Strategies for prevention of postoperative delirium: a systematic review and meta-analysis of randomized trials

The Role of Delirium on Short- and Long-Term Postoperative Outcomes Following Major Gastrointestinal Surgery for Cancer

INTRODUCTION

The growing burden of an aging population has raised concerns about demands on healthcare systems and resources, particularly in the context of surgical and cancer care. Delirium can affect treatment outcomes and patient recovery. We sought to determine the prevalence of postoperative delirium among patients undergoing digestive tract surgery for malignant indications and to analyze the role of delirium on surgical outcomes.

METHODS

Medicare claims data were queried to identify patients diagnosed with esophageal, gastric, hepatobiliary, pancreatic, and colorectal cancers between 2018 and 2021. Postoperative delirium, occurring within 30 days of operation, was identified via International Classification of Diseases, 10th edition codes. Clinical outcomes of interested included "ideal" textbook outcome (TO), characterized as the absence of complications, an extended hospital stay, readmission within 90 days, or mortality within 90 days. Discharge disposition, intensive care unit (ICU) utilization, and expenditures also were examined.

RESULTS

Among 115,654 cancer patients (esophageal: n = 1854, 1.6%; gastric: n = 4690, 4.1%; hepatobiliary: n = 6873, 5.9%; pancreatic: n = 8912, 7.7%; colorectal: n = 93,325, 90.7%), 2831 (2.4%) were diagnosed with delirium within 30 days after surgery. On multivariable analysis, patients with delirium were less likely to achieve TO (OR 0.27 [95% CI 0.25-0.30]). In particular, patients who experienced delirium had higher odds of complications (OR 3.00 [2.76-3.25]), prolonged length of stay (OR 3.46 [3.18-3.76]), 90-day readmission (OR 1.96 [1.81-2.12]), and 90-day mortality (OR 2.78 [2.51-3.08]). Furthermore, patients with delirium had higher ICU utilization (OR 2.85 [2.62-3.11]). Upon discharge, patients with delirium had a decreased likelihood of being sent home (OR 0.40 [0.36-0.46]) and instead were more likely to be transferred to a skilled nursing facility (OR 2.17 [1.94-2.44]). Due to increased utilization of hospital resources, patients with delirium incurred in-hospital expenditures that were 55.4% higher (no delirium: $16,284 vs. delirium: $28,742) and 90-day expenditures that were 100.7% higher (no delirium: $2564 vs. delirium: $8226) (both p < 0.001). Notably, 3-year postoperative survival was adversely affected by delirium (no delirium: 55.5% vs. delirium: 37.3%), even after adjusting risk for confounding factors (HR 1.79 [1.70-1.90]; p < 0.001).

CONCLUSIONS

Postoperative delirium occurred in one in 50 patients undergoing surgical resection of a digestive tract cancer. Delirium was linked to a reduced likelihood of achieving an optimal postoperative outcome, increased ICU utilization, higher expenditures, and a worse long-term prognosis. Initiatives to prevent delirium are vital to improve postoperative outcomes among cancer surgery patients.

Machine learning for the prediction of delirium in elderly intensive care unit patients

PURPOSE

This study aims to develop and validate a prediction model for delirium in elderly ICU patients and help clinicians identify high-risk patients at the early stage.

METHODS

Patients admitted to ICU for at least 24 h and using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database (76,943 ICU stays from 2008 to 2019) were considered. Patients with a positive delirium test in the first 24 h and under 65 years of age were excluded. Two prediction models, machine learning extreme gradient boosting (XGBoost) and logistic regression (LR) model, were developed and validated to predict the onset of delirium.

RESULTS

Of the 18,760 patients included in the analysis, 3463(18.5%) were delirium positive. A total of 22 significant predictors were selected by LASSO regression. The XGBoost model demonstrated superior performance over the LR model, with the Area Under the Receiver Operating Characteristic (AUC) values of 0.853 (95% confidence interval [CI] 0.846-0.861) and 0.831 (95% CI 0.815-0.847) in the training and testing datasets, respectively. Moreover, the XGBoost model outperformed the LR model in both calibration and clinical utility. The top five predictors associated with the onset of delirium were sequential organ failure assessment (SOFA), infection, minimum platelets, maximum systolic blood pressure (SBP), and maximum temperature.

CONCLUSION

The XGBoost model demonstrated good predictive performance for delirium among elderly ICU patients, thus assisting clinicians in identifying high-risk patients at the early stage and implementing targeted interventions to improve outcome.

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

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

Risk stratification and predictive modeling of postoperative delirium in chronic subdural hematoma

Background- Postoperative delirium is a common complication associated with the elderly, causing increased morbidity and prolonged hospital stay. However, its risk factors in chronic subdural hematoma patients have not been well studied. Methods- A total of 202 consecutive patients with chronic subdural hematoma at Peking University Third Hospital between January 2018 and January 2023 were enrolled. Various clinical indicators were analyzed to identify independent risk factors for postoperative delirium using univariate and multivariate regression analyses. Delirium risk prediction models were developed as a nomogram and a Markov chain. Results- Out of the 202 patients (age, 71 (IQR, 18); female-to-male ratio, 1:2.7) studied, 63 (31.2%) experienced postoperative delirium. Univariate analysis identified age (p < 0.001), gender (p = 0.014), restraint belt use (p < 0.001), electrolyte imbalance (p < 0.001), visual analog scale score (p < 0.001), hematoma thickness (p < 0.001), midline shift (p < 0.001), hematoma side (p = 0.013), hematoma location (p = 0.018), and urinal catheterization (p = 0.028) as significant factors. Multivariate regression analysis confirmed the significance of restraint belt use (B = 7.657, p < 0.001), electrolyte imbalance (B = -3.993, p = 0.001), visual analog scale score (B = 2.331, p = 0.016), and midline shift (B = 0.335, p = 0.007). Hematoma thickness and age had no significant impact. Conclusion- Increased midline shift and visual analog scale scores, alongside restraint belt use and electrolyte imbalance elevate delirium risk in chronic subdural hematoma surgery. Our prediction models may offer reference value in this context.

Association Between Anesthetics and Postoperative Delirium in Elderly Patients Undergoing Spine Surgery: Propofol Versus Sevoflurane

STUDY DESIGNS

Retrospective Observational StudyObjectives: To compare the incidence of POD after propofol- and sevoflurane-based anesthesia in elderly patients undergoing spine surgery.

METHODS

In this study, the medical records of elderly patients ≥ 65 years of age who underwent spine surgery under total intravenous anesthesia with propofol or inhalational anesthesia with sevoflurane were reviewed. The primary outcome was the incidence of POD after propofol- and sevoflurane-based anesthesia. Secondary outcomes included postoperative 30-day complications, length of postoperative hospital stay, associations of patient characteristics, and surgery- and anesthesia-related data with the development of POD, and associations of anesthetics with clinical outcomes such as postoperative 30-day complications, and length of postoperative hospital stay.

RESULTS

Of the 281 patients, POD occurred in 29 patients (10.3%). POD occurred more frequently in the sevoflurane group than in the propofol group (15.7% vs. 5.0%, respectively; P=.003). The multivariable logistic regression analysis showed that sevoflurane-based anesthesia was associated with an increased risk of POD compared with propofol-based anesthesia (odds ratio [OR], 4.120; 95% confidence interval [CI], 1.549-10.954; P = .005), whereas anesthetics were not associated with postoperative 30-day complications and the length of postoperative hospital stay. Older age (OR, 1.242 CI, 1.130-1.366; P < .001) and higher mean pain score at postoperative day 1 (OR, 1.338 CI, 1.056-1.696; P = .016) were also associated with an increased risk of POD.

CONCLUSIONS

Propofol-based anesthesia was associated with a lower incidence of POD than sevoflurane-based anesthesia in elderly patients after spine surgery.

Delirium is frequently underdiagnosed among older hospitalised patients despite available information in hospital medical records

BACKGROUND

In-hospital delirium is associated with adverse outcomes and is underdiagnosed, limiting research and clinical follow-up.

OBJECTIVE

To compare the incidence of in-hospital delirium determined by chart-based review of electronic medical records (D-CBR) with delirium discharge diagnoses (D-DD). Furthermore, to identify differences in symptoms, treatments and delirium triggers between D-CBR and D-DD.

METHOD

The community-based cohort included 2,115 participants in the Hordaland Health Study born between 1925 and 1927. Between 2018 and 2022, we retrospectively reviewed hospital electronic medical records from baseline (1997-99) until death prior to 2023. D-DD and D-CBR were validated using The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria for delirium.

RESULTS

Of the 2,115 participants, 638 had in-hospital delirium. The incidence rate (IR) of D-CBR was 29.8 [95% confidence interval 28, 32] per 1,000 person-years, whereas the IR by D-DD was 3.4 [2.8, 4.2]. The IR ratio was 9.14 (P < 0.001). Patients who received pharmacological treatment for delirium (n = 121, odds ratio (OR) 3.4, [2.1, 5.4], P < 0.001), who were affected by acute memory impairment (n = 149, OR 2.8, [1.8, 4.5], P < 0.001), or change in perception (n = 137, OR 2.9, [1.8, 4.6] P < 0.001) had higher odds for D-DD. In contrast, post-operative cases (OR 0.2, [0.1, 0.4], P < 0.001) had lower odds for D-DD.

CONCLUSION

Underdiagnosis of in-hospital delirium was a major issue in our study, especially in less severe delirium cases. Our findings emphasise the need for integrating systematic delirium diagnostics and documentation into hospital admission and discharge routines.

Role of supplemental regional blocks on postoperative neurocognitive dysfunction after major non-cardiac surgeries: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND/IMPORTANCE

Postoperative neurocognitive dysfunction (PNCD) is a frequent and preventable complication after surgery. The large high-quality evidence for the efficacy of supplemental regional analgesia blocks (RAB) for preventing PNCD is still elusive.

OBJECTIVE

The objective of this meta-analysis was to evaluate the effect of RAB versus standard anesthesia care on the incidence of PNCD in adult patients undergoing major non-cardiac surgery.

EVIDENCE REVIEW

PubMed, EMBASE, Scopus, and the Cochrane Central Registers of Controlled Trials (CENTRAL) were searched for randomized controlled trials (RCTs) from 2017 until June 2022. The primary outcome was the incidence of PNCD within 1 month of surgery. A random-effects model with an inverse variance method was used to pool results, and OR and mean differences were calculated for dichotomous and continuous outcomes. Various exploratory subgroup analyses were performed to explore the possibility of the association between the various patient, technique, and surgery-related factors. Grading of Recommendation, Assessment, Development, and Evaluation guidelines were used to determine the certainty of evidence.

FINDINGS

Twenty-six RCTs comprizing 4414 patients were included. The RAB group was associated with a significant reduction in the incidence of PNCD with an OR of 0.46 (95% CI 0.35 to 0.59; p<0.00001; I2=28%) compared with the control group (moderate certainty). Subgroup analysis exhibited that the prophylactic efficacy of RAB persisted for both delirium and delayed neurocognitive recovery.

CONCLUSIONS

Current evidence suggests that supplemental RAB are beneficial in preventing PNCD in patients after major non-cardiac surgery.

PROSPERO REGISTRATION NUMBER

CRD42022338820.

Online interpretable dynamic prediction models for postoperative delirium after cardiac surgery under cardiopulmonary bypass developed based on machine learning algorithms: A retrospective cohort study

OBJECTIVE

Postoperative delirium (POD) is strongly associated with poor early and long-term prognosis in cardiac surgery patients with cardiopulmonary bypass (CPB). This study aimed to develop dynamic prediction models for POD after cardiac surgery under CPB using machine learning (ML) algorithms.

METHODS

From July 2021 to June 2022, clinical data were collected from patients undergoing cardiac surgery under CPB at Nanjing First Hospital. A dataset from the same center (October 2022 to November 2022) was also used for temporal external validation. We used ML and deep learning to build models in the training set, optimized parameters in the test set, and finally validated the best model in the validation set. The SHapley Additive exPlanations (SHAP) method was introduced to explain the best models.

RESULTS

Of the 885 patients enrolled, 221 (25.0%) developed POD. 22 (22.0%) of 100 validation cohort patients developed POD. The preoperative and postoperative artificial neural network (ANN) models exhibited optimal performance. The validation results demonstrated satisfactory predictive performance of the ANN model, with area under the receiver operator characteristic curve (AUROC) values of 0.776 and 0.684 for the preoperative and postoperative models, respectively. Based on the ANN algorithm, we constructed dynamic, highly accurate, and interpretable web risk calculators for POD.

CONCLUSIONS

We successfully developed online interpretable dynamic ANN models as clinical decision aids to identify patients at high risk of POD before and after cardiac surgery to facilitate early intervention or care.

A pre-anesthetic bolus of ketamine versus dexmedetomidine for prevention of postoperative delirium in elderly patients undergoing emergency surgery: a randomized, double-blinded, placebo-controlled study

BACKGROUND

We aimed to evaluate whether a single dose of ketamine or dexmedetomidine before induction of general anesthesia could reduce the incidence of postoperative delirium (primary outcome) or cognitive dysfunction (secondary outcome) in elderly patients undergoing emergency surgery.

PATIENTS AND METHODS

This randomized, double-blinded, placebo-controlled trial included 60 elderly patients who were scheduled for emergency surgery. The patients were randomly assigned into one of three groups (n = 20): group I received 0.9% normal saline, group II received 1 µg/kg dexmedetomidine, and group III received 1 mg/kg ketamine right before anesthesia induction. Patients were observed for three days after surgery and tested for postoperative delirium and cognitive dysfunction using the delirium observation screening scale and the mini-mental state examination score, respectively.

RESULTS

The dexmedetomidine group had the lowest incidence of delirium (p = 0.001) and cognitive dysfunction (p = 0.006) compared to the ketamine and placebo groups. The multivariate logistic regression model revealed that dexmedetomidine reduced the incidence of postoperative delirium by 32% compared to placebo (reference) (OR = 0.684, 95% CI: 0.240-0.971, p = 0.025), whereas ketamine increased the risk by threefold (OR = 3.012, 95% CI: 1.185-9.681, p = 0.013). Furthermore, dexmedetomidine reduced the incidence of postoperative cognitive dysfunction by 62% (OR = 0.375, 95% CI: 0.091-0.543, p = 0.012), whereas ketamine increased the risk by 4.5 times (OR = 4.501, 95% CI: 1.161-8.817, p = 0.006).

CONCLUSION

A single pre-anesthetic bolus of dexmedetomidine is a practical choice for preventing postoperative delirium in elderly patients undergoing emergency surgery.

TRIAL REGISTRATION

This study was approved by the Ethics Committee of Aswan University Hospital (approval number: aswu/548/7/2021; registration date: 06/07/2021) and registered on ClinicalTrials.gov (NCT05341154) (22/04/2022).

Ramelteon and suvorexant for postoperative delirium in elderly patients with esophageal cancer

BACKGROUND

There is no clear evidence on the prevention of postoperative delirium with pharmacotherapy in elderly patients with esophageal cancer. This retrospective study aimed to evaluate the efficacy of ramelteon and suvorexant in preventing postoperative delirium in this patient group.

METHODS

Data on 251 patients who received radical esophagectomy for thoracic esophageal cancer were collected from January 2010 to September 2021. In total, 74 patients did not receive preventive intervention, and 177 received ramelteon and suvorexant. After propensity score matching, the rate of postoperative delirium was compared between the two groups.

RESULTS

Seventy-two well-balanced patients in each group demonstrated similar clinical and pathological characteristics. The mean ages of the intervention and control groups were 70.8 and 70.3 years, respectively. All the patients underwent McKeown esophagectomy, and in the volume of intraoperative blood loss or operative time did not significantly differ between the two groups. The incidence rates of postoperative hyperactive delirium were 7% (5/72) in the intervention group and 32% (23/72) in the control group (p < 0.001). No severe adverse event potentially attributable to the intervention drug was observed. The multivariate analysis showed that the use of ramelteon and suvorexant was the only independent protective factor against postoperative delirium (hazard ratio 0.157, 95% CI 0.055-0.448, p < 0.001).

CONCLUSIONS

Ramelteon and suvorexant may play an important role in reducing postoperative delirium in elderly patients with esophageal cancer.

Effects of non-pharmacologic prevention on delirium in critically ill patients: A network meta-analysis

BACKGROUND

Delirium is a common complication among patients in the intensive care unit (ICU). It is important to prevent the occurrence of delirium in critically ill patients.

AIM

This review aimed to evaluate the efficacy of non-pharmacological interventions and determine what combination of these is effective in preventing delirium among Intensive Care Unit patients.

STUDY DESIGN

A systematic review and meta-analysis. This review follows the guidelines of the Preferred Reporting Items for Systematic reviews and Meta Analysis statements for Network Meta-Analysis (PRISMA-NMA). Data sources included the Cumulative Index to Nursing & Allied Health Literature., MEDLINE, and Cochrane library databases. The integrated data were investigated with odds ratio (OR) and 95% confidence interval (95% CI), using the random-effects Mantel-Haenszel model. Data were considered significant when p < 0.05. Furthermore, to reveal what combination of care is effective, we performed a network meta-analysis estimated OR, 95% CI.

RESULTS

We identified three randomized controlled trials and eight controlled before-after trials (11 in total, with 2549 participants). The pooled data from 11 trials of multicomponent intervention had a significant effect on delirium prevention (OR 0.58, 95% CI 0.44-0.76, p < 0.001). As a result of network meta-analysis, two bundles were effective compared to the control group in reducing the incidence of delirium: a) the combination of sleep promotion (SP), cognitive stimulation (CS), early mobilization (EM), pain control (PC), and assessment (AS) (OR 0.47, 95% CI 0.35-0.64, p < 0.002), and b) the combination of SP and CS (OR 0.46, 95% CI 0.28-0.75, p < 0.001).

CONCLUSION

This study revealed that non-pharmacological interventions, particularly multicomponent interventions, helped to prevent delirium in critically ill patients. In the network meta-analysis, the most effective care combination for reducing incidence of delirium was found to be multicomponent intervention, which comprises SP-CS-EM-PC-AS, and SP-CS.

RELEVANCE TO CLINICAL PRACTICE

These findings reveal an efficient combination of multicomponent interventions for preventing delirium, which may be a very important prerequisite in planning care programs in the future.

Development and validation of an international preoperative risk assessment model for postoperative delirium

BACKGROUND

Postoperative delirium (POD) is a frequent complication in older adults, characterised by disturbances in attention, awareness and cognition, and associated with prolonged hospitalisation, poor functional recovery, cognitive decline, long-term dementia and increased mortality. Early identification of patients at risk of POD can considerably aid prevention.

METHODS

We have developed a preoperative POD risk prediction algorithm using data from eight studies identified during a systematic review and providing individual-level data. Ten-fold cross-validation was used for predictor selection and internal validation of the final penalised logistic regression model. The external validation used data from university hospitals in Switzerland and Germany.

RESULTS

Development included 2,250 surgical (excluding cardiac and intracranial) patients 60 years of age or older, 444 of whom developed POD. The final model included age, body mass index, American Society of Anaesthesiologists (ASA) score, history of delirium, cognitive impairment, medications, optional C-reactive protein (CRP), surgical risk and whether the operation is a laparotomy/thoracotomy. At internal validation, the algorithm had an AUC of 0.80 (95% CI: 0.77-0.82) with CRP and 0.79 (95% CI: 0.77-0.82) without CRP. The external validation consisted of 359 patients, 87 of whom developed POD. The external validation yielded an AUC of 0.74 (95% CI: 0.68-0.80).

CONCLUSIONS

The algorithm is named PIPRA (Pre-Interventional Preventive Risk Assessment), has European conformity (ce) certification, is available at http://pipra.ch/ and is accepted for clinical use. It can be used to optimise patient care and prioritise interventions for vulnerable patients and presents an effective way to implement POD prevention strategies in clinical practice.

Postoperative Delirium and Cognitive Dysfunction after General and Regional Anesthesia: A Systematic Review and Meta-Analysis

Background: Perioperative disorders of neurocognitive function are a set of heterogeneous conditions, which include transient post-operative delirium (POD) and more prolonged post-operative cognitive dysfunction (POCD). Since the number of annually performed surgical procedures is growing, we should identify which type of anesthesia is safer for preserving neurocognitive function. The purpose of this study was to compare the effect of general anesthesia (GA) and regional anesthesia (RA) in patients undergoing surgical procedures under general anesthesia and regional anesthesia. Material and methods: We searched for randomized controlled studies, which studied post-operative cognitive outcomes after general and regional anesthesia in the adult patient population. Results: Thirteen articles with 3633 patients: the RA group consisted of 1823 patients, and the GA group of 1810 patients, who were selected for meta-analysis. The overall effect of the model shows no difference between these two groups in terms of risk for post-operative delirium. The result is insensitive to the exclusion of any study. There was no difference between RA and GA in terms of post-operative cognitive dysfunction. Conclusions: There was no statistically significant difference between GA and RA in the incidence of POD. There was no statistically significant difference in the incidence of POCD per-protocol analysis, psychomotor/attention tests (preoperative/baseline, post-operative), memory tests (postoperatively, follow up), mini-mental state examination score 24 h postoperatively, post-operative reaction time three months postoperatively, controlled oral word association test, and digit copying test. There were no differences in the incidence of POCD in general and regional anesthesia at one week postoperatively, three months postoperatively, or total events (one week or three months). The incidence of post-operative mortality also did not differ between two groups.

Incidence of postoperative delirium in older adults undergoing surgical procedures: A systematic literature review and meta-analysis

BACKGROUND

With the increase in life expectancy around the globe, the incidence of postoperative delirium (POD) among older people (≥65 years) is growing. Previous studies showed a wide variation in the incidence of POD, from 4% to 53%, with a lack of specific evidence about the incidence of POD by specific surgery type among older people. The aim of this systematic review and meta-analysis was to determine the incidence of POD by surgery type within populations 65 years and over.

METHODS

Databases including PubMed, Cochrane library, Embase, and CINAHL were searched until October 2020. Due to the relatively higher number of meta-analyses undertaken in this area of research, a streamlined systematic meta-analysis was proposed.

RESULTS

A total of 28 meta-analyses (comprising 284 individual studies) were reviewed. Data from relevant individual studies (n = 90) were extracted and included in the current study. Studies were grouped into eight surgery types and the incidence of POD for orthopedic, vascular, spinal, cardiac, colorectal, abdominal, urologic, and mixed surgeries was 20%, 14%, 13%, 32%, 14%, 30%, 10%, and 26%, respectively. POD detection instruments were different across the studies, with Confusion Assessment Method (CAM & CAM-ICU) being the most frequently adopted.

LINKING EVIDENCE TO ACTION

This study showed that POD incidence in older people undergoing surgery varied widely across surgery type. The more complex surgeries like cardiac and abdominal surgeries were associated with a higher risk of POD. This highlights the need to include the level of surgery complexity as a risk factor in preoperative assessments.

The impact of rounds with a psychiatry team in the intensive care unit: A prospective observational pilot study evaluating the effects on delirium incidence and outcomes

BACKGROUND

Delirium in the intensive care unit (ICU) is a common but serious condition that has been associated with in-hospital mortality and post-discharge psychological dysfunction. The aim of this before and after study is to determine the effect of a multidisciplinary care model entailing daily ICU rounds with a psychiatrist on the incidence of delirium and clinical outcomes.

OBJECTIVE

To assess the impact of a proactive psychiatry consultation model in the surgical ICU on the incidence and duration of delirium.

METHODS

This was a prospective, single institution, observational controlled cohort pilot study of adult patients admitted to a surgical ICU. A control group that received standard of care (SOC) with daily delirium prevention care bundles in the pre-intervention period was compared to an intervention group, which had a psychiatrist participate in daily ICU rounds (post-intervention period). The primary outcome was delirium incidence. The secondary outcomes were: delirium duration, ventilator days, hospital and ICU length of stay, and in-hospital mortality.

RESULTS

A total of 104 patients were enrolled and equally split between SOC and intervention groups; 95 contributed to analysis. The overall incidence of ICU delirium was 19%. SOC and intervention groups had similar rates of delirium (21% vs 18%, p = 0.72). None of the secondary outcomes statistically significantly differed between the two groups.

CONCLUSION

Delirium in ICU patients is a potentially preventable condition with serious sequelae. There was no difference in delirium incidence or duration between patients receiving SOC or patients who had multidisciplinary rounds with a psychiatrist.

Non-pharmacological prevention of postoperative delirium by occupational therapy teams: A randomized clinical trial

Background

Patients who develop postoperative delirium (POD) have several clinical complications, such as increased morbidity, increased hospital stays, higher hospital costs, cognitive and functional impairment, and higher mortality. POD is a clinical condition preventable by standard non-pharmacological measures An intensive Occupational Therapy (OT) intervention has been shown to be highly effective in preventing delirium in critically ill medical patients, but it is unknown the effect in surgical patients. Thus, we designed a prospective clinical study with the aim to determine whether patients undergoing intervention by the OT team have a lower incidence of POD compared to the group treated only with standard measures.

Methods

A multicenter, single-blind, randomized clinical trial was conducted between October 2018 and April 2021, in Santiago of Chile, at a university hospital and at a public hospital. Patients older than 75 years undergoing elective major surgery were eligible for the trial inclusion. Patients with cognitive impairment, severe communication disorder and cultural language limitation, delirium at admission or before surgery, and enrolled in another study were excluded. The intervention consisted of OT therapy twice a day plus standard internationally recommended non-pharmacological prevention intervention during 5 days after surgery. Our primary outcome was development of delirium and postoperative subsyndromal delirium.

Results

In total 160 patients were studied. In the interventional group, treated with an intensive prevention by OT, nine patients (12.9%) developed delirium after surgery and in the control group four patients (5.5%) [p = 0.125, RR 2.34 CI 95 (0.75-7.27)]. Whereas subsyndromal POD was present in 38 patients in the control group (52.1%) and in 34 (48.6%) in the intervention group [p = 0.4, RR 0.93 CI95 (0.67-1.29)]. A post hoc analysis determined that the patient's comorbidity and cognitive status prior to hospitalization were the main risk factors to develop delirium after surgery.

Discussion

Patients undergoing intervention by the OT team did not have a lower incidence of POD compared to the group treated only with standard non-pharmacological measures in adults older than 75 years who went for major surgery.

Clinical trial registration

www.ClinicalTrials.gov, identifier NCT03704090.

Elderly Patients and Management in Intensive Care Units (ICU): Clinical Challenges

There is a growing population of older adults requiring admission to the intensive care unit (ICU). This population outpaces the ability of clinicians with geriatric training to assist in their management. Specific training and education for intensivists in the care of older patients is valuable to help understand and inform clinical care, as physiologic changes of aging affect each organ system. This review highlights some of these aging processes and discusses clinical implications in the vulnerable older population. Other considerations when caring for these older patients in the ICU include functional outcomes and morbidity, as opposed to merely a focus on mortality. An overall holistic approach incorporating physiology of aging, applying current evidence, and including the patient and their family in care should be used when caring for older adults in the ICU.

Postoperative Delirium in Neurosurgical Patients: Recent Insights into the Pathogenesis

Postoperative delirium (POD) is a complication characterized by disturbances in attention, awareness, and cognitive function that occur shortly after surgery or emergence from anesthesia. Since it occurs prevalently in neurosurgical patients and poses great threats to the well-being of patients, much emphasis is placed on POD in neurosurgical units. However, there are intricate theories about its pathogenesis and limited pharmacological interventions for POD. In this study, we review the recent insights into its pathogenesis, mainly based on studies within five years, and the five dominant pathological theories that account for the development of POD, with the intention of furthering our understanding and boosting its clinical management.

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.

Impacting Outcomes in the Hospitalized Oncology Patient: Evidence-Informed Quality and Safety Project to Implement Routine Screening for Delirium

Background: Delirium can occur in cancer patients during an acute hospitalization or in the terminal stages of cancer. Iatrogenic delirium can complicate hospital stays for over 2.6 million older persons by increasing fall risk, restraint use, length of stay, postacute placement, and costs. The purpose of this evidence-based quality improvement project was to implement routine screening for delirium with a consistent instrument and adopt an interprofessional plan of care for delirium. Methods: This project was identified as an interprofessional improvement initiative. The project leader identified a deficiency in the screening for delirium, convened stakeholders, evaluated evidence, reviewed screening instruments, and developed a plan of care for delirium management. Practice changes incorporated routine delirium screening across the inpatient units. A delirium interprofessional plan of care was integrated into the electronic health record for ease of adoption and workflow modification. Results: Routine screening for delirium and early interprofessional interventions reduced length of stay by 2.27 days for patients screening positive for delirium. The percentage of inpatient falls that were linked to an episode of delirium during hospitalization reduced from 23.4% to 17%. Discussions: Routine screening and targeted interventions are a first step in prevention and identification of those inpatients at risk of developing delirium. Delirium prevention is the goal for potential associated iatrogenic conditions.

Effect of regional anesthesia on the postoperative delirium: A systematic review and meta-analysis of randomized controlled trials

Objective

Postoperative delirium (POD) starts in the recovery room and occurs up to 5 days after surgery. However, the POD guidelines issued by the European Society of Anesthesiology (ESA) suggest that the effect of regional anesthesia on POD is controversial. This meta-analysis aims to investigate whether perioperative regional anesthesia reduced the incidence of POD.

Methods

Standard Published randomized controlled trails (RCTs) were searched from bibliographic databases to identify all evidence that reported regional anesthesia assessing incident delirium following diverse surgeries. The primary outcome was the incidence of POD, and the secondary outcomes were POD scores, pain scores, and emergence time. The relative risk (RR) for dichotomous outcomes and the weighted or standardized mean difference (WMD, SMD) for continuous outcomes were estimated using a random-effects model.

Results

Twenty RCTs with 2110 randomized participants undergoing different surgeries were included. Meta-analysis showed that regional anesthesia was associated with less POD incidence compared to general anesthesia (total intravenous anesthesia (TIVA) or inhalation anesthesia) (relative risk (RR) = 0.62, 95% confidence interval (CI) = 0.45–0.85)). Subgroup analysis showed that the decrease in POD incidence was associated with a nerve block (0.46, 95% CI = 0.32–0.67) and regional-combined-general anesthesia (0.42, 95% CI = 0.29–0.60). Regional anesthesia significantly reduced POD incidence in the recovery room after pediatric surgeries (0.41, 95% CI = 0.29–0.56). Regional anesthesia also reduced the POD score (SMD −0.93, 95% CI = −1.55 to −0.31) and pain score (SMD −0.95, 95% CI = −1.72 to −0.81). There was no significant difference in emergence time between regional anesthesia and general anesthesia (WMD −1.40, 95% CI = −3.83 to 6.63).

Conclusions

There was a significant correlation between regional anesthesia and the decrease in POD incidence, POD score, and pain score.

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.

Intraoperative low tidal volume ventilation and the risk of ICD-10 coded delirium and the use for antipsychotic medications

BACKGROUND

Low tidal volume (V_T) ventilation and its associated increase in arterial carbon dioxide (PaCO₂) may affect postoperative neurologic function. We aimed to test the hypothesis that intraoperative low V_T ventilation affect the incidence of postoperative ICD-10 coded delirium and/or the need for antipsychotic medications.

METHODS

This is a post-hoc analysis of a large randomized controlled trial evaluating low vs. conventional V_T ventilation during major non-cardiothoracic, non-intracranial surgery. The primary outcome was the incidence of ICD-10 delirium and/or the use of antipsychotic medications during hospital stay, and the absolute difference with its 95% confidence interval (CI) was calculated.

RESULTS

We studied 1206 patients (median age of 64 [55-72] years, 59.0% males, median ARISCAT of 26 [19-37], and 47.6% of ASA 3). ICD-10 coded delirium and /or antipsychotic medication use was diagnosed in 11.2% with similar incidence between low and conventional V_T ventilation (11.1% vs. 11.3%; absolute difference, -0.24 [95%CI, -3.82 to 3.32]; p = 0.894). There was no interaction between allocation group and type of surgery.

CONCLUSION

In adult patients undergoing major surgery, low V_T ventilation was not associated with increased risk of ICD-10 delirium and/or the use of antipsychotic medications during hospital stay.

TRIAL REGISTRATION

ANZCTR Identifier: ACTRN12614000790640 .

Non-Pharmacological Nursing Interventions to Prevent Delirium in ICU Patients-An Umbrella Review with Implications for Evidence-Based Practice

Delirium in ICU patients is a complication associated with many adverse consequences. Given the high prevalence of this complication in critically ill patients, it is essential to develop and implement an effective management protocol to prevent delirium. Given that the cause of delirium is multifactorial, non-pharmacological multicomponent interventions are promising strategies for delirium prevention. (1) Background: To identify and evaluate published systematic review on non-pharmacological nursing interventions to prevent delirium in intensive care unit patients. (2) Methods: An umbrella review guided by the Joanna Briggs Institute was utilized. Data were obtained from PubMed, Scopus, EBSCO, Web of Science, Cochrane Library, and Google Scholar. The last search was conducted on 1 May 2022. (3) Results: Fourteen reviews met the inclusion criteria. Multicomponent interventions are the most promising methods in the fight against delirium. The patient's family is an important part of the process and should be included in the delirium prevention scheme. Light therapy can improve the patient's circadian rhythm and thus contribute to reducing the incidence of delirium. (4) Conclusions: Non-pharmacological nursing interventions may be effective in preventing and reducing the duration of delirium in ICU patients.

The Effects of Dexmedetomidine on Perioperative Neurocognitive Outcomes After Cardiac Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The purpose of this systematic review and meta-analysis is to examine the effect of DEX on delayed dNCR (cognitive dysfunction ≥ 1 week postoperative) after cardiac surgery.

BACKGROUND

DEX has salutary effects on cognitive outcomes following cardiac surgery, however, studies are limited by inconsistent assessment tools, timing, and definitions of dysfunction. It is imperative to identify accurate point estimates of effect of DEX on clinically relevant changes in cognitive function.

METHODS

Randomized trials of adults undergoing cardiac surgery comparing perioperative DEX to placebo or alternate sedation and assessing cognitive function ≥ 1 week postoperative were included. Data was abstracted by three reviewers independently and in parallel according to PRISMA guidelines. The primary outcome is dNCR. To classify as dNCR, cognitive function must decrease by at least the minimal clinically important difference or accepted alternate measure (eg, Reliable Change Index ≥1.96). Bias was assessed with the Cochrane Collaboration tool. Data was pooled using a random effects model.

RESULTS

Nine trials (942 participants) were included in qualitative analysis, of which seven were included in the meta-analysis of dNCR. DEX reduced the incidence of dNCR (OR 0.39, 95% CI 0.25-0.61, P < 0.0001) compared to placebo/no DEX. There was no difference in the incidence of delirium (OR 0.69, 95% CI 0.35-1.34, P = 0.27) or incidence of hemodynamic instability (OR 1.14, 95% CI 0.59-2.18, P = 0.70) associated with perioperative DEX.

CONCLUSIONS

DEX reduced the incidence of dNCR 1 week after cardiac surgery. Although this meta-analysis demonstrates short term cognitive outcomes are improved after cardiac surgery with perioperative DEX, future trials examining long term cognitive outcomes, using robust cognitive assessments, and new perioperative neurocognitive disorders nomenclature with objective diagnostic criteria are necessary.

Changes of consultation-liaison psychiatry practice in Italian general hospitals: A comparative 20-year multicenter study

INTRODUCTION

Conducted under the auspices of the Italian Society of Consultation Liaison Psychiatry (SIPC) the aim of this study was to describe the characteristics of Consultation Liaison Psychiatry (CLP) activity in Italy (SIPC-2-2018) over the past 20 years by comparing with data from the first Italian nation-wide study (SIPC-1-1998).

METHODS

We collected data on CLP visits of 3,943 patients from 10 Italian hospitals over a period of 1 year. Data were compared with those from the SIPC-1 1998 study (4,183 participants). Patients were assessed with the same ad hoc 60-item Patient Registration Form recording information from five different areas: Sociodemographic, hospitalization-related, consultation-related, interventions and outcome.

RESULTS

Compared with participants from the previous study, SIPC-2-2018 participants were significantly older (d = 0.54) and hospitalized for a longer duration (d = 0.20). The current study detected an increase in the proportion of referrals from surgical wards and for individuals affected by onco-hematologic diseases. Depressive disorders still represented the most frequent psychiatric diagnosis, followed by adjustment and stress disorders and delirium/dementia. Also, CLP psychiatrists prescribed more often antidepressants (Φ = 0.13), antipsychotics (Φ = 0.09), mood stabilizers (Φ = 0.24), and less often benzodiazepines (Φ = 0.07).

CONCLUSION

CLP workload has increased considerably in the past 20 years in Italy, with changes in patient demographic and clinical characteristics. A trend toward increase in medication-based patient management was observed. These findings suggest that the psychiatric needs of patients admitted to the general hospital are more frequently addressed by referring physicians, although Italian CLP services still deserve better organization and autonomy.

Inclusion of interleukin-6 improved performance of postoperative delirium prediction for patients undergoing coronary artery bypass graft (POD-CABG): A derivation and validation study

BACKGROUND

Patients undergoing coronary artery bypass graft (CABG) are at high risk for developing postoperative delirium (POD). A simple prediction rule may benefit patients from early identification of POD followed by adequate preventive strategies. The purpose of the current study was to develop and validate a POD prediction rule for patients undergoing CABG (POD-CABG), by considering all possible perioperative factors.

METHODS

In this prospective cohort study, patients who underwent first elective isolated CABG were continuously enrolled from May 2014 to November 2015 in a tertiary hospital. Delirium was assessed using the Confusion Assessment Method for Intensive Care Unit. Patients' perioperative risk factors were collected through interviews and review of medical records. The area under receiver-operating characteristic curve (AUC) was used to assess the overall performance of the predictive rule.

RESULTS

A total of 242 and 148 patients were enrolled in the derivation and validation cohorts, respectively. Multiple logistic regression analysis identified seven variables that were independently associated with POD: age (≥65 years), gender (female), history of myocardial infarction and diabetes mellitus, postoperative atrial fibrillation, the use of intra-aortic balloon pump, and serum interleukin-6 ≥478 pg/ml at 18 hours after surgery. The AUC of the POD-CABG was 0.84 (95% CI, 0.79-0.90) in the derivation cohort, and was 0.86 (95% CI, 0.80-0.91) after bootstrap resampling. The AUC was 0.81 (95% CI, 0.73-0.88) after the POD-CABG was applied to the validation cohort.

CONCLUSIONS

The POD-CABG with inclusion of interleukin-6 demonstrated good performance in predicting POD.

A scientometric study of publications on delirium from 2001 to 2020

AIM

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

METHODOLOGY

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

RESULTS

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

CONCLUSION

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

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.

Effects of Intraoperative Dexmedetomidine Infusion on Postoperative Delirium in Elderly Patients Undergoing Total Hip Arthroplasty

Objective

To investigate the effects of dexmedetomidine on postoperative delirium in elderly patients undergoing total hip arthroplasty.

Methods

A total of 100 patients, 42 male and 58 female, ages 60 to 85 years, American Society of Anesthesiologists grade I or II, who were undergoing total hip arthroplasty were randomly divided into 2 groups: a dexmedetomidine group (group D; n = 50) and a control group (group C; n = 50). Group D patients were infused with 0.3 μg · kg−1 · h−1 of dexmedetomidine from 5 minutes prior to anesthesia induction until the end of surgery. Group C patients received an equal volume of saline. Heart rate and mean arterial pressure (MAP) were recorded before anesthesia induction (T0), 1 minute before extubation (T1), and 30 minutes after extubation (T2). The Visual Analog Score (VAS) at 1, 2, and 3 days after surgery, the incidence and duration of postoperative delirium, and the length of hospital stay were recorded. Adverse reactions, such as nausea, vomiting, and lethargy, were also recorded.

Results

The Visual Analog Scores in the 2 groups were similar. In group D, there was no significant difference in heart rate (P = 0.232) and MAP (P = 0.056) between T0 and T1. However, in group C, heart rate significantly increased by 15.3 bpm (P = 0.000) and MAP significantly increased by 10.7 mmHg (P = 0.001) at T1 compared with those at T0. The incidence of postoperative delirium in group D (10%) was significantly lower than that in group C (26%; P = 0.037). The duration of delirium in group D (1.3 ± 0.6 days) was shorter than that in group C (3.0 ± 0.5 days; P = 0.000). The length of hospital stay in group D (13.2 ± 0.9 days) was shorter than that in group C (16.1 ± 0.7 days; P = 0.000). No significant differences were observed in adverse effects between the 2 groups.

Conclusion

Intravenous infusion of dexmedetomidine can not only reduce the incidence and duration of postoperative delirium, but also shorten the length of hospital stay in elderly patients undergoing total hip arthroplasty.

How We Prevent and Treat Delirium in the ICU

Delirium is a serious and complex problem facing critically ill patients, their families, and the health care system. When delirium develops, it is associated with prolonged hospital stays, increased costs, and long-term cognitive impairment in many patients. This article uses a clinical case to discuss our approach to delirium prevention and treatment in the ICU. We believe that an effective strategy to combat delirium requires implementation and adherence to a pain and sedation protocol as part of bundled care, use of a validated tool to detect delirium when present, and a focus on nonpharmacologic care strategies, including reorientation, early mobility, and incorporating family into care when possible. At present, the evidence does not support the routine administration of medications to prevent or treat delirium. A pharmacologic approach may be needed for agitated delirium, and we discuss our evaluation of the evidence for and against particular medications. Although delirium can be a distressing problem, there is evidence that it can be addressed through careful attention to prevention, detection, and minimizing the long-term impact on patients and their families.

Are treatment effects consistent with hypothesized mechanisms of action proposed for postoperative delirium interventions? Reanalysis of systematic reviews

Aim: Postoperative delirium (POD) is associated with increased morbidity and is poorly understood. The aim of this review was to identify putative mechanisms through re-analysis of randomized trials on treatment or prevention of POD. Materials & methods: A systematic review was performed to identify systematic reviews of treatments for POD. Constituent randomized controlled trials were identified, and interventions were grouped according to hypothesized mechanisms of action. Effects were meta-analyzed by hypothesized mechanism and timing of intervention. Results: A total of 116 randomized controlled trials described 47 individual interventions for POD, with nine mechanisms identified. The largest effects were observed for postoperative inflammation reduction, and preoperative reinforcement of sleep-wake cycle. Conclusion: This approach identifies treatments focused on mechanisms of action that may be front runners for future trials and interventions.

Anaesthetic depth and delirium: a challenging balancing act

This editorial highlights the findings of the Balanced Anaesthesia Delirium study, a 515-patient substudy of the 6644 patient Balanced Anaesthesia trial, which found that targeting deep anaesthesia in patients undergoing major noncardiac surgery was not associated with significantly increased postoperative death or major morbidity. The substudy found that using bispectral index (BIS) guidance with the intention of deliberately achieving deep volatile agent-based anaesthesia (target BIS reading 35 vs 50) significantly increased delirium incidence (28% vs 19%), although not subsyndromal delirium incidence (45% vs 49%). We discuss the implications of these findings for anaesthetic practice, and address whether the BIS should be used as a guide to deliver precision anaesthesia for delirium prevention. We posit that subpopulation-based differences within this multicentre substudy could have affected delirium occurrence, since the findings appeared to rest on outcomes in patients from East Asia. We conclude that questions of whether and for whom deep anaesthesia is deliriogenic remain unanswered.

Interventions to Reduce Hospital Length of Stay in High-risk Populations: A Systematic Review

IMPORTANCE

Many strategies to reduce hospital length of stay (LOS) have been implemented, but few studies have evaluated hospital-led interventions focused on high-risk populations. The Agency for Healthcare Research and Quality (AHRQ) Learning Health System panel commissioned this study to further evaluate system-level interventions for LOS reduction.

OBJECTIVE

To identify and synthesize evidence regarding potential systems-level strategies to reduce LOS for patients at high risk for prolonged LOS.

EVIDENCE REVIEW

Multiple databases, including MEDLINE and Embase, were searched for English-language systematic reviews from January 1, 2010, through September 30, 2020, with updated searches through January 19, 2021. The scope of the protocol was determined with input from AHRQ Key Informants. Systematic reviews were included if they reported on hospital-led interventions intended to decrease LOS for high-risk populations, defined as those with high-risk medical conditions or socioeconomically vulnerable populations (eg, patients with high levels of socioeconomic risk, who are medically uninsured or underinsured, with limited English proficiency, or who are hospitalized at a safety-net, tertiary, or quaternary care institution). Exclusion criteria included interventions that were conducted outside of the hospital setting, including community health programs. Data extraction was conducted independently, with extraction of strength of evidence (SOE) ratings provided by systematic reviews; if unavailable, SOE was assessed using the AHRQ Evidence-Based Practice Center methods guide.

FINDINGS

Our searches yielded 4432 potential studies. We included 19 systematic reviews reported in 20 articles. The reviews described 8 strategies for reducing LOS in high-risk populations: discharge planning, geriatric assessment, medication management, clinical pathways, interdisciplinary or multidisciplinary care, case management, hospitalist services, and telehealth. Interventions were most frequently designed for older patients, often those who were frail (9 studies), or patients with heart failure. There were notable evidence gaps, as there were no systematic reviews studying interventions for patients with socioeconomic risk. For patients with medically complex conditions, discharge planning, medication management, and interdisciplinary care teams were associated with inconsistent outcomes (LOS, readmissions, mortality) across populations. For patients with heart failure, clinical pathways and case management were associated with reduced length of stay (clinical pathways: mean difference reduction, 1.89 [95% CI, 1.33 to 2.44] days; case management: mean difference reduction, 1.28 [95% CI, 0.52 to 2.04] days).

CONCLUSIONS AND RELEVANCE

This systematic review found inconsistent results across all high-risk populations on the effectiveness associated with interventions, such as discharge planning, that are often widely used by health systems. This systematic review highlights important evidence gaps, such as the lack of existing systematic reviews focused on patients with socioeconomic risk factors, and the need for further research.

Effects of perioperative interventions for preventing postoperative delirium: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) not only increases the medical burden but also adversely affects patient prognosis. Although some cases of delirium can be avoided by early intervention, there is no clear evidence indicating whether any of these measures can effectively prevent POD in specific patient groups.

OBJECTIVE

The aim of this meta-analysis was to compare the efficacy and safety of the existing preventive measures for managing POD.

METHODS

The PubMed, OVID (Embase and MEDLINE), Web of Science, and the Cochrane Library databases were searched for articles published before January 2020. The relevant randomized controlled trials (RCTs) were selected based on the inclusion and exclusion criteria. Data extraction and methodological quality assessment were performed according to a predesigned data extraction form and scoring system, respectively. The interventions were compared on the basis of the primary outcome like incidence of POD, and secondary outcomes like duration of delirium and the length of intensive care unit and hospital stay.

RESULTS

Sixty-three RCTs were included in the study, covering interventions like surgery, anesthesia, analgesics, intraoperative blood glucose control, cholinesterase inhibitors, anticonvulsant drugs, antipsychotic drugs, sleep rhythmic regulation, and multi-modal nursing. The occurrence of POD was low in 4 trials that monitored the depth of anesthesia with bispectral index during the operation (P < .0001). Two studies showed that supplementary analgesia was useful for delirium prevention (P = .002). Seventeen studies showed that perioperative sedation with α2-adrenergic receptor agonists prevented POD (P = .0006). Six studies showed that both typical and atypical antipsychotic drugs can reduce the incidence of POD (P = .002). Multimodal nursing during the perioperative period effectively reduced POD in 6 studies (P < .00001). Furthermore, these preventive measures can reduce the duration of delirium, as well as the total and postoperative length of hospitalized stay for non-cardiac surgery patients. For patients undergoing cardiac surgery, effective prevention can only reduce the length of intensive care unit stay.

CONCLUSION

Measures including intraoperative monitoring of bispectral index, supplemental analgesia, α2-adrenergic receptor agonists, antipsychotic drugs, and multimodal care are helpful to prevent POD effectively. However, larger, high-quality RCTs are needed to verify these findings and develop more interventions and drugs for preventing postoperative delirium.

Where should patients with or at risk of delirium be treated in an acute care system? Comparing the rates of delirium in patients receiving usual care vs alternative care: A systematic review and meta-analysis

BACKGROUND

Delirium is an acute condition that occurs in hospitalised patients and leads to poor patient outcomes that can last long term. Therefore, the importance of prevention is undeniable and adopting new models of care for at-risk patients should be prioritised.

OBJECTIVES

This systematic review and meta-analysis will assess the effectiveness of different interventions designed to prevent or manage delirium in acutely unwell hospitalised patients.

METHODS

MEDLINE, EMBASE, PsycINFO, OpenGrey, Web of Science and reference lists of journals were searched. Eligible studies reported on incidence or duration of delirium, used a validated delirium diagnostic tool and compared an intervention to either a control or another intervention group. Meta-analyses were conducted, and GRADEpro software was used to assess the certainty of evidence. This review is registered on PROSPERO.

RESULTS

A total of 59 studies were included and 33 were eligible for meta-analysis. Delirium incidence was most significantly reduced by non-pharmacological multicomponent interventions compared with usual care, with pooled risk ratios of 0.57 (95% CI: 0.44 to 0.73, 10 randomised controlled trials) and 0.47 (95% CI: 0.35 to 0.64, six observational studies). Single-component interventions did not significantly reduce delirium incidence compared with usual care in seven randomised trials (risk ratio = 0.92, 95% CI: 0.81 to 1.04). The most effective single-component intervention in reducing delirium incidence was a hospital-at-home intervention (risk ratio = 0.29, 95% CI: 0.09 to 0.87).

CONCLUSIONS

Non-pharmacological multicomponent interventions are effective in preventing delirium; however, the same cannot be said for other interventions because of uncertain results. There is some evidence that providing multicomponent interventions in patients' homes is more effective than in a hospital setting. Therefore, researching the benefits of hospital-at-home interventions in delirium prevention is recommended.

Impaired Executive Function and Depression as Independent Risk Factors for Reported Delirium Symptoms: An Observational Cohort Study Over 8 Years

Background

Acute medical illnesses, surgical interventions, or admissions to hospital in older individuals are frequently associated with a delirium. In this cohort study, we investigated the impact of specific cognitive domains and depression before the occurrence of delirium symptoms in an 8-year observation of older non-hospitalized individuals.

Methods

In total, we included 807 participants (48–83 years). Deficits in specific cognitive domains were measured using the CERAD test battery, and depressive symptoms were measured using Beck Depression Inventory and the Geriatric Depression Scale (GDS) before the onset of a delirium. Delirium symptoms were retrospectively assessed by a questionnaire based on the established Nursing Delirium Screening Scale.

Results

Fifty-eight of eight hundred seven participants (7.2%) reported delirium symptoms over the 8-year course of the study. Sixty-nine percent (n = 40) of reported delirium symptoms were related to surgeries. In multivariate regression analysis, impaired executive function was an independent risk factor (p = 0.034) for the occurrence of delirium symptoms. Furthermore, age (p = 0.014), comorbidities [captured by the Charlson Comorbidity Index (CCI)] (p < 0.001), and depression (p = 0.012) were significantly associated with reported delirium symptoms.

Conclusion

Especially prior to elective surgery or medical interventions, screening for impaired executive function and depression could be helpful to identify patients who are at risk to develop delirium symptoms.

Melatonin and melatonergic agents for the prevention of postoperative delirium: A meta-analysis of randomized placebo-controlled trials

Studies on melatonin and melatonergic agents (MMA) for the prevention of postoperative delirium (POD) have produced inconsistent findings. We conducted a meta-analysis to assess the effect of perioperative MMA on the prevention for POD. This meta-analysis is registered in the PROSPERO (CRD42020164900). We searched PubMed, Embase, and Cochrane Library through August 1, 2020 to identify randomized placebo-controlled trials (RCTs) that assessed MMA for the prevention for POD in adult patients undergoing surgery. The primary outcome was POD. Relative risk (RR) with 95% confidence interval (CI) was pooled using a random-effects model. Nine RCTs with 1452 patients were included. The incidence of POD was 23.8% (173/726) and 24.4% (177/726) in the MMA and placebo groups, respectively. Compared with placebo, MMA did not reduce the occurrence of POD (9 trails, 1452 patients, RR 0.93, 95% CI 0.70-1.24), with modest heterogeneity (I² = 40%). Sensitivity analyses suggested that MMA also did not reduce the occurrence of POD in elderly patients (age ≥65 years) (6 trails, 810 patients, RR 0.71, 95% CI 0.38-1.32), patients given melatonin (4 trails, 806 patients, RR 0.78, 95% CI 0.43-1.41) or ramelteon (4 trails, 345 patients, RR 0.89, 95% CI 0.44-1.78), and patients undergoing general anesthesia (4 trails, 681 patient, RR 1.02, 95% CI 0.82-1.28). Based on the current evidence, perioperative MMA may have no effect on the prevention of POD.

Multi-Component Care Bundle in Geriatric Fracture Hip for Reducing Post-Operative Delirium

Background:

Delirium in elderly orthopaedic patients poses an enormous medical, social and financial burden to the healthcare system, and causes significant distress to patients and their caregivers. We examined whether a Multi-component Care Bundle (MCB) could reduce the incidence of post-operative delirium (POD) in fractured hip patients.

Methods:

An observational study was conducted, analyzing 154 patients (mean age ± SD, 85 ± 7.8, 68% women) admitted to Queen Mary Hospital with hip fracture. Half of the patients were cared for in the control group before MCB was introduced, which included installation of orientation aids, introduction of a Caregiver Empowerment Program, and incorporation of ultrasound-guided Fascia Iliaca Block (FIB) into the analgesia protocol.

Results:

There were fewer patients with POD in the MCB group, compared with the control group (18/76, 23.4% v 34/76, 44.2%, p = 0.006). Patients in MCB group consumed less opioid ( 4/77 v 13/77, p = 0.048), experienced less post-operative dizziness (2/77, 2.6% v 13/77, 16.9%, p = 0.003) and had a shorter median day to start walking post-operatively (day 1 [IQR 1-2] vs day 2 [IQR 2-3]; p = 0.001) than the control group. Length of stay was not affected.

Conclusion:

MCB effectively reduces POD, postoperative dizziness, opioid consumption, and days to start mobilization postoperatively.

A narrative review of preventive measures for postoperative delirium in older adults

Postoperative delirium (POD) is an acute neurological condition associated with changes in cognition and attention and disorganised thinking. Although delirium can affect patients from any age group, it is common in older patients and could lead to a longer hospital stay and a higher risks of mortality. This article presents findings from a literature review that identifies various strategies used by health professionals globally to prevent POD. A database search resulted in 25 articles that met the inclusion criteria. Thematic analysis and coding were used to combine recurrent ideas that emerged from the literature. Three themes were identified: early identification and screening, modifiable risk factors, and preventive interventions. Further research focusing on education and improving awareness about POD among nurses is essential.

[Evidence-based non-pharmacological delirium prevention on general wards - A systematic literature review]

BACKGROUND

Delirium is a disturbance of attention and consciousness and a serious complication, especially in older hospitalized patients. For non-pharmacological delirium prevention, mainly so-called multicomponent programmes are described, which have to be adapted to the individual risk profile. The aim of this systematic review was to summarize the current status of the available evidence on non-pharmacological delirium prevention in general wards.

METHOD

The databases MEDLINE via Pubmed, CINAHL, EMBASE, PsycINFO and Cochrane Library were searched for the period from 1990 to November 2018; the methodological quality of the systematic reviews and meta-analyses was evaluated with AMSTAR 2. In order to reflect the broad spectrum of delirium prevention, international guidelines were included in the systematic review.

RESULTS

A total of 77 titles were read in full text, nine reviews and six guidelines were included in the analysis. Eight meta-analyses demonstrated that non-pharmacological multicomponent programmes for delirium prevention reduce the incidence of delirium compared to standard care (RR 0.65 to 0.73; OR 0.47 to 0.64, with varying methodological quality). The effect size was similar in the surgical (RR 0.63 to 0.71; OR 0.64) and non-surgical (RR 0.65 to 0.73; OR 0.47) general ward setting. The multicomponent programmes for delirium prevention each consisted of a different number of interventions. In addition to twelve person-related interventions, e. g. promotion of orientation, mobility, day-night rhythm, environmental adjustments and staff training programmes, were considered.

CONCLUSION

Non-pharmacological multicomponent programmes for the prevention of delirium in general wards effectively reduce the incidence of delirium and must be adapted to the individual risk factors of each patient.

Development of a Simple and Practical Delirium Screening Tool for Use in Surgical Wards

BACKGROUND

Delirium is an important and common medical condition, particularly in hospitalized patients, that is associated with adverse outcomes. The identification, prevention, and treatment of delirium are increasingly regarded as major public health priorities.

PURPOSE

The aim of this study was to create a simple-to-use screening tool for delirium in hospitalized patients using clinical manifestations of delirium regularly observed by nurses.

METHODS

This study was conducted using data on 2,168 patients who had been admitted to the surgical ward between January 2011 and December 2014. Data were collected retrospectively from medical records. Univariate and multivariate analyses were performed, and a logistic regression model was constructed for the development of a predictive screening tool. After constructing a new screening tool for delirium, a receiver operating characteristic curve was drawn, the most appropriate cutoff value was decided, and the area under the curve was obtained. Bootstrapping was used for the internal model validation.

RESULTS

A screening tool for delirium (Subjective Delirium Screening Scale by Nurse) with a total score of 5 points was constructed as follows: 2 points for disorientation and 1 point each for restlessness, somnolence, and hallucination. The area under the curve for the Subjective Delirium Screening Scale by Nurse was 81.9% (95% CI [77.9%, 85.8%]), and the most appropriate cutoff value was determined to be 2 (sensitivity of 61.0% and specificity of 96.7%). Bootstrapped validation beta coefficients of the predictive factors were similar to the original cohort beta coefficients.

CONCLUSIONS

We created a screening tool for delirium using factors that were regularly observed and recorded by nurses. This tool is simple and practical and has adequate diagnostic accuracy.

Pharmacological strategies to prevent postoperative delirium: a systematic review and network meta-analysis

Background

Postoperative delirium (POD) is a condition of cerebral dysfunction and a common complication after surgery. This study aimed to compare and determine the relative efficacy of pharmacological interventions for preventing POD using a network meta-analysis.

Methods

We performed a systematic and comprehensive search to identify and analyze all randomized controlled trials until June 29, 2020, comparing two or more pharmacological interventions, including placebo, to prevent or reduce POD. The primary outcome was the incidence of POD. We performed a network meta-analysis and used the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of the pharmacological interventions evaluated.

Results

According to the SUCRA value, the incidence of POD decreased in the following order: the combination of propofol and acetaminophen (86.1%), combination of ketamine and dexmedetomidine (86.0%), combination of diazepam, flunitrazepam, and pethidine (84.8%), and olanzapine (75.6%) after all types of anesthesia; combination of propofol and acetaminophen (85.9%), combination of ketamine and dexmedetomidine (83.2%), gabapentin (82.2%), and combination of diazepam, flunitrazepam, and pethidine (79.7%) after general anesthesia; and ketamine (87.1%), combination of propofol and acetaminophen (86.0%), and combination of dexmedetomidine and acetaminophen (66.3%) after cardiac surgery. However, only the dexmedetomidine group showed a lower incidence of POD than the control group after all types of anesthesia and after general anesthesia.

Conclusions

Dexmedetomidine reduced POD compared with the control group. The combination of propofol and acetaminophen and the combination of ketamine and dexmedetomidine seemed to be effective in preventing POD. However, further studies are needed to determine the optimal pharmacological intervention to prevent POD.

Development and validation of a delirium risk prediction preoperative model for cardiac surgery patients (DELIPRECAS): An observational multicentre study

STUDY OBJECTIVE

To develop and validate a delirium risk prediction preoperative model for patients undergoing cardiac surgery.

DESIGN

Observational prospective multicentre study.

SETTING

Six intensive care units in Spain.

PATIENTS

689 patients undergoing cardiac surgery consecutively, aged ≥18 years.

MEASUREMENTS

The primary outcome measure was the development of delirium, diagnosed using the Confusion Assessment Method in Intensive Care Units (CAM-ICU), during the stay in the intensive care unit after cardiac surgery.

MAIN RESULTS

The model was developed with 345 consecutive patients undergoing cardiac surgery at six hospitals and validated with another 344 patients from the same hospitals. The prediction model contained four preoperative risk factors: age over 65 years, Mini-Mental State Examination (MMSE) score of 25-26 points (possible impairment of cognitive function) or < 25 (impairment of cognitive function), insomnia needing medical treatment and low physical activity (walk less than 30 min a day). The model had an area under the receiver operating characteristics curve of 0.825 (95% confidence interval: 0.76-0.89). The validation resulted in an area under the curve of 0.79 (0.73-0.85) and the pooled area under the receiver operating characteristics curve (n = 689) was 0.81 (0.76-0.85). We stratified patients in groups of low (0%-20%), moderate (> 20%-40%), high (> 40%-60%) and very high (> 60%) risk of developing delirium, with a positive and negative predictive value for the very high risk group of 70.97% and 85.56%, respectively.

CONCLUSION

The DELIPRECAS model (DELIrium PREvention CArdiac Surgery), consisting of four well-defined clinical risk factors, can predict in the preoperative period the risk of developing postoperative delirium in patients undergoing cardiac surgery. An automatic version of the risk calculator is available.

A 'real-world' analysis of risk factors for post liver transplant delirium and the effect on length of stay

BACKGROUND

The development of delirium has been previously demonstrated to be associated with an increased risk of mortality and length of stay post liver transplant (LTx) with multiple risk factors being identified in previous studies. In this study, we have aimed to identify the most important variables associated with the onset of post-LTx delirium and understand the effect on length of stay (LOS).

METHODS

All liver transplants for chronic liver disease between 1 August 2012 and 1 August 2017 were included (n = 793). Data were collected for analysis retrospectively from electronic patient records.

RESULTS

Delirium is associated with an overall increased hospital and ICU LOS but not one-year mortality. The risk of developing post-LTx delirium was the greatest among patients: with post-LTx sepsis, who required renal sparing immunosuppression, who received donation after cardiac death (DCD) grafts and who were older. Patients with autoimmune hepatitis, primary biliary cholangitis or primary sclerosing cholangitis seemed to be at lower risk of post-LTx delirium. However, global patient LOS was only prolonged in patients with sepsis and renal failure.

CONCLUSION

Many of the risk factors previously described to be associated with the development of post-LTx delirium were not demonstrated to be significant in this study. Sepsis, renal failure, older age and DCD use are associated with delirium post-LTx. It is unclear if this syndrome is an independent risk factor for increased LOS or if it is a symptom of well established syndromes associated with increased LOS. The role for prophylactic strategies to reduce the incidence of post-LTx delirium is therefore unclear.

Antipsychotic Drugs in Prevention of Postoperative Delirium-What Is Known in 2020?

Delirium is one of the most frequently reported neuropsychiatric complications in the perioperative period, especially in the population of elderly patients who often suffer from numerous comorbidities undergoing extensive or urgent surgery. It can affect up to 80% of patients who require hospitalization in an intensive care setting postoperatively. Delirium increases mortality, morbidity, length of hospital stay, and cost of treatment. An episode of delirium in the acute phase may lower the general quality of life and increases the risk of cognitive decline long-term. Since pharmacological treatment of delirium is not highly effective, focus of research has shifted towards developing preventive strategies. We aimed to perform a review of the topic based on the most recent literature. We conclude that, based on the available data, it seems impossible to make strong recommendations for using antipsychotic drugs in prophylaxis. Further research should answer the question what, if any, benefit patients receive from the pharmacological prevention of delirium, and which agents should be used.

Multi-disciplinary and pharmacological interventions to reduce post-operative delirium in elderly patients: A systematic review and meta-analysis

STUDY OBJECTIVE

An estimated 80% of older people undergoing surgery develop postoperative delirium (POD) making them a high-risk group. Research in this area is growing fast but there is no established consensus on strategies for POD prevention or management. A systematic review and meta-analysis were conducted to synthesise data on clinical interventions used to reduce POD among older people undergoing elective and emergency surgery.

METHODS

A range of database searches generated 336 papers. A total of 25 studies met the inclusion criteria and were assessed using the Joanna Briggs Institute Critical Appraisal Checklist. The studies were undertaken across the world.

RESULTS

This review identified a range of intervention approaches: comparisons between anaesthetic and sedatives agents, medication-specific interventions and multidisciplinary models of care. Results found more consistencies across multidisciplinary interventions than the pharmacological interventions. In pooled analyses, haloperidol (OR 0.74; 95% CI (confidence interval) 0.44, 1.26) was not statistically significantly associated with reduced POD incidence any more than a placebo.

CONCLUSION

There is a need to implement multidisciplinary interventions, as well as collaboration between clinicians on pre- and postoperative care practices regarding pharmacological interventions to more effectively reduce and manage POD in older people.

Delirium risk prediction models for intensive care unit patients: A systematic review

OBJECTIVE

To systematically review the delirium risk prediction models for intensive care unit (ICU) patients.

METHODS

A systematic review was conducted. The Cochrane Library, PubMed, Ovid and Web of Science were searched to collect studies on delirium risk prediction models for ICU patients from database establishment to 31 March 2019. Two reviewers independently screened the literature according to the pre-determined inclusion and exclusion criteria, extracted the data and evaluated the risk of bias of the included studies using the CHARMS (CHecklist for critical Appraisal and data extraction for systematic Reviews of prediction Modelling Studies) checklist. A descriptive analysis was used to describe and summarise the data.

RESULTS

A total of six models were included. All studies reported the area under the receiver operating characteristic curve (AUROC) of the prediction models in the derivation and (or) validation datasets as over 0.7 (from 0.75 to 0.9). Five models reported calibration metrics. Decreased cognitive reserve and the Acute Physiology and Chronic Health Evaluation II (APACHE-II) score were the most commonly reported predisposing and precipitating factors, respectively, of ICU delirium among all models. The small sample size, lack of external validation and the absence of or unreported blinding method increased the risk of bias.

CONCLUSION

According to the discrimination and calibration statistics reported in the original studies, six prediction models may have moderate power in predicting ICU delirium. However, this finding should be interpreted with caution due to the risk of bias in the included studies. More clinical studies should be carried out to validate whether these tools have satisfactory predictive performance in delirium risk prediction for ICU patients.

American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on Postoperative Delirium Prevention

Postoperative delirium is a geriatric syndrome that manifests as changes in cognition, attention, and levels of consciousness after surgery. It occurs in up to 50% of patients after major surgery and is associated with adverse outcomes, including increased hospital length of stay, higher cost of care, higher rates of institutionalization after discharge, and higher rates of readmission. Furthermore, it is associated with functional decline and cognitive impairments after surgery. As the age and medical complexity of our surgical population increases, practitioners need the skills to identify and prevent delirium in this high-risk population. Because delirium is a common and consequential postoperative complication, there has been an abundance of recent research focused on delirium, conducted by clinicians from a variety of specialties. There have also been several reviews and recommendation statements; however, these have not been based on robust evidence. The Sixth Perioperative Quality Initiative (POQI-6) consensus conference brought together a team of multidisciplinary experts to formally survey and evaluate the literature on postoperative delirium prevention and provide evidence-based recommendations using an iterative Delphi process and Grading of Recommendations Assessment, Development and Evaluation (GRADE) Criteria for evaluating biomedical literature.