quality observational studies should be conducted to explore the impact of ADB on delirium and subsyndromal delirium.

CLINICAL TRIAL REGISTRATION

The protocol was published in the International Prospective Register of Systematic Reviews (PROSPERO) [Ref: CRD42022353649].

Brain-Hazardous Medications and Potential Subadequate Antidepressant Dosing in Older Surgical Patients Receiving Home Antidepressants: An Observational Study of a Large US Health System

BACKGROUND

Older surgical patients with depression often experience poor postoperative outcomes. Poor outcomes may stem from brain-hazardous medications and subadequate antidepressant dosing.

METHODS

This was a retrospective, observational cohort study covering the period between January 1, 2021 and December 31, 2021. Patients ≥60 years of age who underwent inpatient surgery and had an overnight stay at an integrated academic health care system comprising 14 hospitals were eligible. We analyzed the prevalence of home central nervous system (CNS)-active potentially inappropriate medication (PIM) and potential subadequate antidepressant dosing in older surgical patients receiving home antidepressants. Univariable and multivariable regression models were used to identify factors associated with home CNS-active PIM prescribing and potential subadequate antidepressant dosing. Additionally, outcomes were compared among patients receiving and not receiving CNS-active PIMs and patients receiving and not receiving subadequate antidepressant dosing.

RESULTS

A total of 8031 patients were included in this study (47% female, mean age = 70 years) of whom 2087 (26%) were prescribed antidepressants. Roughly one-half (49%, 95% confidence interval [CI], 46.5-50.1) of patients receiving home antidepressants were also receiving ≥1 CNS-active PIM and 29% (95% CI, 27.0-29.3) were receiving a potential subadequate dose. Factors associated with an increased likelihood of receiving a home CNS-active PIM included female sex (adjusted odds ratio [aOR], 1.46), anxiety (aOR, 2.43), asthma or chronic obstructive pulmonary disease (aOR, 1.39), and serotonin-norepinephrine reuptake inhibitor use (aOR, 1.54). Patients aged ≥75 years (aOR, 1.57), black race (aOR, 1.48) and those with congestive heart failure (aOR, 1.33) were more likely to be prescribed a potential subadequate antidepressant dose. Patients receiving potential subadequate antidepressant doses were discharged home less often (64% vs 73%), had a longer hospital length of stay (9 days vs 7 days), and a higher mortality rate (18% vs 10%) compared to patients receiving adequate home antidepressant doses (P-value for all <0.01). No differences in these outcomes were found among patients receiving home antidepressants with or without CNS-active PIMs.

CONCLUSIONS

Older surgical patients receiving antidepressants are frequently prescribed brain-hazardous medications and potentially subadequate antidepressant doses. Those receiving subadequate antidepressant doses may be at risk for worse postoperative outcomes compared to patients receiving adequate doses. The role of preoperative medication optimization to improve outcomes for older surgical patients should be evaluated.

Comprehensive signal detection of delirium-associated medication using the Food and Drug Administration Adverse Event Reporting System

OBJECTIVE

Several medications are associated with delirium; however, studies with adequate statistical power are limited, and it is difficult to determine the effects of the various concomitant medications used in clinical practice. Therefore, in this study, we aimed to comprehensively evaluate the safety signals of delirium-associated drugs using a spontaneous adverse event reporting system.

METHOD

The JAPIC AERS (Food and Drug Administration Adverse Event Reporting System pre-processed by the Japan Pharmaceutical Information Center) was used for the analysis in this pharmacovigilance study. The reporting odds ratio (ROR) for delirium was adjusted for using multivariate logistic regression analysis with sex, age, indication, and melatonin receptor agonist use, and 22 drug categories were targeted as covariates.

RESULTS

After excluding patients with missing information, 7,527,568 patients were included in the study. Delirium signals were detected even after adjusting for covariates in 17 drug categories, including benzodiazepines (adjusted ROR, 1.76; 95% confidence interval [CI], 1.64-1.89), opioids (adjusted ROR, 4.42; 95% CI, 4.21-4.64), and tricyclic antidepressants (adjusted ROR, 2.44; 95% CI, 2.20-2.71).

CONCLUSIONS

These findings suggest that many drug classes, such as benzodiazepines, are independent risk factors for delirium and strengthen the evidence of an association between delirium and medications.

Development and validation of a new drug-focused predictive risk score for postoperative delirium in orthopaedic and trauma surgery patients

BACKGROUND

Postoperative delirium (POD) is the most common complication following surgery in elderly patients. During pharmacist-led medication reconciliation (PhMR), a predictive risk score considering delirium risk-increasing drugs and other available risk factors could help to identify risk patients.

METHODS

Orthopaedic and trauma surgery patients aged ≥ 18 years with PhMR were included in a retrospective observational single-centre study 03/2022-10/2022. The study cohort was randomly split into a development and a validation cohort (6:4 ratio). POD was assessed through the 4 A's test (4AT), delirium diagnosis, and chart review. Potential risk factors available at PhMR were tested via univariable analysis. Significant variables were added to a multivariable logistic regression model. Based on the regression coefficients, a risk score for POD including delirium risk-increasing drugs (DRD score) was established.

RESULTS

POD occurred in 42/328 (12.8%) and 30/218 (13.8%) patients in the development and validation cohorts, respectively. Of the seven evaluated risk factors, four were ultimately tested in a multivariable logistic regression model. The final DRD score included age (66-75 years, 2 points; > 75 years, 3 points), renal impairment (eGFR < 60 ml/min/1.73m2, 1 point), anticholinergic burden (ACB-score ≥ 3, 1 point), and delirium risk-increasing drugs (n ≥ 2; 2 points). Patients with ≥ 4 points were classified as having a high risk for POD. The areas under the receiver operating characteristic curve of the risk score model were 0.89 and 0.81 for the development and the validation cohorts, respectively.

CONCLUSION

The DRD score is a predictive risk score assessable during PhMR and can identify patients at risk for POD. Specific preventive measures concerning drug therapy safety and non-pharmacological actions should be implemented for identified risk patients.

Types, predictors, and consequences of medicines related problems (MRPs) in frail older adults admitted to hospital from primary care - A retrospective cohort study

Introduction

Medicines related problems (MRPs) can be common in frail older people due to age-compromised body systems and a propensity to be on multiple drugs concurrently. This group of people can also succumb to a rapid deterioration in health. Thus, it is important to investigate MRPs in frail older people. The objectives of the study were to evaluate prevalence of MRPs, types of MRPs, risk factors and deterioration that can be associated with MRPs in frail older people admitted to an English teaching hospital from primary care.

Methods

Included in the sample were frail older adults, aged 65 years and over, admitted from primary care. Data was retrieved from the hospital's electronic patient record system, anonymised, and reviewed for MRPs. MRPs which were retrospectively identified at admission were coded with the WHO-ICD10,2016 (World Health Organisation-International Classification of Diseases version 10, 2016). Descriptive and inferential statistics were performed on the data using SPSS Version 25. Primary outcome was the prevalence of MRPs in frail older patients. Secondary outcome was the association of deterioration indicated as fall, delirium, or NEWs ≥3 with presence of MRPs.

Results

Among the 507 frail older people (≥4 on Rockwood scale) that met criteria for inclusion, 262 (51.8%) were patients with MRPs and 244 (48.2%) without. The Median age of sample as a whole was 85 years (IQR = 80-89). Prevalence of MRPs was 33.28%. Types of MRPs were adverse drug reaction (ADR-20%), non-compliance (9.1%), unintentional poisoning (3.3%) and inappropriate polypharmacy (0.8%). In logistic regression, potentially inappropriate medicines (PIM), social support, number of comorbidities and winter were significant predictors of MRPs. Risk of deteriorating with delirium was two times higher in patients with MRPs than in patients without MRPs, RR 2.613 (95% CI, 1.049 to 6.510).

Conclusion

MRPs and risks of deterioration associated with MRPs in frail older people can be reduced. This is because factors associated with MRPs can be modified.

Evaluation of pharmacists' role in preoperative medication review in a Veterans Affairs Health Care System

PURPOSE

Use of high-risk medications preoperatively may increase the incidence of postoperative complications. Available literature evaluating pharmacists' role in preoperative medication review is limited, and guidance is not currently available on which patients should have a medication review performed by a pharmacist before surgery. A preoperative rehabilitation pilot project in which clinical pharmacists reviewed medication profiles before scheduled surgeries was developed. This review aimed to evaluate pharmacists' role in reviewing medication profiles preoperatively and to identify specific patient factors that suggest a medication review is warranted.

METHODS

This retrospective review utilized the electronic medical records of nonfrail adults undergoing preplanned surgeries enrolled in the pilot project from August 2021 to April 2022. Endpoints were determined using descriptive statistics and regression models. A multivariate analysis was performed evaluating high-risk medications and VIONE (Vital, Important, Optional, Not indicated, and Every medication has an indication) polypharmacy risk score.

RESULTS

Forty patients were included, with at least one recommendation made in 83% of chart reviews. Many patients (95%) were taking at least one high-risk medication. Of the high-risk medication classes evaluated independently, only antiplatelets were predictive of pharmacy intervention (P = 0.01). Only high-risk medications were independently predictive of pharmacist intervention (P < 0.01) when multivariate analysis was performed.

CONCLUSION

Pharmacists made a recommendation in the majority of medication reviews and were most likely to make a recommendation in patients taking high-risk medications. A larger sample size may provide more insight regarding patient-specific factors warranting a preoperative medication review.

Influence of Regional Nerve Block in Addition to General Anesthesia on Postoperative Delirium, Pain, and In-hospital Stay in Patients Undergoing Cardiothoracic Surgery: A Meta-analysis

ABSTRACT

This study aims to investigate whether venous injection of sedative agent or regional nerve block in alliance with major anesthesia could decrease the risk of postoperative delirium occurrence in patients receiving cardiothoracic surgery. Electronic academic databases were retrieved for related publications, and statistical software was used for data pooling and analysis. Forest plot was used to show the pooled sensitivity, specificity, and diagnostic odds ratio. Combined receiver operating characteristic curve was used to show the area under the curve of complex data. Seven studies were included for analysis. The risk of occurrence of delirium still showed no difference (risk rate = 0.93, 95% CI, 0.85-1.03) between the intervention group and placebo group. Postoperative pain feeling was more alleviated in patients with prophylactic application of regional nerve block. In addition, prophylactic application of regional nerve block could decrease the risk of postoperative in-hospital stay (risk rate = 0.28, 95% CI, 0.02-0.54). Our study demonstrated that, in elderly patients or pediatric patients undergoing cardiac surgery, prophylactic application of regional nerve block failed to decrease the incidence of postoperative delirium. However, the option of regional nerve block could decrease the duration of in-hospitalization stay and alleviate the acute pain during the postoperative period after open-heart surgery.

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).

Impact of cardiac rehabilitation on cardiovascular event in Korea

This study aimed to evaluate the effects of cardiac rehabilitation (CR) on major adverse cardiac events (MACE) among patients who underwent PCI procedure. We used data from the electronic medical records (EMR) of a tertiary hospital in Seoul, Korea, from January 2014 to February 2020. Data from 2988 patients who had experienced their first acute coronary syndrome (ACS) and had undergone percutaneous coronary intervention (PCI) were included during the study period. we classified patients into CR participants and non-participants based on their participation in the cardiac rehabilitation (CR) program within 30 days after discharge. And the outcome was the incidence of myocardial infarction (MI) and stroke within 1 year after discharge. The association between participation in CR and risk of developing MACE was evaluated using the Cox proportional hazards model. Patients who achieved CR after undergoing PCI were at a lower risk of developing MI (HR 0.68, CI 0.53-0.86). There was no significant association between participation in CR and the incidence of stroke. Among patients who had more than three stenotic vessels, the risk of developing MI within 1 year of discharge was reduced in CR users compared to non-users (3 or more stenosis vessels: HR 0.55, CI 0.35-0.86). Among patients who used two and more stents during PCI procedures, the risk of developing MI within 1 year of discharge was reduced in CR users compared to non-users (2 and more stents: HR 0.54, CI 0.35-0.85). Among people diagnosed with ACS and receiving PCI, patients who participated in CR within one month of discharge reduced risk of developing MI. Our study reinforced the current evidence on the effect of CR among patients receiving PCI and presented the expansion and enhancement of the CR program.

Early incident and subsyndromal delirium in older patients undergoing elective surgical procedures: a randomized clinical trial of an avoid delirium protocol

Background

Pharmacological avoidance guidelines for preventing delirium have been suggested; however, there are limited pragmatic studies of these strategies. Early (<24 h) delirium can be observed in the postoperative care unit and is associated with an increased risk of subsequent delirium. We examined the effectiveness of an avoid delirium protocol (ADP) in older (>65 years) patients undergoing elective surgeries.

Methods

The randomized controlled trial assessed an ADP developed using the American Geriatric Society's Clinical Practice Guidelines for Postoperative Delirium in Older Adults, on early (<24 h) incident or subsyndromal delirium. Delirium was assessed using the confusion assessment method before surgery, in the post-anesthesia care unit, and on postoperative day 1. The primary outcome of early delirium was the combined incidence of incident or subsyndromal delirium.

Results

Early delirium was identified in 24/235 patients (10.2%) with a risk ratio of 1.27 (95% CI 0.59-2.73, P = 0.667) for patients randomized to the ADP. In cases with protocol adherence and no benzodiazepine use, early delirium was present in 10/ 73 (13.7%) compared to 14/148 (9.5%) in non-adherent cases [risk ratio 1.45 (95% CI 0.57-3.10, P = 0.362)]. Lower American Society of Anesthesiologists physical class [odds ratio 3.31 (95% CI 1.35-8.92, P = 0.008)] and an inpatient admission [odds ratio 2.67 (95% CI 1.55-4.87, P = 0.0002)] were associated with early delirium.

Conclusions

Our findings suggest that pharmacological avoidance protocols limiting or avoiding the use of specific classes of medications are not effective in reducing early incident or subsyndromal delirium in older patients undergoing elective surgery.

Comparative Study About Different Doses of Remimazolam in Short Laparoscopic Surgery: A Randomized Controlled Double-Blind Trial

Objective

To study the efficacy and safety of different doses of remimazolam used for induction and maintenance in short laparoscopic surgery.

Methods

A randomized controlled trial was conducted between May 2021 and May 2022 on patients underwent laparoscopic surgery for 30 minutes to an hour. Based on the drug used and the infusion rate, included patients were allocated into the Low-group of remimazolam (using a constant infusion rate of 6.0 mg/kg/h for induction and the rate of 1 mg/kg/h for maintenance), the Median-group (9.0 mg/kg/h for induction, 2 mg/kg/h for maintenance), the High-group (12.0 mg/kg/h for induction, 3.0 mg/kg/h for maintenance), and the Propofol group. The postoperative extubation time was used as the primary outcome.

Results

A total of 192 patients were included in the study, with 47, 48, 48, and 49 patients in the Low-, Median-, High-, and Propofol group, respectively. There was a significant difference in postoperative extubation time, with the High-group having the highest duration of 15.21±2.34 minutes compared to the Median-group (13.17±1.71 minutes, p<0.001), Low- group (12.72±1.31 minutes, p<0.001), and the Propofol group (12.24±1.23 minutes, p<0.001). No significant difference was found between the Low-group and the Propofol group, while the Median-group still showed higher postoperative extubation time compared to the Propofol group (p=0.008).

Conclusion

Compared to propofol, total intravenous induction and maintenance with high and median dosages of remimazolam may prolong postoperative extubation time. Remimazolam can be safely used for induction and maintenance at various doses while not increasing the likelihood of adverse events.

Benzodiazepines and postoperative delirium: should we be as cautious as we are?

A recent systematic review and meta-analysis by Wang and colleagues in the British Journal of Anaesthesia calls into question the concept that perioperative benzodiazepine administration is associated with development of postoperative delirium in older individuals after anaesthesia and surgery. This editorial focuses on potential bias within the systematic review and addresses major concerns surrounding benzodiazepine use in the older perioperative population.

Risk factors for hyperactive delirium after laparoscopic radical gastrectomy under general anesthesia in patients with gastric cancer

OBJECTIVE

This study aimed to analyze the risk factors for the occurrence of postoperative hyperactive delirium after laparoscopic radical gastrectomy under general anesthesia in patients with gastric cancer.

METHODS

The clinical data of 280 gastric cancer patients who underwent laparoscopic radical gastrectomy under general anesthesia in First Affiliated Hospital of Gannan Medical University from January 2020 to June 2023 were retrospectively analyzed, and the types and incidence of postoperative delirium were recorded. The factors influencing the occurrence of postoperative hyperactive delirium were analyzed.

RESULTS

Multi-factor logistic regression analysis showed that older age, high dosage of anesthetic drug consumption, high American Society of Anesthesiologists (ASA) classification (or ASA grade 3-4), long Post-anesthesia Care Unit (PACU) stay, and long extubation time were independent risk factors for the occurrence of hyperactive delirium after laparoscopic radical gastrectomy (OR > 1, P < 0.05). The area under the curve of the nomogram was used to predict the occurrence of hyperactive delirium after laparoscopic radical gastrectomy under general anesthesia was 0.903 (95% CI: 0.846-0.978).

CONCLUSION

Older age, high dosage of anesthetic drug consumption, high ASA classification (or ASA grade 3-4), long PACU stay, and long extubation time were independent risk factors affecting the occurrence of hyperactive delirium after laparoscopic radical gastrectomy under general anesthesia.

Prevalence of preoperative cognitive impairment among elderly thoracic surgery patients and association with postoperative delirium: a prospective observational study

Background

Preoperative cognitive impairment (PCI) may increase the incidence of postoperative delirium (POD), yet screening for cognitive impairment is rarely performed. This study hypothesized that Mini-Cog for preoperative cognitive impairment screening predicts postoperative delirium.

Methods

The prospective observational study recruited 153 elderly patients presenting for elective thoracic surgery. Cognitive function of these patients was screened using Mini-Cog preoperatively. We considered that patients with Mini-Cog scores ≤ 3 had cognitive impairment. Delirium was assessed using the Short CAM scale on postoperative days 1-5.

Results

Of the 153 participants, 54 (35.3%) were assigned to the PCI group, and 99 (64.7%) were assigned to the Normal group. Place of residence, education level, and history of hypertension were significantly different between the two groups (P < 0.05). 51 (33.3%) patients developed POD. Multifactorial analysis revealed that PCI (OR = 2.37, P = 0.028), older age (OR = 1.13, P = 0.009), ASA grade III (OR = 2.75, P = 0.012), and longer duration of anesthesia (OR = 1.01, P = 0.007) were associated with POD.

Conclusion

Preoperative cognitive impairment is strongly associated with POD. Mini-Cog could be recommended for screening PCI.

Clinical trial registration

ClinicalTrials.gov, identifier NCT05798767.

The Association of Infection with Delirium in the Post-Operative Period after Elective CABG Surgery

Delirium is one of the most common complications of coronary artery by-pass graft (CABG) surgery. The identification of patients at increased risk of delirium and the implementation of preventive measures to reduce the risk of postoperative delirium is necessary to improve treatment outcomes after CABG. The aim of this study was to assess the association between postoperative delirium and postoperative infection and 10-year mortality in patients undergoing CABG surgery. This is a retrospective, observational cohort study of patients undergoing planned on-pump CABG between April 2010 and December 2012. We analysed a group of 3098 patients operated on in our cardiac surgery centre, from whom we selected a cohort of patients undergoing planned CABG surgery. All patients were assessed for postoperative infection, such as pneumonia, bloodstream infections (BSIs) and surgical site infections (SSIs). Patients who experienced postoperative delirium were significantly more likely to have infection (7.4% vs. 22%; p = 0.0037). As regards particular types of infection, significant differences were only found for pneumonia and sternal SSIs. Patients who experienced postoperative delirium had significantly lower 5-year (p = 0.0136) and 10-year (p = 0.0134) survival. Postoperative delirium significantly increases long-term mortality in patients undergoing CABG surgery. Pneumonia and sternal SSIs significantly increase the risk of postoperative delirium in cardiac surgery patients.

Data-driven categorization of postoperative delirium symptoms using unsupervised machine learning

Background

Phenotyping analysis that includes time course is useful for understanding the mechanisms and clinical management of postoperative delirium. However, postoperative delirium has not been fully phenotyped. Hypothesis-free categorization of heterogeneous symptoms may be useful for understanding the mechanisms underlying delirium, although evidence is currently lacking. Therefore, we aimed to explore the phenotypes of postoperative delirium following invasive cancer surgery using a data-driven approach with minimal prior knowledge.

Methods

We recruited patients who underwent elective invasive cancer resection. After surgery, participants completed 5 consecutive days of delirium assessments using the Delirium Rating Scale-Revised-98 (DRS-R-98) severity scale. We categorized 65 (13 questionnaire items/day × 5 days) dimensional DRS-R-98 scores using unsupervised machine learning (K-means clustering) to derive a small set of grouped features representing distinct symptoms across all participants. We then reapplied K-means clustering to this set of grouped features to delineate multiple clusters of delirium symptoms.

Results

Participants were 286 patients, of whom 91 developed delirium defined according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria. Following the first K-means clustering, we derived four grouped symptom features: (1) mixed motor, (2) cognitive and higher-order thinking domain with perceptual disturbance and thought content abnormalities, (3) acute and temporal response, and (4) sleep-wake cycle disturbance. Subsequent K-means clustering permitted classification of participants into seven subgroups: (i) cognitive and higher-order thinking domain dominant delirium, (ii) prolonged delirium, (iii) acute and brief delirium, (iv) subsyndromal delirium-enriched, (v) subsyndromal delirium-enriched with insomnia, (vi) insomnia, and (vii) fit.

Conclusion

We found that patients who have undergone invasive cancer resection can be delineated using unsupervised machine learning into three delirium clusters, two subsyndromal delirium clusters, and an insomnia cluster. Validation of clusters and research into the pathophysiology underlying each cluster will help to elucidate the mechanisms of postoperative delirium after invasive cancer surgery.

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

BACKGROUND

Postoperative delirium (POD) is a common postoperative complication associated with multiple adverse consequences on patient outcomes and higher medical expenses. Preoperative anxiety has been suggested as a possible precipitating factor for the development of POD. As such, we aimed to explore the association between preoperative anxiety and POD in older surgical patients.

METHODS

Electronic databases including MEDLINE (via PubMed), EMBASE (via Embase.com), Web of Science Core Collection, Cumulative Index to Nursing and Allied Health Literature (CINAHL Complete; via EBSCOhost) and clinical trial registries were systematically searched to identify prospective studies examining preoperative anxiety as a risk factor for POD in older surgical patients. We used Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies to assess the quality of included studies. The association between preoperative anxiety and POD was summarized with odds ratios (ORs) and 95% confidence intervals (CIs) using DerSimonian-Laird random-effects meta-analysis.

RESULTS

Eleven studies were included (1691 participants; mean age ranging between 63.1-82.3 years). Five studies used a theoretical definition for preoperative anxiety, with the Anxiety subscale of Hospital Anxiety and Depression Scale (HADS-A) as the instrument being most often used. When using dichotomized measures and within the HADS-A subgroup analysis, preoperative anxiety was significantly associated with POD (OR = 2.17, 95%CI: 1.01-4.68, I² = 54%, Tau² = 0.4, n = 5; OR = 3.23, 95%CI: 1.70-6.13, I² = 0, Tau² = 0, n = 4; respectively). No association was observed when using continuous measurements (OR = 0.99, 95%CI: 0.93-1.05, I² = 0, Tau² = 0, n = 4), nor in the subgroup analysis of STAI-6 (six-item version of state scale of Spielberger State-Trait Anxiety Inventory, OR = 1.07, 95%CI: 0.93-1.24, I² = 0, Tau² = 0, n = 2). We found the overall quality of included studies to be moderate to good.

CONCLUSIONS

An unclear association between preoperative anxiety and POD in older surgical patients was found in our study. Given the ambiguity in conceptualization and measurement instruments used for preoperative anxiety, more research is warranted in which a greater emphasis should be placed on how preoperative anxiety is operationalized and measured.

Association between remimazolam and postoperative delirium in older adults undergoing elective cardiovascular surgery: a prospective cohort study

PURPOSE

Postoperative delirium is one of the most common complications after cardiovascular surgery in older adults. Benzodiazepines are a reported risk factor for delirium; however, there are no studies investigating remimazolam, a novel anesthetic agent. Therefore, we prospectively investigated the effect of remimazolam on postoperative delirium.

METHODS

We included elective cardiovascular surgery patients aged ≥ 65 years at Hamamatsu University Hospital between August 2020 and February 2022. Patients who received general anesthesia with remimazolam were compared with those who received other anesthetics (control group). The primary outcome was delirium within 5 days after surgery. Secondary outcomes were delirium during intensive care unit stay and hospitalization, total duration of delirium, subsyndromal delirium, and differences in the Mini-Mental State Examination scores from preoperative to postoperative days 2 and 5. To adjust for differences in the groups' baseline covariates, we used stabilized inverse probability weighting as the primary analysis and propensity score matching as the sensitivity analysis.

RESULTS

We enrolled 200 patients; 78 in the remimazolam group and 122 in the control group. After stabilized inverse probability weighting, 30.3% of the remimazolam group patients and 26.6% of the control group patients developed delirium within 5 days (risk difference, 3.8%; 95% confidence interval -11.5% to 19.1%; p = 0.63). The secondary outcomes did not differ significantly between the groups, and the sensitivity analysis results were similar to those for the primary analysis.

CONCLUSION

Remimazolam was not significantly associated with postoperative delirium when compared with other anesthetic agents.

The value of the ACEF II score in Chinese patients with elective and non-elective cardiac surgery

OBJECTIVE

To evaluate the value of the ACEF II score in predicting postoperative hospital death and acute kidney injury requiring dialysis (AKI-D) in Chinese patients.

METHODS

This retrospective study included adult patients who underwent cardiopulmonary bypass open heart surgery between January 2010 and December 2015 at Guangdong Provincial People's Hospital. ACEF II was evaluated to predict in-hospital death and AKI-D using the Hosmer-Lemeshow goodness of fit test for calibration and area under the receiver operating characteristic (ROC) curve for discrimination in non-elective and elective cardiac surgery.

RESULTS

A total of 9748 patients were included. Among them, 1080 underwent non-elective surgery, and 8615 underwent elective surgery. Mortality was 1.8% (177/9748). In elective surgery, the area under the ROC (AUC) of the ACEF II score was 0.704 (95% CI: 0.648-0.759), similar to the ACEF score of 0.709 (95% CI: 0.654-0.763). In non-elective surgery, the AUC of the ACEF II score was 0.725 (95% CI: 0.663-0.787), higher than the ACEF score (AUC = 0.625, 95% CI: 0.553-0.697). The incidence of AKI-D was 3.5% (345/9748). The AUC of the ACEF II score was 0.718 (95% CI: 0.687-0.749), higher than the ACEF score (AUC = 0.626, 95% CI: 0.594-0.658).

CONCLUSION

ACEF and ACEF II have poor discrimination ability in predicting AKI-D in non-elective surgery. The ACEF II and ACEF scores have the same ability to predict in-hospital death in elective cardiac surgery, and the ACEF II score is better in non-elective surgery. The ACEF II score can be used to assess the risk of AKI-D in elective surgery in Chinese adults.

Correlation Analysis of Inflammatory Markers CRP and IL-6 and Postoperative Delirium (POD) in Elderly Patients: A Meta-Analysis of Observational Studies

Background

Postoperative delirium (POD) is very common in the elderly surgical population, and its occurrence is associated with multiple factors such as preoperative, intraoperative, and postoperative factors, and the increase of serum inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) is considered to be associated with the occurrence of POD, but the results of multiple studies are inconsistent. In this study, we investigated the correlation between inflammatory markers CRP and IL-6 and POD in elderly patients by literature search and meta-analysis.

Methods

We searched PubMed, Web of Science, the Cochrane library, Embase, Ovid, and Springer Link for cohort studies or case-control studies that investigated the factors involved in the occurrence of POD, used the Newcastle-Ottawa Scale (NOS) to assess the quality of the selected literature, and combined the differences in serum CRP and IL-6 levels between POD and non-POD patients after surgery to evaluate the predictive value of CRP and IL-6 for the occurrence of POD.

Results

This research comprised 16 papers for quantitative analysis, with a total of 2967 patients, 758 with POD and 2209 with non-POD. There were 16 cohort studies (100%) and 0 case-control studies (0%) across all the collected literatures; there were 15 prospective cohort studies and 1 retrospective cohort research. A meta-analysis revealed a statistically significant difference in serum IL-6 levels between POD patients after surgery and non-POD patients [MD = 115.68, 95% CI (25.70, 206.66), Z = 2.52, P = 0.012], as well as a statistically significant difference in serum CRP levels [MD = 27.67, 95% CI (12.77, 42.58), Z = 3.64, P = 0.0003]. Discussion. Early after surgery, serum IL-6 and CRP levels were considerably higher in POD patients than in non-POD patients, indicating that early serum inflammatory variables are likely to be predictors of POD. After surgery, the levels of the aforementioned inflammatory factors should be actively monitored to forecast the emergence of delirium, and active treatment should be used to limit the creation and release of the aforementioned inflammatory factors.

Benzodiazepines and Related Drugs in Orthopaedics

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Benzodiazepines are among the most commonly prescribed drugs worldwide and are often used as anxiolytics, hypnotics, anticonvulsants, and muscle relaxants.

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The risk of dependence on and abuse of these medications has recently gained more attention in light of the current opioid epidemic.

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Benzodiazepines can increase the risk of prolonged opioid use and abuse.

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Given the prevalence of the use of benzodiazepines and related drugs, orthopaedic patients are often prescribed these medications.

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Orthopaedic surgeons need to be aware of the prevalence of benzodiazepine and related drug prescriptions in the general population, their current uses in orthopaedic surgery, and the risks and adverse effects of their use.

Preoperative Inflammatory Markers and the Risk of Postoperative Delirium in Patients Undergoing Lumbar Spinal Fusion Surgery

We investigated the possible associations between postoperative delirium (POD) and routinely available preoperative inflammatory markers in patients undergoing lumbar spinal fusion surgery (LSFS) to explore the role of neuroinflammation and oxidative stress as risk factors for POD. We analyzed 11 years’ worth of data from the Smart Clinical Data Warehouse. We evaluated whether preoperative inflammatory markers, such as the neutrophil-to-lymphocyte ratio (NLR), the monocyte-to-lymphocyte ratio (MLR), and the CRP-to-albumin ratio (CAR), affected the development of POD in patients undergoing LSFS. Of the 3081 subjects included, 187 (7.4%) developed POD. A significant increase in NLR, MLR, and CAR levels was observed in POD patients (p < 0.001). A multivariate analysis showed that the second, third, and highest quartiles of the NLR were significantly associated with the development of POD (adjusted OR (95% CI): 2.28 (1.25−4.16], 2.48 (1.3−4.73], and 2.88 (1.39−5.96], respectively). A receiver operating characteristic curve analysis showed that the discriminative ability of the NLR, MLR, and CAR for predicting POD was low, but almost acceptable (AUC (95% CI): 0.60 (0.56−0.64], 0.61 (0.57−0.65], and 0.63 (0.59−0.67], respectively, p < 0.001). Increases in preoperative inflammatory markers, particularly the NLR, were associated with the development of POD, suggesting that a proinflammatory state is a potential pathophysiological mechanism of POD.

Association Between Perioperative Medication Use and Postoperative Delirium and Cognition in Older Adults Undergoing Elective Noncardiac Surgery

BACKGROUND

Postoperative delirium is frequent in older adults and is associated with postoperative neurocognitive disorder (PND). Studies evaluating perioperative medication use and delirium have generally evaluated medications in aggregate and been poorly controlled; the association between perioperative medication use and PND remains unclear. We sought to evaluate the association between medication use and postoperative delirium and PND in older adults undergoing major elective surgery.

METHODS

This is a secondary analysis of a prospective cohort study of adults ≥70 years without dementia undergoing major elective surgery. Patients were interviewed preoperatively to determine home medication use. Postoperatively, daily hospital use of 7 different medication classes listed in guidelines as risk factors for delirium was collected; administration before delirium was verified. While hospitalized, patients were assessed daily for delirium using the Confusion Assessment Method and a validated chart review method. Cognition was evaluated preoperatively and 1 month after surgery using a neurocognitive battery. The association between prehospital medication use and postoperative delirium was assessed using a generalized linear model with a log link function, controlling for age, sex, type of surgery, Charlson comorbidity index, and baseline cognition. The association between daily postoperative medication use (when class exposure ≥5%) and time to delirium was assessed using time-varying Cox models adjusted for age, sex, surgery type, Charlson comorbidity index, Acute Physiology and Chronic Health Evaluation (APACHE)-II score, and baseline cognition. Mediation analysis was utilized to evaluate the association between medication use, delirium, and cognitive change from baseline to 1 month.

RESULTS

Among 560 patients enrolled, 134 (24%) developed delirium during hospitalization. The multivariable analyses revealed no significant association between prehospital benzodiazepine (relative risk [RR], 1.44; 95% confidence interval [CI], 0.85-2.44), beta-blocker (RR, 1.38; 95% CI, 0.94-2.05), NSAID (RR, 1.12; 95% CI, 0.77-1.62), opioid (RR, 1.22; 95% CI, 0.82-1.82), or statin (RR, 1.34; 95% CI, 0.92-1.95) exposure and delirium. Postoperative hospital benzodiazepine use (adjusted hazard ratio [aHR], 3.23; 95% CI, 2.10-4.99) was associated with greater delirium. Neither postoperative hospital antipsychotic (aHR, 1.48; 95% CI, 0.74-2.94) nor opioid (aHR, 0.82; 95% CI, 0.62-1.11) use before delirium was associated with delirium. Antipsychotic use (either presurgery or postsurgery) was associated with a 0.34 point (standard error, 0.16) decrease in general cognitive performance at 1 month through its effect on delirium (P = .03), despite no total effect being observed.

CONCLUSIONS

Administration of benzodiazepines to older adults hospitalized after major surgery is associated with increased postoperative delirium. Association between inhospital, postoperative medication use and cognition at 1 month, independent of delirium, was not detected.

Guidelines for Perioperative Care in Elective Abdominal and Pelvic Surgery at Primary and Secondary Hospitals in Low-Middle-Income Countries (LMIC's): Enhanced Recovery After Surgery (ERAS) Society Recommendation

Background

This is the first Enhanced Recovery After Surgery (ERAS®) Society guideline for primary and secondary hospitals in low–middle-income countries (LMIC’s) for elective abdominal and gynecologic care.

Methods

The ERAS LMIC Guidelines group was established by the ERAS® Society in collaboration with different representatives of perioperative care from LMIC’s. The group consisted of seven members from the ERAS® Society and eight members from LMIC’s. An updated systematic literature search and evaluation of evidence from previous ERAS® guidelines was performed by the leading authors of the Colorectal (2018) and Gynecologic (2019) surgery guidelines (Gustafsson et al in World J Surg 43:6592–695, Nelson et al in Int J Gynecol Cancer 29(4):651–668). Meta-analyses randomized controlled trials (RCTs), prospective and retrospective cohort studies from both HIC’s and LMIC’s were considered for each perioperative item. The members in the LMIC group then applied the current evidence and adapted the recommendations for each intervention as well as identifying possible new items relevant to LMIC’s. The Grading of Recommendations, Assessment, Development and Evaluation system (GRADE) methodology was used to determine the quality of the published evidence. The strength of the recommendations was based on importance of the problem, quality of evidence, balance between desirable and undesirable effects, acceptability to key stakeholders, cost of implementation and specifically the feasibility of implementing in LMIC’s and determined through discussions and consensus.

Results

In addition to previously described ERAS® Society interventions, the following items were included, revised or discussed: the Surgical Safety Checklist (SSC), preoperative routine human immunodeficiency virus (HIV) testing in countries with a high prevalence of HIV/AIDS (CD4 and viral load for those patients that are HIV positive), delirium screening and prevention, COVID 19 screening, VTE prophylaxis, immuno-nutrition, prehabilitation, minimally invasive surgery (MIS) and a standardized postoperative monitoring guideline.

Conclusions

These guidelines are seen as a starting point to address the urgent need to improve perioperative care and to effect data-driven, evidence-based care in LMIC’s.

Delirium risk factors in hospitalized patient: a comprehensive evaluation of underlying diseases and medications in different wards of a large Urban Hospital Center in Iran

BACKGROUND

Delirium is a neurobehavioral syndrome, which is characterized by a fluctuation of mental status, disorientation, confusion and inappropriate behavior, and it is prevalent among hospitalized patients. Recognizing modifiable risk factors of delirium is the key point for improving our preventive strategies and restraining its devastating consequences. This study aimed to identify and investigate various factors predisposing hospitalized patients to develop delirium, focusing mostly on underlying diseases and medications.

METHOD

In a prospective, observational trial, we investigated 220 patients who had been admitted to the internal, emergency, surgery and hematology-oncology departments. We employed the Confusion Assessment Method (CAM) questionnaire, The Richmond Agitation Sedation Scale (RASS), the General Practitioner Assessment of Cognition (GPCOG), demographic questionnaire, patient interviews and medical records. Multivariate logistic regression models were used to analyze the predictive value of medications and underlying diseases for daily transition to delirium.; demographics were analyzed using univariate analysis to identify those independently associated with delirium.

RESULTS

Two hundred twenty patients were enrolled; the emergency department had the most incident delirium (31.3%), and the surgery section had the least (2.4%); delirium was significantly correlated with older ages and sleep disturbance. Among multiple underlying diseases and the medications evaluated in this study, we found that a history of dementia, neurological diseases and malignancies increases the odds of transition to delirium and the use of anticoagulants decreases the incident delirium.

CONCLUSION

Approximately 1 out of 10 overall patients developed delirium; It is important to evaluate underlying diseases and medications more thoroughly in hospitalized patients to assess the risk of delirium.

Anticholinergic Drug Exposure Increases the Risk of Delirium in Older Patients Undergoing Elective Surgery

Introduction

Postoperative delirium (POD) is a common and serious adverse event of surgery in older people. Because of its great impact on patients' safety and quality of life, identification of modifiable risk factors could be useful. Although preoperative medication intake is assumed to be an important modifiable risk factor, the impact of anticholinergic drugs on the occurrence of POD seems underestimated in elective surgery. The aim of this study was to investigate the association between preoperative anticholinergic burden and POD. We hypothesized that a high preoperative anticholinergic burden is an independent, potentially modifiable predisposing and precipitating factor of POD in older people.

Methods

Between November 2017 and April 2019, 1,470 patients of 70 years and older undergoing elective orthopedic, general, cardiac, or vascular surgery were recruited in the randomized, prospective, multicenter PAWEL trial. Anticholinergic burden of a sub-cohort of 899 patients, who did not receive a multimodal intervention for preventing POD, was assessed by two different tools at hospital admission: The established Anticholinergic Risk Scale (ARS) and the recently developed Anticholinergic Burden Score (ABS). POD was detected by confusion assessment method (CAM) and a validated post discharge medical record review. Logistic regression analyses were performed to evaluate the association between anticholinergic burden and POD.

Results

POD was observed in 210 of 899 patients (23.4%). Both ARS and ABS were independently associated with POD. The association persisted after adjustment for relevant confounding factors such as age, sex, comorbidities, preoperative cognitive and physical status, number of prescribed drugs, surgery time, type of surgery and anesthesia, usage of heart-lung-machine, and treatment in intensive care unit. If a patient was taking one of the 56 drugs listed in the ABS, risk for POD was 2.7-fold higher (OR = 2.74, 95% CI = 1.55–4.94) and 1.5-fold higher per additional point on the ARS (OR = 1.54, 95% CI = 1.15–2.02).

Conclusion

Preoperative anticholinergic drug exposure measured by ARS or ABS was independently associated with POD in older patients undergoing elective surgery. Therefore, identification, discontinuation or substitution of anticholinergic medication prior to surgery may be a promising approach to reduce the risk of POD in older patients.

White-Cell Derived Inflammatory Biomarkers in Prediction of Postoperative Delirium in Elderly Patients Undergoing Surgery for Lower Limb Fracture Under Non-General Anaesthesia

Purpose

The aim of this study was to investigate whether white-cell derived biomarkers could serve as potential markers in prediction of postoperative delirium (POD) after lower limb fracture.

Patients and Methods

Elderly patients with surgery for lower limb fracture under non-general anaesthesia were included. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and platelet-to-white cell ratio (PWR), which were most recently measured preceding surgery and measured within 24h after surgery, were calculated. Delirium was measured with Confusion Assessment Method (CAM) once daily from preoperative day 1 to postoperative day 3 or hospital discharge.

Results

The incidence of POD was 32.6% (60/184). Between patients with and those without POD, there were significant differences in preoperative hematological biomarkers (neutrophil count, lymphocyte count, NLR and PWR) and postoperative hematological biomarkers (white cell count, neutrophil count, lymphocyte count, NLR, PLR and PWR). More obvious changes before and after operation for NLR, PLR and C-reactive protein (CRP) were found in patients with POD. Multivariate logistic regression showed that benzodiazepines (OR, 7.912; 95% CI, 1.884–33.230; p = 0.005), change of CRP (OR, 1.017; 95% CI, 1.007–1.027; p = 0.001) and postoperative NLR (OR, 1.358; 95% CI, 1.012–1.823; p = 0.041) were associated with POD. When the changes of NLR, PLR and PWR entered multivariate logistic regression, older age (OR, 1.073; 95% CI, 1.001–1.149; p = 0.046), benzodiazepines (OR, 6.811; 95% CI, 1.652–28.081; p = 0.008), greater change of CRP (OR, 1.015; 95% CI, 1.006–1.023; p = 0.001) and greater change of NLR (OR, 1.266; 95% CI, 1.035–1.549; p = 0.022) were associated with increased risk of POD. Postoperative NLR had high accuracy to predict POD with area under curve (AUC) of 0.790 (95% CI 0.708 to 0.872).

Conclusion

Age, benzodiazepines, postoperative NLR, change of NLR and change of CRP were independent predictable markers for POD in elderly patients undergoing surgery for lower limb fracture under non-general anaesthesia. Early postoperative NLR may help to recognize POD as soon as possible.

Yokukansan suppresses neuroinflammation in the hippocampus of mice and decreases the duration of lipopolysaccharide- and diazepam-mediated loss of righting reflex induced by pentobarbital

Neuroinflammation is associated with the development of hypoactive delirium, which results in poor clinical outcomes. Drugs effective against hypoactive sur have not yet been established. Yokukansan has an anti-neuroinflammatory effect, making it potentially effective against hypoactive delirium. This study aimed to examine the effect of Yokukansan on the pentobarbital-induced loss of righting reflex duration extended with lipopolysaccharide (LPS)-induced neuroinflammation and diazepam-induced gamma-aminobutyric acid receptor stimulation in a mouse model. The active ingredients in Yokukansan and its anti-neuroinflammatory effect on the hippocampus were also investigated. Furthermore, we examined the in vitro anti-inflammatory effects of Yokukansan on LPS-stimulated BV2 cells, a murine microglial cell line. Findings revealed that treatment with Yokukansan significantly decreased the duration of pentobarbital-induced loss of righting reflex by attenuating the LPS-induced increase in interleukin-6 and tumor necrosis factor-alpha levels in the hippocampus. Moreover, treatment with Yokukansan significantly decreased the number of ionized calcium-binding adapter molecule-1-positive cells in the hippocampal dentate gyrus after 24 h of LPS administration. In addition, glycyrrhizic acid, an active ingredient in Yokukansan, partially decreased the duration of pentobarbital-induced loss of righting reflex. Treatment with Yokukansan also suppressed the expression of inducible nitric oxide, interleukin-6, and tumor necrosis factor mRNA in LPS-stimulated BV2 cells. Thus, these findings suggest that Yokukansan and glycyrrhizic acid may be effective therapeutic agents for treating neuroinflammation-induced hypoactive delirium.

The Relationship between Perioperative Blood Transfusion and Postoperative Delirium in Patients Undergoing Spinal Fusion Surgery: Clinical Data Warehouse Analysis

Background and Objectives: For preventing postoperative delirium (POD), identifying the risk factors is important. However, the relationship between blood transfusion and POD is still controversial. The aim of this study was to identify the risk factors of POD, to evaluate the impact of blood transfusion in developing POD among people undergoing spinal fusion surgery, and to show the effectiveness of big data analytics using a clinical data warehouse (CDW). Materials and Methods: The medical data of patients who underwent spinal fusion surgery were obtained from the CDW of the five hospitals of Hallym University Medical Center. Clinical features, laboratory findings, perioperative variables, and medication history were compared between patients without POD and with POD. Results: 234 of 3967 patients (5.9%) developed POD. In multivariate logistic regression analysis, the risk factors of POD were as follows: Parkinson’s disease (OR 5.54, 95% CI 2.15–14.27; p < 0.001), intensive care unit (OR 3.45 95% CI 2.42–4.91; p < 0.001), anti-psychotics drug (OR 3.35 95% CI 1.91–5.89; p < 0.001), old age (≥70 years) (OR 3.08, 95% CI 2.14–4.43; p < 0.001), depression (OR 2.8 95% CI 1.27–6.2; p < 0.001). The intraoperative transfusion (OR 1.1, 95% CI 0.91–1.34; p = 0.582), and the postoperative transfusion (OR 0.91, 95% CI 0.74–1.12; p = 0.379) had no statistically significant effect on the incidence of POD. Conclusions: There was no relationship between perioperative blood transfusion and the incidence of POD in spinal fusion surgery. Big data analytics using a CDW could be helpful for the comprehensive understanding of the risk factors of POD, and for preventing POD in spinal fusion surgery.

Multicentre analysis of practice patterns regarding benzodiazepine use in cardiac surgery

BACKGROUND

There is controversy regarding optimal use of benzodiazepines during cardiac surgery, and it is unknown whether and to what extent there is variation in practice. We sought to describe benzodiazepine use and sources of variation during cardiac surgeries across patients, clinicians, and institutions.

METHODS

We conducted an analysis of adult cardiac surgeries across a multicentre consortium of USA academic and private hospitals from 2014 to 2019. The primary outcome was administration of a benzodiazepine from 2 h before anaesthesia start until anaesthesia end. Institutional-, clinician-, and patient-level variables were analysed via multilevel mixed-effects models.

RESULTS

Of 65 508 patients cared for by 825 anaesthesiology attending clinicians (consultants) at 33 institutions, 58 004 patients (88.5%) received benzodiazepines with a median midazolam-equivalent dose of 4.0 mg (inter-quartile range [IQR], 2.0-6.0 mg). Variation in benzodiazepine dosage administration was 54.7% attributable to institution, 14.7% to primary attending anaesthesiology clinician, and 30.5% to patient factors. The adjusted median odds ratio for two similar patients receiving a benzodiazepine was 2.68 between two randomly selected clinicians and 4.19 between two randomly selected institutions. Factors strongly associated (adjusted odds ratio, <0.75, or >1.25) with significantly decreased likelihoods of benzodiazepine administration included older age (>80 vs ≤50 yr; adjusted odds ratio=0.04; 95% CI, 0.04-0.05), university affiliation (0.08, 0.02-0.35), recent year of surgery (0.42, 0.37-0.49), and low clinician case volume (0.44, 0.25-0.75). Factors strongly associated with significantly increased likelihoods of benzodiazepine administration included cardiopulmonary bypass (2.26, 1.99-2.55), and drug use history (1.29, 1.02-1.65).

CONCLUSIONS

Two-thirds of the variation in benzodiazepine administration during cardiac surgery are associated with institutions and attending anaesthesiology clinicians (consultants). These data, showing wide variations in administration, suggest that rigorous research is needed to guide evidence-based and patient-centred benzodiazepine administration.

Immune, Blood Cell, and Blood Gas Biomarkers of Delirium in Elderly Individuals with Hip Fracture Surgery

BACKGROUND

Postoperative delirium in elderly people with hip fracture is associated with various adverse clinical outcomes. Nevertheless, the pathophysiological processes underpinning delirium have remained elusive.

OBJECTIVES

The aim of this study was to explore the associations between delirium and its features and immune-inflammatory and blood gas biomarkers.

METHODS

In this prospective study, we examined 65 patients who underwent a hip fracture surgery and assessed the Confusion Assessment Method for the Intensive Care Unit, Richmond Agitation-Sedation Scale (RASS), and Delirium Rating Scale Revised-98 (DRS-R-98) before and during 4 days after the surgery. Complete blood count and venous blood gas markers were obtained at the same time points.

RESULTS

Delirium was observed in 19 patients and was accompanied by significantly increased pO2, number of white blood cells, neutrophil percentage, and neutrophil/lymphocyte ratio, and lower mean platelet volume (MPV) after adjusting for age, central nervous system (CNS) disease, blood loss during surgery, sleep disorders, and body mass index. The severity of delirium was associated with lowered number of platelets and MPV. Psychomotor disorders were associated with lower bicarbonate levels. The requirement of physical restraint of the patients was predicted by increased percentages of neutrophils and lymphocytes. Prior CNS disease was together with these biomarkers a significant predictor of delirium and severity of delirium.

CONCLUSION

Delirium and psychomotor disorders following hip fracture and surgery may be caused by immune-inflammatory and oxidative stress pathways probably attributable to an aseptic inflammatory process.

Delirium and other neuropsychiatric manifestations of COVID-19 infection in people with preexisting psychiatric disorders: a systematic review

BACKGROUND

Psychiatric disorders increase risk of neuropsychiatric disease and poor outcomes, yet little is known about the neuropsychiatric manifestations of COVID-19 in the psychiatric population. The primary objective is to synthesize neuropsychiatric outcomes of COVID-19 in people with preexisting psychiatric disorders.

METHODS

Data were collected during an ongoing review of the impact of pandemics on people with existing psychiatric disorders. All study designs and gray literature were included. Medline, PsychInfo, CINAHL, EMBASE, and MedRx were searched from inception to September 1 2020. Risk of bias was assessed using a published tool that can accommodate all study types. Two independent authors screened the studies and extracted data. Data were narratively synthesized, as there were insufficient data to meta-analyze. Evidence was appraised according to GRADE.

RESULTS

Four case reports were included, comprising 13 participants from three countries. Many large-sample, relevant papers were omitted for not reporting psychiatric history, despite reporting other comorbidities. Included participants (n = 13) were hospitalized with COVID-19 and appeared to meet criteria for delirium. Myoclonus, rigidity, and alogia were also reported. The most commonly reported preexisting psychiatric diagnoses were mood disorders, schizophrenia, and alcohol use disorder.

CONCLUSIONS

People with preexisting psychiatric disorders may experience delirium, rigidity, myoclonus, and alogia during COVID-19 infection; although higher quality and longitudinal data are needed to better understand these phenomena. Relevant COVID-19 literature does not always report psychiatric history, despite heightened neuropsychiatric vulnerability within this population.

TRIAL REGISTRATION

 PROSPERO (CRD42020179611).

Delirium and Its Pharmacological Causes in Older People, Part Three

Delirium is a syndrome that can arise from many causes or underlying conditions, and though it has been reported in younger patients, it is more prevalent in older people, though it can occur in other age groups as well. Identifying delirium is challenging in older people because of the coexistence of underlying dementia or depression, which may further complicate the presentation. Drug-induced delirium is one of the major causes of delirium, and evaluation of this potential cause or contribution is an important component of the evaluation process, since it can lead to poor patient outcomes. Part one of this three part series reviewed the epidemiology, pathophysiology, evaluation, diagnostic process, and causes of delirium in older people. Parts two and three continued to review the pharmacological classes of medications that cause or contribute to delirium in older people.

The Risk of Preoperative Central Nervous System-Acting Medications on Delirium Following Hip or Knee Surgery: A Matched Case-Control Study

INTRODUCTION

Medicines acting on the central nervous system can increase the risk of postoperative delirium, but the specific medicines associated with greatest risk remain unclear.

OBJECTIVES

We aimed to examine the risk of individual central nervous system-acting medicines used preoperatively on delirium after hip or knee surgery.

METHODS

A matched case-control study was conducted using data from the Australian Government Department of Veterans' Affairs. We included people aged 65 years or older who had knee or hip surgery between 2000 and 2019. People with hip or knee surgery who developed postoperative delirium were cases and controls were people with hip or knee surgery but who did not develop postoperative delirium. Use of medicines including anxiolytics, sedatives, and hypnotics, opioid analgesics and antidepressants prior to surgery was compared between cases and controls.

RESULTS

A total of 2614 patient cases with postoperative delirium were matched by same sex, age (±2 years), and year of admission (±2 years) with 7842 controls without postoperative delirium. Cases were more likely to be exposed to nitrazepam (odds ratio [OR] = 1.81, 95% confidence interval [CI] 1.24-2.64), sertraline (OR = 1.50, 95% CI 1.20-1.87), mirtazapine (OR = 1.38, 95% CI 1.11-1.74), venlafaxine (OR = 1.42, 95% CI 1.02-1.98), citalopram (OR = 1.54, 95% CI 1.19-1.99), escitalopram (OR = 1.42, 95% CI 1.06-1.89) or fluvoxamine (OR = 5.01, 95% CI 2.15-11.68) prior to surgery than controls. At the class level, exposure to benzodiazepines (OR = 1.20, 95% CI 1.05-1.37) and antidepressants (OR = 1.64, 95% CI 1.47-1.83) prior to surgery was significantly higher in cases than in controls. The numbers needed to treat to harm for one additional delirium case were 43 for sertraline, 40 for citalopram, 57 for mirtazapine and 26 for nitrazepam. Whereas, the numbers needed to treat to harm were found to be 20 for sertraline, 17 for citalopram, 19 for mirtazapine and 10 for nitrazepam in the 85 years or older age group, indicating that the harmful effect of these medicines is pronounced as age advances.

CONCLUSIONS

People who developed delirium following hip or knee surgery were more likely to be exposed to nitrazepam, sertraline, mirtazapine, venlafaxine, citalopram, escitalopram or fluvoxamine at the time of admission for surgery. Planning to reduce use of these medicines well prior to surgery may decrease the risk of postoperative delirium.

Ethical Tenets of PRN Medicines Management in Healthcare Settings: A Clinical Perspective

Prescription and administration of pro re nata (PRN) medications has remained a poorly discussed area of the international literature regarding ethical tenets influencing this type of medication practice. In this commentary, ethical tenets of PRN medicines management from the clinical perspective based on available international literature and published research have been discussed. Three categories were developed by the authors for summarising review findings as follows: 'benefiting the patient', 'making well-informed decision', and 'follow up assessment' as pre-intervention, through-intervention, and post-intervention aspects, respectively. PRN medicines management is mainly intertwined with the ethical tenets of beneficence, nonmaleficence, dignity, autonomy, justice, informed consent, and error disclosure. It is a dynamic process and needs close collaboration between healthcare professionals especially nurses and patients to prevent unethical practice.

The Use of Cerebral Oximetry in Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The evidence on the use of cerebral oximetry during surgery to minimize postoperative neurologic complications remains uncertain in the literature. The present authors aimed to assess the value of cerebral oximetry in the prevention of postoperative cognitive dysfunction, postoperative delirium, and postoperative stroke in adults undergoing surgery.

DESIGN

A systematic review and meta-analysis.

SETTING

The surgery room.

PARTICIPANTS

Adult patients (ages ≥18 years) undergoing surgery.

INTERVENTIONS

Cerebral oximetry monitoring.

MEASUREMENTS AND MAIN RESULTS

Databases of Ovid MEDLINE, Ovid EMBASE, and CENTRAL were systematically searched from their inception until December 2020 for randomized controlled trials comparing cerebral oximetry monitoring with either blinded or no cerebral oximetry monitoring in adults undergoing surgery. Observational studies, case reports, and case series were excluded. Seventeen studies (n = 2,120 patients) were included for quantitative meta-analysis. Patients who were randomized to cerebral oximetry monitoring had a lower incidence of postoperative cognitive dysfunction (studies = seven, n = 969, odds ratio [OR] 0.23, 95% confidence interval [CI] 0.11-0.48, p = 0.0001; evidence = very low). However, no significant differences were observed in the incidence of postoperative delirium (studies = five, n = 716, OR 0.81, 95% CI 0.53-1.25, p = 0.35; evidence = high), and postoperative stroke (studies = seven, n = 1,087, OR 0.72, 95% CI 0.30-1.69, p = 0.45; evidence = moderate).

CONCLUSION

Adult patients with cerebral oximetry monitoring were associated with a significant reduction of postoperative cognitive dysfunction. However, given the low certainty of evidence and substantial heterogeneity, more randomized controlled trials using standardized assessment tools for postoperative cognitive dysfunction and interventions of correcting cerebral desaturation are warranted to improve the certainty of evidence and homogeneity.

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.

Risk factors for postoperative delirium: An umbrella review of systematic reviews

BACKGROUND

Postoperative delirium (POD) is associated with increased mortality, increased length of hospital stays and increased rates and severity of subsequent cognitive decline including dementia. A wide range of risk factors for POD have been suggested in the literature across multiple surgical specialities. However few are validated and no accurate prognostic models exist. We therefore aimed to map the existing evidence regarding risk factors for POD to help guide future research by undertaking an umbrella review of systematic reviews examining risk factors for POD in any context.

MATERIALS AND METHODS

We systematically searched multiple medical databases for systematic reviews examining the risk factors for POD in adults undergoing any surgery. We then selected relevant reviews with minimal overlap in primary studies and extracted information about individual risk factors.

RESULTS

Thirty-five relevant reviews were identified of which ten were in trauma and orthopaedic surgery patients (four exclusively examined hip fractures), five were in cardiac surgery patients, and four were in vascular surgery patients. Due to substantial overlap in reviews, eighteen reviews were analysed in detail finding the widely examined and consistent risk factors were increasing age, nursing home residency, pre-existing cognitive impairment, psychiatric disorders, cerebrovascular disease, end stage renal failure, low albumin, higher ASA score, and intra-operative blood transfusion. Many other risk factors were examined, but they were either not studied in multiple systematic reviews, or inconsistent either in results or in categorisation (which for many factors was heterogenous even within systematic reviews). There are also a large number of existing prognostic models, many of which remain unvalidated.

CONCLUSION

Given the wealth of existing literature, future research should avoid simple risk factor evaluation except for novel candidates, validate existing prognostic models where possible, and instead focus on interventional research.

Prehabilitation to prevent complications after cardiac surgery - A retrospective study with propensity score analysis

Background

The rising prevalence of modifiable lifestyle-related risk factors (e.g. overweight and physical inactivity) suggests the need for effective and safe preoperative interventions to improve outcomes after cardiac surgery. This retrospective study explored potential short-term postoperative benefits and unintended consequences of a multidisciplinary prehabilitation program regarding in-hospital complications.

Methods

Data on patients who underwent elective cardiac surgery between January 2014 and April 2017 were analyzed retrospectively. Pearson’s chi-squared tests were used to compare patients who followed prehabilitation (three times per week, at a minimum of three weeks) during the waiting period with patients who received no prehabilitation. Sensitivity analyses were performed using propensity-score matching, in which the propensity score was based on the baseline variables that affected the outcomes.

Results

Of 1201 patients referred for elective cardiac surgery, 880 patients met the inclusion criteria, of whom 91 followed prehabilitation (53.8% ≥ 65 years, 78.0% male, median Euroscore II 1.3, IQR, 0.9–2.7) and 789 received no prehabilitation (60.7% ≥ 65 years, 69.6% male, median Euroscore II 1.6, IQR, 1.0–2.8). The incidence of atrial fibrillation (AF) was significantly lower in the prehabilitation group compared to the unmatched and matched standard care group (resp. 14.3% vs. 23.8%, P = 0.040 and 14.3% vs. 25.3%, P = 0.030). For the other complications, no between-group differences were found.

Conclusions

Prehabilitation might be beneficial to prevent postoperative AF. Patients participated safely in prehabilitation and were not at higher risk for postoperative complications. However, well-powered randomized controlled trials are needed to confirm and deepen these results.

A clinical risk analysis of early post-operative delirium after laparoscopic colorectal cancer surgery in elderly patients: a retrospective study

PURPOSE

Early post-operative delirium (EPOD) is a frequent complication following colorectal surgery. The present study investigated the risk factors for EPOD after laparoscopic colorectal surgery in elderly patients.

METHODS

A retrospective study was conducted among 208 patients ≥70 years old who underwent laparoscopic colorectal surgery. Univariate and multivariate analyses were performed to determine the clinicopathological factors associated with the EPOD.

RESULTS

The overall incidence of EPOD was 10.1% (21/208). The univariate analysis showed that an older age (≥80 years old; P=0.002), sleeping pill medication before surgery (P=0.037), a history of dementia (P=0.030) and cerebrovascular disease (P=0.017), elevated levels of D-dimer (P=0.016), maximum intraoperative temperature ≥37 °C (P=0.036), and non-continuous usage of droperidol with analgesia (P=0.005) were associated with EPOD. The multivariate logistic regression analysis revealed an older age (≥80 years old; odds ratio [OR]: 6.26, 95% confidence interval [CI]: 1.94-20.15, P=0.002), sleeping pill medication before surgery (OR: 5.39, 95% CI: 1.36-21.28, P=0.016), history of cerebrovascular disease (OR: 3.91, 95% CI: 1.12-13.66, P=0.033), and maximum intraoperative temperature ≥37 °C (OR: 5.10, 95% CI: 1.53-16.92, P=0.008) to be independent risk factors. When the patients were divided into groups according to the number of positive risk factors, the prevalence rate was 6.5%, 16.0%, and 63.6% for patients with 1, 2, and 3 positive risk factors, respectively.

CONCLUSION

Our findings suggest that an older age, sleeping pill medication before surgery, history of cerebrovascular disease, and maximum intraoperative temperature ≥37 °C are independent risk factors of EPOD after laparoscopic colorectal surgery in elderly patients.

Relation between preoperative benzodiazepines and opioids on outcomes after total joint arthroplasty

To examine the association of preoperative opioids and/or benzodiazepines on postoperative outcomes in total knee and hip arthroplasty, we retrospectively compared postoperative outcomes in those prescribed preoperative opioids and/or benzodiazepines versus those who were not who underwent elective total knee and hip arthroplasty at a single urban academic institution. Multivariable logistic regression was performed for readmission rate, respiratory failure, infection, and adverse cardiac events. Multivariable zero-truncated negative binomial regression was used for length of stay. After exclusions, there were 4307 adult patients in the study population, 2009 of whom underwent total knee arthroplasty and 2298 of whom underwent total hip arthroplasty. After adjusting for potential confounders, preoperative benzodiazepine use was associated with increased odds of readmission (p < 0.01). Preoperative benzodiazepines were not associated with increased odds of respiratory failure nor increased length of stay. Preoperative opioids were not associated with increased odds of the examined outcomes. There were insufficient numbers of infection and cardiac events for analysis. In this study population, preoperative benzodiazepines were associated with increased odds of readmission. Preoperative opioids were not associated with increased odds of the examined outcomes. Studies are needed to further examine risks associated with preoperative benzodiazepine use.

Metabolic disturbance affects postoperative cognitive function in patients undergoing cardiopulmonary bypass

OBJECTIVES

Postoperative delirium is a common neuropsychiatric syndrome after coronary artery bypass grafting (CABG). We aimed to assess and compare clinical outcomes of CABG patients with delirium with a specific focus on the blood biochemical parameters.

METHODS

This investigation was carried out on the 90 eligible patients undergoing CABG. Delirium was measured using the Neecham confusion scale and assessed patients were divided into two groups of delirium (n = 43) and non-delirium (n = 47). Preoperative variables and intraoperative and postoperative outcomes were compared.

RESULTS

Delirium patients were older (p = 0.003) and had longer intubation time (p = 0.003). Non-delirium patients obtained a significantly higher Neecham confusion score (p = 0.001), and delirium patients experienced a hyperglycemic state at intraoperative (p = 0.004), intubation (p = 0.03), and extubation time (p = 0.02). Lower value of pH was seen at intubation (p = 0.03) and extubation periods (p = 0.001) in delirium group. A significant difference in base excess was observed between two groups at intubation (p = 0.04) and extubation periods (p = 0.004). Potassium level showed a significant decrease in delirium group at intubation (p = 0.01) and extubation periods (p = 0.001). Multivariate regression indicated that aging (OR = 1.08, p = 0.01), narcotic consumption (OR = 3.27, p = 0.05), DM (OR = 3.03, p=0.03), and prolonged intubation (OR = 1.18, p = 0.03) are predictors of delirium. Postoperative hyperglycemia (OR = 1.01, p = 0.002), low pH value (OR = 2.62, p = 0.02), and low potassium level (OR = 3.25, p = 0.03) are associated with development of delirium.

CONCLUSIONS

Postoperative metabolic disturbance and electrolyte imbalances are closely related to the development of delirium after CABG and need to be considered more carefully. Aging, DM, and preoperative use of narcotics are strong predictors of delirium following CABG.

Music intervention for sleep quality in critically ill and surgical patients: a meta-analysis

OBJECTIVE

Sleep disruption occurs frequently in hospitalised patients. Given the potential of music intervention as a non-pharmacological measure to improve sleep quality, we aimed to assess and quantify current literature on the effect of recorded music interventions on sleep quality and quantity in the adult critical care and surgical populations.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Embase, MEDLINE Ovid, Cochrane Central, Web of Science and Google Scholar.

ELIGIBILITY CRITERIA FOR STUDIES

Randomised controlled trials assessing the effect of music on sleep quality in critically ill and surgical patients.

METHODS

The electronic databases were systematically searched from 1 January 1981 to 27 January 2020. Data were screened, extracted and appraised by two independent reviewers. Primary outcomes were sleep quality and quantity, assessed with validated tools. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Random effects meta-analysis was performed, and pooled standardised mean differences (SMDs) with 95% CIs were reported.

RESULTS

Five studies (259 patients) were included in qualitative (risk of bias) and quantitative analysis (meta-analysis). Pooled data showed a significant effect of recorded music on subjective sleep quality in the critical care and surgical population (SMD=1.21 (95% CI 0.50 to 1.91), p<0.01, excluding one non-English study; SMD=0.87 (95% CI 0.45 to 1.29), p<0.01). The SMD of 1.21 corresponded to a 27.1% (95% CI 11.2 to 42.8) increase in subjective sleep quality using validated questionnaires. A significant increase in subjective sleep quantity of 36 min was found in one study. Objective measurements of sleep assessed in one study using polysomnography showed significant increase in deeper sleep stage in the music group.

CONCLUSIONS

Recorded music showed a significant improvement in subjective sleep quality in some critical care and surgical populations. Therefore, its use may be relevant to improve sleep, but given the moderate potential for bias, further research is needed.

PROSPERO REGISTRATION NUMBER

CRD42020167783.

Patients with psychiatric disease: implications for anesthesiologists

PURPOSE OF REVIEW

Psychiatric illness is common in patients presenting for surgery. Overall health and surgical outcomes are adversely affected by the presence of psychiatric comorbidities.

RECENT FINDINGS

As new treatment modalities become available, their perioperative implications need to be evaluated. These implications include drug-drug interactions, hemodynamic effects, bleeding risk, and factors affecting perioperative exacerbation of the underlying psychiatric illness.

SUMMARY

From our review of the recent literature we continue to support the continuation of psychoactive agents in the perioperative period, taking into consideration the effects these agents have on concomitant drug use in the perioperative period; and the risks of withholding them at a high-stress time.

Risk Factors for Delirium after Vascular Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Vascular surgery is considered a risk factor for the development of postoperative delirium (POD). In this systematic review we provide a report on the incidence and risk-factors of POD after vascular surgery.

METHODS

A systematic literature search was conducted using Pubmed with the MeSH terms and key words "delirium" or "confusion", "vascular surgery procedures" and "risk factors or "risk assessment". Studies were selected for review after meeting the following inclusion criteria: vascular surgery, POD diagnosed using validated screening tools, and DSM-derived criteria to assess delirium. A meta-analysis was performed for each endpoint if at least two studies could be combined.

RESULTS

Sixteen articles met the abovementioned criteria. The incidence of delirium ranged from 5% to 39%. Various preoperative risk factors were identified that is, age (Random MD 3.96, CI 2.57-5.35), hypertension (Fixed OR 1.30, CI 1.05-1.59), diabetes mellitus (Random OR 2.15, CI 1.30-3.56), hearing impairment (Fixed OR 1.89, CI 1.28-2.81), history of cerebrovascular incident or transient ischemic attack (Fixed OR 2.20, CI 1.68-2.88), renal failure (Fixed OR 1.61, CI 1.19-2.17), and pre-operative low haemoglobin level (fixed MD -0.76, CI -1.04 to -0.47). Intra-operative risk factors were duration of surgery (Random MD 15.68; CI 2.79-28.57), open aneurysm repair (Fixed OR 4.99, CI 3.10-8.03), aortic cross clamping time (fixed MD 7.99, CI 2.56-13.42), amputation surgery (random OR 3.77, CI 2.13-6.67), emergency surgery (Fixed OR 4.84, CI 2.81-8.32) and total blood loss (Random MD 496.5, CI 84.51-908.44) and need for blood transfusion (Random OR 3.72, CI 1.57-8.80). Regional anesthesia on the other hand, had a protective effect. Delirium was associated with longer ICU and hospital length of stay, and more frequent discharge to a care facility.

CONCLUSIONS

POD after vascular surgery is a frequent complication and effect-size pooling supports the concept that delirium is a heterogeneous disorder. The risk factors identified can be used to either design a validated risk factor model or individual preventive strategies for high-risk patients.

Midazolam Premedication Immediately Before Surgery Is Not Associated With Early Postoperative Delirium

BACKGROUND

Postoperative delirium is common among older surgical patients and may be associated with anesthetic management during the perioperative period. The aim of this study is to assess whether intravenous midazolam, a short-acting benzodiazepine used frequently as premedication, increased the incidence of postoperative delirium.

METHODS

Analyses of existing data were conducted using a database created from 3 prospective studies in patients aged 65 years or older who underwent elective major noncardiac surgery. Postoperative delirium occurring on the first postoperative day was measured using the confusion assessment method. We assessed the association between the use or nonuse of premedication with midazolam and postoperative delirium using a χ2 test, using propensity scores to match up with 3 midazolam patients for each control patient who did not receive midazolam.

RESULTS

A total of 1266 patients were included in this study. Intravenous midazolam was administered as premedication in 909 patients (72%), and 357 patients did not receive midazolam. Those who did and did not receive midazolam significantly differed in age, Charlson comorbidity scores, preoperative cognitive status, preoperative use of benzodiazepines, type of surgery, and year of surgery. Propensity score matching for these variables and American Society of Anesthesiology physical status scores resulted in propensity score-matched samples with 1-3 patients who used midazolam (N = 749) for each patient who did not receive midazolam (N = 357). After propensity score matching, all standardized differences in preoperative patient characteristics ranged from -0.07 to 0.06, indicating good balance on baseline variables between the 2 exposure groups. No association was found between premedication with midazolam and incident delirium on the morning of the first postoperative day in the matched dataset, with odds ratio (95% confidence interval) of 0.91 (0.65-1.29), P = .67.

CONCLUSIONS

Premedication using midazolam was not associated with higher incidence of delirium on the first postoperative day in older patients undergoing major noncardiac surgery.

Elements not Graded in the Cardiac Enhanced Recovery After Surgery Guidelines Might Improve Postoperative Outcome: A Comprehensive Narrative Review

Enhanced Recovery Programs (ERPs) are protocols involving the whole patient surgical journey. These protocols are based on multimodal, multidisciplinary, evidence-based, and patient-centered approaches aimed at improving patient recovery after a surgical intervention. Such programs have shown striking positive results in different surgical specialties. However, only a few research groups have incorporated preoperative, intraoperative, and postoperative evidence-based interventions in bundles used to standardize care and build cardiac surgery ERPs. The Enhanced Recovery After Surgery Society recently published evidence-based recommendations for perioperative care in cardiac surgery. Their recommendations included 22 perioperative interventions that may be part of any cardiac ERP. However, various components integrated in already-published cardiac ERPs were neither graded nor reported in these recommendations. The goals of the current review are to present published cardiac ERPs and their effects on patient outcomes and reported components incorporated into these ERPs and to discuss the objectives and scope of cardiac ERPs.

Stratified delirium risk using prescription medication data in a state-wide cohort

OBJECTIVE

Delirium is a common condition associated with increased morbidity and mortality. Medication side effects are a possible source of modifiable delirium risk and provide an opportunity to improve delirium predictive models. This study characterized the risk for delirium diagnosis by applying a previously validated algorithm for calculating central nervous system adverse effect burden arising from a full medication list.

METHOD

Using a cohort of hospitalized adult (age 18-65) patients from the Massachusetts All-Payers Claims Database, we calculated medication burden following hospital discharge and characterized risk of new coded delirium diagnosis over the following 90 days. We applied the resulting model to a held-out test cohort.

RESULTS

The cohort included 62,180 individuals of whom 1.6% (1019) went on to have a coded delirium diagnosis. In the training cohort (43,527 individuals), the medication burden feature was positively associated with delirium diagnosis (OR = 5.75, 95% CI 4.34-7.63) and this association persisted (aOR = 1.95; 1.31-2.92) after adjusting for demographics, clinical features, prescribed medications, and anticholinergic risk score. In the test cohort, the trained model produced an area under the curve of 0.80 (0.78-0.82). This performance was similar across subgroups of age and gender.

CONCLUSION

Aggregating brain-related medication adverse effects facilitates identification of individuals at high risk of subsequent delirium diagnosis.