Postoperative Delirium in Older Adults: Best Practice Statement from the American Geriatrics Society

Delirium in a surgical context from a nursing perspective: A hybrid concept analysis

Background

The term delirium has been defined in medical diagnosis criteria as a multidimensional disorder, and the term acute confusion is included in nursing classifications. Delirium can be a serious complication assessed in a patient after a surgical procedure. Still, the patient's delirium frequently remains unrecognised. Care of patients with delirium after surgical procedure is complex, and it challenges nursing expertise. From the nurses' viewpoint, delirium is associated with ambiguity of concepts and lack of knowledge. Therefore, reseach on how nurses perceive patients with delirium in a surgical context is needed.

Objective

The aim of this study was to describe the concepts of delirium and acute confusion, as well as the associated dimensions, in adult patients in a surgical context from the nursing perspective.

Design

The study used Schwartz and Barcott's hybrid concept analysis with theoretical, fieldwork, and final analytical phases.

Settings

Surgical wards, surgical intensive care units, and post-anaesthesia care units.

Data sources

A systematic literature search was performed through Pubmed (Medline), Cinahl, PsycInfo, and Embase.

Participants

Registered nurses and licensed practical nurses (n = 105) participated in the fieldwork phase.

Methods

In the theoretical phase, the concepts' working definitions were formulated based on a systematic literature search with the year limitations from 2000 until February 2021. At the fieldwork phase, the nurses' descriptions of patients with delirium were analysed using the deductive content analysis method. At the final analytical phase, findings were combined and reported.

Results

The concepts of delirium, subsyndromal delirium, and acute confusion are well defined in the literature. From the perspective of the nurses in the study, concepts were seen as a continuum not as individual diagnoses. Nurses described the continuum of delirium as a process with acute onset, duration, and recovery with the associated dimensions of symptoms, symptom severity, risk factors, and early signs. The acute phase of delirium was emphasised, and preoperative or prolonged disturbance did not seem to be relevant in the surgical care context. Patients' compliance with care may be decreased with the continuum of delirium, which might challenge both patients' recovery from surgery and the quality of nursing care.

Conclusions

In clinical practice the nurses used term confusion inaccurately. The term acute confusion might be used when illustrating an early stage of delirium. Nurses could benefit from further education where the theoretical knowledge is combined with the clinical practice. The discussion about the delirium, which covers the time both before surgery and after the acute phase should be increased.

Impact of early mobilization on the duration of delirium in elderly hospitalized patients: A retrospective cohort pilot study

Development of delirium during hospitalization impairs the activities of daily living in elderly hospitalized patients. In clinical practice, early mobilization from bed is recommended to reduce delirium incidence and hospitalization stay. However, the effects of early mobilization on elderly inpatients with delirium have not been established yet. The aim of this study was to investigate the association between early mobilization and the duration of delirium in elderly inpatients with delirium. This retrospective cohort pilot study examined 45 participants (23 males, 22 females; mean age: 84.5 ± 6.6 years), who developed delirium during hospitalization. Of the participants, 28 were surgically treated and 17 were non-surgically treated. We classified early or delayed mobilization based on the median number of days until the start of mobilization and compared after propensity score matching to adjust for baseline characteristics. Additionally, we examined the correlation between the number of days until the start of mobilization and the duration of delirium. The duration of delirium was significantly shorter in the early mobilization group, particularly in terms of sitting on the bed and wheelchair use than that in the delayed mobilization group {median: 4.0 [interquartile range (IQR): 2.0-6.0] vs 8.0 [IQR: 7.0-14.5] days, P = .013; median: 3.0 [IQR: 2.0-5.5] vs 11.0 [IQR: 7.5-14.5] days, P = .004, respectively}. Moreover, the duration of delirium significantly positively moderate correlated with the time until the start of sitting on the bed and wheelchair use (Spearman r = 0.527; P = .012, Spearman r = 0.630; P = .002, respectively). The results of this study suggest that early mobilization from sitting on the bed or wheelchair use after hospitalization or surgery may shorten the duration of delirium. Because the sample size of this pilot study is small, careful interpretation is needed, and further research is warranted.

Risk factor stratification for postoperative delirium: A retrospective database study

METHODS

The EHR of 32734 patients >18 years of age undergoing surgery and had POD assessment were reviewed. Patient characteristics and study variables were summarized between delirium groups. We constructed univariate logistic regression models for POD using each study variable to estimate odds ratios (OR) and constructed a multivariable logistic regression model with stepwise variable selection. In order to create a clinically useful/implementable tool we created a nomogram to predict risk of delirium.

RESULTS

Overall, we found a rate of POD of 3.7% across our study population. The Model achieved an AUC of the ROC curve of 0.83 (95% CI 0.82-0.84). We found that age, increased American Society of Anesthesiologists (ASA) score (ASA 3-4 OR 2.81, CI 1.49-5.28, P < .001), depression (OR 1.28, CI 1.12-1.47, P < .001), postoperative benzodiazepine use (OR 3.52, CI 3.06-4.06, P < .001) and urgent cases (Urgent OR 3.51, CI 2.92-4.21, P < .001; Emergent OR 3.99, CI 3.21-4.96, P < .001; Critically Emergent OR 5.30, CI 3.53-7.96, P < .001) were associated with POD.

DISCUSSION

We were able to distinguish the contribution of individual risk factors to the development of POD. We created a clinically useful easy-to-use tool that has the potential to accurately identify those at high-risk of delirium, a first step to prevent POD.

The hotspots and publication trends in postoperative delirium: A bibliometric analysis from 2000 to 2020

Background

Postoperative delirium (POD) is a common aging-associated postoperative complication that has received increasing attention in the context of the aging global population and the number of articles published on POD is gradually increasing. This study aimed to quantify the basic information of scholarly publications on POD and identify the most impactful literature, trends, and hotspots in POD research.

Materials and methods

We searched articles on POD through the Science Citation Index Expanded databases published from 2000 to 2020. Bibliographic information, including year, country, authorship, type, journal, funding, affiliations, subject areas, and hotspots, was collected for further analysis.

Results

A total of 2,114 articles on POD from 2000 to 2020 were identified. The highest number of studies (n = 748) were published in the United States, comprising the most total citations (13,928), followed by China (n = 278), and Germany (n = 209). Inouye, Sharon K. was the most productive author, with 66 publications on POD. The Journal of the American Geriatrics Society published the highest number of articles (n = 80), with the most total citations (4,561) and average (57.01), followed by Anesthesia and Analgesia (n = 52), and the British Journal of Anaesthesia (n = 43). Harvard University was the most productive institute, with the highest H-index (n = 46) and highest degree centrality (n = 191). The top hotspots in the field of POD during this period were "elderly," "cardiac surgery," "cognitive impairment," "hip fracture," and "intensive care unit."

Conclusion

This study provides an overview of developments in the field of POD over the past 20 years using bibliometric analysis. Overall, research on POD has flourished worldwide. The United States (US) has a relatively high academic impact owing to its productive expertise and institutions in this field. Despite much research illustrating the diagnosis and management of POD in clinical practice, more basic research is needed.

Recipe for primary prevention of delirium in hospitalized older patients

Delirium is an acute fluctuating syndrome characterized by a change in consciousness, perception, orientation, cognition, sleep-wake rhythm, psychomotor skills, and the mood and feelings of a patient. Delirium and delirium prevention remain a challenge for healthcare professionals, especially nurses who form the basis of patient care. It also causes distress for patients, their caregivers and healthcare professionals. However, delirium is preventable in 30-40% of cases. The aim of this article is to summarize the delirium risk models, delirium screening tools, and (non-pharmacological) delirium prevention strategies. A literature search of review articles supplemented by original articles published in PubMed, Cinahl, and Cochrane between 1 January 2000 and 31 December 2020 was carried out. Among the older patients, delirium is a common condition with major consequences in terms of mortality and morbidity, but prevention is possible. Despite the fact that delirium risk models, delirium screening scales and non-pharmacological prevention are available for the development of a hospital delirium prevention programme, such a programme is still not commonly used on a daily basis.

The prevention of delirium in elderly surgical patients with obstructive sleep apnea (PODESA): a randomized controlled trial

BACKGROUND

Obstructive sleep apnea (OSA) is associated with neurocognitive impairment - a known risk factor for postoperative delirium. However, it is unclear whether OSA increases the risk of postoperative delirium and whether treatment is protective. The objectives of this study were to identify OSA with a home sleep apnea test (HSAT) and to determine whether auto-titrating positive airway pressure (APAP) reduces postoperative delirium in older adults with newly diagnosed OSA undergoing elective hip or knee arthroplasty.

METHODS

We conducted a multi-centre, randomized controlled trial at three academic hospitals in Canada. Research ethics board approval was obtained from the participating sites and informed consent was obtained from participants. Inclusion criteria were patients who were [Formula: see text]0 years and scheduled for elective hip or knee replacement. Patients with a STOP-Bang score of ≥ 3 had a HSAT. Patients were defined as having OSA if the apnea-hypopnea index was ≥ 10/h. These patients were randomized 1:1 to either: 1) APAP for 72 h postoperatively or until discharge, or 2) routine care after surgery. The primary outcome was postoperative delirium, assessed twice daily with the Confusion Assessment Method for 72 h or until discharge or by chart review. The secondary outcome measures included length of stay, and perioperative complications occurring within 30 days after surgery.

RESULTS

Of 549 recruited patients, 474 completed a HSAT. A total of 234 patients with newly diagnosed OSA were randomized. The mean age was 68.2 (6.2) years and 58.6% were male. Analysis was performed on 220 patients. In total, 2.7% (6/220) patients developed delirium after surgery: 4.4% (5/114) patients in the routine care group, and 0.9% (1/106) patients in the treatment group (P = 0.21). The mean length of stay for the APAP vs. the routine care group was 2.9 (2.9) days vs. 3.5 (4.5) days (P = 0.24). On postoperative night 1, 53.5% of patients used APAP for 4 h/night or more, this decreased to 43.5% on night 2, and 24.6% on night 3. There was no difference in intraoperative and postoperative complications between the two groups.

CONCLUSIONS

We had an unexpectedly low rate of postoperative delirium thus we were unable to determine if postoperative delirium was reduced in older adults with newly diagnosed OSA receiving APAP vs. those who did not receive APAP after elective knee or hip arthroplasty.

TRIAL REGISTRATION

This trial was retrospectively registered in clinicaltrials.gov NCT02954224 on 03/11/2016.

Risk factors for postoperative delirium in geriatric patients with hip fracture: A systematic review and meta-analysis

Objectives

This systematic review and meta-analysis was conducted to identify the potential risk factors for postoperative delirium in geriatric patients with hip fracture.

Methods

PubMed, EMBASE, and Cochrane Library were searched from inception until December 31st, 2021. A combined searching strategy of subject words and free words was adopted. Studies involving risk factors for postoperative delirium in elderly patients undergoing hip fracture surgeries were reviewed. Qualities of included studies were assessed using the Newcastle–Ottawa Scale. Data were pooled and a meta-analysis was performed using Review Manager 5.3.

Results

A total of 37 studies were included. The following risk factors were significant: advanced age (per year increase) (OR: 1.05, 95% CI 1.04–1.07), age>80 years (OR: 2.26, 95% CI 1.47–3.47), male (OR: 1.53, 95% CI 1.37–1.70), preoperative cognitive impairment (OR:3.20, 95% CI 2.12–4.83), preoperative dementia (OR: 2.74, 95% CI 2.18–3.45), preoperative delirium (OR: 9.23, 95% CI 8.26–10.32), diabetes (OR: 1.18, 95% CI 1.05–1.33), preoperative functional dependence (OR: 1.31, 95% CI 1.11–1.56), ASA level (per level increase) (OR: 1.63, 95% CI 1.04–2.57), ASA level≥3(OR: 1.76, 95% CI 1.39–2.24), low albumin (OR: 3.30, 95% CI 1.44–7.55), medical comorbidities (OR: 1.15, 95% CI 1.06–1.25), Parkinson's disease (OR: 4.17, 95% CI 1.68–10.31) and surgery delay>48 h (OR: 1.90, 95% CI 1.36–2.65).

Conclusions

Clinicians should be alert to patients with those risk factors. To identify the risk factors more precisely, more research studies with larger sample size and better design should be conducted.

Effects of subanaesthetic S-ketamine on postoperative delirium and cognitive function in elderly patients undergoing non-cardiac thoracic surgery: a protocol for a randomised, double-blinded, placebo-controlled and positive-controlled, non-inferiority trial (SKED trial)

INTRODUCTION

Postoperative delirium (POD) is a common and distressing complication after thoracic surgery. S-ketamine has neuroprotective properties as a dissociative anaesthetic. Emerging literature has indicated that S-ketamine can reduce cognitive impairment in patients with depression. However, the role of S-ketamine in preventing POD remains unknown. Therefore, this study aims to evaluate the effect of intraoperative prophylactic S-ketamine compared with that of dexmedetomidine on the incidence of POD in elderly patients undergoing non-cardiac thoracic surgery.

METHODS AND ANALYSIS

This will be a randomised, double-blinded, placebo-controlled, positive-controlled, non-inferiority trial that enrolled patients aged 60-90 years undergoing thoracic surgery. The patients will be randomly allocated in a ratio of 1:1:1 to S-ketamine, dexmedetomidine or normal saline placebo groups using computer-generated randomisation with a block size of six. The primary outcome will be the incidence of POD within 4 days after surgery and this will be assessed using a 3-Minute Diagnostic Confusion Assessment Method two times per day. The severity and duration of POD, the incidence of emergence delirium, postoperative pain, quality of sleep, cognitive function, and the plasma concentrations of acetylcholine, brain-derived neurotrophic factor, tumour necrosis factor-α and incidence of adverse events will be evaluated as secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Institutional Review Board of the Cancer Hospital and the Institute of Guangzhou Medical University (ZN202119). At the end of the trial, we commit to making a public disclosure available, regardless of the outcome. The public disclosure will include a publication in an appropriate journal and an oral presentation at academic meetings.

TRIAL REGISTRATION NUMBER

ChiCTR2100052750 (NCT05242692).

The mortality burden in patients with hip fractures and dementia

PURPOSE

Dementia is strongly associated with postoperative death in patients subjected to hip fracture surgery. Nevertheless, there is a distinct lack of research investigating the cause of postoperative mortality in patients with dementia. This study aims to investigate the distribution and the risk of cause-specific postoperative mortality in patients with dementia compared to the general hip fracture population.

METHODS

All adults who underwent emergency hip fracture surgery in Sweden between 1/1/2008 and 31/12/2017 were considered for inclusion. Pathological, conservatively managed fractures, and reoperations were excluded. The database was retrieved by cross-referencing the Swedish National Quality Registry for Hip Fracture patients with the Swedish National Board of Health and Welfare quality registers. A Poisson regression model was used to determine the association between dementia and all-cause as well as cause-specific 30-day postoperative mortality.

RESULTS

134,915 cases met the inclusion criteria, of which 20% had dementia at the time of surgery. The adjusted risk of all-cause 30-day postoperative mortality was 67% higher in patients with dementia after hip fracture surgery compared to patients without dementia [adj. IRR (95% CI): 1.67 (1.60-1.75), p < 0.001]. The risk of cause-specific mortality was also higher in patients with dementia, with up to a sevenfold increase in the risk cerebrovascular mortality [adj. IRR (95% CI): 7.43 (4.99-11.07), p < 0.001].

CONCLUSIONS

Hip fracture patients with dementia have a higher risk of death in the first 30 days postoperatively, with a substantially higher risk of mortality due to cardiovascular, respiratory, and cerebrovascular events, compared to patients without dementia.

Association between Baseline Cognitive Score and Postoperative Delirium in Parkinson’s Disease Patients following Deep Brain Stimulation Surgery

Background

Deep brain stimulation of the subthalamic nuclei (STN-DBS) is a standard treatment option for advanced Parkinson's disease (PD) patients. Delirium following DBS electrode implantation is common, by several studies, and cognitive impairment is a risk factor for developing postoperative delirium (POD). This prospective observational study was conducted to identify whether preoperative baseline cognitive status has an association with POD in PD patients undergoing DBS surgery.

Methods

Preoperatively, neuropsychiatric and neuropsychological assessments of the patients were performed including clinical dementia rating (CDR) score, instrumental activities of daily living (IADL) score, mini-mental state exam (MMSE) score, Montreal cognitive assessment (MoCA) score, Hamilton anxiety (HAMA) and Hamilton depression (HAMD) scores, and numerical cancellation test. POD was identified by the confusion assessment method (CAM) twice per day on postoperative day 1 until discharge.

Results

Twenty-seven (21.6%) of 125 patients developed POD. Among the variables screened, age, CDR score, MMSE score, and HAMA score were indicated to be independent influence factors of POD. The cutoff score, AUC, sensitivity, and specificity of age, CDR score, MMSE score, and HAMA score associated with POD was 58.5, 0.751, 92.6%, 52.0%; 0.5, 0.848, 77.8%, 91.8%; 27.5, 0.827, 88.9%, 62.2%; and 12.5, 0.706, 85.2%, 54.1%, respectively.

Conclusions

We observed age, CDR score, MMSE score, and HAMA score were independent influence factors of POD in PD patients who received DBS. It is necessary to assess the cognitive status of PD patients before surgery to identify high-risk patients.

HDAC3 of dorsal hippocampus induces postoperative cognitive dysfunction in aged mice

Postoperative cognitive dysfunction (POCD) affects a substantial number of aged individuals. Although advanced age has been regarded as the only independent risk factor for cognitive decline following anesthesia and surgery, the exact cellular and molecular mechanisms remain poorly understood. Histone deacetylase 3 (HDAC3), an epigenetic regulator of memory plays an important role in age-dependent disease. In this study, we investigated the role of HDAC3 in POCD using a laparotomy mouse model. The results showed that the level of HDAC3 in the dorsal hippocampus (DH) was elevated in aged mice compared with young mice. The surgery impaired the spatial-temporal memory in aged mice, as indicated in the object location memory (OLM) and temporal order memory (TOM) tests. Model mice also exhibited increased expression of HDAC3 protein and decreased levels of dendritic spine density and synaptic plasticity-related proteins in the DH. Selectively blocking HDAC3 in the DH of aged mice reversed spatial-temporal memory impairment induced by surgery and restored dendritic spine density and synaptic plasticity-related proteins in the DH. Overexpression of HDAC3 by adeno-associated virus in the DH of young mice mimicked the behavioral deficits induced by anesthesia and surgery. Our results indicated that HDAC3 negatively regulates spatial-temporal memory in aged mice after anesthesia and surgery. Targeting HDAC3 might represent a potential therapy to avoid POCD.

Cognitive prehabilitation for geriatric patients undergoing elective surgery: a PRISMA-P-compliant protocol for a systematic review

INTRODUCTION

The ageing of the population, as well as advances and improvements in surgery, and anaesthesia have greatly increased the demand for surgical services in geriatric patients. Neurocognitive disorders are the most common complications experienced in the postoperative period by older individuals. Improving perioperative brain health in older adults has become key actions for the multidisciplinary perioperative care teams. This comprehensive systematic review will assess the effectiveness and safety of cognitive prehabilitation programmes prior to surgery on cognitive functional capacity and postoperative cognitive outcomes in geriatric patients undergoing elective surgery.

METHODS AND ANALYSIS

This protocol was prepared using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. The following key electronic bibliographic databases will be searched from inception to July 2022: MEDLINE, EMBASE, CINAHL, CENTRAL, PEDro, PsycINFO, CBM, CNKI, WANFANG database and VIP. We will include randomised controlled trials published in English or Chinese that examine the effects of cognitive prehabilitation programmes on geriatric patients undergoing elective surgery. To construct the search strategy, the Patient, Intervention, Comparison, Outcome, Study scheme will be used. Two reviewers will independently complete the study screening, selection, data extraction and quality rating. The Physiotherapy Evidence Database scale will be used to assess the methodological quality of the included studies. A narrative or quantitative synthesis will be conducted based on the final data. The planned start and end dates for the study were 1 September 2021 and 1 August 2023.

ETHICS AND DISSEMINATION

Ethical approval will not be required for this protocol. The results of the final review will be disseminated via peer-reviewed journals and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42021277191.

Cerebral dysfunctions caused by sepsis during ageing

Systemic inflammation elicited by sepsis can induce an acute cerebral dysfunction known as sepsis-associated encephalopathy (SAE). Recent evidence suggests that SAE is common but shows a dynamic trajectory over time. Half of all patients with sepsis develop SAE in the intensive care unit, and some survivors present with sustained cognitive impairments for several years after initial sepsis onset. It is not clear why some, but not all, patients develop SAE and also the factors that determine the persistence of SAE. Here, we first summarize the chronic pathology and the dynamic changes in cognitive functions seen after the onset of sepsis. We then outline the cerebral effects of sepsis, such as neuroinflammation, alterations in neuronal synapses and neurovascular changes. We discuss the key factors that might contribute to the development and persistence of SAE in older patients, including premorbid neurodegenerative pathology, side effects of sedatives, renal dysfunction and latent virus reactivation. Finally, we postulate that some of the mechanisms that underpin neuropathology in SAE may also be relevant to delirium and persisting cognitive impairments that are seen in patients with severe COVID-19.

Effects of Glucocorticoids on Postoperative Neurocognitive Disorders in Adult Patients: A Systematic Review and Meta-Analysis

Background

Postoperative neurocognitive disorders (PNDs) is common among surgical patients, however, the effect of glucocorticoids for preventing PNDs is not clear. This review aims to evaluate the effect of glucocorticoids on the incidence of PNDs in adult patients undergoing surgery.

Methods

The databases of PubMed/Medline, Embase, the Cochrane Library, and Web of science were searched for all available randomized controlled trials (RCTs) from inception to April 30, 2022. RCTs comparing the effect of glucocorticoids with placebo on the incidence of PNDs in adult surgical patients (≥18 years old) were eligible. Subgroup analyses and meta-regressions were performed to evaluate sources of clinical heterogeneity. The level of certainty for main outcomes were assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology.

Results

Eleven trials with a total of 10,703 patients were identified. Compared with the control group, glucocorticoids did not reduce the incidence of PNDs (RR: 0.84, 95% CI: 0.67 to 1.06, P = 0.13, GRADE = moderate). Secondary analyses for primary outcome did not change the result. In addition, the length of ICU stay was decreased in glucocorticoids group (RR: −13.58, 95% CI: −26.37 to −0.80, P = 0.04, GRADE = low). However, there were no significant differences between groups with regards to the incidence of postoperative infection (RR: 0.94, 95% CI: 0.84 to 1.06, P = 0.30, GRADE = moderate), blood glucose level (RR: 1.05, 95% CI: −0.09 to 2.19, P = 0.07, GRADE = low), duration of mechanical ventilation (RR: −2.44, 95% CI: −5.47 to 0.59, P = 0.14, GRADE = low), length of hospital stay (RR: −0.09, 95% CI: −0.27 to 0.09, P = 0.33, GRADE = moderate) and 30-day mortality (RR: 0.86, 95% CI: 0.70 to 1.06, P = 0.16, GRADE = moderate).

Conclusions

This meta-analysis suggests that perioperative administration of glucocorticoids may not reduce the incidence of PNDs after surgery. The effect of glucocorticoids on decreased length of ICU stay needs further researches. Future high-quality trials using acknowledged criteria and validated diagnostic tools are needed to determine the influence of glucocorticoids on long-term PNDs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022302262, identifier: CRD42022302262.

Impact of combined epidural anaesthesia/analgesia on postoperative cognitive impairment in patients receiving general anaesthesia: a meta-analysis of randomised controlled studies

BACKGROUND

To investigate the efficacy of combined epidural anaesthesia/analgesia (EAA) against postoperative delirium/cognitive dysfunction (POD/POCD) in adults after major non-cardiac surgery under general anaesthesia (GA).

METHODS

The databases of PubMed, Google scholar, Embase and Cochrane Central Register were searched from inception to November 2021 for available randomised controlled trials (RCTs) that assessed the impact of EAA on risk of POD/POCD. The primary outcome was risk of POD/POCD, while the secondary outcomes comprised postoperative pain score, length of hospital stay (LOS), risk of complications, and postoperative nausea/vomiting (PONV).

RESULTS

Meta-analysis of eight studies with a total of 2376 patients (EAA group: 1189 patients; non-EAA group: 1187 patients) revealed no difference in risk of POD/POCD between the EAA and the non-EAA groups [Risk ratio (RR): 0.68; 95% CI: 0.41 to 1.13, p = 0.14, I² = 73%], but the certainty of evidence was very low. Nevertheless, the EAA group had lower pain score at postoperative 24 h [mean difference (MD): -1.49, 95% CI: -2.38 to -0.61; I² = 98%; five RCTs; n = 476] and risk of PONV (RR = 0.73, 95% CI: 0.57 to 0.93, p = 0.01, I² = 0%; three RCTs, 1876 patients) than those in the non-EAA group. Our results showed no significant impact of EAA on the pain score at postoperative 36-72 h, LOS, and risk of complications.

CONCLUSION

This meta-analysis demonstrated that EAA had no significant impact on the incidence of POD/POCD in patients following non-cardiac surgery.

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

PURPOSE

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

DESIGN

A scoping review.

METHODS

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

FINDINGS

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

CONCLUSION

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

Historical and Modern Evidence for the Role of Reward Circuitry in Emergence

Increasing evidence supports a role for brain reward circuitry in modulating arousal along with emergence from anesthesia. Emergence remains an important frontier for investigation, since no drug exists in clinical practice to initiate rapid and smooth emergence. This review discusses clinical and preclinical evidence indicating a role for two brain regions classically considered integral components of the mesolimbic brain reward circuitry, the ventral tegmental area and the nucleus accumbens, in emergence from propofol and volatile anesthesia. Then there is a description of modern systems neuroscience approaches to neural circuit investigations that will help span the large gap between preclinical and clinical investigation with the shared aim of developing therapies to promote rapid emergence without agitation or delirium. This article proposes that neuroscientists include models of whole-brain network activity in future studies to inform the translational value of preclinical investigations and foster productive dialogues with clinician anesthesiologists.

The association between preoperative Mini-Cog© score and postoperative delirium (POD): a retrospective cohort study

Background

The onset of delirium after major surgery is associated with worse in-hospital outcomes for major surgical patients. Best practice recommends assessing surgical patients for delirium risk factors and this includes screening for cognitive impairment. The Mini-Cog© is a short instrument which has been shown to predict postoperative delirium (POD) and other complications in elderly patients undergoing major elective surgery. The primary aim of this study was to ascertain whether a positive preoperative Mini-Cog© is associated with postoperative delirium in elective colorectal surgery patients at high-risk of mortality due to age or comorbidity. Secondary outcomes were 90-day mortality and length of stay.

Methods

This is a retrospective analysis of data gathered prospectively between October 2015 and December 2017. Baseline data were collected at a preoperative screening clinic, and postoperative data during daily ward rounds by the Perioperative Medicine team at The York Hospital.

Results

Three hundred nineteen patients were included in the final analysis, of which 52 (16%) were found to be cognitively impaired on the Mini-Cog©. Older patients (median difference 10 years, p < 0.001) and patients with cognitive impairment (OR 3.04, 95%CI 1.15 to 8.03, p = 0.019) were more likely to develop postoperative delirium in univariate analysis; however, cognitive impairment (OR 0.492, 95%CI 0.177 to 1.368, p = 0.174) loses its significance when controlled for by confounding factors in a logistic regression model. Cognitive impairment (OR 4.65, 95%CI 1.36 to 15.9, p = 0.02), frailty (OR 7.28, 95%CI 1.92 to 27.58, p = 0.009), American Society of Anesthesiologists (ASA) grade (OR 5.95, 95%CI 1.54 to 22.94, p = 0.006) and age (median difference 10 years, p = 0.002) were significantly associated with 90-day mortality in univariate analysis. Sex was the only factor significantly associated with length of stay in the multiple regression model, with males having a 3-day longer average length of stay than females (OR = 2.94, 95%CI 0.10–5.78).

Conclusions

Mini-Cog© is not independently associated with post-operative delirium in high-risk elective colorectal surgery patients in this cohort. Mini-Cog© shows promise as a possible predictor of 90-day mortality. Larger studies exploring preoperative cognitive status and postoperative confusion and mortality could improve risk-stratification for surgery and allocation of resources to those patients at higher risk.

Effect of Electroencephalography Spectral Edge Frequency (SEF) and Patient State Index (PSI)-Guided Propofol-Remifentanil Anesthesia on Delirium After Laparoscopic Surgery: The eMODIPOD Randomized Controlled Trial

BACKGROUND

The effect of SedLine electroencephalography (EEG)-guided anesthetic care on postoperative delirium (POD) has not been studied.

METHODS

This single-center randomized EEG Monitoring tO Decrease the Incidence of Post-Operative Delirium (eMODIPOD) trial involved 1560 patients aged 50 years or above undergoing laparoscopic surgery. Propofol-remifentanil anesthesia was guided either by SedLine (EEG-guided care, n=779) or not (usual care, n=781). The goal of EEG-guided care was to maintain spectral edge frequency between 10 and 15 and patient state index (PSI) between 25 and 50. The primary outcome was the incidence of POD on postoperative days 1 to 5. The secondary outcomes included emergence delirium, composite moderate-to-severe complications, length of hospital stay, intensive care unit admission, 30-day hospital readmission and all-cause mortality, and intraoperative awareness.

RESULTS

Of the 1560 randomized patients, 1545 were included in the modified intention-to-treat analysis. The median propofol administered for anesthesia maintenance was 900 mg and 1000 mg in the EEG-guided and usual care groups, respectively (P=0.21). POD occurred in 1.0% (8/771) and 1.2% (9/774) of patients in the EEG-guided and usual care groups, respectively (risk ratio: 0.89; 95% confidence interval: 0.35-2.30). There were no between-group differences in all secondary outcome measures. Emergence delirium occurred in 11.8% (91/771) and 13.2% (102/774) of the EEG-guided care and usual care groups, respectively (risk ratio: 0.90; 95% confidence interval: 0.69-1.17; P=0.41). Three patients from each group reported intraoperative awareness.

CONCLUSIONS

Compared with usual care, SedLine spectral edge frequency-guided and patient state index-guided propofol-remifentanil anesthetic care neither alters anesthetic delivery nor decreases the unexpected low incidence of POD in relatively young Chinese patients undergoing laparoscopic surgery.

Review of Postoperative Delirium in Geriatric Patients After Hip Fracture Treatment

Introduction

Postoperative delirium (POD) is a serious complication occurring in 4–53.3% of geriatric patients undergoing surgeries for hip fracture. Incidence of hip fractures is projected to grow 11.9% from 258,000 in 2010 to 289,000 in 2030 based on 1990 to 2010 data. As prevalence of hip fractures is projected to increase, POD is also anticipated to increase.

Signficance

Postoperative delirium remains the most common complication of emergency hip fracture surgery leading to high morbidity and mortality rates despite significant research conducted regarding this topic. This study reviews literature from 1990 to 2021 regarding POD in geriatric hip fracture management.

Results

Potentially modifiable and non-modifiable risk factors for developing POD include, but are not limited to, male gender, older age, multiple comorbidities, specific comorbidities (dementia, cognitive impairment, diabetes, vision impairment, and abnormal blood pressure), low BMI, preoperative malnutrition, low albumin, low hematocrit, blunted preoperative cytokines, emergency surgery, time to admission and surgery, preoperative medical treatment, polypharmacy, delirium-inducing medications, fever, anesthesia time, and sedation depth and type. Although the pathophysiology remains unclear, the leading theories suggest neurotransmitter imbalance, inflammation, and electrolyte or metabolic derangements as the underlying cause of POD. POD is associated with increased length of hospital stay, cost, morbidity, and mortality. Prevention and early recognition are key factors in managing POD. Methods to reduce POD include utilizing interdisciplinary teams, educational programs for healthcare professionals, reducing narcotic use, avoiding delirium-inducing medications, and multimodal pain control.

Conclusion

While POD is a known complication after hip fracture surgery, further exploration in prevention is needed. Early identification of risk factors is imperative to prevent POD in geriatric patients. Early prevention will enhance delivery of health care both pre- and post-operatively leading to the best possible surgical outcome and better quality of life after hip fracture treatment.

The Perioperative Use of Benzodiazepines for Major Orthopedic Surgery in the United States

BACKGROUND

Despite numerous indications for perioperative benzodiazepine use, associated risks may be exacerbated in elderly and comorbid patients. In the absence of national utilization data, we aimed to describe utilization patterns using national claims data from total hip/knee arthroplasty patients (THA/TKA), an increasingly older and vulnerable surgical population.

METHODS

We included data on 1,863,996 TKAs and 985,471 THAs (Premier Healthcare claims data, 2006-2019). Benzodiazepine utilization (stratified by long- and short-acting agents) was assessed by patient- and health care characteristics, and analgesic regimens. Given the large sample size, standardized differences instead of P values were utilized to signify meaningful differences between groups (defined by value >0.1).

RESULTS

Among 1,863,996 TKA and 985,471 THA patients, the utilization rate of benzodiazepines was 80.5% and 76.1%, respectively. In TKA, 72.6% received short-acting benzodiazepines, while 7.9% received long-acting benzodiazepines, utilization rates 68.4% and 7.7% in THA, respectively. Benzodiazepine use was particularly more frequent among younger patients (median age [interquartile range {IQR}]: 66 [60-73]/64 [57-71] among short/long-acting compared to 69 [61-76] among nonusers), White patients (80.6%/85.4% short/long-acting versus 75.7% among nonusers), commercial insurance (36.5%/34.0% short/long-acting versus 29.1% among nonusers), patients receiving neuraxial anesthesia (56.9%/56.5% short/long-acting versus 51.5% among nonusers), small- and medium-sized (≤500 beds) hospitals (68.5% in nonusers, and 74% and 76.7% in short- and long-acting benzodiazepines), and those in the Midwest (24.6%/25.4% short/long-acting versus 16% among nonusers) in TKA; all standardized differences ≥0.1. Similar patterns were observed in THA except for race and comorbidity burden. Notably, among patients with benzodiazepine use, in-hospital postoperative opioid administration (measured in oral morphine equivalents [OMEs]) was substantially higher. This was even more pronounced in patients who received long-acting agents (median OME with no benzodiazepines utilization 192 [IQR, 83-345] vs 256 [IQR, 153-431] with short-acting, and 329 [IQR, 195-540] with long-acting benzodiazepine administration). Benzodiazepine use was also more frequent in patients receiving multimodal analgesia (concurrently 2 or more analgesic modes) and regional anesthesia. Trend analysis showed a persistent high utilization rate of benzodiazepines over the last 14 years.

CONCLUSIONS

Based on a representative sample, 4 of 5 patients undergoing major orthopedic surgery in the United States receive benzodiazepines perioperatively, despite concerns for delirium and delayed postoperative neurocognitive recovery. Notably, benzodiazepine utilization was coupled with substantially increased opioid use, which may project implications for perioperative pain management.

Effects of anesthetics on expression of dopamine and acetylcholine receptors in the rat brain in vivo

Dopamine D₂ and acetylcholine M₁ receptors might be related to post-operative cognitive dysfunction. The aim of the present study is to investigate whether several anesthetics which are used for general anesthesia and/or sedation, affect expression of dopamine D₂ and acetylcholine M₁ receptors in the rat brain. Thirty-six male rats aged 5-9 weeks old were divided into six groups (n = 6 in each group); five groups for anesthetics and one for control. The five groups were anesthetized with either dexmedetomidine 0.4 µg/kg/min, propofol 50 mg/kg/h, midazolam 25 mg/kg/h, sevoflurane 3.3%, or nitrous oxide 75% for 4 h. Then, the rats were decapitated, and the cerebral cortex, hippocampus, corpus striatum, brain stem, and cerebellum were collected from all rats. Then, real-time polymerase chain reaction was performed to examine the expression of Drd2 (cord dopamine D₂ receptor) and Chrm1 (cord acetylcholine M₁ receptor). There were no significant differences among the groups regarding Drd2 and Chrm1 mRNA expression of each region of the brain. Postsynaptic changes of dopamine D₂ and acetylcholine M₁ receptors due to administration of dexmedetomidine, propofol, midazolam, sevoflurane, and nitrous oxide are unlikely to occur at the doses of each anesthetic used in the present study.

The association between the inflammatory response following surgery and post-operative delirium in older oncological patients: a prospective cohort study

INTRODUCTION

Post-operative delirium (POD) is associated with increased morbidity and mortality rates in older patients. Neuroinflammation, the activation of the intrinsic immune system of the brain, seems to be one of the mechanisms behind the development of POD. The aim of this study was to explore the association between the perioperative inflammatory response and the development of POD in a cohort of older oncological patients in need for surgery.

METHODS

In this prospective cohort study, patients 65 years and older in need for oncologic surgery were included. Inflammatory markers C-reactive protein (CRP), interleukin-1 beta (IL-1β), IL-6, IL10 and Neutrophil gelatinase-associated lipocalin (NGAL) were measured in plasma samples pre- and post-operatively. Delirium Observation Screening Scale (DOS) was used as screening instrument for POD in the first week after surgery. In case of positive screening, diagnosis of POD was assessed by a clinician.

RESULTS

Between 2010 and 2016, plasma samples of 311 patients with median age of 72 years (range 65-89) were collected. A total of 38 (12%) patients developed POD in the first week after surgery. The perioperative increase in plasma levels of IL-10 and NGAL were associated with POD in multivariate logistic regression analysis (OR 1.33 [1.09-1.63] P = 0.005 and OR 1.30 [1.03-1.64], P = 0.026, respectively). The biomarkers CRP, IL-1β and IL-6 were not significantly associated with POD.

CONCLUSIONS

Increased surgery-evoked inflammatory responses of IL-10 and NGAL are associated with the development of POD in older oncological patients. The outcomes of this study contribute to understanding the aetiology of neuroinflammation and the development of POD.

Analysis of Adverse Effects of Multimodal Gabapentin in Abdominal Wall Reconstruction

BACKGROUND

Multimodal analgesia, a key component of enhanced recovery after surgery protocols, emphasizes the use of nonopioid analgesics. Preoperative and postoperative gabapentin is often included within multimodal analgesia because it has been shown to reduce postoperative opioid use. However, the role of gabapentin has been questioned because of concerns of adverse effects, particularly in the elderly. In an effort to better understand the specific role of gabapentin within the context of an established enhanced recovery after surgery protocol, the authors studied the prevalence of its adverse effects in patients undergoing abdominal wall reconstruction.

METHODS

Following institutional review board approval, a retrospective review of a prospectively collected database of 267 consecutive patients who underwent abdominal wall reconstruction performed by a single surgeon was conducted. Demographic variables; operative details; postoperative analgesic use; the presence of dizziness, lightheadedness, or altered mental status; hypotension; negative Richmond Agitation Sedation Scale scores; and postoperative falls were recorded and analyzed according to postoperative gabapentin administration.

RESULTS

Two hundred thirteen patients (80 percent) met inclusion criteria, of which 138 (65 percent) received postoperative gabapentin. Postoperative gabapentin use was not associated with dizziness, lightheadedness, or altered mental status; hypotension; negative Richmond Agitation Sedation Scale scores; or falls. Furthermore, even among those aged 65 years or older, postoperative gabapentin use was not significantly associated with these adverse events.

CONCLUSIONS

In patients undergoing abdominal wall reconstruction, postoperative gabapentin administration was not associated with an increase in adverse effects. Further prospective analysis may better allow the characterization of the adverse effects of perioperative gabapentin.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Delirium in geriatric patients

Delirium is the most common acute disorder of cognitive function in older patients. Delirium is life threatening, often under-recognized, serious, and costly. The causes are multifactorial, with old age and neurocognitive disorders as the main risk factors. Etiologies are various and multifactorial, and often related to acute medical illness, adverse drug reactions, or medical complications. To date, diagnosis is clinically based, depending on the presence or absence of certain features. In view of the multifactorial etiology, multicomponent approaches seem most promising for facing patients’ needs. Pharmacological intervention, neither for prevention nor for treatment, has been proven effective unanimously. This article reviews the current clinical practice for delirium in geriatric patients, including etiology, pathophysiology, diagnosis, prognosis, treatment, prevention, and outcomes.

Burst Suppression During General Anesthesia and Postoperative Outcomes: Mini Review

In the last decade, burst suppression has been increasingly studied by many to examine whether it is a mechanism leading to postoperative cognitive impairment. Despite a lack of consensus across trials, the current state of research suggests that electroencephalogram (EEG) burst suppression, duration and EEG emergence trajectory may predict postoperative delirium (POD). A mini literature review regarding evidence about burst suppression impact and susceptibilities was conducted, resulting in conflicting studies. Primarily, studies have used different algorithm values to replace visual burst suppression examination, although many studies have since emerged showing that algorithms underestimate burst suppression duration. As these methods may not be interchangeable with visual analysis of raw data, it is a potential factor for the current heterogeneity between data. Even though additional research trials incorporating the use of raw EEG data are necessary, the data currently show that monitoring with commercial intraoperative EEG machines that use EEG indices to estimate burst suppression may help physicians identify burst suppression and guide anesthetic titration during surgery. These modifications in anesthetics could lead to preventing unfavorable outcomes. Furthermore, some studies suggest that brain age, baseline impairment, and certain medications are risk factors for burst suppression and postoperative delirium. These patient characteristics, in conjunction with intraoperative EEG monitoring, could be used for individualized patient care. Future studies on the feasibility of raw EEG monitoring, new technologies for anesthetic monitoring and titration, and patient-associated risk factors are crucial to our continued understanding of burst suppression and postoperative delirium.

Individual Pharmacotherapy Management (IPM) - I: a group-matched retrospective controlled clinical study on prevention of complicating delirium in the elderly trauma patients and identification of associated factors

Background

Delirium is one of the most frequent complications in hospitalized elderly patients with additional costs such as prolongation of hospital stays and institutionalization, with risk of reduced functional recovery, long-term cognitive impairment, and increased morbidity and mortality. We analyzed the effect of individual pharmacotherapy management (IPM) in the University Hospital Halle in geriatric trauma patients on complicating delirium and aimed to identify associated factors.

Methods

In a retrospective controlled clinical study of 404 hospitalized trauma patients ≥70 years we compared the IPM intervention group (IG) with a control group (CG) before IPM implementation. Delirium was recorded from the hospital discharge letter. The medication review and data records included baseline data, all medications, diagnoses, electrocardiogram (ECG), laboratory and vital parameters during hospitalization. The IPM internist and the senior trauma physician guaranteed personnel and structural continuity in the implementation of the interdisciplinary patient rounds.

Results

There was a highly matched congruence between CG and IG in terms of age, gender, residency, BMI, most diagnoses, and injury patterns to compare the two groups. The total number of medications per patient was 11.1 ± 4.9 (CG) versus 10.4 ± 3.6 (IG). Our targeted IPM focus on 6 frontline aspects with reduction of antipsychotics, anticholinergic burden, benzodiazepines, serotonergic opioids, elimination of pharmacokinetic and pharmacodynamic drug interactions and overdosage reduced complicating delirium from 5% to almost zero at 0.5%. The association of IPM with a significant 10-fold reduction, OR = 0.09 [95% CI 0.01–0.7], in univariable regression, maintained of clinical relevance in multivariable regression OR = 0.1 [95% CI 0.01–1.1]. Factors most strongly associated with complicating delirium in univariable regression were cognitive dysfunction, nursing home residency, muscle relaxants, antiparkinsonian agents, xanthines, transient disorientation documented in the fall risk scale, antibiotic-requiring infections, antifungals, antipsychotics, and intensive care stay, the two latter maintaining significance in multivariable regression.

Conclusions

IPM is associated with a highly effective prevention of complicating delirium in the elderly trauma patients. For patient safety it should be integrated as an essential preventative contribution. The associated factors help identify patients at risk.

Geriatric Preoperative Optimization: A Review

This review summarizes best practices for the perioperative care of older adults as recommended by the American Geriatrics Society, American Society of Anesthesiologists, and American College of Surgeons, with practical implementation strategies that can be readily implemented in busy preoperative or primary care clinics. In addition to traditional cardiopulmonary screening, older patients should undergo a comprehensive geriatric assessment. Rapid screening tools such as the Mini-Cog, Patient Health Questionnaire-2, and Frail Non-Disabled Survey and Clinical Frailty Scale, can be performed by multiple provider types and allow for quick, accurate assessments of cognition, functional status, and frailty screening. To assess polypharmacy, online resources can help providers identify and safely taper high-risk medications. Based on preoperative assessment findings, providers can recommend targeted prehabilitation, rehabilitation, medication management, care coordination, and/or delirium prevention interventions to improve postoperative outcomes for older surgical patients. Structured goals of care discussions utilizing the question-prompt list ensures that older patients have a realistic understanding of their surgery, risks, and recovery. This preoperative workup, combined with engaging with family members and interdisciplinary teams, can improve postoperative outcomes.

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.

Prediction of Postoperative Delirium in Geriatric Hip Fracture Patients: A Clinical Prediction Model Using Machine Learning Algorithms

Introduction

Postoperative delirium in geriatric hip fracture patients adversely affects clinical and functional outcomes and increases costs. A preoperative prediction tool to identify high-risk patients may facilitate optimal use of preventive interventions. The purpose of this study was to develop a clinical prediction model using machine learning algorithms for preoperative prediction of postoperative delirium in geriatric hip fracture patients.

Materials & Methods

Geriatric patients undergoing operative hip fracture fixation were queried in the American College of Surgeons National Surgical Quality Improvement Program database (ACS NSQIP) from 2016 through 2019. A total of 28 207 patients were included, of which 8030 (28.5%) developed a postoperative delirium. First, the dataset was randomly split 80:20 into a training and testing subset. Then, a random forest (RF) algorithm was used to identify the variables predictive for a postoperative delirium. The machine learning-model was developed on the training set and the performance was assessed in the testing set. Performance was assessed by discrimination (c-statistic), calibration (slope and intercept), overall performance (Brier-score), and decision curve analysis.

Results

The included variables identified using RF algorithms were (1) age, (2) ASA class, (3) functional status, (4) preoperative dementia, (5) preoperative delirium, and (6) preoperative need for mobility-aid. The clinical prediction model reached good discrimination (c-statistic = .79), almost perfect calibration (intercept = −.01, slope = 1.02), and excellent overall model performance (Brier score = .15). The clinical prediction model was deployed as an open-access web-application: https://sorg-apps.shinyapps.io/hipfxdelirium/.

Discussion & Conclusions

We developed a clinical prediction model that shows promise in estimating the risk of postoperative delirium in geriatric hip fracture patients. The clinical prediction model can play a beneficial role in decision-making for preventative measures for patients at risk of developing a delirium. If found to be externally valid, clinicians might use the available web-based application to help incorporate the model into clinical practice to aid decision-making and optimize preoperative prevention efforts.

Spinal Anesthesia with Targeted Sedation based on Bispectral Index Values Compared with General Anesthesia with Masked Bispectral Index Values to Reduce Delirium: The SHARP Randomized Controlled Trial

BACKGROUND

Reducing depth of anesthesia and anesthetic exposure may help prevent delirium, but trials have been conflicting. Most studies were conducted under general anesthesia or in cognitively impaired patients. It is unclear whether reducing depth of anesthesia beyond levels consistent with general anesthesia reduces delirium in cognitively intact patients. The authors' objective was to determine whether a bundled approach to reduce anesthetic agent exposure as determined by Bispectral Index (BIS) values (spinal anesthesia with targeted sedation based on BIS values) compared with general anesthesia (masked BIS) reduces delirium.

METHODS

Important eligibility criteria for this parallel-arm randomized trial were patients 65 yr or greater undergoing lumbar spine fusion. The intervention group received spinal anesthesia with targeted sedation to BIS greater than 60 to 70. The control group received general anesthesia (masked BIS). The primary outcome was delirium using the Confusion Assessment Method daily through postoperative day 3, with blinded assessment.

RESULTS

The median age of 217 patients in the analysis was 72 (interquartile range, 69 to 77). The median BIS value in the spinal anesthesia with targeted sedation based on BIS values group was 62 (interquartile range, 53 to 70) and in the general anesthesia with masked BIS values group was 45 (interquartile range, 41 to 50; P < 0.001). Incident delirium was not different in the spinal anesthesia with targeted sedation based on BIS values group (25.2% [28 of 111] vs. the general anesthesia with masked BIS values group (18.9% [20 of 106]; P = 0.259; relative risk, 1.22 [95% CI, 0.85 to 1.76]). In prespecified subgroup analyses, the effect of anesthetic strategy differed according to the Mini-Mental State Examination, but not the Charlson Comorbidity Index or age. Two strokes occurred among patients receiving spinal anesthesia and one death among patients receiving general anesthesia.

CONCLUSIONS

Spinal anesthesia with targeted sedation based on BIS values compared with general anesthesia with masked BIS values did not reduce delirium after lumbar fusion.

EDITOR’S PERSPECTIVE

[Nonpharmaceutical concepts for prevention and treatment of delirium]

BACKGROUND

Cognitive impairment is common among older patients in German hospitals (40%). Dementia, other brain diseases and frailty significantly increase the risk of delirium and pose great challenges to interdisciplinary and interprofessional teams. Delirium prevention is achievable but requires complex interdepartmental strategies with specific components for timely recognition of the individual delirium risk, to carry out structured and sustained implementation of appropriate measures for delirium prevention as well as prompt etiological diagnostics and immediate treatment when delirium occurs.

OBJECTIVE

The present work aims to shed light on the role of interprofessional and interdisciplinary collaboration in evidence-based, nonpharmacological delirium prevention programs.

MATERIAL AND METHODS

Narrative review of international best practice programs.

RESULTS

Nonpharmacological prevention of delirium is effective but requires differentiated risk identification, regular delirium screening and daily targeted cognitive activation and sleep promotion. This can only be achieved in close interprofessional collaboration and is mostly carried out interdepartmentally by specialized teams.

DISCUSSION

Interprofessional multicomponent programs for delirium prevention hold the potential to reduce delirium and complication rates in older high-risk patients in regular care, thereby improving treatment and long-term quality of life. Additional interprofessional delirium prevention teams are deployed in different settings simultaneously and provide regular training on optimal delirium management. Demonstration of the effectiveness of cross-setting programs requires large multicenter studies and is therefore particularly laborious.

Approach to Altered Mental Status and Inpatient Delirium

Altered mental status is a nonspecific diagnosis that encompasses a wide spectrum of disease and is frequently cited as a reason for both hospital admission and inpatient neurologic consultation. There are numerous etiologies of altered mental status, and so although many are facile with the workup of this potentially life-threatening entity, it can nevertheless be overwhelming. Our goal was to provide a practical framework embedded in a current, comprehensive review of the epidemiology, clinical evaluation, and management of undifferentiated altered mental status. We pay particular attention to the management of a critical yet underdiagnosed subtype of altered mental status: delirium.

Lack of Association Between Perioperative Medication and Postoperative Delirium in Hip Fracture Patients in an Orthogeriatric Care Pathway

OBJECTIVES

Units for perioperative geriatric care are playing a growing role in the care of older patients after hip fracture surgery. Postoperative delirium is one of the most common complications after hip fracture, but no study has assessed the impact of therapeutics received during a dedicated orthogeriatric care pathway on its incidence. Our main objective was to assess the association between drugs used in emergency, operating, and recovery departments and postoperative delirium during the acute stay.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

All patients ≥70 years old admitted for hip fracture to the emergency department and hospitalized in our unit for perioperative geriatric care after hip fracture surgery under general anesthesia between July 2009 and December 2019 in an academic hospital in Paris.

METHODS

Demographic, clinical, and biological data and all medications administered pre-, peri-, and postoperatively were prospectively collected by 3 geriatricians. Postoperative delirium in the unit for perioperative geriatric care was assessed by using the confusion assessment method scale. Logistic regression analysis was used to assess variables independently associated with postoperative delirium.

RESULTS

A total of 490 patients were included [mean (SD) age 87 (6) years]; 215 (44%) had postoperative delirium. The occurrence was not associated with therapeutics administered during the dedicated orthogeriatric care pathway. Probability of postoperative delirium was associated with advanced age [>90 years, odds ratio (OR) 2.03, 95% confidence interval (CI) 1.07-3.89], dementia (OR 3.51, 95% CI 2.14--5.82), depression (OR 1.85, 95% CI 1.14-3.01), and preoperative use of beta-blockers (OR 1.75, 95% CI 1.10-2.79).

CONCLUSIONS AND IMPLICATIONS

No emergency or anesthetic drugs were significantly associated with postoperative delirium. Further studies are needed to demonstrate a possible causal link between preoperative use of beta-blockers and postoperative delirium.

Delirium risk of histamine-2 receptor antagonists and proton pump inhibitors: A study based on the adverse drug event reporting database in Japan

OBJECTIVE

Although histamine-2 receptor antagonists (H2RAs) have been shown to be more likely to cause delirium than proton pump inhibitors (PPIs), these results were not adjusted for potential confounding factors. Accordingly, we investigated whether H2RAs and PPIs are risk factors for delirium, even when adjusting for other risk factors by analyzing adverse drug event reports compiled in the post-marketing stages of drugs provided by the Japanese regulatory authorities.

METHOD

We analyzed 577,431 reports in the Japanese Adverse Drug Event Report database from April 2004 to July 2020.

RESULTS

Of all reports analyzed, 2532 described delirium, and 574,899 described other adverse events. Delirium was associated with H2RAs (crude reporting odds ratio, ROR, 4.17; 95% CI, 3.34-5.22) but not PPIs (crude ROR 0.62; 95% CI 0.43-0.90). Even with adjustment for age, sex, history of dementia or depression, and concomitant drugs reported as risk factors for delirium, the use of H2RAs showed a significantly higher adjusted ROR than that of PPIs (H2RAs: adjusted ROR 3.99; 95% CI 3.18-5.01 and PPIs: adjusted ROR 0.58; 95%CI 0.40-0.84).

CONCLUSIONS

These results suggest that, from a cognitive perspective, PPIs may be preferable to H2RAs for patients with or at risk for delirium.

Perioperative Pain Management Issues Unique to Older Adults Undergoing Surgery: A Narrative Review

INTRODUCTION

The older population is growing and with this growth there is a parallel rise in the operations performed on this vulnerable group. The perioperative pain management strategy for older adults is unique and requires a team-based approach for provision of high-quality surgical care.

METHODS

Literature search was performed using PubMed in addition to review of relevant protocols and guidelines from geriatric, surgical, and anesthesia societies. Systematic reviews and meta-analyses, randomized trials, observational studies, and society guidelines were summarized in this review.

MANAGEMENT

The optimal approach to a pain management strategy for older adults undergoing surgery involves addressing all phases of perioperative care. For example, preoperative assessment of a patient's cognitive function and presence of chronic pain may impact the pain management plan. Consideration should be also given to intraoperative strategies to improve pain control and minimize both the dose and side effects from opioids (e.g. regional anesthetic techniques). Postoperative pain control (e.g. under or over treatment of pain) may impact the development of elderly-specific complications such as postoperative delirium and functional decline. Finally, pain management does not stop after the older adult patient leaves the hospital. Both discharge planning and post-operative clinic follow-up provide important opportunities for collaboration and intervention.

CONCLUSIONS

An opioid-sparing pain management strategy for older adults can be accomplished with a comprehensive and collaborative interdisciplinary strategy addressing all phases of perioperative care.

Postoperative Cardiovascular Surgery Delirium: Interrater Agreement Between Nurses and Clinical Nurse Specialist and Factors Associated With Prevalence

PURPOSE

The aims of this study were to examine interrater agreement of delirium between clinical nurses and a clinical nurse specialist, determine delirium subtype prevalence, and examine associated patient, procedure, and hospital factors.

DESIGN

A descriptive cross-sectional design and a convenience sample of nurses and patients on progressive care units were used in this study.

METHODS

Clinical nurse specialist data were collected on a case report form, and clinician and patient data were obtained from electronic databases. Interrater agreement of delirium prevalence was assessed by κ statistic, and logistic regression models were used to determine patient factors associated with delirium.

RESULTS

Of 216 patients, 23 had delirium; clinical nurses identified fewer cases than the clinical nurse specialist: 1.8% versus 10.7%; κ agreement, 0.27 (0.06, 0.49). By delirium subtype, hypoactive delirium was more frequent (n = 10). Factors associated with delirium were history of cerebrovascular disease (odds ratio [95% confidence interval], 2.8 [1.01-7.7]; P = .044), history of mitral valve disease (odds ratio [95% confidence interval], 0.31 [0.09-0.90]; P = .041), and longer perfusion time (odds ratio [95% confidence interval], 1.7 [1.1-2.7]; P = .016). One factor was associated with hypoactive delirium, longer perfusion time (odds ratio [95% confidence interval], 2.2 [1.3-4.2]; P = .008).

CONCLUSIONS

Because clinician-clinical nurse specialist delirium agreement was low and hypoactive delirium was common, clinical interventions are needed.

Postoperative Delirium in Patients After Brain Tumor Surgery

BACKGROUND

Postoperative delirium is a common surgical complication that can be associated with poorer outcome. Many patients with brain tumors experience delirium after surgery. We hypothesize that patients who experience delirium after resection of a brain tumor will have worse outcomes post surgery in terms of mortality, disposition, and length of stay compared with those without postoperative delirium. We also examine differences between nurse and physician diagnoses of delirium.

METHODS

Data from patients undergoing brain tumor resection at University of Missouri Hospital were retrospectively collected. Delirium was defined using Diagnostic and Statistical Manual-5 criteria. Patients with delirium were compared with patients without delirium using chi-squared test, Cohen Kappa value, and binomial proportion analysis at 95% confidence intervals or P < 0.05.

RESULTS

Of 500 patients having brain tumor resections, 93 (18.6%) were diagnosed with postoperative delirium. Patients with delirium had higher 30-day mortality (9.78% vs. 1.48%; P < 0.0001), required restraints more often (42.39% vs. 5.91%, P < 0.0001), had longer hospital length of stay (14.3 vs. 6.3 days; P < 0.0001), and increased skilled nursing facility disposition (57.3% vs. 26.11%; P < 0.0001) than patients without delirium. Diagnosis of delirium between nursing staff and clinicians moderately correlated (Kappa 0.5677 ± 0.0536).

CONCLUSIONS

Delirium, a common postoperative complication after brain tumor surgery, is associated with longer length of stay, increased disposition to skilled nursing facility, and increased 30-day mortality. These findings reinforce the importance of early recognition, diagnosis, and treatment of postoperative delirium in brain tumor resection patients.

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

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

Systemic inflammation induced the delayed reduction of excitatory synapses in the CA3 during ageing

Sepsis-associated encephalopathy (SAE) represents diverse cerebral dysfunctions in response to pathogen-induced systemic inflammation. Peripheral exposure to lipopolysaccharide (LPS), a component of the gram-negative bacterial cell wall, has been extensively used to model systemic inflammation. Our previous studies suggested that LPS led to hippocampal neuron death and synaptic destruction in vivo. However, the underlying roles of activated microglia in these neuronal changes remained unclear. Here, LPS from two different bacterial strains (Salmonella enterica or E. coli) were compared and injected in 14- to 16-month-old mice and evaluated for neuroinflammation and neuronal integrity in the hippocampus at 7 or 63 days post-injection (dpi). LPS injection resulted in persistent neuroinflammation lasting for seven days and a subsequent normalisation by 63 dpi. Of note, increases in proinflammatory cytokines, microglial morphology and microglial mean lysosome volume were more pronounced after E. coli LPS injection than Salmonella LPS at 7 dpi. While inhibitory synaptic puncta density remained normal, excitatory synaptic puncta were locally reduced in the CA3 region of the hippocampus at 63 dpi. Finally, we provide evidence that excitatory synapses coated with complement factor 3 (C3) decreased between 7 dpi and 63 dpi. Although we did not find an increase of synaptic pruning by microglia, it is plausible that microglia recognised and eliminated these C3-tagged synapses between the two time-points of investigation. Since a region-specific decline of CA3 synapses has previously been reported during normal ageing, we postulate that systemic inflammation may have accelerated or worsened the CA3 synaptic changes in the ageing brain.

Delirium Prevention in Postcardiac Surgical Critical Care

This review provides an overview for health care teams involved in the perioperative care of cardiac surgery patients. The intention is to summarize key determinants of delirium, its impact on short- and long-term outcomes as well as to discuss effective management strategies. The first component of this review examines the prevalence and the factors associated with an increased risk of postoperative delirium. A multitude of predisposing (eg, baseline vulnerability and comorbidities) and precipitating (eg, type of cardiac surgery and postoperative care) factors that contribute to the occurrence of delirium are discussed.

Cerebral oximetry and preventing neurological complication post-cardiac surgery: a systematic review

OBJECTIVES

This systematic review aims to provide an up-to-date summary of the current literature examining the relationship between intraoperative regional cerebral oxygen saturation and neurological complications after cardiac surgery.

METHODS

Observational and interventional studies investigating the link between regional cerebral oxygen saturation and postoperative delirium, cognitive dysfunction and stroke were included. After database searching and study screening, study characteristics and major findings were extracted.

RESULTS

Twenty-seven studies were identified. Of the observational studies (n = 17), 8 reported that regional cerebral oxygen desaturations were significantly associated with neurological complications after cardiac surgery. Of the interventional studies (n = 10), 3 provided evidence for monitoring cerebral oximetry during cardiac surgery as a means of reducing incidence of postoperative cognitive dysfunction or stroke. There was significant heterogeneity in the tools and rigor used to diagnose neurological complications.

CONCLUSIONS

Studies to date show an inconsistent relationship between regional cerebral oxygen saturation and neurological outcomes after cardiac surgery, and lack of clear benefit of targeting cerebral oximetry to minimize neurological complications. Standardized assessments, definitions of impairment and desaturation thresholds will help determine the benefits of cerebral oximetry monitoring during cardiac surgery.

Does cognitive decline/dementia increase Delirium risk after stroke?

BACKGROUND

Delirium is a common contributor to mortality and hospital costs in stroke patients. Different observational studies have showed inconsistent results regarding the association between cognitive decline/dementia and delirium after acute stroke. Therefore, we performed this meta-analysis with the aim of determining whether cognitive decline/dementia is related to the risk of delirium after acute stroke.

METHODS

We systematically searched PubMed, Embase, Google Scholar, and Web of Science for relevant studies from inception to September 2020. We calculated the pooled odds ratio (OR) with 95% confidence interval (CI) by using fixed or random effects models based on heterogeneity measured by the I² index.

RESULTS

The association between cognitive decline/dementia and post-stroke delirium was examined in 13 studies with 3183 participants. After pooled analysis, we found that cognitive decline/dementia was significantly associated with susceptibility to delirium in post-stroke patients (OR = 3.70, 95%CI: 2.90-4.71, P < 0.001). Subgroup analysis suggested that cognitive decline/dementia was associated with an increased risk of delirium in Caucasians (OR = 3.73, 95%CI: 2.73-5.11, P < 0.001), non-Caucasians (OR = 3.65, 95%CI: 2.50-5.33, P < 0.001), samples with <200 subjects (OR = 3.70, 95%CI: 2.17-6.31, P < 0.001), samples with ≥200 subjects (OR = 3.70, 95%CI: 2.82-4.85, P < 0.001), studies published in 1990-2009 (OR = 3.17, 95%CI: 1.48-6.77, P = 0.003), and studies published in 2010-2020 (OR = 3.76, 95%CI: 2.92-4.86, P < 0.001).

CONCLUSIONS

We identified an association between cognitive decline/dementia and the risk of developing delirium. Cognitive decline/dementia may be a promising predictor for delirium in post-stroke patients.

The adenosine A2A receptor alleviates postoperative delirium-like behaviors by restoring blood cerebrospinal barrier permeability in rats

Postoperative delirium (POD) is a common post-operative complication in elderly patients that is associated with increased morbidity and mortality. However, the neuropathogenesis of this complication remains unknown. The blood-cerebrospinal fluid barrier (BCB) and brain-blood barrier (BBB) are composed of tight junctions between cells that form physical barriers, and BBB damage plays an important role in the neuropathogenesis of POD. Nevertheless, the role of BCB in POD remains to be elucidated. Herein, we investigated the effect of adenosine A_2A receptor (A_2A R), a key regulator of the permeability of barriers, on surgery-induced increased permeability of BCB and POD-like behaviors. Open field, buried food, and Y maze tests were used to evaluate behavioral changes in rats after surgery. Levels of tight junction proteins, adherens junction proteins, A_2A R, GTP-RhoA, and ROCK2 in the choroid plexus were assessed by western blotting. The concentrations of NaFI and FITC-dextran in the cerebrospinal fluid (CSF) were detected by fluorescence spectrophotometry. Transmission electron microscopy was applied to observe the ultrastructure of the choroid plexus. Surgery/anesthesia decreased the levels of tight junction (e.g., ZO-1, occludin, and claudin1) proteins, increased concentrations of NaFI and FITC-dextran in CSF, damaged the ultrastructure of choroid plexus, and induced POD-like behaviors in rats. An A_2A R antagonist alleviated POD-like behaviors in rats. Furthermore, the A_2A R antagonist increased the levels of tight junction proteins and restored the permeability of BCB in rats with POD. Fasudil, a selective Rho-associated protein kinase 2 (ROCK2) inhibitor, ameliorated POD-like behaviors induced by A_2A R activation. Moreover, fasudil also abolished the increased levels of GTP-RhoA/ROCK2, decreased levels of tight junction proteins, and increased permeability of BCB caused by A_2A R activation. Our findings demonstrate that A_2A R might participate in regulating BCB permeability in rats with POD via the RhoA/ROCK2 signaling pathway, which suggests the potential of A_2A R as a therapeutic target for POD.